Date of this Version


Document Type

DNP Project


Tourniquets are often used in orthopedic surgery because empirical data suggests that they significantly reduce blood loss and transfusion requirements, facilitate the identification of critical anatomical structures, and provide an optimum operating field. In ischemic limbs, tourniquet inflation increases arterial pressures and results in hypoxia, acidosis, and hyperkalemia.1-3 When a tourniquet is removed, metabolites produced from ischemic areas enter the systemic circulation, resulting in hypotension and hypoxia. Excessive oxygen-free radicals are produced during reperfusion and oxygenation, contributing to leucocytic activation and endothelial damage in blood vessels.2,4 The excess oxygen-free radicals peroxide polyunsaturated fatty acids in membrane and plasma lipoproteins directly inhibit mitochondrial respiratory chain enzymes, affecting major organ functions. As a result, oxygen-free radicals play a crucial role in developing significant cardiovascular complications following reperfusion injury.1-4 These complications are especially problematic in patients with preexisting cardiovascular disease undergoing orthopedic procedures such as total knee replacement (TKR) with tourniquet application. 5,6