NEW ZEALAND MOUNT
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First edition 1974 Second edition 1991
The Council is funded by an annual grant from the New Zealand Lottery Grants Board
The production and printing of this new Hypothermia Manual have been substantially assisted by a special grant from the Accident Compensation Corporation
ACCIDENT COMPENSATION CORPORATION
Illustrations: Eric Dyne
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Mountain Safety Manual 24
by Margaret Anderson and Dick Price
Edited by Pippa Wisheart
NEW ZEALAND MOUNTAIN SAFETYCOUNCIL INC. P.O. Box 6027, Te Aro, Wellington Tel: (04) 857-162 Fax: (04) 857-366 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
MEMBER ORGANISATIONS OF THE COUNCIL Federated Mountain Clubs of N .Z. Inc . N .Z. Deerstalkers Association Inc. N.Z. Ski Council Department of Conservation N.Z. Police Department of Education Department of Internal Affairs Ministry of Defence (Army) N .Z. Tourism Department N.Z. Water Safety Council Inc. Accident Compensation Corporation
ROLES OF THE COUNCIL •
To promote safe practices in all aspects of bush and mountain activities, especially tramping, mountaineering, skiing and the use of firearms.
To encourage the general public to enjoy and participate safely in bush and mountain activities.
NEWZEALANDMOUNTAINSAFETYCOUNCIL INC. 3rd Floor, 15-19 Tory Street, Wellington Tel: (04) 857-162 Fax: (04) 857-366 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
PREFACE The New Zealand Mountain Safety Council has two roles - firstly to promote safe practices in all aspects of bush and mountain activities, especially tramping, mountaineering, skiing and the use of firearms; and secondly to encourage the general public to enjoy and participate safely in bush and mountain activities. Inevitably in outdoor recreation, difficulties do occur and accidents happen which may delay or immobilise the participants. The Council has become increasingly involved in the teaching of what to do when things go wrong, and is now a Special Centre of the Order of St John, charged with the teaching of outdoor first aid . In the outdoor environment, particularly at higher altitudes, the weather is a major factor, and every outdoor recreationist needs to be aware of the possibilities of coldrelated problems. In particular hypothermia will always be a serious concern. Forced delays or inactivity, injuries and shock, can all play a role in the onset of hypothermia. Accidents have a nasty habit of happening in bad weather. Early stages of hypothermia may well be present in many cases of poor decision-making, injuries from falls or mild disorientation. The Council has always recognised the importance of hypothermia as a potentially life-threatening situation, and nearly twenty years ago one of its first manuals, by Mr Paul Mountfort, gave basic information about hypothermia for outdoor users. Since then there has been considerable development in the information available, particularly because of many mountaineering expeditions, advances in medical knowledge, and improvements in outdoor protective clothing. As the contents of this book clearly show, it is much easier to take steps to prevent hypothermia than to treat it in the field. Nevertheless sound principles for treatment are carefully outlined, and should be known by every outdoor user, and particularly by leaders of parties . The book starts from a simple understanding and approach, and develops to cover advanced treatment. The New Zealand Mountain Safety Council is most grateful to the many people who have contributed to this book. Some of the major contributors are acknowledged below, but many others have given help and suggestions . In particular the Council acknowledges most gratefully the work of the two authors - Dr Dick Price and Miss Margaret Anderson, who between major overseas expeditions and university and medical commitments, have found time to bring together this book.
Alan Trist Executive Director
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ACKNOWLEDGEMENTS Dept of Anaesthesia, Otago University, Dunedin Dept of Anaesthesia, Otago University, Dunedin Dept of Anaesthesia, Otago University, Christchurch Dept of Psychiatry, Otago University, Dunedin Physiology, Canada Physiology, Canada Mountain Medicine Data Centre, St Bartholomews Hospital, U.1.A.A. London. Alaskan Ambulance Service Otago Canoe Club Instructors Graham Egarr, Education Officer, New Zealand Water Safety Council Prof. B. Baker Dr D. Pilditch Dr M. Davis Dr J. Anderson Dr M. Collis Dr J . Hayward Dr C. Clarke
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CHAPTER 1: WHAT IS HYPOTHERMIA? . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . How does the body gain or lose heat? . . . . . . . . . . . . . . . . . . - Sources of body heat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Distribution of body heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Heat loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Mechanisms to prevent heat loss . . . . . . . . . . . . . . . . . . . . . . - What you can do to prevent heat loss . . . . . . . . . . . . . . . . . - Causes of body cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Conditions which may lead to excessive heat loss . . . . . . . What happens when the body cools down? . . . . . . . . . . . . . . Signs and symptoms of hypothermia . . . . . . . . . . . . . . . . . . . .
1 1 1 1 2 2 4 4 4 7 7 10
CHAPTER 2: PREVENTION OF HYPOTHERMIA Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preparation and planning .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Personal survival kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Clothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Equipment .. . . . .. . .... . ......... . . . . . ... . . . ........ - Shelter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Food and water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Fir es and stoves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Route plan ning , navigation . . . . . . . . . . . . . . . . . . . . . . . . . . - Weathe r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - First aid training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Contents of first aid kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Physical fitness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11 12 12 12 16 18 20 21 22 22 25 26 27
CHAPTER 3: WHAT TO DO IF THINGS GO WRONG PART 1: SURVIVAL Emergency situations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clothing and equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mental attitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Does anyone survive in emergencies ? . . . . . . . . . . . . . . . . . . .
28 28 31 31
PART 2: SENDING FOR HELP . . . . . . . . . . . . . . . . . . . . . . .
CHAPTER 4: BASIC TREATMENT OF HYPOTHERMIA Immediate action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recognition .. . . Â·. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Cold shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40 40 40
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- Exhaustion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Other conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assessment of patient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Severe hypothermia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Mild or moderate hypothermia . . . . . . . . . . . . . . . . . . . . . . . Basic treatment (in the field, first responder) . . . . . . . . . . . . . Treatment for severe hypothermia, with vital signs . . . . . . . . Treatment for severe hypothermia, with no vital signs. . . . . CHAPTER 5: ADVANCED TREATMENT OF HYPOTHERMIA Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Factors which are important for survival . . . . . . . . . . . . . . . . Rewarming techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ten factors to consider in hypothermia care . . . . . . . . . . . . . CHAPTER 6: IMMERSION IN COLD WATER Cold water survival . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Longer term immersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Effect of alcohol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - What to do in cold water . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Survival in water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Clothing and buoyancy aids / lifejackets . . . . . . . . . . . . . . . . - Survival skills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cold water near drowning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - General points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - Evaluation and treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . -At the scene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -Special treatment for divers . . . . . . . . . . . . . . . . . . . . . . . . . . -Hospital treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
42 42 42 43 43 43 43 44 44 47 47
48 48 49 54 54 54 54 54 54 58 59 59 59 60 60
APPENDICES: 1. 2. 3. 4. 5. 6. 7. 8.
Signs and symptoms of hypothermia . . . . . . . . . . . . . . . . . Survival rate 1977-80 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Warming techniques . ............ . .... ..... .. ... .... Case statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air warming equipment......................... . ... Equipment for hypothermia treatment . . . . . . . . . . . . . . . . Communication and organising a rescue . . . . . . . . . . . . . . Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TREATMENT IN THE FIELD/HOSPITAL-CHART
63 63 64 64 65 66 67 71
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LIST OF ILLUSTRATIONS Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure
1: 2: 3: 4: 5: 6: 7: 8: 9: 10: 11: 12: 13: 14: 15: 16: 17: 18: 19: 20: 21: 22: 23: 24: 25: 26: 27:
Wear appropriate clothing . . . . . . . . . . . . . . . . . . . . . . . . . . .
Body heat production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wind chill graph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thermograph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Warning signs of hypothermia . . . . . . . . . . . . . . . . . . . . . . . Carry clothing for all conditions . . . . . . . . . . . . . . . . . . . . . A suggested clothing guide . . . . . . . . . . . . . . . . . . . . . . . . . . Suggested personal equipment . . . . . . . . . . . . . . . . . . . . . . . Suggested party equipment . . . . . . . . . . . . . . . . . . . . . . . . . . Emergency shelter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Firelighting equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sources of weather information . . . . . . . . . . . . . . . . . . . . . . Weather map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Survival kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Help Form (Intentions Sheet) . . . . . . . . . . . . . . . . . . . . . . . . Search and Rescue Emergency form . . . . . . . . . . . . . . . . . . How to help searchers find you .................. 36, 37, Basic treatment of hypothermia . . . . . . . . . . . . . . . . . . . . . . Cardiopulmonary Resuscitation . . . . . . . . . . . . . . . . . . . . . . ECG graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cold water survival (H.E.L.P. and Huddle) . . . . . . . . . . . Average cooling rates chart . . . . . . . . . . . . . . . . . . . . . . . . . . Keep out of cold water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rescue from water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Search and rescue operation . . . . . . . . . . . . . . . . . . . . . . . . .
3 5 6 8 10 13 15 16 17 19 21 23 24 29 30 34 35 38 41 45 51 55 57 57 59 67 71
INTRODUCTION The purpose of this manual is to help all outdoor users to understand what hypothermia is, to recognise symptoms of hypothermia and know how to treat it. All people who regularly go into the outdoors should be prepared and able to treat and care for a hypothermia victim until more skilled help is available. How you use the information contained in this manual will depend on what you need to do to save a life. If you are the only person available to treat a hypothermia victim and cannot reach medical help quickly, you may need to provide treatment to an advanced level. If however you can get a doctor to the victim quickly you will probably only need to provide basic treatment to prevent the victim deteriorating until medical help arrives. For this reason the manual includes information on both basic and advanced hypothermia treatment which will help anyone who must treat a hypothermia victim. The advanced treatment section does include information for use by doctors and hospital staff and the complex procedures described here should not be attempted unless you have the appropriate training, knowledge and skills. The main purpose of including both basic and advanced treatment information is to encourage you and to give you confidence to do all you can to save the life of a hypothermia victim. Although some symptoms of hypothermia may seem easy to recognise they can also be signs of other conditions (i.e. cold shock and exhaustion). The only way of telling whether a person has hypothermia or some other condition is to take the person's temperature using a low reading thermometer. This is illustrated in the following stories: (a) A tramping party finds a person lying at the side of a track. Does that person have hypothermia or is s/he merely exhausted? The only way to be sure is to take the victim's oral (i.e. in the mouth) temperature using a low reading thermometer . If the temperature reading is above 35 Â° the person is probably only exhausted; if it is below 35 Â° the victim probably has hypothermia. This can then only be confirmed by taking the victim's body core (i.e. rectal) temperature. (b) A person falls into the harbour in the middle of winter. S/he is pulled out quickly but immediately collapses. Do you treat the person for cold shock or hypothermia? In this case the person is probably suffering from cold shock but a low reading thermometer should be used to take the oral temperature as above. (c) A skier gets out of the car to put chains on. Some time later s/he collapses. Does s/he have cold shock, hypothermia or a coronary? Use a low reading thermometer to check the victim's condition. In all of the above cases the only way to determine whether the victim is suffering from hypothermia is to take the temperature with a low reading themometer. A wrong diagnosis could result in the death of the victim, i.e. a hypothermia victim could die if the party decides s/he is merely suffering from exhaustion and travels on to the nearest hut to seek shelter. This has happened in the past. One of the aims of this manual is to encourage all outdoor users to carry a low reading thermometer as part of their standard first aid equipment. Low reading thermometers are not yet widely available in this country however it is hoped they will be in the future. For information about obtaining these thermometers see Appendix 8, page 71. viii
BODY ~CORETEMrERATURE~ above 35 °C
above 35 °C
COLD SHOCK (sudden cold)
below 35 °C
! rapid rewarming e.g. warm bath, fire, activity, body heat, calories, warm sweet drinks.
rest, followed by gradual activity, calories, warmth.
prevent further heat loss; rest for at least 48 hours; gradual rewarming.
NOTE:Information about prevention and treatment of hypothermia contained in this manual is intended to give general guidance. The authors are aware that some methods of treatment remain subject to debate.
What Is Hypothermia? INTRODUCTION Hypothermia occurs when the body CORE temperature drops to a level where normal brain and muscle functioning is impaired, usually at, or below, 35°C. Normal body temperature varies depending on where in the body it is measured. Rectal temperature is normally 37.5°C while oral (in the mouth) is 37°C and in the armpit is 36.5°C. The temperatures referred to here are all core temperatures. The rectal temperature gives the closest practical measurement of the core temperature. The body has a built-in thermostat to maintain a balance between heat loss and heat gain and to keep the body temperature within one degree of normal. If this balance is not maintained, even at one degree above or below normal, the vital organs such as the brain, heart, and lungs, do not function properly and may be damaged. Even if the outer body shell cools down the body attempts to keep the central CORE, containing these vital organs, warm. A useful definition of hypothermia is "when the body core cools below 35 °C" or: HYPOTHERMIA= COLD BODY CORE.
HOW DOES THE BODY GAIN OR LOSE HEAT? SOURCES OF BODY HEAT The body gains heat from several important sources: Radiation The sun, fires, and many chemical or electrical sources provide radiant energy which the body can absorb through the skin. These are usually of little importance in cold temperatures as the body is insulated against heat transfer by clothing and so cannot absorb radiant heat. These sources may, however, provide a means of preventing heat loss, or of rewarming a person who is already cold, when used in a controlled environment or shelter. Exercise The activity of body muscles during exercise can provide up to 70% of body heat but uses up a lot of stored energy reserves. Special involuntary muscles produce heat by rapid activity known as shivering and this can be nearly as effective as a fast walk or jog. These muscles also use up a lot of energy reserves and do not work when the body core cools down. Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
Food (stored chemical energy) Food is burned up in the body to provide energy and heat. Hot food and drinks also give heat directly, through warming the stomach. Types of high energy foods include: - Sugars which give instant energy but are soon used up. - Carbohydrates (starches) which can be stored and released later when the energy is needed . Complex starches, such as pasta, will last longer than sugars or simple starches, such as bread or biscuits. - Fats and oils which are very high energy foods and can be stored until they are needed. More food needs to be eaten on very active days, to replace the energy stores which have been used up. (FOOD) CALORIES -> MUSCLE ENERGY AND HEAT
DISTRIBUTION OF BODY HEAT The body is kept warm by heat being distributed from warmer areas (which are using energy) to cooler areas (which cannot produce their own heat). This distribution is controlled by the nervous and circulatory systems with blood carrying heat around the body. Some hormones, such as adrenalin, open up the blood flow to the muscles to allow for sudden movement and action but also restrict flow to the skin. The part of the body which must be kept warm at all times is the CORE, containing the vital organs such as the HEART and the BRAIN. HEAT LOSS The body loses heat through: Radiation Heat is radiated directly from the body surface to the external environment. If the external environment is below 5Â°C up to 50% of body heat may be lost from a bare head and neck. Convection Air next to the skin is warmed by body heat and then carried away to be replaced by colder air. Wind and cold air greatly increase this heat loss, causing wind chill. Movement in cold water (such as swimming) also greatly increases this heat loss. Conduction Heat is carried away from the body when it is in direct contact with cold water, snow, ice or a cold ground surface. This heat loss is greatly increased when a large surface area of the body is immersed in cold water, lying on cold ground, or wet clothing is being worn. Evaporation When sweat or water evaporates from the skin surface it takes a lot of body heat with it. This is greatly increased by wind blowing onto wet skin. Breathing introduces cold air into the lungs and the upper airway warms and humidifies this air. During exercise both heat and water are rapidly lost from the body by increased breathing and sweating. This loss continues after the heat-generating exercise has ceased, leading to an overall heat loss and dehydration.
