What is a nerve block?
A nerve block is a procedure where a solution of local anaesthetic is injected close to nerves. The local anaesthetic numbs the area of the body supplied by those nerves. A nerve block can be used as the main anaesthetic for an operation, along with sedative medications to help you relax. Alternatively a nerve block can be used, in combination with a general anaesthetic, to control pain after the surgery.
What surgery can I have a nerve block for?
Your anaesthetist will discuss whether a nerve block is an option for your surgery. Many different surgeries can be performed using nerve blocks, each aimed at different nerves throughout the body. Not all operations can be done under a nerve block.
What are the benefits of having a nerve block as the only anaesthetic for the operation?
Having a general anaesthetic is very safe. However there are some risks and side effects associated with general anaesthesia, which may be avoided by having a nerve block.
If you avoid a general anaesthetic, you will feel less sore after the operation, you are less likely to feel sick and you will be able to eat and drink sooner. This is important in some patients such as those who have diabetes.
Other medical conditions may make general anaesthesia more complicated and a nerve block may be an easier or safer alternative.
Your anaesthetist will ask you about your medical history and discuss this with you.
What are the benefits of having a nerve block to provide pain relief after the operation?
After your operation it is usual to expect some pain in the area of the body affected by the surgery. Controlling this pain is very important to help you make a quick, uneventful recovery. Nerve blocks can completely eliminate these painful sensations and help you avoid the side effects of pain medications, such as nausea and vomiting, itchiness, drowsiness and problems with your breathing.
They are especially useful if you are taking strong pain medications prior to surgery as your pain may be more difficult to control.
What are the risks associated with a nerve block?
Nerve blocks do not always work perfectly. If the nerve block is used as the only
anaesthetic and it is not blocking the nerves completely, then your anaesthetist or surgeon may need to inject more local anaesthetic. Sometimes a general anaesthetic may need to be given.
If the nerve block is used for pain relief after the operation and you are not comfortable in the recovery area, then other pain relieving medications can be given.
Nerve blocks, like general anaesthetics, are very safe. Occasionally during a nerve block procedure, nerves can be damaged resulting in numbness or weakness in the arm or leg. Most commonly the damage is only temporary.
Rarely, the damage can be permanent.
Other uncommon complications are:
A bruise, or haematoma, at the injection site
An infection at the site of injection
A reaction to the local anaesthetic, which can involve seizures or heart rhythm problems
How will the nerve block be performed?
A specially trained doctor (an Anaesthetist) will perform the nerve block. To start with, you will have a drip, or a small needle, inserted into one of your veins. Your pulse and blood pressure will be monitored. You may be given some sedative medication to help you relax whilst the nerve block is being performed. Your anaesthetist will then identify the correct area to inject local anaesthetic around the nerves. Most commonly this is done using an ultrasound machine but other techniques can also be used to identify your nerves. The whole procedure should take between 10 and 20 minutes and you should experience only mild discomfort. The local anaesthetic will take 10-30 minutes to work. Your anaesthetist will check to make sure the block is working before the surgeons begin the operation.
How long will the nerve block last?
Depending on the type of nerve block, numbness lasting from 2 to 48 hours is normal. Occasionally a fine plastic tube is left beside the nerves and local anaesthetic solution is infused into this tube. This provides pain relief for a number of days following the operation.
Can I change my mind?
You are free to change your mind about whether to have a nerve block at any stage before your operation. If you choose not to have a nerve block and you experience severe pain after your operation that is difficult to control with pain medications, a “rescue” nerve block can be performed. There may be a brief delay in arranging this “rescue” nerve block. Occasionally the dressings or plaster casts from the surgery may interfere with performing a nerve block in this situation.
What do I do if I have questions about nerve blocks after reading this information?
If you have any questions about nerve blocks or your anaesthetic please write them down. You will have the opportunity to discuss them with your anaesthetist on the day of your surgery.