Information
- 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 the 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 17).
- Etiologies of hyperthermia include infection, transfusion reaction, hyperthyroidism, malignant hyperthermia, serotonin syndrome, and neuroleptic malignant syndrome. Symptomatic treatment should be limited to situations in which hyperthermia is potentially dangerous, such as in young children or patients with compromised respiratory or cardiac reserve. Acetaminophen (suppositories 650-1300 mg or 10 mg/kg in children) and cooling blankets are commonly used. Hyperthermia can cause sinus tachycardia.