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Figure 1: Wear appropriate
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Dehydration or loss of water from the body can increase the risk of hypothermia as the blood volume and pressure drop, leading to weakness, apathy, and the possibility of collapse. The body normally requires at least one to two litres of water a day and much more during exercise and/or at high altitude. In cold temperatures and at high altitudes the air is drier, so more water vapour is lost during breathing. Cold also increases urine output, contributing to dehydration and heat loss. NOTE: Wet, cold, and windy conditions or immersion in cold water, will rapidly remove body heat by all or most of the above methods and will cause very rapid chilling and the sudden onset of hypothermia. There may be as little as 30 minutes between the first obvious signs of hypothermia and unconsciousness or serious impairment. MECHANISMS TO PREVENT HEAT LOSS The body attempts to maintain a normal temperature in cold conditions by using a number of responses. If these heat conserving mechanisms fail then circulation and brain failure occur as a result of the drop in core temperature. Reduced blood flow to skin and limbs The blood vessels which supply the exposed areas of skin and fat constrict and reduce the flow and this cool layer forms a barrier to further heat loss from the body core. Reduced blood flow to cold limbs reduces heat loss but also causes muscle inefficiency and clumsiness. Shivering Heat production is increased by the rapid activity of special muscles which produce the equivalent amount of heat to a fast walk or a jog but which use up a lot of stored energy reserves. At low body core temperatures, less than 32 Â°C, these muscles cease to work and shivering stops. Some victims never shiver. Exercise Strenuous exercise can increase the body's heat output by up to 700Jobut also uses up a lot of stored energy. Heat loss is increased by sweating, increased breathing and the re-opening of constricted blood vessels to the skin and limbs. Exhaustion occurs more quickly at cold temperatures as body heat is lost more quickly to the environment and more energy is used to produce the same amount of warmth. WHAT YOU CAN DO TO PREVENT HEAT LOSS Insulate your body from cold, wet or windy conditions. Clothing can lose up to 900Jo of its insulating power when it gets wet, so you will need an outer layer which is waterproof and windproof. Remember to cover all parts of your body including your head, neck, hands, legs, and feet. Some ventilation is also needed to prevent condensation from gathering on the inside and soaking into the inner layers of clothing.
WET+WIND=900/o LOSS of INSULATION.
CAUSES OF BODY COOLING (outer shell or inner core) The body cannot keep warm because of: excessive heat loss, or - reduced heat production. 4
% at rest
% at work
Chest and abdominal organ s
Skin and muscle
Heat production at rest and in work of various parts of the bodv expressed in calories per 100 gm of tissue per minute. /Adapted from J. Aschoff and R. Wever, Naturwissenschaften 45:477, 1958 .J
Al rest Cal 1OOg/m,n
11111 450 1111 3.05 C=:J
Figure 2: Body heat production.
l\l ~ ~ ~ ~
~ ..J ..J
'9 (.) 0
Figure 3: Wind chill graph. 6 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
CONDI'fIONS WHICH MAY LEAD TO EXCESSIVE HEAT LOSS INCLUDE: - Wet, wind, cold. Need to insulate, especially children and thin people, who have a greater surface area to volume ratio and lose core heat more rapidly. Clothing should protect from wet, cold and wind, which can whip away body heat as fast as it is produced . - Lack of exercise. Body heat is lost very rapidly from skin and breathing after exercise, and extra clothing is needed to prevent this cooling . Sweating will make clothing wet, adding to the heat loss by evaporation and conduction. If you need to stop for a rest put on extra clothing (preferably windproof) and find shelter from wind or rain. A long stop to attend to an injury or other emergency will put the whole group at risk from hypothermia and this should be taken into account when making decisions . - Lack of energy, due to lack of food, exhaustion, lack of fitness or dehydration. Exercise burns up calories and these must be replaced. High energy foods such as sugar, sweets or chocolate can be used to replenish energy supplies very quickly but longer term supply needs complex carbohydrates, such as starch, or fats as well as sugar . If the body runs low on energy rich food it will use up reserves from storage and eventually need to burn up its own tissues. A lot of water vapour is lost in cold conditions and dehydration can be a major problem along with heat loss. Warm sweet drinks will replace the water loss while providing calories and warmth. Cold drinks will further chill the core . - Lack of fitness places an increased demand on energy reserves and uses up energy at a faster, less efficient rate. Puffing and panting increases heat and water loss from the lungs and increased muscle activity increases sweating and heat loss from the skin . - Recent illness or injury can slow down activity, reduce fitness or lower the body 's resistance to cold. Some illnesses such as flu can make people less resistant to cold, while conditions like asthma, angina or diabetes may be aggravated by cold. Always assume that any accident victim is, or soon will be, at risk from hypothermia. - Overloading with heavy packs or other equipment , or restriction of body movement from gear, clothing or packs , increases the risk of chilling and exhaustion. - Fear and excitement alter the hormonal control of blood flow and thus the flow of warm blood to the skin, leading to heat loss from cold limbs. Fear can cause sweating, which leads to more heat loss through wet clothing and skin . Individual and group morale needs to 'be considered, especially in emergency situations. Pushing people to the "limit" is not character building, it is dangerous.
WHAT HAPPENS WHEN THE BODY COOLS DOWN? - Outer shell cools first. - Muscles and skin get cold, may feel cold or painful. - Reduced blood flow to surface makes skin pale, bluish. - Shivering to generate more heat. At this stage exercise will rewarm the body, as up to 70% of body heat can be produced by muscle activity, and although the body shell is cold, the inner core is still warm. This requires a lot of available energy (i.e. food). Sudden Âˇcooling, such as immersion in cold water, may chill the outer body shell 7
Figure 4: Thermograph. 8
before any cooling of the inner body core can occur. Further cooling will lead to hypothermia but this type of cold shock can be quickly reversed if stopped in time . If the body continues to cool however, the inner core will also cool, causing serious changes to brain, heart and breathing activity, eventually leading to death.
SIGNS AND SYMPTOMS OF HYPOTHERMIA The two main groups of signs/symptoms arise from: - COLD BODY SHELL i.e. MUSCLES, SKIN - COLD BODY CORE i.e. BRAIN, HEART The first signs of cooling are associated with cold skin and muscles as the outer shell of the body cools down. These usually include feeling cold, shivering and some loss of muscle efficiency. The victim's skin may be pale and lips bluish in colour as the blood flow to the surface is reduced. S/ he may feel some pain especially in limbs exposed to the cold. Early signs of hypothermia often look like fatigue; the victim may not complain of feeling cold and may not shiver . LOOK OUT FOR: - tiredness, exhaustion - lack of interest - lethargy, slowness to respond - clumsiness, falling over, poor co-ordination - slurred speech - irrational behaviour . Often the first sign that something is wrong is when the person gets left behind, becomes clumsy or falls down repeatedly . S/he may stagger, have slurred speech or just appear drunk. These signs indicate an impairment of brain function and not just muscular inefficiency- the body core is starting to cool. The victim is in a serious condition because the body cannot generate enough heat to keep the core warm. If one person is in this condition, assume that all other members of the group are also developing hypothermia, including yourself. The type of person most likely to suffer from hypothermia is one who has walked too far too fast , carried too heavy a load and is unfit, hungry, demoralised and exhausted. Children become demoralised and fearful easily, unless they have strong and encouraging leaders. Once the core starts to cool the process of recovery involves two important steps: - Preventing any further heat loss. - Rewarming (active or passive). If the core continues to cool, serious changes to brain, heart and breathing function occur, and other body organs may be damaged. The victim may stop shivering, although s/he is still very cold, and lapse into a semi-conscious or unconscious state with very slow pulse and breathing. If the core cools below 28Â°C the heart may stop (cardiac arrest) and the person will appear dead. As it is very difficult to be sure that the person is dead, do not assume that this is so, but continue to treat and keep vital function (heart, breathing) going. NOTE: Any cooling of the body core below 35 Â°C is a serious condition and must be dealt with promptly. Rough handling of the person may lead to cardiac arrest, so people with suspected hypothermia must be treated very gently and not allowed to exercise or move around. 9
WARNINGSIGNS OF HYPOTHERMIA TIREDNESS ; RELUCTANCE TO KEEP MOVING
Figure 5: Warning signs of hypothermia. 10
Prevention of Hypothermia INTRODUCTION Two separate studies of fatal accidents involving hypothermia (one in New Zealand and one in Great Britain) have analysed more than 60 accident reports and have found similar circumstances in which hypothermia is likely to occur. Common factors found in most cases included: - cold, wet and windy conditions , often as a result of unexpected changes in the weather - inadequate clothing which had become soaking wet and gave very little protection - inexperienced and poorly equipped parties - hypothermia not adequately treated once it had developed - pushing on to reach suitable shelter, often until the victim was at the point of collapse (death of victim occurred within 1 or 2 hours) . Other important factors highlighted included: - dangers of parties of Jess than 4 people - general fitness and balance of the parties , with those who were Jess fit becoming exhausted from struggling to keep up with the other s - part ies having unreasonable goals - failure to recognise symptoms of hypothermia until the y were seriou s - Jack of knowledge and skills to cope with emergencies. In most of these accidents serious injury was not involved and the symptoms showed a pattern of slowness , stumbling and slurred speech, followed by falling, unreasonable behaviour, delirium , collapse and death . Shivering was not noticed in most cases of serious hypothermia and only a few of the victims complained of feeling cold . Many more fatal accidents may have involved hypothermia (especially if symptoms such as clumsiness, apathy and impaired judgement were present) but have been attributed to other causes such as falls or serious injuries. The exposed nature of many recreational areas in New Zealand and the abrupt weather changes make adequate clothing and shelter essential for survival. Two types of intelligent action are called for to prevent hypothermia: (i) prevention or reduction of heat Joss, and (ii) an increase of heat production . The risk of hypothermia in the outdoors could be almost completely removed if people were prevented from using the sea, rivers and lakes, or from going into the mountains. This is not however desirable in a free society and there still remains the risk of urban hypothermia, especially amongst the elderly and lower income groups . 11
The element of "risk" may be part of the reason people participate in dangerous sports or recreation but some risks are unacceptable, especially if they also endanger others, such as rescuers. Attitudes such as "attempting the impossible" or "it is good for the character to push people to the limit" increase the risk of serious injury or death when in the outdoors. Fortunately they are now being replaced with advice, such as "go to ground early" in bad weather rather than trying to carry on. It is also no longer "sissy" to wear a lifejacket when boating. Factors which contribute to hypothermia include attitudes of selfishness, lack of thought or planning, ignoring hazards and warning signs, not heeding advice and sticking to over ambitious plans. Fear and disappointment may decrease the will to survive once an accident has occurred . Accidents and disasters can often be traced back to a series of small and avoidable errors of judgement or bad decisions, which may have been compounded by gear failure or bad weather and then led to major problems. Reports of fatal accidents often make others wonder how such a situation could have arisen and what they would do in similar circumstances. A major factor in these reports is that those involved did not seem to know when to turn back, or had put themselves into a situation where this option was no longer available to them. Turning back, "going to ground", or seeking help needs to be presented as a sensible, commonsense thing to do, rather than as "giving in" or as a sign of weakness.
PREPARATION AND PLANNING The best prevention of hypothermia is to avoid getting into situations where it can develop and this requires careful preparation and planning in advance. Situations in which hypothermia is likely to occur include: - Cold, wet windy conditions with inadequate clothing or shelter. - Illness, injury or gear failure, forcing a delay or a stop . - Lack of food, fatigue, unfitness, fear, loss of morale. - Unexpected immersion in cold water, snow or flooded rivers, or sudden bad weather. - Getting lost or finding the planned route can not be used. Prevention means avoiding, or being prepared to cope with, these situations. PERSONAL SURVIVAL KIT A personal survival kit should be carried by each member of your party (see Chapter 3, Fig. 15 for suggestions of contents). CLOTHING Cold, wet, windy conditions require clothing which gives adequate cover, is appropriate to the conditions and is worn in sufficient amounts to be effective. Too little clothing cannot keep the body warm, while too much can restrict movement and cause sweating into inner layers, which reduces their insulating effect. Wearing too much clothing during exercise will also lead to excessive heat build up. This places stress on the heart and lungs and leads to exhaustion. Maintain a balance between the amount of clothing you wear and the effects of exercise on heat production and sweating, i.e. wear clothing in sufficient amounts to keep your body warm but not sweating. 12 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
Figure 6: Carry clothing for all conditions. 13
Take off some clothing during exercise and put it on again as soon as activity stops. Adequate clothing should protect the head and neck from heat loss and be sufficient to trap a layer of air for insulation. This may require several layers of clothing, the outer one being waterproof and windproof, to prevent heat loss and windchill. The insulation value of most clothing is reduced by 300Joto 400Join wind and by another 500Jowhen wet, leading to a disastrous 900Joloss of insulation if a protective outer layer is not worn. WIND+ WET= 90o/o LOSS OF INSULATION
Wet clothing also acts as a "wick" and draws body heat out to the surface layer of clothing where it is easily lost. Wear garments made of materials which will still keep you warm when wet. Wool can retain up to 500Joinsulation when it is wet and some synthetic fibres are even better because they do not retain moisture e.g. polypropylene. Down is a good insulator when dry but it packs down and mats when wet so is best used at high altitudes or very cold climates, with dry snow and very little rain. Fibrefill is heavier and bulkier than down but gives better insulation when wet and so is used in clothing and sleeping bags for wetter conditions . Your protective covering or layer of clothing should have provision for ventjlation so body moisture does not soak into inner layers and reduce the insulation value . There is no material currently available which is fully waterproof and provides ventilation, but some materials like Goretex ÂŽ and Entrant ÂŽ come close to this. In cold, wet, windy conditions cover all exposed skin, including the legs, with at least a windproof and waterproof layer.
