Alternative Resuscitation Protocol For Special Population

Alternative Resustitation Protocol for Special Population

Aaron Morton MMSc, PA-C, ATC, FAPACVS

Emory Center for Critical Care / Emory University Hospital Atlanta, Georgia

David Lizotte MPAS, PA-C, FAPACVS

Cardiac Advanced Resuscitation Education / Fenton, Missouri

Amanda Murray MMSc, PA-C, FAPACVS

Appleton, Wisconsin

ABSTRACT

Purpose: The purpose of this article is to inform readers of the presence and need for alternative resuscitation protocol and review the evidence surrounding post-cardiac surgery patients. Method: A PubMed search was completed reviewing evidence behind specific protocols. Search terms included post-cardiac surgery arrest management, epinephrine in cardiac surgery, emergent resternotomy, and internal cardiac massage. Additionally, MeSH terms were searched including heart arrest, resuscitation, cardiac surgery complications. Results: Significant evidence supporting utilization of alternative protocol and interventions were well supported within the body of published literature. Conclusion: An alternative evidenced-based resuscitation protocol for post-cardiac surgery patients who suffer cardiac arrest is well supported. The protocol which deviates from Advanced Cardiac Life Support (ACLS) with alternation in medication dosing, emphasis on electrical therapy via epicardial pacing, defibrillation and cardioversion, as well as emergent resternotomy reduces the failure to rescue rate. Further adoption of protocol and team-based training will be necessary to provide the best opportunity for survival in this special population. Keywords: post-operative cardiac surgery arrest, resternotomy, cardiac surgery complications.

INTRODUCTION

Advanced Cardiac Life Support (ACLS) is taught to scores of healthcare providers every year regardless of their role or specialty. Many providers are required to maintain ACLS certification even though it is not the best protocol for their patient population. While standard

ACLS protocol works well for a large assortment of patients, it fails to consider multiple clinical features of the post cardiac surgery patient.1 Some of these features include the presence of an endotracheal tube, chest tubes, temporary epicardial pacing wires, utilization of peri-operative chronotropic and inotropic medications, as well as the use of intravenous (IV) sedation and analgesic medications.2 The ACLS guideline, as published by the American Heart Association fails to address any of the significant clinical features for the post cardiac surgery patient. Multiple national and international resuscitation and surgical specialty groups have outlined the clinical benefit and appropriateness of an alternative protocol. The European Resuscitation Council (ERC), European Association of Cardiothoracic Surgery (EACTS), The Society of Thoracic Surgery (STS) and the American Heart Association (AHA) have outlined benefits of components of the protocol. Most recently, the ERC, which has for years endorsed an alternative protocol, now highly recommends team-based training in the care of post cardiac surgery arresting patients take place.3 Additionally, Cardiac Advanced Resuscitation Education, which is a specialized educational organization, has formed and developed a specific educational platform to support knowledge of alternative protocols.4 Over the course of the previous decade, the recognition for the need of a specialized alternative protocols has grown widely; the understanding and utilization of these protocols has not. A review of the protocol and the evidence behind it will help increase the understanding and clinical utilization.

DISCUSSION

In the United States there are approximately 500,000 cardiac surgeries performed in 1,120 cardiac surgery centers each year.5 Post-cardiac surgery cardiac arrest occurs between 0.7% - 8% of all cases.5-12 This represents a substantial annual number of patients who present a clinical quandary for cardiac surgery and cardiothoracic critical care providers who must direct the resuscitation efforts. As much of the evidence used to support the ACLS protocol is based out of prehospital studies and populations, it is not well suited for post-operative cardiac surgery patients. As mentioned above many support devices utilized in post-operative cardiac surgery patients are not addressed in ACLS, nor is the presence of a highly educated, multi-disciplined expert team at the ready to respond to the highly monitored in hospital arrests. A well-researched and specialized alternative protocol is of great benefit to the medical teams who respond to specialized cardiac arrest patients.

