Background: Bloodless field is an integral part of orthopedic surgery. Use of tourniquet is associated with a risk of skeletal muscle ischemia and reperfusion injury. The purpose of this prospective, open-randomized study was to determine if the use of a tourniquet system using low pressure, with a wide, curved cuff connected to a microprocessor pump is safer than a standard tourniquet system with a narrow, straight cuff using higher inflation pressures.
Methods: Test parameters used as markers of muscular injury and anaerobic metabolism were femoral vein blood lactate, pH, pCO2, pO2, potassium, aspartate aminotransferase activity, myoglobin, creatine kinase and creatine kinase-MM activity levels after release of tourniquet. Twenty-six ASA I-II patients were studied.
Results: Tourniquet times varied between 30 and 144 min. Deflation of the tourniquet caused a significant release of lactate, myoglobin and potassium detected in the femoral vein blood. pCO2 increased, but pH and pO2 decreased after tourniquet deflation. There were no differences between the study groups. The tourniquet time showed a significant correlation with femoral vein lactate.
Conclusion: The main finding of this study was that the metabolic changes were more pronounced with the longer tourniquet time. The results of the study did not show any difference on metabolic markers of muscular injury during the first hour after release of tourniquet between the two tourniquet systems.