Hands and feet present a special problem in cold conditions because while it is important to keep them from freezing, they should not be warmer than the rest of the body. The brain relies on the hands and feet for information about whether the body is cooling down. Warm hands or feet could mislead the brain into thinking the rest of the body is warm too, so it does not initiate action to prevent heat loss . Cool hands and feet actually help to keep the rest of the body warm, while a warm body acts to keep the hands and feet comfortable . Put on an extra jacket or jersey to help prevent cold hands and feet. Mittens are warmer than gloves. In extremely cold conditions several layers of mittens, including a thick insulation and a wind/waterproof outer layer (such as down or fibrefill mittens with a canvas, leather or synthetic outer cover) may be needed . Boots must be suitable for the conditions. While trampers and hunters in the valleys and bush may be able to cope with wet feet from wading across rivers, snow and ice climbers and skiers must keep their socks and boots dry to help prevent frostbite . Skiing and climbing boots have very rigid outer shells of non-porous plastic materials which keep out snow and water but can make feet and socks wet if the feet sweat. A further problem with rigid boots occurs after several hours of wear, when the feet swell and the blood circulation is cut off. Any reduction of circulation in a cold environment can lead to frostbite and this has been a major problem in some cold areas such as Alaska. Wearing several pairs of socks will also compress the feet and increase the risk of frostbite. Climbers can keep their climbing boots dry by wearing spare boots or running shoes when crossing rivers on their way into the mountains. Spare footwear will also be 14
Figure 7: A suggested clothing guide. 15
SUGGEST D PERSONAL QUIPMENT SLEEPING BAG/PACK
MAP/COMPASS/ FIRST AID KIT
Figure 8: Suggested personal equipment. 16 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
BILLIES AND FRYING PAN
FIRST AID KIT
'SAFETY IN THE MOUNTAINS' MOUNTAIN RADIO BOOKLET
Figure 9: Suggested party equipment. 17
useful in case boots get lost, damaged or give blisters. Some boots and socks are available with a plastic vapour barrier built in between layers of insulation. This reduces heat loss but leads to condensation problems when the feet sweat, by soaking the socks and affecting the skin of the feet. Underwear and layers of clothing next to the skin become damp with body moisture and so should be made of materials such as wool or polypropylene, which do not lose all their insulating properties when wet. String singlets next to the body help to keep a movement of air over the skin to remove moisture but they should be nonabsorbent so they don't soak up this moisture. Do not neglect headgear. As much as 70% of body heat can be lost from the head and neck areas in cold conditions. Wear a hat which fits well and covers your head, ears and back of neck. Parka hoods (while not much good for preventing heat loss on their own) will keep a woollen hat dry and cut down the effect of windchill to your head. Wear a hat at night to prevent heat loss as your head will often be outside the insulated protection of your sleeping bag. In severe conditions balaclavas are useful as they protect parts of the face and neck as well as the head. Face masks are available but tend to ice up, with condensation from breathing, in cold conditions. Always cover the head and neck of a sick or injured person in a sleeping bag. (Further information: NZMSC Bushcraft Manual Chapter 4; NZMSC Outdoor Kitset Module 2 Clothing and Equipment). Special Clothing
Clothing appropriate for extreme conditions may need to be highly specialized. Activities which require special insulated clothing include: - Skiing, mountaineering . - Water sports (on the water)-canoeing, surfing, rafting, sailing. - Water sports (in the water)-scuba diving. Protective clothing is not only bulky, awkward to carry and expensive but can restrict movement or cause heat stress and dehydration. (Further information: Chapter 6 of this manual; NZMSC Mountaincraft Manual Chapter 2; NZMSC new series pamphlet No. 2 Going Skiing). SHELTER
In very cold conditions the combination of exercise and suitable clothing may not be enough to keep the body warm, so some form of shelter will be needed. Shelters should be waterproof and windproof and provide some insulation from cold, wet ground. Any shelter which is dry and blocks out wind will dramatically reduce cooling. The most effective shelters are huts, snow shelters, bivvies, caves, igloos, or holes dug into banks or snow and covered with a tent. Tents are not completely windproof and often require additional windbreaks, such as trees or rocks and snow, to make them comfortable. Condensed water can also collect on the inside surface and drip on people. Once inside your shelter avoid contact with anything which conducts heat away from your body, such as water, cold ground, ice, snow, rock and metal. Use insulating pads of spare clothing in plastic bags, or sit and sleep on packs or boots to help prevent heat loss. Wood and other plant material will give some protection from the cold ground if nothing else is available. Heat loss can be reduced by up to 30% if you 18 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
.~. I -·..,,.. '
r , (,"/
,_,, _-= . ,.,,,
' ~ -~ .-· ~~ ,.,
.:.. ___ b\-"-
-'\;,~· · / ~._,/>. ~
Figure 10: Emergency shelter (a) Plastic shelter (b) Snow shelter. 19
sit huddled (see Fig. 22- HELP position in water) as this reduces the amount of body surface exposed to the cold. Any shelter you find or make must have adequate ventilation, especially if you are using fires or stoves for cooking and heating. Emergency shelters can be constructed using large plastic bags (e.g. NZMSC packliners) or sheets of plastic, but some practice is needed to work out how they can be used most effectively and they are no use if they are left at home or back at base camp! Learn how to find or make an emergency shelter and carry the materials you 'll need, even if only on a short day trip. (Further information: NZMSC Bushcraft Manual Chapter 5; NZMSC Outdoor Kitset Module 7 Shelter; NZMSC Mountaincraft Manual Chapter 4, igloos, snow shelters). FOOD AND WATER:
Food: The energy value and amount of food eaten should be adequate for strenuous activity as well as for keeping the body warm. Make sure you eat plenty of high energy food when tramping, climbing , skiing, canoeing or taking part in other outdoor activities. All these activities require a lot more energy than most people need for normal daily life, especially when conditions are cold. Walking in cold conditions requires a fast pace just to generate enough heat to keep warm. People who are unfit or slowed by fatigue will gradually cool even while walking so it is important to keep eating high energy foods and to stop before you become exhausted. Hot food and drinks provide extra warmth while cold food or drinks can chill the body core through the stomach. Inadequate food intake (such as a skimpy breakfast and no snacks during the day) has been a contributing factor in many hypothermia cases. A restriction in energy intake, or not resupplying energy as fast as it is being used, results in low blood sugar and leaves the body open to exhaustion or cold . Low blood sugar also affects the brain, leading to inattention, carelessness, impaired judgement and deteriorating physical performance. High blood sugar allows for better performance without exhaustion and for faster recovery after exhaustion has set in. Problems with food intake will arise when people are not used to eating large meals (especially breakfast), are on "diets", or food supplies are inadequate . Some high energy food should always be set aside at the start of a trip, for use in emergencies. Give children smaller meals often , with plenty of snacks and check they are eating their food but not their emergency rations. Every person should carry some emergency food (biscuits, sweets, drink powder, "scroggin") in a personal survival kit, or in pockets. Healthy people do not need to worry about a properly balanced diet even on a trip of several weeks duration, as the body can retain stores of vitamins and minerals, including water soluble vitamins (B and C). It is more important to have plenty of high energy food which contains some fibre, is light to carry and can be prepared easily and quickly. Divide up food supplies for your party so everyone carries something. This is necessary in case someone gets lost or is separated from the party. Make sure your emergency rations contain some food which doesn't need to be heated (in case heating is not possible) or which needs very little cooking once heated (to save fuel). It is also a good idea to carry some fuel for heating food and drink in an emergency. 20
If you do run out of food you're not likely to starve; a much greater problem is that if you are hungry you may make unwise or impulsive decisions.
Drinks: Water is more essential than food for immediate survival. Healthy people can survive for several weeks without food but only a few days without water. A lot of water is lost through breathing and sweating during strenuous exercise and dehydration can lead to exhaustion and hypothermia. The minimum amount of water required each day by an adult is one to two litres (two to three pints), and much more is needed during exercise or in cold dry conditions. Water may also be needed to prepare and cook dry food and this should be taken into account when seeking a supply of water. In cold conditions heat drinks and never eat snow or ice without melting it first. Salt loss from sweating must also be replaced with salty foods. (Further information: NZMSC Bushcraft Manual Chapter 6; NZMSC Outdoor Kitset Module 3 Food). FIRES AND STOVES: Some kind of fire or stove is useful for heating food, drying clothes and keeping warm. A fire is also a great morale booster, especially at night. If your party is going above the bushline carry a stove and fuel (white spirits, kerosene, gas) as very little firewood is available in these areas. Solid fuels are available but do not give off much heat compared to liquid or gas fuels and are best used to light a fire. All stoves produce fumes, including carbon monoxide, so make sure ventilation is adequate when you are using them.
Figure 11: Firelighting equipment. 21
Firelighting is a skill which must be learned and practiced in all conditions including rain and wind or when using wet wood. Carry a firelighting aid, such as a candle stub (as part of a personal survival kit), as well as matches or a lighter in a waterproof container. *FIRE CAN DESTROY YOUR SHELTER AND THREATEN YOUR LIFE*
(Further information: NZMSC Bushcraft Manual Chapter 7; NZMSC Outdoor Kitset Module 4 Fires and Cooking). ROUTE PLANNING, NAVIGATION: Check out your intended route, and any alternatives, prior to your trip. Leave a detailed note of your intentions at home with a responsible person (see Fig. 16). Listen to all advice given even if it is not what you want to hear. Using your map note obvious landmarks before you leave and look for them during the trip. Looking back the way you have just come will help you recognise the route if you have to go back that way. Make sure all members of your party: - know the nature of the trip and are familiar with the route (in case of separation) - have access to the map or guide book carried and know exactly where they are at all times - can read a map and use a compass - are aware of basic navigation skills such as how to find north by the sun or stars (or carry a compass), which direction the river and streams flow in and any obvious features of the landscape - know what to do if they get separated from the party - have a personal survival kit in case they get lost - know what to do if they get lost. REMEMBER: People are less likely to get lost or injured if everyone stays together and the party keeps to the planned route. If you do get lost however there are a few simple rules to follow: â€˘ Stop, keep calm and think. â€˘ If possible, stay where you are, make a shelter (use your emergency shelter), light a fire, eat some food and drink plenty of water. Searchers will start looking in the area where you were last seen. (Further information: NZMSC Bushcraft Manual Chapters 3, 9, 10, 15; NZMSC Outdoor Kitset Module 6 If things go wrong ... what next? and Module 5 Finding Your Way; NZMSC new series pamphlet No. 6 Survival). WEATHER: Understanding weather patterns and the effects of weather changes on the area you are going into may be essential for survival. In most areas of New Zealand weather can change rapidly with very little warning. This is especially true of mountain areas which are subject to sudden storms and are exposed to winds from all directions. While the prevailing weather and wind patterns may be known, it is often sudden, unexpected changes which catch people out. Weather forecasts: are broadcast on national radio and television and local radio stations. 22
SOURCES OF WEATHER INFORMATION Always be prepared to cancel or postpone if weather conditions are unfavourable
Figure 12: Source s of weather information. 23
WESTERN DISTRICTS EASTERN DISTRICTS
The New Zealand Meteorological Service general forecasts are prepared for the districts shown on the map . These forecasts on radio, television and in the press are not specifically for the mountains.
Note that the mountain ranges are in many cases the boundaries between districts . If you are in the mountains, or about to make a trip, listen to the forecasts for the districts on both sides of the mountain range .
The weather in the mountains will probably be similar to that of the adjacent district for which the worst weather was forecast . Whenever possible , obtain a special mountain forecast.
