Published online Nov 27, 2015. doi: 10.5313/wja.v4.i3.58
Peer-review started: May 8, 2015
First decision: June 3, 2015
Revised: June 24, 2015
Accepted: July 21, 2015
Article in press: July 23, 2015
Published online: November 27, 2015
Processing time: 204 Days and 18.1 Hours
Perioperative hypothermia, core temperature below 36.0 °C, transpires due to disruption of thermoregulation by anesthesia coupled with cold exposure to procedural surroundings and cleansing agents. Although most publications have focused on thermoregulation disruption with general anesthesia, neuraxial anesthesia may also cause significant hypothermia. The clinical consequences of perioperative hypothermia are multiple and include patient discomfort, shivering, platelet dysfunction, coagulopathy, and increased vasoconstriction associated with a higher risk of wound infection. Furthermore, postoperative cardiac events occur at a higher rate; although it is unclear whether this is due to increased oxygen consumption or norepinephrine levels. Hypothermia may also affect pharmacokinetics and prolong postoperative recovery times and hospital length of stay. In order to combat perioperative hypothermia, many prevention strategies have been examined. Active and passive cutaneous warming are likely the most common and aim to both warm and prevent heat loss; many consider active warming a standard of care for surgeries over one hour. Intravenous nutrients have also been examined to boost metabolic heat production. Additionally, pharmacologic agents that induce vasoconstriction have been studied with the goal of minimizing heat loss. Despite these multiple strategies for prevention and treatment, hypothermia continues to be a problem and a common consequence of the perioperative period. This literature review presents the most recent evidence on the disruption of temperature regulation by anesthesia and perioperative environment, the consequences of hypothermia, and the methods for hypothermia prevention and treatment.
Core tip: Thermoregulation tightly controls core temperature to ensure optimal organ and enzymatic function. Anesthesia disrupts normal thermoregulation and, when combined with patient exposure to a cold procedural environment, leads to hypothermia. However, hypothermia is not a benign issue. It is associated with postoperative complications including infection, bleeding, cardiac events, changes in drug metabolism, patient discomfort, and increased length of stay. Although multiple preventive strategies have been explored, their utility varies. This review explores the impact of anesthesia on perioperative hypothermia and the evidence for associated complications and outcomes. Preventative strategies are also examined and future directions for research are discussed.