Peripheral Nerve Block (Lower Limbs)
This document is intended for information purposes only. It should not replace advice that your conusultant would give you.
What is a peripheral nerve block?
A peripheral nerve block is a form of regional anaesthetic. It involved an injection of local anaesthetics and other pain killers near the major nerves to your leg, temporarily numbing your nerves to give pain relief. A nerve block for your leg can be used:
- On its own while you are awake
- With sedation
- With a spinal anaesthetic or general anaesthetic
Operations on lower limbs are usually performed under a general or spinal anaesthetic, with a nerve block providing additional pain relief after the procedure. Depending on the operation, the injection may be given behind your thigh or knee, in your ankle or foot, or near your groin (see figure 1). A peripheral lower limb nerve block can be used for most people, usually giving a safe and effective form of pain relief. The pain relief can last up to 18 hours.
What is involved in the procedure?
Before the procedure, your anaesthetist may offer you a sedative to help you relax. They usually then use an ultrasound scanner and nerve stimulator or order to help guide them where to inject the anaesthetic. Once your anaesthetist is certain they have located the right position, they will insert the needle and inject anaesthetic through it. Occasionally your anaesthetist may insert a small tube through the needle before they remove it. This tube is left in place so they are able to inject more anaesthetic.
Are there any complications?
While your anaesthetist will try to make the nerve block as safe as possible, complications can happen. Some of these issues, while rare, are serious and can cause death. Complications include:
- Failure of the nerve block to provide pain relief
- Allergic reaction to the anaesthetics
- Nerve damage (which is usually temporary and will lead to symptoms of numbness of weakness lasting up to 12 weeks)
- Local anaesthetic toxicity (this usually only makes your lips tingle or your ears ring and is temporary)
References: EIDO Healthcare Limited – The operation and treatment information on this website is produced using information from EIDO Healthcare Ltd and is licensed by Aspen Healthcare. Author: Dr Rakesh Kapila MBChB FRCA. Illustrations: Medical Illustration Copyright © Nucleus Medical Art. All rights reserved. www.nucleusinc.com
The information should not replace advice that your relevant health professional would give you.