Prevention of perioperative hypothermia in plastic surgery

The reader is presumed to have a broad understanding of plastic surgical procedures and concepts. After studying this article, the participant should be able to: 1. Explain how and why hypothermia develops in the perioperative environment. 2. Describe the potential complications and consequences that may be induced by perioperative hypothermia. 3. Evaluate the various approaches for preventing perioperative hypothermia and know which ones are most effective. Physicians may earn 1 AMA PRA Category 1 credit™ by successfully completing the examination based on material covered in this article. The examination begins on page 572. ASAPS members can also complete this CME examination online by logging onto the ASAPS Members-Only Web site at http://www.surgery.org/members and clicking on “Clinical Education” in the menu bar. While inadvertent perioperative hypothermia has received serious attention in many surgical specialties, few discussions of hypothermia have been published in the plastic surgery literature. This article reviews the physiology of thermoregulation, describes how both general and regional anesthesia alter the normal thermoregulatory mechanisms, indicates risk factors particularly associated with hypothermia, and discusses the most effective current methods for maintaining normothermia. Hypothermia is typically defined as a core body temperature of ≤36°C (≤96.8°F), though patient outcomes are reportedly better when a temperature of ≥36.5°C is maintained. Unless preventive measures are instituted, inadvertent hypothermia occurs in 50% to 90% of surgical patients, even those undergoing relatively short procedures lasting one to one-and-a-half hours. During either general or regional anesthesia, a patient's natural behavioral and autonomic responses to cold are unavailable or impaired, and the combination of general and neuraxial anesthesia produces the highest risk for inadvertent perioperative hypothermia. Unless hypothermia is prevented, the restoration of normothermia can take more than 4 hours once anesthesia is stopped. Consequences of hypothermia are serious and affect surgical outcomes in plastic surgery patients. Potential complications include morbid cardiac events, coagulation disorders and blood loss, increased incidence of surgical wound infection, postoperative shivering, longer hospital stays, and increased costs associated with surgery. Measures for preventing hypothermia are emphasized in this article, especially those proven most