Is there a role for ischaemic pre-conditioning in orthopaedic and trauma surgery? A systematic review and meta-analysis of randomised controlled trials

Abstract

Surgical procedures using a tourniquet submit tissues to ischaemia and reperfusion on restoring blood flow. Ischaemia-reperfusion may lead to local or remote tissue damage resulting in pain and complications. We aimed to evaluate the effectiveness of ischaemic preconditioning with a tourniquet in preventing pain, disability, adverse events, inflammation and facilitating recovery and discharge in patients receiving orthopaedic and trauma surgery. We conducted a systematic review of randomised controlled trials investigating ischaemic preconditioning in patients undergoing trauma and orthopaedic surgery. We searched The Cochrane Library, Medline and Embase until January 2021. Where possible continuous data were pooled and meta-analysis performed. Ten RCTs met inclusion criteria, eight of which underwent meta-analysis. Three studies reported lower acute post-operative pain or morphine consumption in patients randomised to IPC. We found weak evidence for shorter length of stay in the intervention group (MD-0.54 days; 95%CI-1.11, 0.03; p=0.0615). Malondialdehyde levels were lower in patients randomised to IPC at two hours following tourniquet deflation (MD -1.39 nmol/ml; 95%CI-2.23, -0.55; p=0.0012). We found no between group differences in Tumour Necrosis Factor-α, Lactate or Interleukin-6. The mechanism behind IPC may be related to reduced lipid peroxidation rather than reduced inflammation. There is evidence IPC reduces post-operative pain following knee surgery that merits further study.