Comparison

In October 2020 the American Heart Association published their Scientific Update on Resuscitation and the updated algorithm for ACLS. The updated algorithm for Ventricular Fibrillation or Pulseless Ventricular Tachycardia in the 2020 ACLS protocol instructs one shock followed by two minutes of Cardiopulmonary Resuscitation (CPR), followed by a rhythm check. If shockable, another shock is administered to the patient as well as Epinephrine 1mg 1:10,000 Intravenous (IV), followed by two minutes of CPR, and another rhythm check. If shockable, a third shock and an additional two minutes of CPR and administration of an IV anti-arrhythmic agent such as Amiodarone or Lidocaine.2 In comparison, the specialized protocol for post-cardiac surgery cardiac arrest patients has a significant difference from the AHA protocol. For Ventricular Fibrillation or Pulseless Ventricular Tachycardia, the alternative protocol instructs

to first attempt defibrillation or cardioversion with three sequential shocks. If return of spontaneous circulation (ROSC) is not achieved, CPR is initiated, and an Amiodarone bolus is to be given, immediately followed by preparations for emergent resternotomy.5 (see Appendix 1) An obvious and key difference from ACLS is the absence of reflexive epinephrine administration, stacked or sequential shocks and emergent resternotomy. Additionally, the alternative postcardiac surgery protocol permits one minute without CPR to allow for application of electrical therapies via defibrillator or epicardial pacemaker generator.5

For Asystole and Pulseless Electrical Activity (PEA), the 2020 ACLS update instructs administration of 1mg 1:10,000 Epinephrine IV and immediate CPR for two minutes followed by a rhythm and pulse check.2 For the Bradycardia algorithm, administration of Atropine 1mg IV every three to five minutes is recommended.13 For the alternative post-cardiac surgery arrest protocol, asystole and severe bradycardia and PEA are separated into two distinct response actions. For asystole and severe bradycardia, initial rescue involves immediate attempts at epicardial pacing via pacing wires. If pacing is unsuccessful, CPR is initiated as a bridge to emergent resternotomy.5 Transcutaneous pacing may also be attempted. For post-cardiac surgery PEA, it recommends immediate CPR, a quick review of H’s and T’s, and emergent resternotomy. Patients who are paced via epicardial pacing wires at the time of their PEA arrest should be removed from the epicardial generator to ensure the patient is not in fine Ventricular Fibrillation and able to be defibrillated.5 In summary, the alternative protocol seeks to avoid CPR, with preference for electrical attempts at rescue and attention to emergent resternotomy for the benefits of access to the mediastinum which will be discussed.

Evidence-based alternative approach. As presented above, there are some significant and striking differences between ACLS and the alternative post-cardiac surgery arrest protocol. It is worth breaking down the key differences with a review of the available evidence. Most apparent is the reduced emphasis on early initiation of CPR in most presenting arrest scenarios. This is counterculture to the well accepted practice of immediate chest compressions in ACLS, however in the post-cardiac surgery patient CPR carries an added risk of increased mortality. Multiple studies have demonstrated significant risk associated with chest compressions in the general population. These risks include rib fractures, sternal fractures, conduction system injuries, airway injuries, hepatic contusions, to name a few. A recent publication reported thoracic injuries in up to 85% of patients who receive CPR.14 An additional meta-analysis surveying 23 publications has reported an incident rate of 9% for retrosternal hematomas and upwards of 10% for all mediastinal bleeding in non-divided sternums.15 This is particularly worrisome as these injuries were found in the non-sternotomy out of hospital arrest (OCHA) population. In the post-cardiac surgery patient, a fresh sternotomy increases the risk of injury following CPR. Multiple publications in the late 1990s and into the 2000s have recognized the inherent risk with recent sternotomy and chest compressions with reports of hemopericardium, Right Ventricle lacerations from posterior sternal recoil during chest compressions, and dehiscence of prosthetic valves.16-18 Deferring immediate CPR in fresh sternotomy patients, allows time to intervene with electrical therapies which are very effective in post-cardiac surgery patients while avoiding the risk of chest compressions.

