What is a nerve block?
A nerve block of your arm means numbing the nerves that supply your arm with feeling and power by injecting local anaesthetic around them. The arm can be made numb enough to be operated on.
Although the nerve block by itself is sufficient for an operation, your anaesthetist can discuss additional sedation or general anaesthesia with you.
The block will last a few hours, then it will start to wear off and normal feeling and strength will return.
How is the block done?
In the anaesthetic room the anaesthetist will insert a cannula into the hand on the other side and attach monitoring for your heart and lungs.
The nerves to your arm run from your neck through the armpit and into the arm. The anaesthetist can find them either by ultrasound or with a nerve stimulator. The nerve stimulator will cause twitching of the muscles in your arm. You can have light sedation for this.
The nerves are numbed by injecting local anaesthetic around them. This can sometimes be a little uncomfortable, and later there may be tiny marks from the injections. Soon the arm will feel warm and tingly. After about 30 minutes, the arm will be quite numb and weak, although you may still feel dull pressure or your arm being moved around. This is normal.
During surgery, a member of the anaesthetic or theatre team will be with you all the time. You are welcome to take your own music and headphones into the operating theatre.
After surgery the arm will continue to be numb for about 8 hours, but this can last between 4 and 24 hours. The block will wear off gradually and again start to feel tingly. Eventually normal strengthand feeling will return.
What are the benefits?
By numbing the arm you may avoid a general anaesthetic.
This is good for you because:
- You avoid side effects such as nausea and vomiting or confusion.
- You avoid the need for strong painkillers which may make you drowsy.
- It reduces the stress on the body associated with a general anaesthetic.
- You may eat and drink earlier.
If you have a general anaesthetic as well, this can be lighter and you may still have the benefits listed above.
What are the risks?
Your anaesthetist will be experienced in placing nerve blocks and most patients won’t have any, or only minor, temporary complications. However, all medical procedures carry risks.
As a guide:
|1 in 100||1 in 1,000||1 in 10,000||1 in 100,000|
- Nerve damage: about 1 in 10 patients report some numbness or tingling up to 5 days, but permanent damage from a nerve block is rare. Other possible causes of nerve damage include existing disease, injury or surgery
- Bleeding: some mild bruising around the injection site is common and will resolve. Bleeding from a larger blood vessel is uncommon and is easily controlled at the time
- Infection: precautions against infection are taken. Any infection may need treatment with antibiotics (uncommon)
- Inadequate block: if you are awake and uncomfortable, the anaesthetist or surgeon can add local anaesthetic, you can have painkillers injected or you may need a general anaesthetic. Conversion to general anaesthesia is common
What happens afterwards?
Depending on you and the surgery, you may either have to stay in hospital or you may be able to go home the same day. Your surgeon will discuss this with you.
Whilst your arm is numb, it will be protected by bandages and a sling. You should still take care that the arm is not injured, for example by pressure or heat, which you will not be able to feel.
You can start to eat and drink after the operation when you feel like it and it is safe.
It is difficult to predict how long each block will last. As the block starts to wear off, some people find the tingling sensation also uncomfortable. You will be given some painkillers to take home with you. This is a good time to start taking them. You should also take painkillers if you are going to bed and the arm is still numb. If you have concerns about taking painkillers, discuss these with your surgeon or anaesthetist.
You should take painkillers regularly for 48 hours. Then you can decide if you still need them.
Frequently Asked Questions
Can I eat and drink before a nerve block?
No. You will still need to follow the fasting guidelines you were given by the hospital. This is in case you need to have a general anaesthetic after all.
Must I stay fully conscious?
No. Your anaesthetist will discuss with you the choices of being awake, being sedated and being anaesthetised. It is possible to combine a nerve block with sedation or a light anaesthetic. If you have had sedation or an anaesthetic, you will need somebody to pick you up and stay with you for 24 hours.
Will I see or hear anything?
If you are anaesthetised, you will not see or hear anything. If you are sedated or awake, there will be a screen between you and the operation, and you will not be able to watch. You are welcome to bring your own music to listen to through headphones. Whilst you are awake, you may be able to keep your hearing aids in and your spectacles on.
If you have any concerns once you are home, please contact the hospital where you had the operation:
Sussex Orthopaedic Treatment Centre, Haywards Heath 01444 448770
Royal Sussex County Hospital, Brighton 01273 696955
Out of hours, please try and contact your GP, your nearest Accident and Emergency Unit or the hospital switchboard.
You will find more information about nerve blocks on these websites:
www.rcoa.ac.uk ‘For Patients and Relatives’.
Please look here for a video on surgery under nerve block on the Regional Anaesthesia United Kingdom website.
This information is intended for patients receiving care in Brighton & Hove or Haywards Heath.
The information here is for guidance purposes only and is in no way intended to replace professional clinical advice by a qualified practitioner.