Is lower tourniquet pressure during total knee arthroplasty effective? A prospective randomized controlled trial

BackgroundHigher tourniquet pressures may be associated with an increased risk of complications. We aimed to determine (1) whether a lower tourniquet pressure [systolic blood pressure (SBP)+120mmHg] is as effective as conventional tourniquet pressure (SBP+150mmHg) in providing a bloodless surgical field and decreasing blood loss, and (2) whether lowering the tourniquet pressure decreases tourniquet-related complications compared to conventional inflation pressure.MethodsOne hundred and sixty knees in 124 patients undergoing total knee arthroplasty (TKA) were randomly allocated to either conventional (n=80) or lower inflation pressure group (n=80). The quality of the initial surgical field and occurrence of intraoperative blood oozing, hemoglobin drop, drained volume and calculated blood loss were assessed as efficacy variables. Safety outcome variables included post-operative pain, tourniquet site skin problems (ecchymosis, bullae, skin necrosis), and other tourniquet-related complications such as nerve palsy, venous thromboembolism, and delayed rehabilitation.ResultsA comparable bloodless surgical field was successfully provided in both groups (100% vs. 99%, p=1.000). One case in the conventional pressure group and two cases in the lower pressure group showed intraoperative blood oozing (p=1.000), which was successfully controlled after an increase of 30mmHg in the tourniquet inflation pressure. There was no difference in the hemoglobin drop, drained volume, and calculated blood loss. The two groups did not differ in any safety outcomes such as post-operative pain, thigh complications, and other tourniquet related complications.ConclusionThis study demonstrates that a tourniquet inflation pressure of 120mmHg above the SBP is effective method during TKA.Trial registrationThe trial was with ClinicalTrials.gov (NCT01993758) on November 25, 2013.