Peripheral Nerve Block

Peripheral Nerve Block How do we perform a peripheral nerve block?

A peripheral nerve block is usually done in the operating theatre under sterile conditions.

Your anaesthetist will explain to you what he will be doing and what you will feel. The procedure is done while you are awake or mildly sedated because your cooperation is important.

What is peripheral nerve block analgesia?

It is a method of injecting local anaesthetic close to a nerve or nerve bundles to provide numbness and pain relief to the arm or leg in preparation for surgery. This may be the sole form of anaesthesia or it can be combined with general anaesthesia. You will have the dual benefit of being totally unaware as well as pain-free during and after the operation.

The nerve block is done using an ultrasound machine that ensures greater safety and accuracy. A nerve stimulator may also be used to help localise the nerve. You will experience muscle twitches during this process. They are usually painless.

Some numbing medicine will be given initially to reduce any discomfort. During the nerve block procedure you may

experience some pressure and tingling sensation in your arm or leg. This is normal and expected.

You should inform the anaesthetist immediately if you: • Feel pain • Feel light-headed or giddy • Start having a funny taste in your mouth • Start hearing noises in your ears After the nerve block you will slowly start to feel numb and weak in your arm or leg. We will ensure that the numbness is complete before the surgery can proceed.

For major operations such as total knee replacement, the anaesthetist will insert a small tubing near the nerve and connect it to a pump to provide you with continuous pain relief for 2 to 3 days. This is to help reduce pain during movement and physiotherapy exercises.

What are the benefits of peripheral nerve block?

• You will experience minimal post-operative pain.

• You can do your physiotherapy exercises with less pain.

• It reduces the use of morphine or morphine-like medications and their side-effects.

• There may be a shorter hospital stay because of faster return of body function.

•...........................•...........................•...........................•...........................• No pain

Mild pain

Moderate pain

What are the side effects of peripheral nerve block?

• You may feel an awkward numbness, heaviness or weakness in your arm or leg for several hours. Depending on the amount and type of local anaesthetic that is used, the duration of these effects will vary from 6 to 24 hours. Unaided activity should be restricted.

We suggest that you make sure that your grip is firm and that your legs have enough strength before attempting to get out of bed.

• As the pain medicine wears off, you may experience a pins-andneedles sensation in your arm or leg. This is normal.

• There may be soreness and swelling around the site of injection. This will usually subside with time.

Severe pain

Worst pain

What are the possible complications of peripheral nerve block?

Partial or inadequate pain relief Unfortunately, some nerve blocks provide inadequate or less than expected pain relief. In such instances, more local anaesthetic will be administered. If this does not work, we will supplement the nerve bock with alternative forms of pain relief like oral pain-killers or injection forms. Your right to pain relief will not be affected.

Giddiness, light-headedness, numbness around your lips, or fits and convulsions may occur if there is too much absorption of the local anaesthetic into the blood vessels. These are uncommon symptoms. However, please inform the ward staff if you experience them. The risk of nerve injury or permanent nerve damage is very low at less than 0.1%.

Who will look after me in the ward?

The pain team doctor and nurse will assess your pain level daily in the ward. You will be asked to score your pain level from a scale of 0 (no pain) to 10 (worst pain).

From your pain score, the doctor will know whether the nerve block is working effectively and adjust the pain medication accordingly.

The Pain Team will also assess you for side effects or complications.

Do let the team know if the pain control is not to your satisfaction and they will do their best to make you comfortable.

When can I NOT have a peripheral nerve block?

If you have a serious skin or blood infection, it is unsafe to offer you a peripheral nerve block. Those who suffer from abnormal blood clotting disorder or are on bloodthinning medications such as

warfarin will also not be offered a nerve block. You also cannot have a peripheral nerve block if you are allergic to local anaesthetia.

What if I decide NOT to have a peripheral nerve block?

A peripheral nerve block is only performed with your consent. You will be offered other forms of pain relief. Available options include oral painkillers or intravenous morphine or morphine-like medication.

If you have further questions regarding peripheral nerve block, you can call the anaesthetic clinic during office hours or speak to your anaesthetist on the day of your surgery.

Yishun Health is a network of medical institutions and health facilities in the north of Singapore, under the National Healthcare Group.

Admiralty Medical Centre • (65) 6807 8000 • www.admiraltymedicalcentre.com.sg Khoo Teck Puat Hospital • (65) 6555 8000 • www.ktph.com.sg Yishun Community Hospital • (65) 6807 8800 • www.yishuncommunityhospital.com.sg The information is correct at the time of printing and subject to revision without further notice.

ANA.PE.03.0120