[Non-therapeutic intraoperative hypothermia: causes, complications, prevention, and treatment (part I)].

During the first hour of general anesthesia, a patient's body temperature can decrease between 1 and 1.5 degrees C; regional anesthesia also induces central hypothermia. Intraoperative hypothermia interferes with immunological function, particularly with the oxidative capacity of neutrophils. Cutaneous vasoconstriction occurs and blood flow is reduced in tissues subject to surgery. Oxygen transport is also reduced, increasing the risk of postoperative infection. Decreased platelet activity favors blood loss. Hypothermia increases the likelihood of shivering, and with enhanced central nervous system activation, there is increased cardiovascular morbidity. Currently, these effects can be attenuated or even avoided by applying various warming methods available. The efficacy and mechanisms of action of such methods are described in the second part of this review of the literature.