Figure 13: Weather map. 24
Weather maps on television and in newspapers show the positions of anticyclones, cold fronts and low pressure troughs, all of which will help you to predict weather patterns for the followi,1g few days. Special mountain and marine forecasts are also available at certain times and a transistor radio will keep you in touch during the trip. Mountain radios can be hired and allow extra contact as well as access to up-to-date weather information (for telephone numbers see p. 71). Weather changes Don't ever rely totally on weather forecasts; watch for changes in the weather and be aware of local warning signs, such as cloud formations. It is also important to know what these weather changes mean in terms of their effects on the local area. - If it rains, will the rivers rise? how quickly? - If it snows, how will this affect exposed ridges or passes? - How many fine days can be expected, to cross a high alpine area? - What will new snow do to the avalanche risk? - How cold will it get when a cold front passes over? - How long is fog likely to last? - Is thunder and lightning likely? (important in some exposed areas). - Which direction will the wind come from? - Are strong winds or gales likely? Is the dangerous combination of COLD+ WET+ WIND likely to occur? (as in a southerly or southwesterly blizzard). When is it time to turn back? Knowledge about local weather and skills in reading the warning signs can be learned from a basic knowledge of weather patterns and local experience. Talk to people who live in the area or have been there often enough to have gained this experience and take notice of their advice . Be prepared for the very worst weather conditions rather than just hoping for the best. An easy trip becomes much harder in bad weather . (Further information: NZMSC Bushcraft Manual Chapter 11; NZMSC Outdoor Kitset Module 8 Weather; NZMSC Mountaincraft Manual Chapter 5). FIRST AID TRAINING: Carry a fully stocked first aid kit on all trips and ensure at least one member of your party has had first aid training (including CPR) and is able to recognise and treat hypothermia. If you are carrying any special equipment or medication someone must also know how to use this. Practice making a stretcher before you leave on your trip you never know when you may need one. Read a reference manual or include one in your kit (e.g. NZMSC's Outdoor First Aid Manual). Anyone who has a medical condition must always carry their medication with them (not leave it at home or in a hut) and ensure that all other party members know of their condition and how to treat it if necessary (e.g. asthma, epilepsy, allergy to bee stings). Diabetics and others who depend on regular medication must carry extra supplies in case they are away from home longer than planned. Spare medication should always be carried by another member of the party. If you have recently suffered an illness or injury it may be sensible to leave your trip for another time. Recent illness such as the flu can cause some people to become 25
exhausted and develop hypothermia more quickly than usual and recent injuries can recur when on an outdoor trip (especially when under stress). All members of your group should care for each other and be on the alert for signs of minor injury, exhaustion or the effects of cold in others. Prompt treatment could prevent an emergency . CONTENTS OF FIRST AID KIT These will vary depending on the size of the party, the location and length of the trip and any special features which may be encountered, but the suggested contents should include: Click Clack® or similar plastic sealable Tupperware ® type containerxl 23xl5cm cling seal plastic bagx2 Mountain Recreation Emergency Accident Procedure Pamphletxl Writing paperxl Small pencilx l Selection of Handyplast ® or Airstrip ® adhesive dressing stripsxlO Handyplast ® elastic dressing with medicated pad 8cmx0.9mxl Mefix® 5cm width about lm lengthxl Zinc oxide (Leukoplast ®) l inch rollx l Steristrips ®xl packet of 5 Tubigauze ®, Randoflex® or Systanet® bandage extra large (6cm)x30cmxl large x30cmx l + medium x30cmxl + small x30cmx l + Sterile Curit y® eye padxl Sterile gauze squares 75mmx75m " Fivepackxl Safety pins in seal easy plastic bag Large x l Mediumx2 Small x3 Savlon® in small (10 ml) plastic containerxl Small pair of eye scissorsx l Low reading thermometerxl t Sewing needle small xl mediumxl Dimp® in plastic seal bagxl Lipscreenxl Sunscreenx l Chloromycetin ® or Soframycin ® eye drops or ointx l • Soframycin ® burn and antibacterial qeam 15gmxl • Gastrolyte ® sachet 5gm for diarrhoeaxl Phenergan ® l 0mg one or two every 8 hours for allergy or nauseax20 Paracetamol 500mg one or two every 4 hours for pain, inflammation, headachex8 Soluble Aspirin 300mg one or two every 4 hours for pain, inflammation, headachex8 Pirophen ® one or two every 6 hours for more severe painx4 Puritabs ®for sterilizing waterxl2,or small dropper bottle of iodine salt in labelled film containerx l Spersin® antibiotic powderxl •
Steriswabs®x 10 20cm length of plastic tubing for suction or irrigationxl + 20cc plastic syringe x1+ Paranet® 5cmx5cm (36 pack tin)x 1 Oropharyngeal airway size 4xl + Throat lozengesx4 Amethocaine anaesthetic eye drops (Minims®)xl * to be used under medical supervision Scopoderm® TTS patch for nausea, vomiting, sea sicknessxl * to be used under medical supervision Buccastem® (Prochlorperazine) 3mg for nausea dissolved under top lip every 12 hoursxl * Packing: Pills may be packed in small cling seal plastic bags with stick-on labels and placed together in a plastic medicine container. + If not available via chemist try your doctor. t Your chemist can obtain low reading thermometers from Crombie & Price Importers, Box 121, Oamaru. * Only available on prescription. (For more detailed outdoor first aid information see NZMSC Outdoor First Aid Manual 14.) PHYSICAL FITNESS Lack of fitness stresses the body in a number of ways: - more energy reserves are used up with less efficient activity - a greater amount of heat and water are lost through puffing and panting - increased stress is placed on heart, circulation and breathing - sweating occurs, and heat is lost from the skin - muscles, joints, tendons etc. may get cramp or be injured.
An unfit person : - may struggle to keep up - is slower to recover from fatigue or exhaustion - cannot move fast enough to keep warm in cold conditions - puts others at risk by slowing them down so they get cold, or by stopping everyone ·to attend to exhaustion or injury. If all members of your party are evenly matched for fitness you will be able to move at a comfortable pace for everyone. This is not possible if some of you are unfit. Fitness is your own responsibility so if you are unfit do something about it before leaving on your trip. Lack of fitness is a kind of negligence which can put everyone's life at risk in adverse conditions.
27 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
What To Do If Things Go Wrong PART 1:
EMERGENCY SITUATIONS As shown in the previous chapters the human body must be kept warm. One way to do this is to keep moving, as exercise (particularly when using the large muscles of the upper legs and thighs) can generate up to 7011/oof the required body heat. Âˇ However situations do arise where an individual or a party cannot keep moving and are stranded-often in bad weather and with no shelter or transport readily available. Emergencies can happen when: - someone gets injured or falls ill - someone becomes exhausted or develops hypothermia - the party gets separated, one or more people are lost - the planned route cannot be used or the party is cut off from its route because of a change in the weather, a flooded river, etc. Anything which stops a party or individual from continuing on as planned is an emergency. Sometimes this might be a minor inconvenience, like having to wait overnight to travel on in daylight, but it may be a major, life-threatening situation which requires real survival skills. Any emergency requires a change of plans, so the first thing to do is to stop, stay calm, and think. If it is impossible to go on, th~ following action may be needed, depending on the nature of the emergency: - Turn back (retrace the route you have used). - Dig in and go to ground (stay in that spot, construct or find a shelter, make a fire, and wait for conditions to improve) . - Use an alternative route, if one is known to be available and likely to be usable (e.g. to avoid crossing a flooded river). If the em'!rgency involves injury, illness or hypothermia, do not carry on or seek an alternative route, but stop and find shelter immediately. If you "push on", to try and reach a hut or find help, the exhausted or injured in your party may die. Treat any injury or illness, starting with the most serious condition (often the person who is not complaining is the most seriously injured). Once your party stops moving (especially in cold or exposed conditions) all are in danger of hypothermia and some mean~ )f keeping warm is a priority. Build or dig your shelter first then put on or change into spare dry clothing. A dry shelter, warm clothing and hot food will help to ensure survival even if conditions are severe.
Figure 14: Fire.
Figure 15: Survival kit. The important things to do in an emergency are: - Stop, stay calm and think, assess the situation carefully, look at alternatives. - Attend to any injuries or illness. - Find or make a shelter (from wind, rain, snow, etc.). - Change into warm dry clothing. - Make a fire. Hot food and drinks will help keep you warm. - Maintain morale by being determined to survive; talk to your patient(s). - Look after each other, nor just yourself. Plan what you will do in an emergency before you leave on your trip and make sure you have the necessary skills and knowledge to cope if an emergency does arise. Necessary skills and planning include: - First aid training and a fully stocked first aid kit. - Clothing and equipment adequate for worst conditions. - A personal survival kit (see Fig. 15 for suggestions of items to include). - Emergency rations of food and access to water. - Some way to heat food and drinks- fire or (preferably) stoves. - Firelighting skills, and firelighting aids (see Fig. 11). - Emergency shelter-carry materials and know how to use them (see Fig. 10). - Route finding, know any alternative routes and how to use a map and compass. - Being aware of the weather you could encounter and its effects. - Cold water survival, if using boats, rafts, etc. 30
- Knowing how and where to seek help. - Fitness and good mental attitude towards the trip. Careful planning before the trip can save a lot of time, effort and even lives.
CLOTHING AND EQUIPMENT Always carry spare dry, warm clothing, a warm sleeping bag suitable for the conditions and some means of insulation from cold ground or snow. A personal survival kit carried at all times by each member of your party, will greatly increase the chances of survival, especially if the party becomes separated. (See Fig. 15) Adequate shelter from wet, cold and windy conditions can make the difference between survival and disaster, especially if your party is caught by darkness or bad weather above the bushline and cannot reach a hut. Plan and practice making shelters if you are going into high alpine areas or crossing exposed routes . You will need plenty of practice, as well as special equipment (shovels, ice axes), to make a snow cave or igloo. They can be dangerous if not built and ventilated properly. A plastic sheet or large plastic bag can provide shelter in an emergency- always include one in your gear. Check equipment such as ropes, ice axes, skis, canoes and lifejackets prior to your trip and look after it while in use. Negligence and carelessness with essential equipment can have serious consequences. Attempting to carry on if equipment gets damaged or lost could place your party and rescuers at considerable risk. It is better to retreat if possible , to find another less demanding route, or stay put until conditions change or help arrives .
MENTAL ATTITUDE Survival in an emergency depends on a combination of four essential factors: - Water and food. - Warmth (clothing, hot food, fire). - Shelter . - The will to survive. The first three are all aspects of physical survival but without the will and determination to carry on they are no use. You are more likely to have a positive mental attitude to carry on if you have the knowledge, skills and equipment necessary to ensure physical survival. Fear, panic, disappointment, grief, loneliness or a sense of inadequacy may all reduce your chance of survival, however these can be overcome by learning survival skills and experiencing situations where these skills can be put into practice. Disappointment will be less of a problem if you have set realistic goals, and loneliness can be prevented by staying with your party and making sure you don't get lost. You are more likely to survive an emergency situation if you have a positive reason for carrying on or "something to live for". This can come from the shared care and concern members of a party should have for each other. (Further information: NZMSC Bush craft Manual Chapter 15; NZMSC Outdoor Kitset Module 6 If things go wrong ... what next?; NZMSC Mountaincraft Manual Chapter 4, igloos, snow shelters; NZMSC new series pamphlet No. 6 Survival).
DOES ANYONE SURVIVE IN EMERGENCIES? The survival of individuals and parties in serious emergencies is sometimes reported 31
in newspapers, on radio and television, or told to friends after the incident but does not attract the same publicity as disasters. However, people do survive and their "success" stories are very interesting. A lot can be learned by studying what other people did right as well as wrong. Those who survived were usually experienced, well equipped, and trained in survival skills. Some survived in life threatening situations they had not experienced before because of their intelligent, commonsense approach.
STORY 1: Two girls survived for three days in the Southern Alps by digging into an ice cave. Although they did not have much food they had adequate clothing and sleeping bags. Their survival success was probably due to: - Experience and training. Both girls had been trained in survival by their mountaineering club and were experienced in mountain conditions. - They "went to ground" quickly when the weather turned bad and were able to dig a hole in the snow and ice before they got exhausted or cold. - They got into their sleeping bags on top of their packs, boots and spare clothing, to keep off the ice.
STORY 2: Two people survived for a week in a bad blizzard on Mt Ruapehu. They built an igloo of snow blocks and had some food, adequate clothing, and sleeping bags. They survived because of: - Experience and training. They knew how to build an igloo of snow, even though it took them 4 hours. - They realised that the blizzard was severe and "dug in" early, before getting cold or tired. - They had spare food, which was rationed out over the next week, and a stove to melt ice for water. - They got into their sleeping bags and made a mattress of spare clothing (in plastic bags), boots, packs and a tent, to keep off the snow and ice. In both stories, these people were found alive and well (although cold), by rescuers. They had shivered for most of the time but had not developed serious hypothermia.
STORY 3: Six climbers trapped in the Southern Alps survived for seventeen days before being rescued. They attributed their survival to team work and said later they had looked after one another. Their survival, in what was described as a "ferocious snowstorm", was due to: - Support for each other, maintaining morale. - Experience and training. All were experienced mountaineers and one had climbed the route before and knew the area well. - Having food and equipment for a long stay. The party had set out for a long traverse of the alpine area and had adequate clothing, sleeping bags, tents and food. 32
- Determination to keep going even after one tent and most of the food and gear was buried under snow and had to be dug out. - They stayed put until conditions improved enough after 5 days to allow them to move to a lower level. - Two were able to go for help. This involved two days of tough tramping, with limited food. - The two who went for help marked their route out so that rescuers could follow it back. As one of the group said after they were rescued, "We fought it, we got warmth from each other, only by looking after one another did we stay alive". When they were rescued the o~her four were cold and hungry, with possible frostbite, but otherwise okay.
PART 2: SENDING FOR HELP The -
Police, cir Search and Rescue organisation, cannot help you unless they know: that you are in trouble (a distress call or message) your party is overdue (reported by a relative, friend etc.) where you are likely to be (intentions known) i.e. leave a detailed intentions note (or complete a form, Fig. 16, available from NZ Mountain Safety Council) at home with a responsible person, before setting out on your trip. Use a "Two Minute Form for Safe Boating" if going on a boat trip (available from NZ Water Safety Council, see p. 71). Details in your intentions note should include: - number and names of party members (adults, children) - experience, equipment, (radio, clothing) - any special physical or mental conditions - planned route and alternative route - leaders experience - contact person. To seek help, an individual or party may be able to: - use a radio (mountain radio, carried or in a hut) - send some signal ("SOS" in snow, rifle shots, smoke) - send out a written or verbal message (preferably written as the messenger may be weakened by cold, lack of food, or dehydration and forget all or part of the message. You could use the S.A.R. emergency form, see Fig. 17). To send out a message, a party must decide: - who is to go (at least two people, for their safety) - who is to stay with the injured (never leave them alone) - contents of message (write it down) - best route to seek help (take messengers' safety into account) - any other parties nearby who can help, at a camp or hut. It is much more important for the messengers to reach help safely than it is for them 33
= .. a ~
Party members (cont'd): Family Name First Name
FOR BACK COUNTRY USERS Help us to help you
'C ~ Q
I. Complete this form and leave it with a person you can trust. 2. Contact this person as soon as you return from your trip. 3. This person should notify the POLICE if you have not contacted them by: Time Day Date
.. -=-= = :!.
Intended Route (cont'd): Until the Police are notified no search and rescue action will be taken .
cS' "' 00
4. PARTY MEMBERS Family Name First Name
(continue on reverse): 5. VEHICLE(S): Make & Model Registration No. ______ Colour ____ Parked at ______________ _ INTENDED ROUTE Date /ti me due out: Date in: ________ Route (show alternatives): ________________
(Write any changes of plan in hut logbooks)
Any special medical information
(continue on reverse):
REMEMBER ID INFORM YOUR CONTACT PERSON ON RETURN
New Zealand Mountain Safety Council, P.O. Box 6027, Te Aro, Wellington. Tel: 857-162 Fax: 857-366
S.A.R. EMERGENCY FORM
., To be taken, or telephoned, to the nearest g. Police Station, Park H.Q ., or Ranger Station. ;
. . Nature of Emergency (delete those not applicable) Accident Illness Per son M1ssmg ::i:,Date .................. . . . . . ..... Time . .............. . ........... . ~ . . I . d ~ Name of M1ssmg or nJure person ...... . . ..... .... . . . ... . ........ . ; ........... . ....... . ..... . . . Age . . .... ... ................... Years t"l'j Their Home address . . .... . . . .................... . ...... . . . . . ..... . ci Their next of kin . .... ............ ... . . ..... . ......... . .. .. ....... . ~ Next of Kin's address .. . .. . . . . . . . ........ . .................. . .. . . . . ~ Location of ill or injured person . . .. . ......... . .......... .. ... . .... . I') Map No .. . .. . ... . . Map Reference .. . ... / .. . ..... . . .. .... . . .... . . . ':, Location of remainder of Part y (if different from above) ;
. . . .........