While the etiologies of post-operative arrest can vary, many of them are able to be rescued with electrical therapies. The most prevalent arrhythmias leading to arrest include Ventricular Fibrillation, Ventricular Tachycardia and Bradycardia.5,13,19 Rescue efforts for these rhythms are easily preformed in an intensive care unit (ICU) or hospital ward with standard available equipment. The alternative protocol and most recently the AHA recommend utilization of epicardial pacing as a means for restoration of heart rate in bradycardia or asystole patients.5,13 This therapy option is unique and only available to post-cardiac surgery patients who typically have temporary epicardial pacing wires implanted in the operating room. Additional evidence supports the alternative protocol in patients arresting from Ventricular Fibrillation and Pulseless Ventricular Tachycardia. While the AHA continues to recommend one shock followed by two minutes of CPR, the alternative protocol recommends a sequential shock approach without intervening CPR.5 Multiple retrospective studies revealed a higher rate of ROSC and survival to discharge of in-hospital monitored Ventricular Fibrillation and Pulseless Ventricular Tachycardia arrest if patients receive defibrillation within 2 minutes of the arrest and in a sequential 3 stacked shock approach.20,21 Specifically, post-cardiac surgery Ventricular Fibrillation has high rates of ROSC and survival when treated rapidly with electricity.1,3,11,13,19 This data supports the alternative approach of immediate preferential application of electrical energy for post-cardiac surgery patients to avoid the increased risk of chest compressions. Looking at success rate of each sequential defibrillation attempt, it has been well documented that the success rate of additional shocks decreases substantially. Several studies have found success rates for first defibrillation attempts near 80%, this decreases rapidly to less than 10% on the fourth and subsequent defibrillation attempts.22,23 This further supports the alternative approach of immediate application of electrical energy for post-cardiac surgery patients, chest compressions which carry an increased risk in these patients until electrical attempts have clearly failed. Chest compressions are not the only routine element of the ACLS protocol that carry increased risk following cardiac surgery. The use of Epinephrine is also reduced within the alternative protocol. Multiple studies and case reports have demonstrated harm with the administration of Epinephrine. Specifically, in post-cardiac surgery patients, a well-done case report from 2008 demonstrates risk associated with administration of high dose Epinephrine. This case report highlighted a patient who suffered a tension pneumothorax and arrested, received 1mg IV Epinephrine per routine ACLS protocols and then suffered a rupture of his aortotomy suture line and massive hemorrhage leading to emergent resternotomy and repair.24 While this is admittedly a dated report, the very same event could occur today as dosing and intervals for administration of Epinephrine have not changed. Post-operative endogenous catecholamine elevations following cardiac surgery is a well-known occurrence, additional Epinephrine, as demonstrated above, is not without risk.25,26 Furthermore, there is added controversy regarding the actual dosing intervals of Epinephrine. A large meta-analysis reviewing over 140,000 in hospital cardiac arrest (IHCA), found more frequent dosing was associated with high risk of mortality for both shockable and non-shockable rhythms.27 It specifically found patients with the dosing frequency found within the AHA recommendations has lowest level of survival compared to patients with dosing in the five to six minute range and even as long as nine to ten minute range. What is probably most interesting in resuscitation science is the lack of randomized control trials for the utilization of Epinephrine. In fact, there has been only one randomized control trial completed to date over the use of Epinephrine during cardiac arrest. The Paramedic-2 trial with over 8,000 subjects, completed in

