What is a brachial plexus block?
The brachial plexus is a group of nerves that supply feeling and power to your shoulder, arm and hand. These nerves start in your neck and travel down via your armpit to your arm and hand. A brachial plexus block is a technique whereby your anaesthetist will put local anaesthetic around these nerves to temporarily block the feeling and power. The block can be performed either with an injection in your neck, below your collar bone, or in your armpit, depending on which area needs to be numb.
Why should I have a brachial plexus block?
This can be done to avoid a general anaesthetic. It may be possible to perform your operation with you awake and pain free by blocking the feeling to your arm. This can avoid some of the problems with general anaesthetics, like a sore throat or sickness. It can also be useful if you have specific problems with anaesthetics or have heart or breathing problems.
Pain relief after your operation
A brachial plexus block can be given with a general anaesthetic to provide pain relief after your operation. You can then avoid very strong painkillers, which can make you feel sick or drowsy.
What are the potential complications?
A brachial plexus block is a very safe procedure. However in everything that we do there are potential risks and complications. These are:
Inadequate block (if you have the block instead of a general anaesthetic)
Sometimes the block does not work, or only partially works. If the block does not work at all you will need a general anaesthetic. If it is only partially effective, we can give you some more local anaesthetic. You should not feel sharp pain at any stage during the operation.
Damage to surrounding structures
With all the injections there is a small risk of damage to blood vessels and nerves. Permanent nerve damage is very rare. More common side effects are tingling and numbness in the area, which usually resolves over time.
When the injection is done in your neck, there is a small risk of other surrounding nerves being affected. This may lead to a hoarse voice or some minor breathing difficulties.
These will only be temporary. With the injection below your collar bone, there is a risk of collapse of the lung on the same side. This can be treated if needed.
Reaction to local anaesthetic drugs
This is very rare. If the local anaesthetic is injected into a vein you may experience tingling of your lips, and there is a risk of seizures and heart rhythm problems. These usually only last for a short time, but medication may be needed if they persist.
How will the procedure be performed?
You will need to be nil by mouth as you would for a general anaesthetic. When you come into the anaesthetic room we will monitor your heart, blood pressure and oxygen levels and put a drip into your hand. We will give you a sedative injection into your vein. This will make you slightly drowsy. If you are anxious, and you are also getting a general anaesthetic, you can ask your anaesthetist about the possibility of doing the block while you are asleep.
The nerves will be located using a needle with a small current going through so that your arm twitches when the correct place is found. An ultrasound machine may also be used to help locate the nerves. The local anaesthetic will be injected, and your arm will feel initially warm and tingly, then numb and heavy. The block takes up to 30 minutes to work. The anaesthetist will test the block before the operation starts by spraying your arm with a cold solution.
Recovery
The local anaesthetic will make your arm feel numb and heavy for up to 24 hours. During this time it is important to keep your arm in a sling. Make sure that before you try to use your arm the power and feeling have fully returned. Test the power by first trying to lift your arm against gravity. You can test the sensation by comparing the temperature sensation with your other hand. If your arm still feels weak or has abnormal sensation after 48 hours, please contact A&E and explain what has happened. They will contact an anaesthetist who can come and asses the problem.
When the local anaesthetic wears off, you may start feeling pain from the operation site. We will give you pain relief to take home. You should take them as prescribed so that you have good pain relief when the block wears off.
Understanding risk
Modern anaesthetics and techniques are very safe. Although rare, there is always a risk of complications. The following scale is to help you interpret the words and numbers.
More information?
You can read more about your anaesthetic by asking for an information leaflet from the pre-assessment clinic, or by phoning the Anaesthetic Department on 0191 455 2176
If you have access to the internet, more information can be obtained from The Royal College of Anaesthetists, by following this link: http://www.rcoa.ac.uk
Any Questions?
If you have any questions, please do not hesitate to ask your anaesthetist.