. ... . ... ...... . ...... . .. . ...... . .........
of illness or injury (Delete those not appli cable) Fractures Hypothermia Bleeding Unconsciousne ss Dislocation Heart Attack Gunshot Further information Missing Person Information Experience (give years of serious tramping-shootin g-cli mbin g-sk iingother-) .............. . .................... .. ....... . . .. . . . . . Âˇyears Knowledge of area ......... good . . . . . . ... reasonable ......... none Clothing .............. . ..... . ...... . ....... .. .. . . . .. . ....... . ... . Equipment .. . . . .. . . . .......... . ... . . . . ... . .......... . ... . .. . . .. . . Firearm . ..... . ... Food . . ... . . . .... .. ....... . . .. .. . ......... .... . Physical and mental condition of missing person . . ......... . ......... . Has person previously been lost .. .. . .................. .... .......... . Give detail s .. . ........... . .... .... .. . ......... .. ................. . Detail s of trip . Entry point ............... . .. . . . . . ... ... . . ..... . ... . Date . . . . . . . . . . . .. . . .. . ... . ... . . Time ........ . . . ..... .. . . ..... . .
Purpose of trip tramping shooting climbing skiing Proposed duration of trip ... . . . . . . . ............................ . .. . Proposed route ....... . ..... . .. ....... . .. . . .. .... . . . .... .. . . .... . . Intended exit point . . .. ... .. . ............ . .......... . ............. . Travelling by ... .. ... . . Description of vehicle ... . .. . . ... .... . . . .... . Action already taken . . . . .. . . ......... . . . ....... . ............ . . . .. . Medication already given . ....... . .... . .... ... ..... Times ....... .. . Intention of remainder of party . . . ... . . . .. . ............ . ........... . Assistance required - rescue - search party - Doctor - food Medical supp lies - or ... . ........... . .. ...... . . ................. . Radio . Do you have one in working order -yes -no Type . ............... .. ...... Frequencies .. .. ... . . . ... . . ... ..... . Do you have a transistor radio -yes - no Weather (delete those not applicable) Wind ..... .... .. .... Blizzard - Strong Steady Breeze - None Temperature ....... . .... Freezing Cold Mild Warm Conditions . . Sleet - Snow - Hail - Rain - Fog - Rain Threatening Cloud ... . . . .......... Overcast (high- low) fluffy cloud Visibility ... . ......... .. . . ... ... .. .. ...... . ....... Kilometres-miles Party Members Names
Signed . . . . . . . . . . . . . . . . . . . . . . . . . . . . Party Leader First Aider . . . . . . . .. . ... .. .. ... . . . .
HOW TO HELP SEARCHERSFIND YOU ON THE GROUND
Figure 18a: How to help searchers find you on the ground. 36
HOW TO HELP SEARCHERSFIND YOU FROM THE AIR
DISPLAYEQUIPMENT " . 11,1• "
Figure 18b: How to help searchers find you from the air. 37
Figure 18c: How to help searchers find you in boats or water. 38
to take risks to get help quickly. Messengers should take time to mark their trail on the way out so that rescuers can follow it back. Messages can be sent or carried to: - nearest Police Station (they will organise a search) - Park Conservation Officers or HQ or an alpine hut with a radio - friends, family - local search and rescue, if known (best done through Police) - the nearest people who might be able to help (farms, camps) with transport telephone, radio, etc. Those who stay behind can assist by marking their position as clearly as possible and signalling to searchers. It may not be easy for parties of less than four people to send for help so remember this when deciding party size. If you're with a large party which decides to split up into smaller groups, make sure each group consists of at least four people. If you change your plans or route (from the original plans and route set out in your intentions note) make sure you leave plenty of notes or directions in a logbook at a hut so searchers know where to look for you. Similarly, if you move to a better shelter, hut, or campsite after sending for help, then you must leave a note at the original shelter as this is where searchers will go to first. (Further information: Appendix 7, p. 67, of this manual; NZMSC Bushcraft Manual Chapter 16; NZMSC Outdoor Kitset Module 6. If things go wrong ... what next?; NZMSC new series pamphlet No. 6 Survival).
Basic Treatment of Hypothermia (In The Field) IMMEDIATE
Seek dry shelter out of the wind (make a shelter if necessary). Remove wet clothing (cut off if necessary), replace with dry clothing including hat, gloves, socks. Insulate from cold e.g. sleeping bag, carry mat, packs. RECOGNITION
Distinguish between: COLD SHOCK
fatigue lack of food
long exposure to cold
i i i
If you are carrying a low reading thermometer you will be able to determine which of the above conditions the victim is suffering from but if in doubt treat as hypothermia.
COLD SHOCK: is caused by a sudden drop in blood pressure, due to cold conditions, and is very similar to fainting . It may happen to someone who dives into cold water, goes out of a warm room or hut into cold air, or gets out of a warm vehicle in a cold environment. The signs are very similar to fainting with pale, cool skin, white or blue lips and nausea. Recovery is usually quick and complete as long as the person is not left lying on cold ground or in cold water. Treat as for fainting. Remove the victim from the cold then lie on her/his side or in the recovery position and keep warm . EXHAUSTION: may or may not be accompanied by hypothermia. The mind stays alert and willing to co-operate but the body is not capable of responding. This may be due to a lack of fitness, to hunger or to dehydration and heat. Treat by allowing the victim a short rest but don't let her /him stay inactive for too long or s/he will become chilled. Give some high energy food and a warm drink. This is not a permanent
Figure 19: Basic treatment of hypothermia. 41
condition and recovery is usually quite rapid after a rest and food. If left unattended, exhaustion can lead to hypothermia. OTHER CONDITIONS which may resemble some of the signs of hypothermia include: - diabetes (undiagnosed) high blood sugar, ketone smell - diabetes (diagnosed) high or low blood sugar, insulin imbalance - thyroid hormone problems - stroke - liver failure (low blood sugar) - nutritional problems (hunger, low blood sugar, thirst) - infections, e.g. flu - alcohol or drug intoxication or withdrawal - Parkinsons disease (slow talking, tremor) - altitude sickness - fear and anxiety. COMPLICATIONS caused or aggravated by cold may include:
angina, sudden chest pain (especially in sudden exposure to cold) paralysis, unable to move to generate heat injury, loss of blood, shock frostbite and other tissue damage. Before you leave on your trip: Find out if any of your party members have existing medical conditions and how cold and stress are likely to affect them.
CHECKLIST THINK HEAT!
TREATMENT WARM BATH
CALORIES REST ACTIVITY SURFACE WARMING (See notes 2) CORE WARMING (see notes 3) ALCOHOL MASSAGE OF SKIN HOSPITAL NOTES:
YES YES short YES YES
NO YES yes, followed by gradual YES
NEVER YES 48 hours minimum NO NO
IF CONDITION DETERIORATES
(I) If in doubt, treat as most serious i.e. HYPOTHERMIA.
Condition may deteriorate as core temperature lags behind skin temperature, so keep monitoring and change treatment if necessary. Handle gently
as jolting or jarring may set off cardiac arrest. A person who has been injured or is unable to move could also be suffering from hypothermia. (2) Surface warming includes hot baths, showers, fires, or any heating through the skin. (3) Core warming includes warming the body core by warming the chest and trunk or by introducing warm fluids into the body, and breathing warmed air or warmed oxygen.
ASSESSMENT OF THE PATIENT 1. SEVERE HYPOTHERMIA A victim who is cold and has the following signs or symptoms, is considered to have severe hypothermia: - Very slow pulse, breathing. - Becomes semi-conscious or unconscious, slurred speech, appears clumsy, may stagger & fall. - Abnormal behaviour, loss of reasoning, remoteness, may resist help. - No shivering, in spite of being very cold. - Other significant illness or injury which may have allowed hypothermia to develop. - Appears to be under the influence of alcohol, drugs. - Core (rectal) temperature of 32 Â°C or less (use your low reading thermometer, see Chapter 5, p. 47).
2. MILD OR MOD ERA TE HYPOTHERMIA A victim who is cold but does not have any of the signs or symptoms above, may have mild or moderate hypothermia. If in doubt treat as hypothermia. Check core (rectal) temperature (if below 35 Â°C = hypothermia).
THE FIELD, FIRST RESPONDER
(Preferably someone with first aid training who can give CPR if necessary). 1. Treat very gently, avoid jolting or jarring. Stop moving. 2. Remove all wet clothing (cut off if necessary). Replace with dry clothing or some dry covering all over but move limbs as little as possible. 3. Insulate from cold (Wind and Wet) -+ Shelter. 4. Cover the head, neck, hands and feet with dry clothing or covering (i.e. hat, gloves, socks) as well as the rest of the body. Try to warm the air (exhaled breath, steam). Apply warm objects to the head, neck and chest to prevent further heat loss. These objects should not be too hot to hold in your hand. Use: - hot water bottles (wrapped up to prevent burning) - warm packs (wrapped in clothing or a towel) - warm bodies to prewarm a sleeping bag or clothing - other people to provide warmth by breathing out warm air in a small enclosed space or in the same sleeping bag as victim (people in sleeping bags on both sides of the cocooned victim may be more practical). 43 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
NOTE: (a) Do not apply warm objects to the armpits or groin. This can stop
5. 6. 7. 8. 9. 10. 11.
victim shivering by fooling the brain into thinking the body is warm and lead to further heat loss from the core. (b) Do not place any warm objects on the extremities (limbs). (c) Do not attempt any rapid rewarming. Do not rub or massage the limbs, or move them more than necessary. Do not give coffee or alcohol. Do not put the patient in a shower or bath. Lie the patient down in a sleeping bag or other insulation and protect from cold, wind and wet, including the ground. Keep the victim quiet and inactive for at least 48 hours. Warm, sweet fluids can be given in small quantities only if the victim is fully conscious and able to swallow. If severe hypothermia has developed, treat as above but transport to hospital as soon as possible. Lie or carry victim with head lower than the rest of the body. Consider using a helicopter or plane especially if core temperature is below 32 Â° C. Place an unconscious person in the recovery position if unable to move to hospital. Turn over every two hours to prevent skin damage, and allow to rewarm slowly. Handle gently and do not leave unattended. Be careful what you say in the presence of an unconscious hypothermia victim, s/he may remember what is said. Take care of urine output, and if conscious provide small quantities of soft warm food and warm sweet drinks. Avoid excessive fluid intake or hard foods. Do not allow to move or exercise for at least 48 hours as a relapse is likely. If rewarming watch out for excessive beat. Take core temperature and look for hot, sweating or flushed skin.
TREATMENT FOR SEVERE HYPOTHERMIA, WITH VITAL SIGNS (pulse, respiration present, no CPR required) 1. Provide for basic treatment. Watch for a drop in core temperature which could lead to cardiac arrest. 2. If more than 30 minutes from a hospital, add heat gradually and gently (to prevent further cooling). 3. Transfer to hospital as quickly as possible.
TREATMENT FOR SEVERE HYPOTHERMIA WITH NO VITAL SIGNS (no pulse or respiration, CPR required) 1. Provide basic treatment first to prevent further cooling. 2. Carefully assess for the presence or absence of pulse or respiration. This may be very slow so check over one to two minutes. 3. If no pulse or respiration, start CPR. Recommended CPR rates are 12-15 breaths and 80-100 compressions per minute. Rates as low as 6-12 breaths and 40-60 compressions per minute may however be adequate because higher rates may lower the COilevel too much (affecting the cerebral circulation and ventricular function). The cold heart is stiffer and less compressible than a warm heart. 4. Use mouth-to-mouth breathing rather than a mask and bag. Obtain a core (rectal) temperature if possible, using a low reading thermometer (see Chpt 5, p. 47). 44 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
Cardiopulmonary Resuscitation (CPR)
Establish unresponsiveness Shake and shout . Call for help. Position victim flat on back on firm surface .
OPEN AIRWAY Tilt head well back . Lift chin with fingers .
Look , listen and feel for breathing . If absent ,
Keep victim's head lilted back . Pinch nostrils . Take deep breath, blow firmly with tight seal over victim 's mouth . Give two breaths initially . Chest must rise ar,d fall.
Check carotid pulse. Place two fingers on victim 's Adam 's apple , then slide into groove at its side . If pulse absent ,
BEGIN EXTERNAL CARDIAC COMPRESSION Kneel by patient. With heel of hands , press lower half of breastbone downwards 3-Scm (1 ½ -2") . The fingers may be extended or interlocked , or the top hand may grip the wrist of the hand underneath . Keep arms straight and fingers clear of chest . Press down straight towards spine .
One rescuer : 15 compressio ns (80-100 /minute) 2 breaths . Continue resuscitation until natural breathing starts again and pulse returns or advanced care is available .
EFFECllVECPRREQI.JllUSREPEATD) INSlllUCilON USING TRAINING MANIKINS
The National Heart Foundation ofNew2.ealand •• .
Figure 20: Cardiopulmonary Resuscitation. 45
5. Do not attempt to add heat if less than 30 minutes from a hospital. Transfer to hospital as quickly as possible. 6. If more than 30 minutes from a hospital add heat gradually and gently, as in basic treatment. 7. Monitor the victim's physical status and level of consciousness regularly. 8. In all cases transfer to hospital by emergency services as soon as possible. Beware of wind chill, especially on boats or from helicopter rotors. NOTE: As a general rule a hypothermia victim should not be left alone. However if help is available nearby and you are alone with the victim, put the victim in the recovery position and get help rather than try to do it all yourself. Ensure the victim is alone for the minimum time needed to attract attention or get help. Never leave a victim alone near water or in any other potentially dangerous situation without ensuring s/he is not at further risk. REMEMBER: - In all cases, death is indicated by a failure to recover vital signs (pulse, heartbeat, breathing) on rewarming . - A positive attitude and determination to provide treatment until death can be established by other criteria will avoid unnecessary tragedy. - Other factors which need to be considered include: • serious injury, especially head and neck • pre-existing medical problems • consumption of alcohol or drugs . - The basic rule should be: NOT DEAD UNTIL WARM AND DEAD. - Profound hypothermia protects against cerebral anoxia (lack of oxygen to the brain) for several hours. NOTE: Avalanche victims who have been buried for an hour or longer may still be alive but severely cooled. Look out for any sign of recent breathing (such as an air space in front of the face) as well as possible hypothermia. Treatment is the same as for severe hypothermia and should be started immediately.
(For advanced treatment of hypothermia see Chapter 5. p . 47).