the United Kingdom, was the randomized control trial with administration of Epinephrine during a cardiac arrest for out of hospital arrest patients. The trial, carried out by National Health Service paramedics, made a blinded comparison of saline flush to 1mg Epinephrine 1:10,000 IV. It found the patients who received Epinephrine had higher rates of ROSC at 36% compared to only 11% with saline.28 An analysis of 30-day survival was also slightly higher with Epinephrine at 3.2% compared to the saline placebo group at only 2.4%.28 What is most interesting is looking at the study’s secondary outcomes and statistical analysis. Secondary outcomes of interest included neurologic function, survival at 30 days and survival at 3 months following the arrest. Of note, while the subjects that received Epinephrine had higher rates of ROSC, they also experienced much higher rates of severe neurologic impairment at 31% compared to the placebo group which experienced a rate of 17.8%.28 The statistical evaluation of treatment success the authors found with administration of Epinephrine is exceedingly thought provoking. With a number needed to treat (NNT) of 112, the Paramedic-2 Trial demonstrated there is no clinical benefit in the utilization of Epinephrine.28 Given the inconsistent evidence regarding the use of Epinephrine, dosing interval and long-term outcomes of its use, combined with the well understood risk in fresh post-operative patients, high dose reflexive Epinephrine use is not well supported and not present in the alternative protocol. Additional medication changes for the alternative protocol includes the exclusion of Atropine for non-shockable rhythm patients, specifically PEA, Asystole and Bradycardia. Atropine was removed by the AHA in 2010 following inconsistent evidence for its effectiveness and absence of well powered clinical control trials.29 This was further evaluated with a retrospective study in 2018 that compared ROSC rates prior to the 2010 ACLS update and post exclusion of Atropine. It was found there was no statistical difference in survival with exclusion of Atropine from ACLS protocols.30 In the subsect of cardiac surgical patients who have received a heart transplant, utilization of Atropine is ineffective as the heart is denervated. In fact, administration in this subgroup has been shown to cause high grade atrial-ventricle block and sinus arrest.31 Considering the evidence from the AHA and its follow-up study, the potential risk in a subgroup of cardiac surgery patients, as well as the presence of epicardial pacing wires in post cardiac surgery patients, the utilization of Atropine is not recommended in the alternative protocol.

Emergent Resternotomy is a core tenet of the alternative protocol, and one which is instructed to be completed if early resuscitation efforts are unsuccessful. A unique opportunity presents itself to enhance resuscitation following arrest after cardiac surgery with performance of a resternotomy. Utilization of emergent resternotomy is well solidified in the cardiothoracic surgical literature with multiple focused publications all greater than a decade in age. Performance of rapid emergent resternotomy has been proven to increase survival. If completed within the first 10 minutes of arrest, survival has been demonstrated to increase by four-fold.32 If completed within 5 minutes of the arrest onset, survival rates increased to almost 50%. 33 This increase in survival is likely multifactorial. Re-sternotomy is a key maneuver in post-operative tamponade, by relieving the increased mediastinal pressure which prevents normal loading and unloading of the heart. Additionally, we know from studies completed in the 1960s to the early 2000s, which have not been updated, that access to the mediastinum and performance of internal cardiac massage is a more effective means of resuscitation.33-37 In fact, in human models, internal massage increases coronary perfusion pressure as well the Cardiac Index with transition to internal cardiac massage having been found to increase the Cardiac Index by as much as 1.3 liters / minute.34,36 Concerns do arise, considering an emergent surgical intervention is not always an easy or safe

endeavor, however a retrospective study with over 100 subjects who received emergent resternotomy in the ICU found this safe with no increase in mortality, chest tube drainage, blood transfusion, deep and superficial infection or increase in hospital length of stay.38 Additionally, the authors identified 3 patients from the control arm of the study who died waiting for transport to the operating room for urgent resternotomy secondary to mediastinal bleeding.38 As substantiated in the literature, emergent resternotomy not only allows for possible resolution of the etiology of the arrest, but also enhances resuscitation efforts and survival, and is a key component of the alternative protocol. Resuscitation education and training has varied widely in the previous two decades, with a continuous shift from individual to team-based response.39 Team based resuscitation training and clinical utilization has been found to increase overall task performance and efficiency, team communication, protocol knowledge and adherence, higher survival rates and neurologic outcome.39-41 As the alternative protocol addresses inpatient post-cardiac surgery cardiac arrest with a multitude of disciplines ready to respond, team-based resuscitation training and education in the new protocol will enhance team performance and patient outcomes.

