PRIMA – Pain relief in major amputation

INTERVENTION: Participant pathway: Patients who have a clinical indication for a major lower limb amputation (MLLA) and meet the inclusion/exclusion criteria will be invited to participate. MLLA can be a fairly urgent procedure so there is unlikely to be more than one or two days to discuss this study with the participant. Nonetheless, at the earliest opportunity following the plan for MLLA, patients will be reviewed by a member of the research study team. Here a patient information sheet will be given and the study and any questions will be discussed and answered. Thereafter during the next 12 ‐ 24 hours, the patient will be consented to participate in the study. Baseline documentation and questionnaires on pre‐existing pain and current quality of life will then be completed. The participant will then be randomised at this point to either method of pain control. As per standard care, the participant will be consented by a member of the clinical team for their amputation. They will then head to theatre at their allocated time slot. The 'blocking' anaesthetist will be informed about the pain control method. They will then administer either the allocated single shot block or the nerve catheter. The patient will then undergo the planned MLLA as per the standard operative procedure. The study team will collect data on the level of amputation, incision method to divide nerve, any additional local anaesthetic given along with the closure technique of the wound. The techniques are detailed below. Above Knee Amputation Femoral Nerve Catheter Equipment: Ultrasound Machine/Nerve Stimulator/Anaesthetic Prep Pack/Pajunk Tsui Stimu CONDITION: Pain relief in major amputation ; Surgery PRIMARY OUTCOME: Post‐operative pain (VAS) at day 3 SECONDARY OUTCOME: ; 1. Anaesthetic and operative times measured using patient records at a single time point; 2. Adjunctive pain relief medication such as opioid use, tablets, patches and neuropathic medication measured using patient records at a single time point; 3. Daily pain scores (VAS) from immediately post‐operatively through to day seven; 4. The duration of hospital stay measured using patient records at a single time point; 5. Level of engagement and ability to participate in physiotherapy measured using an in‐house developed two question physiotherapy tool, for the first seven days; 6. The level of opioid induced sedation as measured by the Pasero Opioid‐induced Sedation Scale (POSS) daily for the first 7 days then at week 6; 7. The level of post operative nausea and vomiting (PONV) as assessed by the PONV impact scale daily for the first 7 days; 8. Phantom limb or neuropathic pain as assessed by the S‐LANNS daily for the first 7 days then at week 6 and 1 year; INCLUSION CRITERIA: 1. Patients aged 18 or over 2. Patients undergoing a primary above or below knee amputation for the symptoms resulting from peripheral vascular disease or diabetes 3. Patients undergoing amputation under general anaesthesia 4. Patients able to consent to amputation and study participation 5. Patients able to participate in assessing their pain using a Visual Analogue Scale