46 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
Advanced Treatment of Hypothermia INTRODUCTION Some of the information in this chapter is for doctors and hospital staff only and the complex procedures described here should not be attempted unless you have the appropriate training, knowledge and skills. If however you are the only person available to treat a hypothermia victim, and can not reach medical help quickly you may need to provide treatment to an advanced level. The information included in this chapter will help you to do this and give you confidence to do all you can to save the life of a hypothermia victim.
GENERAL POINTS 1. The evaluation and treatment of hypothermia, whether wet or dry, on land or water, is practically the same as long as the core temperature is less than 35°C . A rectal temperature should be obtained if at all possible. In terms of A, B, C, think: A=Airway B = Breathing C = Circulation D = Detailed examination, including temperature. 2. A low reading thermometer is crucial in the assessment and care of a hypothermia victim. Normal clinical thermometers do not read below 35 °C and so are useless in identifying hypothermia . While obtaining a rectal temperature is important for assessing hypothermia and in any later treatment, it is not always possible to get this reading, so look for other signs and symptoms as well. Individual responses to hypothermia will vary but if in doubt treat as hypothermia rather than some lesser condition. If an oral or armpit temperature greater than 35 °C is obtained it is usually not necessary to take a rectal temperature. Temperatures close to the core can be measured by a urine temperature as it is passed or by using a tympanic membrane (eardrum) thermometer. 3. Remember No No No
to THINK HEAT at all times. cold intravenous fluid cold air or oxygen cold treatment of any kind.
Unheated air or oxygen will further cool the victim, so any air or oxygen should be warm and moist. 4. To prevent further heat loss, insulate the entire patient (including head) and add heat to the brown fat heat generating areas of head, neck and chest. This added heat will prevent further cooling even if it does not actually rewarm the victim . 5. Add heat gradually and gently, by applying warm objects to the head, neck and chest. Use: -
9. 10. 11.
hot water bottles (wrapped up to prevent burning) warm packs (wrapped in clothing or a towel) warm bodies to prewarm a sleeping bag or clothing other people to provide warmth by breathing out warm air in a small enclosed space or in the same sleeping bag as victim (people in sleeping bags on both sides of the cocooned victim may be more practical).
NOTE: (a) Do not apply warm objects to the armpits or groin . This can stop victim shivering, by fooling the brain into thinking the body is warm , and lead to further heat loss from the core. (b) Do not attempt any rapid rewarming . (c) Do not place any warm objects on the extremities (limbs). Give the victim warm, moist air or oxygen to breathe. Exhaled breath from others or steam from a boiling billy, will add heat and moisture to air. Be careful not to burn victim's mouth or trachea by overheating the air or having the steam too close. Oxygen should be moist and warmed to 40-42 Â°C at the mask. Do not use tourniquets or occlusive dressings. Be very careful of all statements and actions while attending to people who appear to be unconscious or require C.P .R. People frequently remember what has been said, and it can produce severe psychological problems later. This applies to both warm and cold hypothermia victims. It is essential to preplan how to handle such an emergency and to know how to use any equipment. Handle the patient carefully and transport to hospital as soon as possible. The inside of any transport (e.g . ambulance, boat, helicopter) should be warm (approximatel y 18-22Â°C), as should any treatment room at the hospital. Beware of wind chill , especially on boats or from helicopter rotors.
FACTORS WHICH ARE IMPORTANT FOR SURVIVAL: prior illness, injury (e.g. diabetes) depth of hypothermia (how cold?) duration of hypothermia (how long?).
REWARMING TECHNIQUES SHOULD BE: non invasive 48
non injurious rapid (active) permit continued access to the patient for treatment appropriate.
TEN FACTORS TO CONSIDER IN HYPOTHERMIA CARE 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 1.
Loss of Loss of Loss of Loss of Loss of Loss of Loss of Damage Trauma. Loss of
heat from the body surface. heat from the body core . control of metabolism. control of brain function. control of breathing. control of heart function. control of kidney function. to skin, gut, pancreas . life.
LOSS OF HEAT FROM THE BODY SURFACE A void ~ WET ~WIN~
! Use: • dry/waterproof clothing • shelter(plastic bag) • bivvy bag
• windproof clothing • shelter(foil, plastic bag) • warm sleeping bag
• warm clothing , hat, gloves • other people • Hiebler jacket
CAUTION: - Use surface warming only if core temperature is greater than 35 °C. - If using hot bath put trunk in, limbs out. - Do not use hot water bottles or rocks in armpits or groin (may cause localized skin burns). 2.
WARMING THE CORE (active rewarming) Indirectly: Via the skin and brown fat areas of the upper trunk, chest e.g. -Hiebler jacket (circulates warm water). -Anaesthetic water bed . Directly: Via the lungs -warm, humidified air, oxygen e.g . air or oxygen warming devices, 40-42 °C at mask. - Peritoneal lavage-fluid at 37°C at high flow rate (e.g. 150 ml/min). - Heated i.v. fluids at 37°C-dextrose / saline. - Cardiopulmonary by-pass; partial by-pass. - Warm fluid lavage of stomach balloon . 49
METABOLISM Needs: Food in the right form, supplied at an appropriate rate and oxygen (AIR) at the right temperature, at an appropriate rate. - If core temperature is greater than 35 째C and patient is co-operative, give sips of warm sweet fluid (not coffee). - If core temperature is less than 35째C and patient is co-operative, give glucose tablets to suck. Nurse on the side and do not leave unattended. - If core temperature is less than 35 째C and patient is semi-conscious or unconscious, DO NOT GIVE ANYTHING BY MOUTH. Commence Dextrose 50Jo i.v. at 37째C, and 80 ml/hr (1 L/ 12 hr). Monitor: Blood sugar e.g. Visidex, Dextrostix, BMstix, Hypocount Laboratory. If blood sugar low (N.R. 3.9-5.6 mmol/L) give 20-50 ml warm 500Jodextrose, i.v .. If a nasogastric tube is placed in the stomach for feeding, take care, as excessive stimulation of the back of the mouth can cause arrhythmias or vomiting. Look out for: Endocrine disorders, e.g. Hypothyroidism,
Take blood for: sugar, ketones, thyroxine level, alcohol and drugs before administering i.v. fluids. Corticosteroids are sometimes given for hypothermia induced adrenal suppression. 4.
BRAIN FUNCTION Irrational behaviour - Use your brain -+ do not fight. Poor co-ordination - Finger-nose and heel-toe coordination test. - Parkinson's disease Look out for: - strokes - paralysis (neck injury?)- head injury.
BREATHING Remember: A, B, C. A = airway B = breathing C = circulation D = disciplined examination (including rectal temperature) E = exposure F = frostbite G = glucose H = hydration Airway:
Recovery position. Suction. Oro pharyngeal airway. Endotracheal tube.
- Mouth-to-mouth. - Ambu or Air Viva.
50 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
- 6-12 breaths/minute may be adequate. - Do NOT hyperventilate. -Aim for 500Jooxygen (no more). Oxygen:
- Warm, humidified (40-42Â°C at mask). -2-4L/min. - Do NOT give cold or dry oxygen (or air).
Look out for:
Chest infections, especially if water has been inhaled, (e.g. pneumonia). X-ray chest when stable.
HEART AND CIRCULATION Stethoscope: For at least 2 minutes (very slow). Pulse: Do NOT use pulse meters. Sphygmomanometer. Cardiac massage: 40-80/minute. ECG Monitor: - Normal Also may have: absent p, inverted T, prolonged PR, QRS and QT. -J Wave. - Ventricular fibrillation, or shivering.
NORMAL J. WAVEf---HI H----t---+--t--H-ttt- -H ,.,.
Figure 21: EGG graphs. 51
Defibrillator: Do not defibrillate until core temperature has risen to 30°C.
-Avoid below 32°C (core temp). - Lignocaine and dopamine (used in dogs). - Bretylium in man for arrhythmias. - If defibrillate, give lignocaine lmg/kg as a bolus then in minutes give 0.5 mg/kg as a bolus. - Dopamine increases cardiac output.
Intravenous fluids at 38°C: Hypothermic patients are also hypovolaemic but take care as the myocardium does not cope with fluid overload. Central line: Risky. Cardiopulmonary by-pass, partial by-pass or heat exchange system: - Only available at a major hospital.
- Heparin. Peritoneal dialysis: Twenty x3 litre cycles of 1.5% Dextrose at 43 °C dialysate
given by catheter over 10 hours. (i.e. 2 cycles= 6 litres per hour). Standard peritoneal dialysate 1 or 2L pack of Glucose 1.5% concentration Na 132 meq/L Ca 3.5 Mg 1.5 Lactate 35 Cl 102 Take blood for: FBC, Platelets, LFT,
Prothrombin Time (dehydration and coagulopathy).
Cold diuresis -+ wet -+ cold-plastic urine bottles. Urinary catheter - urine output reflects circulation. Measure oral and i. v. input vs urine and vomit output. Weigh. Take blood for:
U and E potassium can rise or fall. Bicarbonate balance; alkalosis. pH-metabolic and respiratory acidosis. Gases - correct reading for core temperature.
Take urine for:
- Urinalysis. - Sodium level. - Osmolality. Treat: Metabolic acidosis with bicarbonate (with care). ·NOTE:
Bicarbonate is rarely used now in cardiac arrest.
SKIN, GUT, PANCREAS Closed cell foam etc.: Prevent pressure areas and frostbite. Water, air and ripple mattress: Turn gently two hourly. Peritoneal lavage: Local anaesthetic, scalpel, trochar, tubing, warm sterile fluid. Gastric Balloon: Even with no invasion gastritis is a problem. Take blood for: S Amylase, Pancreatitis.
TRAUMA Cervical collar: Head, neck injury or if unconscious. I.v. fluids: Shock, blood loss. Splints: Other injuries. Carry on stretcher head down, feet up in recovery position. LOSS OF LIFE How do you tell? Must attempt to rewarm first. Who makes the decision? Someone has to . What do you do? Legal obligations need to be considered. What do you say? Patient may not be dead and could remember, or be discouraged from "pulling through". What is "DEAD"? You cannot make this decision until the patient fails to revive with re-warming attempts. Remember:
NOT DEAD UNTIL
When can you stop treating? e.g . severe brain damage evident, cannot detect this in a very cold patient. NOTE: The major problem with severe hypothermia is ventricular fibrillation while rewarming. Ventricular fibrillation may be triggered by: - Endotracheal intubation. - Rapid positive pressure ventilation (including mouth-to-mouth). - Excessive i.v. fluids, electrolytes, bicarbonate or drugs. - Cardiac thump. - Rough handling or physical exertion. - Central invasive cannulation, i.e. i.v. lines or pacing wires. - Rapid external warming. Patients with severe hypothermia should be handled very gently. (See Chapter 6, p. 59 for hospital treatment of "cold water near drowning" victims).
Immersion in Cold Water COLD WATER SURVIVAL INTRODUCTION
Anyone taking part in water sports such as sailing, fishing, canoeing, rafting, wind surfing or diving is at risk from accidental immersion in cold water. Water can remove body heat very quickly and wet clothing provides little warmth in cold water. Even short term immersion , or sudden "dunking" in cold water can have drastic effects. - Cold shock can lead to heart failure . - Cold water on the face can cause hyperventilation and gasping while still under the water. - You may be able to hold your breath for only 15-20 seconds in cold water. - Cold water can cause muscle cramps or loss of coordination when trying to swim or stay afloat, e.g. swimming usually fails after 10-15 minutes in water below 10Â°. - Cold water in the ears can cause disorientation. If under the water you may not be able to find the surface again. - Water turbulence or waves slapping the face can cause drowning even when wearing a lifejacket. LONGER TERM IMMERSION with a lifejacket leads to a different set of problems
including hypothermia. The outer shell of the body cools first, so the muscles and skin feel cold and shivering occurs. Swimming is still an option but this leads to greater heat loss and even a strong swimmer would not be able to swim for more than one kilometre in calm water. Anyone more than half a mile (or 1 km) from shore should adopt a heat conserving strategy instead of trying to swim. (Seep. 56-What to do in cold water). After about 20 minutes in cold water the inner body core starts to cool and survival times can be measured in hours, depending on the temperature of the water. Cooling of the core can also lead to strange and irrational behaviour as the brain cools. Rapid cooling of the core, including the brain, may lead to a condition known as "Cold Water Near Drowning" where the body is protected by the cold from any of the usually fatal effects of drowning and can survive underwater for up to two hours. Near drowning is a state of "suspended animation", and it appears to be the same as biological death, with no pulse, heartbeat, or breathing; fixed dilated pupils, and a cold, rigid body. However, the brain cells are still alive and complete recovery is possible even after long periods under water. The important thing is that victims are not written off as "dead" until they have failed to respond to resuscitation and 54
Figure 22: Cold water survival (H.E.L.P. and Huddle).
rewarming attempts. This is a form of rapidly induced hypothermia. (Seep. 59 for further information). EFFECT OF ALCOHOL: While alcohol can cause some opening of blood vessels to the outer body shell, in cold water the normal mechanisms of heat conservation will overcome this. The two most significant effects of alcohol are: - mild intoxication can impair judgement and performance to the point where it increases the chance of getting cold or falling into cold water in the first place, - greater levels of intoxication are more likely to result in drowning through not being able to stay afloat or hang on to any support in the water. On land intoxication can prevent moving around and so the heat generating capacity of muscle activity to warm the body is not used. In both cases, alcohol increases the risk of accidents and drowning.
WHAT TO DO IN COLD WATER: - Do not try to swim, particularly if water tempc;rature is less than 15 Â° and you are more than one kilometre from shore. This increases heat loss; and exhaustion, cramp and hypothermia develop more quickly (heat loss may increase by 35-50%). - If not wearing a buoyancy aid, try to get out of the water or at least get the upper part of the body out of the water onto some kind of support. Although the skin may feel colder out of the water, especially with a wind blowing, much less heat is lost out of water than in it. - Treading water or "drownproofing" (with the head under and just coming out for air) lead to rapid heat loss and exhaustion but are both better than drowning! - If wearing a buoyancy aid try to keep at least the upper part of the body out of the water. The buoyancy aid should help but it is best to get right out if possible, e.g. onto an upturned boat. - A group of people can reduce heat loss by huddling together with maximum chest contact. (See Fig. 22). - An individual can reduce heat loss by reducing the amount of body surface exposed to the cold water, such as using the HELP (heat escape lessening posture) position. _(See Fig. 22). TO AVOID HYPOTHERMIA STAY OUT OF COLD WATER
SURVIVAL IN WATER The body surrenders its heat to the water many times more quickly than to air of the same temperature and it is often possible to stabilize body temperature once you are out of the water. The less time spent in cold water the greater your chance of survival. Even though you may feel colder out of the water, especially in windy conditions, this feeling of cold is only skin deep and does not reflect any cooling of the body core. Climb onto floating objects such as logs, wreckage or an upturned lifeboat or at least use them to support the upper part of the body out of the water. Small boats should be constructed so they provide some support even when overturned, and other flotation devices, such as life rafts, buoys or even plastic containers filled with air, should be carried. Âˇ 56
Water Temperature (OF)
68 59 50
15 10 0
Cooling Rate (Â°C/hour) 0.5 1.5
2.5 4.0 6.0
Death is probable at 30Â°C body temperature (victims are usually semiconscious and likely to drown). (Hayward 1986) Figure 23: Average cooling rates for non-exercising lightly clothed adults during immersion in cold water of different temperatures.