CONCLUSION

The 2020 AHA ACLS update fails to meet the unique needs of a post-operative cardiac surgery patient, whereas the STS publication and Cardiac Surgical Unit Advanced Life Support (CSUALS) protocol that outlines succinctly the team response to the arresting cardiac surgery patient does. Additionally, as demonstrated, the historical resuscitation approach of early chest compressions, high dose epinephrine and lack of direction with already highly medically supported patients creates significant risk to post-cardiac surgery patients. Utilization of first line electrical therapy interventions, reduced dose inotropic and vasopressive agents, early resternotomy, internal massage and deployment of frequent team-based training can reduce the failure to rescue rate. Increased awareness of alternative resuscitation protocols like CSU-ALS, as well as their widespread adoption, can have positive impact on patient outcomes.

REFERENCES

1. Society of Thoracic Surgeons Task Force on Resuscitation After Cardiac Surgery. The Society of Thoracic Surgeons expert consensus for the resuscitation of patients who arrest after cardiac surgery. Ann Thorac Surg. 2017;103(3):1005-1020. doi:S0003-4975(16)31482-5 2. Merchant RM, Topjian AA, Panchal AR, et al. Part 1: Executive summary: 2020 American

Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2020;142(16_suppl_2):S337-S357. doi:10.1161/CIR.0000000000000918 3. Lott C, Truhlar A, Alfonzo A, et al. European Resuscitation Council guidelines 2021: Cardiac arrest in special circumstances. Resuscitation. 2021;161:152-219. https://www-sciencedirectcom.ezproxy.lynchburg.edu/science/article/pii/S0300957221000642. Accessed May 15, 2021. doi:10.1016/j.resuscitation.2021.02.011

4. About cardiac surgical unit advanced life support course. https://www.csu-als.org/. Accessed

May 16, 2021 5. Jacobs JP, Shahian DM, D'Agostino RS, et al. The Society of Thoracic Surgeons national database 2018 annual report. Ann Thorac Surg. 2018;106(6):1603-1611. doi:S0003-4975(18) 31477-2 6. LaPar DJ, Ghanta RK, Kern JA, et al. Hospital variation in mortality from cardiac arrest after cardiac surgery: An opportunity for improvement? Ann Thorac Surg. 2014;98(2):534-40. doi:S0003-4975(14)00609-2 7. Reddy HG, Shih T, Englesbe MJ, et al. Analyzing "failure to rescue": Is this an opportunity for outcome improvement in cardiac surgery? Ann Thorac Surg. 2013;95(6):1976-81; discussion 1981. doi:S0003-4975(13)00604-8 8. Mackay JH, Powell SJ, Osgathorp J, Rozario CJ. Six-year prospective audit of chest reopening after cardiac arrest. Eur J Cardiothorac Surg. 2002;22(3):421-425. doi:S1010794002002944 9. Pottle A, Bullock I, Thomas J, Scott L. Survival to discharge following open chest cardiac compression (OCCC). A 4-year retrospective audit in a cardiothoracic specialist centre--Royal

Brompton and Harefield NHS trust, United Kingdom. Resuscitation. 2002;52(3):269-272. doi:S0300957201004798

10. Birdi I, Chaudhuri N, Lenthall K, Reddy S, Nashef SA. Emergency reinstitution of cardiopulmonary bypass following cardiac surgery: Outcome justifies the cost. Eur J

Cardiothorac Surg. 2000;17(6):743-746. doi:S101079400000453X 11. Anthi A, Tzelepis GE, Alivizatos P, Michalis A, Palatianos GM, Geroulanos S. Unexpected cardiac arrest after cardiac surgery: Incidence, predisposing causes, and outcome of open chest cardiopulmonary resuscitation. Chest. 1998;113(1):15-19. doi:S0012-3692(16)39542-3 12. Wahba A, Götz W, Birnbaum DE. Outcome of cardiopulmonary resuscitation following open heart surgery. Scand Cardiovasc J. 1997;31(3):147-149. doi:10.3109/14017439709058084 13. Panchal AR, Bartos JA, Cabanas JG FADonnino M, et al. Part 3: Adult basic and advanced life support: 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2020;142(16_suppl_2):S366-S468. doi:10.1161/

