What is a Peripheral Nerve Block?

A peripheral nerve block is a type of regional anaesthetic that involves injecting local anaesthetics and other pain killers near the major nerves to your leg (lower limb). 

How Does a Nerve Block Work?

A nerve block works by temporarily numbing your nerves to give pain relief. Local anaesthetics and other painkillers are injected,using a fine needle, near the nerves to your leg.You may need more than one injection. Operationson lower limbs are usually performed under a general anaesthetic or spinal anaesthetic. A nerve block is usually used in addition to give pain relief afterwards. Depending on the operation, the injection may be given behind your thigh or knee, in your ankle or foot,or near your groin.

Figure 1 - A peripheral nerve block

The Procedure

What Does the Procedure Involve?

Your anaesthetist will usually use an ultrasound scanner or nerve stimulator to help guide them where to inject the anaesthetic. Your anaesthetist will insert the needle and when they are certain that it is in the right position they will inject anaesthetithrough it.They will usually remove the needle.Sometimes your anaesthetist may insert a small tube through the needle before they remove it,leaving the tube in places they can inject more anaesthetic.

What Effect Does a Nerve Block Have?

A nerve block has two main effects.

  • Pain relief –The nerve block numbs the sensory nerves responsible for pain and touch.
  • Weakness –The nerves supplying muscles may also be affected. 

What Complications Can Happen?

Some complications can be serious and can even cause death.

  • Failure of the nerve block
  • Allergic reaction
  • Bleeding
  • Nerve damage 
  • Visual disturbance or loss of vision
  • Local anaesthetic toxicity 
Surgeon in face mask


A peripheral lower limb nerve block can be used for most people, usually giving a safe and effective form of pain relief both during and after the operation. Keep this information document. Use it to help you if you need to talk to the healthcare team.  

For more information on a Private Peripheral Nerve Block procedure, call New Victoria Hospital on 020 8949 9020 or use our online booking form.


Author: Dr Rakesh Kapila MBCh BFR CA

Illustrator: Medical Illustration Copyright©NucleusMedical Art. All rights reserved. www.nucleusinc.com

This document is intended for information purposes only and should not replace advice that you relevant healthcare team would give you.

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