Perineural local anaesthetic catheter after major lower limb amputation trial (PLACEMENT): results from a randomised controlled feasibility trial

OBJECTIVES: To determine the feasibility of undertaking a randomised controlled effectiveness trial evaluating the use of a perineural catheter (PNC) after major lower limb amputation with postoperative pain as the primary outcome. DESIGN: Randomised controlled feasibility trial. SETTING: Two vascular Centres in South Wales, UK. PARTICIPANTS: 50 patients scheduled for major lower limb amputation (below or above knee) for complications of peripheral vascular disease. INTERVENTIONS: The treatment arm received a PNC placed adjacent to the sciatic or tibial nerve at the time of surgery, with continuous infusion of levobupivacaine hydrochloride 0.125% for up to 5 days. The control arm received neither local anaesthetic nor PNC. Both arms received usual perioperative anaesthesia and postoperative analgesia. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes were the proportion of eligible patients who were randomised and the proportion of recruited patients who provided primary effectiveness outcome data. Secondary outcomes were: the proportion of recruited patients reaching 2 and 6 month follow-up and supplying pain data; identification of key cost drivers; development of an economic analysis framework for a future effectiveness trial; identification of barriers to recruitment and site set-up; and identification of the best way to measure postoperative pain. RESULTS: Seventy-six of 103 screened patients were deemed eligible over a 10 month period. Fifty (64.5%) of these patients were randomised, with one excluded in the perioperative period. Forty-five (91.3%) of 49 recruited patients provided enough pain scores on a 4-point verbal rating scale to allow primary effectiveness outcome evaluation. Attrition rates were high; 18 patients supplied data at 6 month follow-up. Costs were dominated by length of hospital stay. Patients and healthcare professionals reported that trial processes were acceptable. CONCLUSIONS: Recruitment of patients into a trial comparing PNC use to usual care after major lower limb amputation with postoperative pain measured on a 4-point verbal rating scale is feasible. Evaluation of longer-term symptoms is difficult. TRIAL REGISTRATION NUMBER: ISRCTN: 85 710 690. EudraCT: 2016-003544-37.