CIR.0000000000000916 14. Dunham GM, Perez-Girbes A, Bolster F, Sheehan K, Linnau KF. Use of whole body CT to detect patterns of CPR-related injuries after sudden cardiac arrest. Eur Radiol. 2018;28 (10):4122-4127. doi:10.1007/s00330-017-5117-0 15. Ram P, Menezes RG, Sirinvaravong N, et al. Breaking your heart-A review on CPR-related injuries. Am J Emerg Med. 2018;36(5):838-842. doi:0735-6757(17)31065-3 16. Miller AC, Rosati SF, Suffredini AF, Schrump DS. A systematic review and pooled analysis of

CPR-associated cardiovascular and thoracic injuries. Resuscitation. 2014;85(6):724-731. doi:10.1016/j.resuscitation.2014.01.028 17. Kempen PM, Allgood R. Right ventricular rupture during closed-chest cardiopulmonary resuscitation after pneumonectomy with pericardiotomy: A case report. Crit Care Med. 1999;27(7):1378-1379. doi:10.1097/00003246-199907000-00033

18. el-Banayosy A, Brehm C, Kizner L, et al. Cardiopulmonary resuscitation after cardiac surgery:

A two-year study. J Cardiothorac Vasc Anesth. 1998;12(4):390-392. doi:S1053-0770(98) 90189-6 19. Mir Mohammad Sadeghi P, Mir Mohammad Sadeghi M. Cardiopulmonary arrest after cardiac surgery: A retrospective cohort of 142 patients with nine year follow up. Heart Lung. 2021;50 (3):382-385. doi:S0147-9563(21)00018-2 20. Davis D, Aguilar SA, Sell R, Minokadeh A, Husa R. A focused investigation of expedited, stack of three shocks versus chest compressions first followed by single shocks for monitored ventricular fibrillation/ventricular tachycardia cardiopulmonary arrest in an in-hospital setting. J Hosp Med. 2016;11(4):264-268. doi:10.1002/jhm.2499 21. Bradley SM, Liu W, Chan PS, et al. Defibrillation time intervals and outcomes of cardiac arrest in hospital: Retrospective cohort study from get with the guidelines-resuscitation registry.

BMJ. 2016;353:i1653. doi:10.1136/bmj.i1653 22. Nichol G, Sayre MR, Guerra F, Poole J. Defibrillation for ventricular fibrillation: A shocking update. J Am Coll Cardiol. 2017;70(12):1496-1509. doi:S0735-1097(17)39140-4 23. Richardson L, Dissanayake A, Dunning J. What cardioversion protocol for ventricular fibrillation should be followed for patients who arrest shortly post-cardiac surgery? Interact

Cardiovasc Thorac Surg. 2007;6(6):799-805. doi:icvts.2007.163899 24. Webb ST. Caution in the administration of adrenaline in cardiac arrest following cardiac surgery. Resuscitation. 2008;78(1):101; author reply 101-2. doi:10.1016/ j.resuscitation.2008.03.001 25. Dunning J, Trevis J. Results of the PARAMEDIC-2 trial and how they relate to resuscitation after cardiac surgery. J Thorac Cardiovasc Surg. 2020;160(6):1519-1522. doi:S0022-5223(20) 30469-4 26. O'Connor E, Fraser JF. The interpretation of perioperative lactate abnormalities in patients undergoing cardiac surgery. Anaesth Intensive Care. 2012;40(4):598-603. doi:20120083 27. Warren SA, Huszti E, Bradley SM, et al. Adrenaline (epinephrine) dosing period and survival after in-hospital cardiac arrest: A retrospective review of prospectively collected data.

