Extended-course antibiotic prophylaxis in lower limb amputation: randomized clinical trial

Abstract

Background: Lower limb amputation (LLA) is typically described as 'clean surgery', but surgical-site infection (SSI) rates are high and there is significant variation in antibiotic prophylaxis practice. This study aimed to determine whether an extended period of antibiotic prophylaxis (5-day course) is superior to a short course (24 h) in preventing SSI in patients undergoing minor and major LLA. Methods: Patients undergoing minor and major amputation from a single vascular unit were recruited and randomized to receive either a 5-day or a 24-h prophylactic course of antibiotics. Patients with significant baseline infection were excluded. Outcomes included the incidence of SSI and impaired wound healing (IWH), both measured using ASEPSIS criteria, the need for further surgery, duration of hospital stay, and mortality up to 1 year. Results: Some 161 patients were recruited to the study, and 152 were included in the analysis. A 5-day course of antibiotics was associated with a lower incidence of SSI (11.8 versus 39.5 per cent; P < 0.001) and lower incidence of IWH (22.4 versus 58 per cent; P < 0.001). Fewer patients receiving the 5-day course required amputation revisional surgery (6.6 versus 21 per cent; P = 0.010). Duration of hospital stay and mortality rates were similar. The presence of SSI (odds ratio (OR) 5.14, 95 per cent c.i. 1.96 to 13.45; P < 0.001) and IWH (OR 4.62, 1.68 to 12.72; P = 0.003) increased the need for revisional surgery. SSI increased the duration of hospital stay: median 28 (i.q.r. 16-40) versus 14 (9-21) days (P = 0.045). Conclusion: SSI and IWH are common after LLA and have a significant impact on outcome. A 5-day course of antibiotic prophylaxis was associated with a reduction in both SSI and IWH compared with a 24-h course, and this reduced the need for further surgery.