A Systematic Review and Meta-Analysis of Tourniquet Pressures in Upper Limb Surgery

Background: Tourniquet pressures used in upper limb surgery are commonly standardized at 250 mmHg. These higher tourniquet pressures have been associated with an increased risk of complications, such as neural compression injury and soft tissue damage. However, there has been limited consensus as to the use of lower tourniquet pressures and their efficacy. This systematic review and meta-analysis aims to examine the current evidence for the use of lower tourniquet pressures in upper limb surgery, comparing them to the standard tourniquet pressures of 250 mmHg and, in some cases, 300 mmHg. This study is registered on PROSPERO (CRD42024511501). The primary outcome was the adequacy and quality of the bloodless field achieved at lower pressures. Secondary outcomes were assessed when reported, including the operative time, pain, and complications. Methods: The databases Medline (via Ovid), Embase (via Ovid), Cochrane, Web of Science (Core Collection) and Scopus, ClinicalTrials.gov, EU Clinical Trials Register, and ISRCTN registry were searched from inception to January 2025. The inclusion criteria included patients undergoing upper limb surgery using regional or general anesthetic with the use of a pneumatic tourniquet. A total of 1994 studies were identified, of which 12 met the inclusion criteria for review and 8 studies were used in the meta-analysis. Risk of bias was assessed using the ROBINS-I and RoB-2 tools. Results: The sample size was 1427 patients with a mean age of 46.8 years. All studies showed a bloodless surgical field at lower tourniquet occlusion pressures. The meta-analysis showed the overall mean tourniquet inflation pressure, estimated using a random effects model, to be 169.3 mmHg with a 95% confidence interval of 144.9-193.6. However, the heterogeneity in the reported results is significant (p < 0.0001) and is a limitation to this review. Conclusions: This systematic review highlights the benefit of the use of a lower tourniquet pressure (below the standard 250 mmHg) to produce an adequate surgical field and influence procedural outcomes.