Resuscitation. 2014;85(3):350-358. doi:S0300-9572(13)00798-3 28. Perkins GD, Ji C, Deakin CD, et al. A randomized trial of epinephrine in out-of-hospital cardiac arrest. N Engl J Med. 2018;379(8):711-721. doi:10.1056/NEJMoa1806842 29. Neumar RW, Otto CW, Link MS, et al. Part 8: Adult advanced cardiovascular life support: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2010;122(18 Suppl 3):729. doi:10.1161/

CIRCULATIONAHA.110.970988 30. Holmberg MJ, Moskowitz A, Wiberg S, et al. Guideline removal of atropine and survival after adult in-hospital cardiac arrest with a non-shockable rhythm. Resuscitation. 2019;137:69-77. doi:S0300-9572(19)30022-X 31. Wang Ji J, Ye S, Haythe J, Schulze PC, Shimbo D. The risk of adverse events associated with atropine administration during dobutamine stress echocardiography in cardiac transplant patients: A 28-year single-center experience. J Card Fail. 2013;19(11):762-767. doi:S1071-9164 (13)01192-5

32. Mackay JH, Powell SJ, Osgathorp J, Rozario CJ. Six-year prospective audit of chest reopening after cardiac arrest. Eur J Cardiothorac Surg. 2002;22(3):421-425. doi:S1010794002002944 33. Pottle A, Bullock I, Thomas J, Scott L. Survival to discharge following open chest cardiac compression (OCCC). A 4-year retrospective audit in a cardiothoracic specialist centre--Royal

Brompton and Harefield NHS trust, United Kingdom. Resuscitation. 2002;52(3):269-272. doi:S0300957201004798 34. Delguercio LR, Feins NR, Cohn JD, Coomaraswamy RP, Wollman SB, State D. Comparison of blood flow during external and internal cardiac massage in man. Circulation. 1965;31:SUPPL 1:171-80. doi:10.1161/01.cir.31.4s1.i-171 35. DeBehnke DJ, Angelos MG, Leasure JE. Comparison of standard external CPR, open-chest

CPR, and cardiopulmonary bypass in a canine myocardial infarct model. Ann Emerg Med. 1991;20(7):754-760. doi:S0196-0644(05)80837-6

36. Bartlett RL, Stewart NJ,Jr, Raymond J, Anstadt GL, Martin SD. Comparative study of three methods of resuscitation: Closed-chest, open-chest manual, and direct mechanical ventricular assistance. Ann Emerg Med. 1984;13(9 Pt 2):773-777. doi:10.1016/s0196-0644(84)80433-3 37. 2005 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations. part 4: Advanced life support.

Resuscitation. 2005;67(2-3). https://pubmed-ncbi-nlm-nihgov.ezproxy.lynchburg.edu/16324990/. Accessed May 27, 2021. doi:10.1016/ j.resuscitation.2005.09.018 38. Dj K, Yc S, Dj K, Js K, C L, Kh P. The safety of resternotomy in the intensive care unit for postcardiotomy bleeding control. Journal of cardiac surgery. 2016;31(11). https://pubmedncbi-nlm-nih-gov.ezproxy.lynchburg.edu/27600712/. Accessed May 27, 2021. doi:10.1111/ jocs.12837 39. Kleinman ME, Brennan EE, Goldberger ZD, et al. Part 5: Adult basic life support and cardio pulmonary resuscitation quality. Circulation. 2015;132(18_suppl_2):S414-S435. https:// www.ahajournals.org/doi/full/10.1161/CIR.0000000000000259. Accessed May 27, 2021. doi:10.1161/CIR.0000000000000259 40. M M, K C, A M. What is the impact of multidisciplinary team simulation training on team performance and efficiency of patient care? an integrative review. Australasian emergency nursing journal : AENJ. 2016;19(1). https://pubmed-ncbi-nlm-nihgov.ezproxy.lynchburg.edu/26614537/. Accessed May 27, 2021. doi:10.1016/ j.aenj.2015.10.001 41. Yang Y, Hu D, Peng D. Team-based resuscitation for out-of-hospital cardiac arrest. The

American Journal of Emergency Medicine. 2018;36(5):889-890. https://www-sciencedirectcom.ezproxy.lynchburg.edu/science/article/pii/S0735675717307489. Accessed May 27, 2021. doi:10.1016/j.ajem.2017.09.023 42. Morton A, Lizotte D, Dunning J, Levine A. Cardiac Surgery Advanced Life Support. 4th ed.

Simpsonville, KY: Cardiac Advanced Resuscitation Education; 2020