Figure 24: Keep out of cold water. 57
CLOTHING AND BUOYANCY AIDS/LIFE.JACKETS Clothing Most clothing is designed to keep the body warm in air and does not provide much insulation in cold water. Water conducts heat away from the body once it has soaked through clothing. Heavy winter clothing can however provide some insulation and you may increase your survival time by 30-40% if you wear as many clothes as possible in the water. DO NOT TAKE OFF CLOTHES OR SHOES - they do not drag you down in water and are only restrictive if you try to swim rapidly. Wet suits will give some protection against cooling. The thinner neoprene suits do not restrict movement as much as other types of wet suits so can be worn for above water activities. Wear windproof clothing (i.e. jacket and trousers) over a wet suit when taking part in water sports on the surface of the water. A dry wet suit or one being worn in the water (with a layer of warm water trapped inside it) is quite effective but once it is wet and you are out of the water it loses heat very rapidly by evaporation. Cold water replaces the layer of trapped warm water every time you go into the water. If you wear windproof clothes over a wet suit heat loss out of the water will be greatly reduced. Canoeists, rafters, windsurfers, small boat sailors and water skiers who wear a wet suit without any other protective clothing risk getting chilled. New dry suits which reduce wind chill more effectively than wet suits are now available. It is best to wear woollen or polypropylene clothing under these suits because heat can be lost rapidly if the suit is in direct contact with your skin. Using a hood and face mask or scarf across your mouth can also help reduce heat loss. A hood insulates the head, especially during unexpected immersions in cold water, and a mask or scarf can help prevent cold water induced hyperventilation and gasping. Some canoeists use nose-clips to prevent cold water going up their nose when they capsize but this may also cause pressure problems in the ear. Another problem facing rafters, canoeists and small boat sailors who survive capsizing, losing their craft and the initial tip-out in cold water is survival on land. You'll need extra (preferably dry) clothing in this situation but it is difficult to carry clothing and keep it dry while you are in the water. Survival suits may be carried on larger boats or on helicopters operating in areas of cold water. If you take part in underwater activities such as scuba diving, you must know what sort of clothing and equipment you will need and how to use it. These activities have different, highly specialized requirements for insulation to cope with breathing under water and changes in pressure as well as cold water. Water conducts heat away from the body at a rate ten to twenty times greater than air and so rapid cooling can occur from any exposed body surface. Cold water on the face and in the nose or ears can produce added problems of hyperventilation, gasping disorientation or even cardiac arrest and death. Scuba divers who get cold may run out of air while still underwater, as cold and shivering greatly increase a divers need for air. Cold may also affect your ability to estimate how long you have been under the water. If you are anxious or panic you will use up more air and may act irrationally and put yourself in even greater danger. Buoyancy aids/lifejackets do not give much protection against heat loss unless they fit tightly against the upper body and are made of some material which does not soak up water (such as closed-cell foam). The properties to look for when choosing a lifejacket include:
- comfortable to wear all the time on the water - "snug" fit over the chest, preferably with sleeves 58 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
- good flotation to support the body and keep the head up out of the water, even when unconscious - highly visible - some insulation (closed cell foam) - a complete body suit of neoprene or waterproof material, with some flotation support.
SURVIVAL SKILLS If you learn and practice survival skills, and always wear a suitable lifejacket your chances of surviving a real immersion accident will be greatly increased. Knowing what to do and how to do it will prevent you panicking, increase your will to survive and will in turn improve your chance of survival. Once hypothermia has developed, any sudden exertion can lead to death by heart failure. Let the rescuers do the lifting and do not try to swim to them.
Figure 25: Rescue from water.
COLD WATER NEAR DROWNING GENERAL POINTS 1. Anyone submerged long enough to be unconscious, and/or requiring CPR and who has been underwater less than one hour should be sent to hospital as quickly as possible. 59
2. 3. 4. 5. 6. 7.
If the person has been underwater for longer than one hour, no attempt at resuscitation is likely to succeed. If it is not known how long the person has been underwater, assume that it has been for less than one hour and treat accordingly. Basically there is no difference in treatment between fresh and salt water near drowning. These points apply to any near drowning, not just those in cold water. Any person who has been submerged for longer than six minutes has a better chance of survival in colder water . The possibility of hypothermia is less critical than the effects of the near drowning on the breathing and circulatory systems. Rewarming needs to be very gentle and gradual, preferably with no invasive techniques. Many near drowning victims die of a particular type of blood clotting problem (disseminated intravascular coagulation), and not from lung (pulmonary) problems.
EVALUATION AND TREATMENT 1. It is very important to clear the airway with any of the standard techniques and to expel water from the lungs. Do not use the Heimlich manoeuvre (fist in the stomach) on these patients. 2. CPR MUST BE STARTED IMMEDIATELY. 3. Assess carefully for associated injuries, especially head and neck . 4. Follow the basic treatment for hypothermia once vital signs have been restored . AT THE SCENE: - Remove from the water. - Start mouth-to-mouth as soon as possible, even in the water. - Carry from water face down and head down (assists drainage of water from airway). - Be very gentle and careful when moving the victim. - CPR- if no pulse or respiration. - Check pulse for at least 2 minutes (very slow). - Remove wet clothing-cut off if necessary, but avoid moving limbs (acidic blood may return to heart). - Suspect head and neck injuries (diving into shallow water). Information which may be helpful for treatment: This should be obtained as soon as possible and passed on to doctors at the hospital. I. Time the victim was in the water-confirmed or suspected. 2. Water temperature-estimate e.g. cold, very cold, warm. 3. Type of water-fresh, salt, swimming pool (chlorine), polluted. 4. Any details about the victim: - age, sex, weight - level of consciousness when taken from the water - existing medical conditions, illness - injury related to the incident (especially head, neck) - medication taken, prior to accident- routine?
- consumption of alcohol or drugs - how much? - any change in condition since removal from the water - any hyperventilation prior to entering the water (alkalosis). 5. Details of treatment given at the scene: - mouth-to-mouth (any delay in starting?) - CPR - how long for? - any other treatment- i.e. for injuries. 6. Method of transport, time taken to transport to doctor or hospital. NOTE: In cases of near drowning, primary treatment is to restore breathing and circulation rather than to treat hypothermia. Any rewarming should be gradual and gentle and not interfere with the primary treatment. Other effects caused by immersion in cold water include: - Frostbite (in very cold water). - Immersion foot or trench foot - in warmer water. SPECIAL TREATMENT FOR DIVERS: Two major problems can arise with near drowning of divers who are then brought rapidly to the surface. These are: - Air embolism. - Decompression sickness ("bends"). A victim with either of these conditions must be placed in a decompression chamber and the air pressure increased, to recompress the bubbles of air or nitrogen in the blood system. Decompression must then be very slow until the air pressure is the same as outside the chamber. It may be necessary to keep special equipment in the chamber to treat other complications and hypothermia, and so medical staff can stay in the chamber to attend to the patient. Hypothermia protects against the harmful effects of both air embolism and decompression sickness so patients should not be rewarmed until they have been transported to the decompression chamber. (Victims may be kept cold by packing in ice during transport, but this treatment is controversial). HOSPITAL TREATMENT Laboratory evaluation (in order): - Arterial blood gases. - Chest x-ray. - 12 lead ECG. - Electrolytes, urea, full blood count. - Serum pinkness (indicating RBC haemolysis). - Cardio-respiratory monitoring. - I.V. fluids. Treatment: - Warm oxygen 40-42Â° at mask . - Endo tracheal airway. - Ventilate. 61
- Active rewarming only while CPR required. - Passive rewarming once circulation established. Caution:
- Warming of the core can overshoot and cause hyperthermia so continue to monitor core temperature. Complications:
- Head and neck injuries. - Respiratory infections, especially in polluted water. - Acute pulmonary oedema (secondary drowning), requires positive pressure ventilation. Although onset is more rapid after fresh water near drowning (15 minutes to 72 hours after) it is more lethal after salt water near drowning. Antibiotics can be used for infection. The use of corticosteroids and diuretics is uncertain. - Haemolysis. - Disseminated intravascular coagulation. - Renal failure. - Cerebral oedema . - Neurological damage. - Spasms and convulsions can be treated with sedation and monitoring. Muscular rigidity can be treated with complete muscular paralysis and ventilation. - Swelling can be reduced by restricting fluid intake (30-500Joof normal intake) and some would recommend intravenous mannitol. Barbiturates tend not to be used now for brain swelling. - Acid- base balance, high levels of acid and CO2can be adjusted using high levels 02 with positive pressure ventilation. PaCO2 should be adjusted and maintained at 30mm Hg. Correct pH by adding 0.147 for each degree below 37Â°. - Cardiac output may be depressed by positive pressure ventilation and can be adjusted by giving more fluids. NOTE: Dopamine does not give a consistently beneficial effect in cases of near
Appendices APPENDIX 1: SIGNS AND SYMPTOMS OF HYPOTHERMIA - Shivering (early stages when body core temperature is above 32Â°C) but some victims will not shiver. - Feeling of numbness. - Drowsiness, and unwilling to do even the simplest of activities, plus decreased level of consciousness. - Slow breathing and pulse rates (seen in cases of prolonged hypothermia). - Failing eyesight (seen in cases of prolonged hypothermia). - Coordination difficulties (the patient may stagger). - Unconsciousness, usually the patient has a "glassy stare" (in extreme cases). - Freezing of body (in the most extreme cases). Action must be taken immediately as the patient may be near death.
SURVIVAL RATE 1977-80 (IN BRITISH LITERATURE)
196 109 40
passive external active external active internal
APPENDIX 3: WARMING TECHNIQUES HEAT GAIN*
1. 2. 3. 4. 5.
Nonshivering metabolic rate Maximal shivering Heated (45°C) humidified 02 at 20 liters/min Heated intravenous solution 45 °C, 1 liter Heated peritoneal dialysis at 45°C, 1 liter; flow rate 6 liters/hr 6. Cardiopulmonary bypass at 45 °C, 1 liter; flow rate 30 liters/hr 7. Trunk immersion in hot water at 45°C Vasoconstriction Vasodilatation
Calories Provided at Core Temp. 28°C+
70 kcal/hr 350 kcal/hr 30 kcal/hr 17 kcal 17 kcal 102 kcal/hr 17 kcal/hr 510 kcal/hr 600 kcal/hr 2400 kcal/hr
• Adapted from Myers, A.M., Britten, J.S., and Cowley, R.A .: Hypothermia: Quantitative aspects of therapy. J.A.C.E.P. 8:523-527, 1979. + Example: A 70-KG human being requires a gain of 60 kcal/hr to increase temperature 1 °C.
COMPARISON OF REWARMING METHODS METHOD Blanket insulation, warm room Body Heat rewarming Radiation treatment (heat cradle) Hot bath rewarming Hot water suits, blankets, mattresses Hot water showers Electric blankets, heat packs Respiratory warming
RATE OF CORE TEMPERATURE INCREASE 0.5-1.0°C/hr Low 0.5-1.0 3-4 1-2 0.5-1 1 0.5-1 (unpublished)
Source: The Field Treatment of Hypothermia by Popplow & Kuehn, Canada.
APPENDIX 4: CASE STATISTICS In a person with a core (rectal) temperature of 30°C, 100% humidified air at 43°C and a flow rate of 7 L/min gives a temperature rise of 0.34°C/hr. Inspiration of cold air at - 20°C results in a drop of core temperature of 0.2 °C/hr . In one North American Study (Paton): - 14 patients with severe hypothermia were put on cardiopulmonary by-pass - 13 had ventricular fibrillation - 11 survived (i.e. 80% survival) 64
APPENDIX 5: AIR WARMING EQUIPMENT Year Dot
Mouth to mouth.
Water's canister Edinburgh (Lloyd et.al).
British Everest Expedition used a Soda Lime system Soda Lime+ CO2 from sparklet + 02 --+ H20 +Heat+ 02 20 lb lb 16 lb
Hayward & Steinmen used a Bennett model water beater and vapouriser 1 L water bath with a thermostatically controlled electric immersion heater. Water temperature 70째C. Mask temp 40-45째C. High flow rates e.g. 12 L/ min . N.B. Small oxygen cylinders carried in ambulances last for 80 minutes at 4 L/min.
Timaru Hospital bubbler filled with water at 70째C. Refilled often. Mask temperature checked each time .
Dr Nelson's brewer New Zealand Everest Expedition Kettle.
Murchison Hospital closed cell foam insulated bubbler on a portable oxygen cylinder with a thermos and thermometer.
Gloucester brain dead on ventilators warmed up by adjusting the humidifier temperature to 40째C. Dr Mike Anderson's Water's cannister system . Also used by Wellington Cavers 1982.
Oamaru Hospital equipment search Wide bore corrugated tubing In line thermometers Heated humidifiers Simple and safe Ohio nebuliser Simple and cheap Puritan Bennett Comple x Aqua Pak Complex and expensive Concha Pak Fisher & Paykel Very good, but bulky
Malcolm Ross (NZIG) helped design a portable 12 volt battery system capable of operating the Puritan Bennett nebuliser for six hours . Possible ambulance application .
. Dr John Hayward boiling pot and reducing valve system copied by Mount Cook rescue team and used in the field.
Strentex Heatapak System brought from the U.K . by Pat Pye. Used for warming the upper trunk and modified for hot air breathing by Bruce Clarke (Otago University Anaesthetics Dept) . 1.5 kg. One cartridge lasts eight hours on one D cell battery. Lottery Board Grant to assist in this research. Designed for Nata but never produced commercially.
