The reperfusion syndrome.

When major vascular occlusion is carried out in the presence of systemic shock and there has been obstruction to blood supply of an extremity, restoration of circulation is not without risk. Morbidity and mortality relate directly to the duration and the degree of ischemia and the mass of tissue involved. The initial problem following the onset of ischemia relates to acidosis and hyperkalemia when limbs are reperfused after several hours of ischemia. When ischemia has been present for more than six to eight hours, there will be death of tissue and reperfusion at this point results in the products of dead and devitalized tissue being washed into the systemic circulation. This produces intravascular coagulation and a diffuse inflammatory response with systemic vascular permeability. Respiratory distress syndrome will develop if the ischemic injury is severe. If patients are not adequately monitored and blood volume maintained, renal failure and multiple organ failure will develop in parallel.