hypothermia

Postoperative hypothermia causes vasoconstriction with secondary elevation of blood pressure, increased myocardial contractility, and tissue hypoperfusion; it impairs platelet function and clot formation and may increase the risk of bleeding. Changes in cardiac repolarization such as prolongation of the QT interval may induce dysrhythmias. In addition, the metabolism of various drugs is slowed and may result in prolonged recovery from the neuromuscular blockade. During rewarming, shivering significantly increases O₂ consumption and CO₂ production, which may be undesirable in patients with limited cardiopulmonary reserve. Hypothermia in the perioperative period can increase length of stay in PACU, wound infection rates, and cardiac morbidity. Heated blankets, forced warm air blankets, and warm IV solutions should be used to correct hypothermia (see Chapter 19).