CT.I.A.A. Mountain Medicine Conference in Chamonix. Dr Lloyd from the U .K. Water's cannister system. French Water's canister insulated and designed for lowering down crevasses. 65
American oxygen/hydrogen equipment designed by Dr Harry Guy ex Christchurch respiratory physician. Light-weight cylinder with a mixture of oxygen 990/o and hydrogen 10/o(or 02 970/o and H2 30/o) released through a metal catalyst creating heat and moisture and fed to the patient via a Hayward type regulator, moisture trap, tubing and mask. Approx. 5 kg. Other systems. WABA air warming system for divers.
APPENDIX 6: EQUIPMENT FOR HYPOTHERMIA TREATMENT * Take as much or as little as you think you'll need for your trip.
Low reading clinical thermometer 25-42 Â°C ~~~
Balaclava Clothing Socks Mittens Glucose sweets Rescue cocoon Pillow Stretchers Water and windproof protection for stretcher victim Water and windproof protection for rescuers Blankets Face cloth x 2 Towel x 1 Thermos flask Heating source for hot water Sweet hot beverage Ordinary thermometer -20 to + 100Â°C Urinal-male and female Portable suction Oropharyngeal airways size 1, 2, 3, 4, 5 Laryngoscope x 2 Oxygen/hydrogen cylinders+ catalyst administering device to give moist warm oxygen via wide base tubing to a mask with an in line thermometer Heibler jacket- a sleeveless rubber jerkin with a network of tubes circulating a flow of warm water around the upper trunk and chest One litre Dextrose/saline+ iv cannula & giving set Blood warmer device for intravenous fluids (cold plastic pack iv fluids could possibly be microwaved but take care not to overheat as it continues to heat after removal from the microwave) ECG defibrillator Air Viva or Ambu Resuscitator Oxygen+ heated hurnidifer with portable power source+ wide base tubing & connectors+ in line thermometer adjacent to Hudson mask Endotracheal tubes, size 1, 2, 3, 4, 5, 6, 7, 8, 8.5, 9. Intravenous lignocaine + syringe & needle Tympanic membrane (ear probe) thermometer Battery operated rectal/oesophageal probe thermometer 66
APPENDIX 7: (a)
COMMUNICATION AND ORGANISING A RESCUE
COMMUNICATION Clear communication saves time and lives. Ensure your message can be understood easily whether using radio or telephone or sending out a written message.
Introduce yourself, e.g. "Bill Huckleberry, mountain guide" and if you are using a telephone or radio say where you are calling from e.g. Copland Shelter.
Say that you have an emergency with one (or more) of your (or another) party who has mild, moderate or severe hypothermia from cold exposure. Because "hypo" and "hyper" can easily be confused over the radio or telephone it is wise to add cold exposure to distinguish hypothermia from hyperthermia (heat exhaustion).
State where the victim is, e.g. in a crevasse 50 metres east of the Copland Pass.
Give details Name: Sex: Age: Address:
of the victim. Joe Hiker Male About 20 from Canada
Figure 26: Communication.
7. 8. 9. 10.
Give the history of the incident: - When the accident occurred: e.g. 5am (0500 hours) today. (Use 24 hour times if you can). - What happened?: He and his companion fell into a crevasse. - What happened to the victim?: He was knocked unconscious for 10 minutes. Regained consciousness but became delirious at midday and unconscious at 1pm (1300 hours). - Examination by person giving first aid: At 2pm (1400 hours) the patient was unconscious. Did not respond to pinching. Pulse 20 per minute. Breathing 6 per minute. Mottled blue and white skin. A slight bruise on the forehead . No other obvious injuries. - Allergies: Is wearing a Medic-Alert bracelet indicating allergy to Penicillin. - Drugs: Takes Adalat tablets for blood pressure - Weight: About 70kg - Build: Lean. - Clothing: Was lightly clothed with no hat or gloves. - Comment on the site: He's in a large open crevasse with a red pack marking the entry point. - The weather : It was snowing all morning but is fine now with good visibility, no wind, warm conditions, about 15Â°C, and 10cm of fresh snow under foot. - Treatment: At 6 am (0600 hours) he had two barley sugars. At 2 pm (1400 hours) we got him into a warm sleeping bag and placed him in the recovery position on a sleeping mat with one of our party in attendance . - People: The companion is safe and well. There are two in our party. That is a total of three able to assist. (It is important for the rescue party to know this). - Equipment: We have a rope and ice axe but no stove, stretcher or portable radio . If using a radio or telephone ask for the message to be repeated back to you to ensure there is no confusion caused by poor reception. Check a written message carefully before sending messengers off. Ask if there is anything further you can do for the patient on the mountain or to expedite the rescue, e.g. stamp out a helicopter pad. Indicate your intentions, e.g. returning to the patient or standing by the radio. Arrange further communication, i.e. a set time for radio call, or a signal which you can send, e.g. smoke, flare, words stamped on snow. Remember you have had time to assess the situation, the person you are asking to help you has not. S/he is, however, most likely to know the quickest and most efficient way of getting help and transferring your patient to hospital. If the plan does not seem appropriate do not be afraid to say so. You must have a better alternative though. Do not fight the rescue coordinator. After all s/he too is trying to help your
68 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
patient. If the sense of urgency is not appreciated you may have to indicate how long you feel the patient is going to survive without further help, e.g. less than an hour. (b)
ORGANISING A RESCUE Believe that you are able to organise a rescue and if necessary follow it through until the victim is safely inside a hospital as there may be no experienced Search and Rescue and medical personnel around to help. If you are not sure whom to contact try telephoning One One One and ask for the Ambulance Service. Explain that you have a serious case of cold exposure i.e. hypothermia. Give the victim's name, age and location and ask how to contact the nearest medical practitioner (G.P.) and the most senior hospital medical person regarding the patient's treatment and urgent transfer to hospital. If you cannot talk to the consultant doctor on call ask that s/he be informed of the victim's condition as soon as possible. Leave your name and means of contact. If a Search and Rescue Operation is required contact the Police (phone One One One) or National Park Ranger Station. In New Zealand the Police coordinate all land and sea S.A.R .. Ask for confirmation of evacuation. Be patient, it will happen. Remember other lives, including your own, may be at risk. There is usually a standard line of command and communication which should also be the quickest. If you feel obliged to short circuit this system ensure that someone notifies those who have been left out, e.g. it's no use flying out a deeply hypothermic victim if there's no ambulance to transfer the victim from the aircraft to the hospital. Know your local system and personnel. Know what equipment, facilities and expertise you have available locally, during transport, at the doctor's surgery , the cottage hospital , base and provincial hospitals .
Any victim with a core temperature of 32 Â°C or less should be transported to a major hospital as quickly and gently as possible . The following factors may influence your choice of transport: - Depth of hypothermia. - Distance and time to travel. - Terrain e.g. ocean, surf, cliff, river, gorge, lake, tussock or hill country, bush, rock or snow face, glacier. - Weather, now and over the next few days. - Availability of transport and personnel. - Amount of handling and transfers. - Comfort. The journey must be gentle. Victim lying in the recovery position. Avoid rescue in an upright posture. - Equipment carried by transport. Stretcher, scoop net or strop, rescue cocoon, on board heating, suction, heated oxygen, defibrillator. - Access to the victim. If the victim vomits can you clear the airway? - Type of transport, e.g. stretcher party, toboggan, motorised toboggan or snow groomer, raft, surfboat or motorised inflatable, hovercraft, jetboat,
Figure 27: Search and rescue operation.
four wheel drive vehicle, truck, car (e.g. sedan or station wagon), ambulance (St John or Red Cross, 4 wheel drive, standard, sedan, intensive care), aircraft (civilian or military) helicopter, fixed wing (air ambulance, standard, float or ski plane). Nominate your preferred means of transport. If you think a helicopter is going to significantly affect the outcome, say so. Remember that if you telephone the ambulance service you will get an ambulance and not an aircraft.
Nominate one person as the "nurse". Introduce the "nurse" to the patient, e.g. "This is Sally/Fred. S/he's our first aid expert and will be your "nurse'"'. Communicate with the victim via the "nurse". To ensure an accurate history is given on arrival at hospital the "nurse" should stay with the victim and assist with the handover. If the handover occurs before hospital prepare the victim for this, e.g. "We are going to stop at Park Headquarters in a few minutes" and "This is your new nurse, Sister Nightingale, who is going to take you to hospital". Use appropriate personnel, e.g. a trained mountaineer will be more able to comfortably administer first aid on a mountain side but may not be familiar with the equipment in the ambulance. Remember that an unconscious person may still be able to hear and recall what you say.
70 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
Don't worry too much about this. If you waste a lot of money everyone will be more than happy to tell you how you should have dealt with the situation. You and others will then know how to manage better next time. To assist the authorities (e.g. Police, Ambulance Service, hospitals) to make a prompt decision about the funding of alternative transport (e.g. helicopter) give them a cut off time. For example: "If we have not had confirmation in 15 minutes we will assume this is okay". This will at least spur someone into making a decision. Be prepared to accept this and remember they have probably had to make this sort of decision on other occasions.
APPENDIX 8: (a)
Mountain Radio Service Wellington Masterton Taupo Hawkes Bay (Napier) Christchurch
Dick Morris Colin Coutts John Head Ron Ward Derek Brown
or Dunedin Southland (lnvercargill) or
Paul White Ron Kingston Dick Sheehan Ray Phillips
660-855 (H) 80-426 (H) 89-194 (H) 442-797 (H) 799-793/834 (W) or 524-472 (H) 665-241 or 325-846 44-664 (H) 59-713 63-751
New Zealand Water Safety Council PO Box 10-126 Wellington Tel: 733-247
Low Reading Thermometer Your chemist can obtain low reading thermometers from Crombie & Price Importers, Box 121, Oamaru.
REFERENCE BOOKS Lloyd, Evan L., Hypothermia and Cold Stress (1986). London. Croon Helm. Steele, Peter, Medical Care for Mountain Climbers (1976). London. Wm. Heinemann. Wilkerson, James A. (Ed.), Medicine for Mountaineering (2nd Edition) (1975). Seattle, Washington. The Mountaineers Books. Wilkerson, James A. (Ed.), Hypothermia, Frostbite and other Cold Injuries (1986). Seattle. Washington. The Mountaineers Books . 71
TREATMENTIN THE FIELD
BODY SIGNS/SYMPTOMS TEMP. (rectal)
37.5°C NORMAL 36 FEELCOLD
Seek dry shelter, replace wet clothing with dry including socks,gloves, hat, cover neck, insulate whole body including HEAD from cold. Exercise but avoid sweating. Externalwarmth (bath, fire) ONLY if CORE TEMP. above 35°C. Warm sweet drinks and food (high calories).
BODY CORE TEMPERATUREBELOW35°C
CLUMSY 34 IRRATIONAL
CONFUSED (may appear drunk) 33 MUSCLESTIFFNESS
= HYPOTHERMIA= HOSPITAL
NO EXERCISE,HANDLEGENTLY,REST. NO EXTERNALWARMTH (exceptto chest, trunk, eg. Hiebler Jacket). Warm sweet drinks and calories. Internalwarming via warm moist air (exhaledair, steam) or warm moist oxygen (40 • 42°C at mask). Monitor pulse, breathing. Restrictall activity, lie down with feet slightly raised.
32 SHIVERINGSTOPS, COLLAPSE.TRANSFERTO HOSPITAL.URGENT. 31 SEMI CONSCIOUS 30 UNCONSCIOUS No responseto painfulstimuli
Nothing by mouth. Check airway remains open. May tolerate plastic airway, put in recoveryposition, check airway, tum every 2 hours to protect skin, monitor pulse and breathing. 29 SLOW PULSEAND BREATHING Slow mouth-to-mouthbreathing, at victim's own rate (may be very slow). 28 CARDIACARREST Check airway. CPR, with mouth-to-mouthbreathing. No obviouspulse or breathing Aim for normal CPR rates of 12-15breaths/min.and Pupilsdilated 80-100compressions/min.but slower rates of 6-12 breaths/min. and 40-60 compressions/min. may be adequate. Continue for as long as you can.
No re-exposureto cold Exerciseto generate body heat but no sweating. Warm bath. Warm sweet drinks, calories Keep warm for several hours. Watch for drop in temperature.
DO NOT massagecold limbs. DO NOT give alcohol or coffee.
CHECK FOR OTHER INJURIES.MINIMUMSTAY - 48 HOURS
34 33 32 31
30 29 28
Watch out for late cardiac arrhythmia. Warm only trunk, chest. Give warm, sweet drinks. Warm moist air or warm moist oxygen, 40-42°C at mask. e.g. Warm IV fluids e.g. Dextrose/Saline5% at 37°C, 50% Dextrose, 20ml. Monitor pulse, respiration, ECG.
NO exercise. NO external warmth except Hiebler warm water type jacket to trunk and chest. NO cold air, oxygen. NO cold drinks. DO NOT overloadwith IV fluids.
JOLTINGDURINGTRANSPORTMAY CAUSE CARDIACARREST. Nil by mouth except glucose jelly. Check airway, recoveryposition. Turn every 2 hours to protect skin. Oropharyngealairway Slow synchronousmouth-to-mouthor mask. Defibrillateif necessary. Intubate if unable to maintain airway.Ventilatewith 50% humidified oxygen at 42°C, CPR at 6-12ventilations/min. and 40-80 compressions/min.Warm peritoneallavage (standarddialysateas fast as it will flow}, or Arteriovenous by-passwarming.
NO food or drink
Endotrachealintubation may precipitate ventricular fibrillation. NO drugs unless CORE temp. above 32°C. e.g. Lignocaine.
BELOW 28°C. NO VITAL SIGNS, COLD. DO NOT GIVE UP TREATMENT.
DO NOT GIVE UP
NOTE: NOT DEAD UNTIL WARMAND DEAD! Avoid rapid rewarmingand HANDLEGENTLYAT ALL TIMES. Core temperaturemay lag behind skin temperatureand continue to drop, so keep monitoring.
Monitor Core temp. Monitor biochemistry(potassium, sugar, acidity) and correct cautiously.
DO NOT defibrillateuntil CORE temp. above 30°C. .
NOTE: CORE temp. lags behind skin temp, watch out for after-drop. Other complicationsmay arise during rewarming (e.g. cardiac, fluid balance).
P.O. BOX 6027, TE ARO, WELLINGTON PHONE: (04) 857-162 FAX: (04) 857-366
MN24 Disclaimer: This publication is available to you for historical purposes. The content in this publication may not be up to date.
The purpose of this manual is to help all outdoor users to understand what hypothermia is, to recognise symptoms of hypothermia and know how...
Published on Jul 27, 2020
The purpose of this manual is to help all outdoor users to understand what hypothermia is, to recognise symptoms of hypothermia and know how...