Hypothermia after vascular surgery: Complications, prevention, and treatment

Virtually all anesthetics render patients poikilothermic and body temperature invariably decreases during surgery. During vascular occlusion and resulting ischemia to the brain, kidneys, and spinal cord, hypothermia is often beneficial by decreasing metabolic demands and protecting from injury. Residual hypothermia, however, in the postoperative period is rarely desirable and hypothermia-related complications are well-known. Even mild hypothermia can exacerbate the stress response by activation of the sympathetic nervous system, resulting in increased catecholamines, which can precipitate myocardial ischemia and cardiac morbidity. As little as 2°C of core hypothermia impairs coagulation and predisposes to postoperative bleeding, which is especially problematic in the presence of fresh vascular anastomoses. Hypothermia also slows emergence from general anesthesia by both pharmacokinetic and pharmacodynamic mechanisms. In vascular surgery patients, body temperature should be carefully monitored and controlled with the same level of attention that is given to the other vital signs. By active cooling and warming at the appropriate perioperative timepoints, outcomes can be improved and morbidity reduced in patients undergoing vascular surgery. Copyright (C) 2000 by W.B. Saunders Company.