PLACEMENT

Perineural local anaesthetic catheter after major lower limb amputation trial.

Background

Having a leg amputation is a life changing event. Around 5,000 leg amputations are performed in the UK every year. These are often very painful, both immediately following surgery and in the longer term. This pain may delay recovery times and may limit what people are able to do for the rest of their lives. Morphine is usually given to help relieve pain. However, morphine has major side effects, including sickness, confusion, and breathing problems. In the longer term, pain can be felt in the leg which is no longer there, called ‘phantom pain’. This interferes with fitting and using an artificial leg.

A group of patients and clinicians from the UK recently met to agree what the most important research topics for amputation surgery are. Reducing pain after amputation was the 4th most important topic. A UK-wide review (published 2014) showed that only one out of every three patients had the ‘best’ pain relief after amputation. High quality research looking at how we can reduce pain after leg amputation is urgently needed.

Study design

This study will test a method for reducing pain after leg amputation. It involves the surgeon placing a tiny tube, called a ‘perineural catheter’, next to the main nerve which is cut during surgery. Local anaesthetic is slowly pumped into the tube for five days. Putting it in and taking it out is easy and complications or side effects are rare. It can replace some (or all) of the morphine usually needed. It may also reduce phantom pain. The study will be a ‘randomised’ trial. This means patients will be randomly chosen to either have surgery with, or without, the tube. Everything else will be the same. The amount of pain will then be compared between those who did and those who did not have the tube.

Patient and public involvement

Two members of the public are a central part of our research team. One has had two amputations, one with and one without a PNC. Our other member lost her father after an amputation. Both helped us plan and run our ‘feasibility’ study and plan this larger study.

We also recently held a discussion group with amputees. They helped us design this study by telling us what is important to them about amputation pain. Our patient group will work with us throughout the study and prepare a summary of the results.