[The effect of sedation with propofol and fentanyl during epidural catheter insertion on intraoperative temperatures]

General anesthesia inhibits thermoregulation by suppressing tonic vasoconstriction and facilitates a core-to-peripheral redistribution of body heat, which is the major cause of core hypothermia during the first hour of anesthesia. We randomly assigned 16 patients to two groups; 1) patients who received fentanyl (1 microgram.kg-1, i.v.) and propofol (1.5 mg.kg-1.h-1) during insertion of epidural catheters (P group), and 2) no drug (control) group (C group). We measured tympanic (Ttym) and skin temperatures at the time of admission to operating rooms, after dural catheter insertion, before induction of anesthesia, just after induction of anesthesia, and one hour after induction. After dural catheter insertion, forearm-finger tip skin temperature gradient of P group was significantly smaller than C group. One hour after induction of anesthesia, Ttym of P group was significantly higher than C group. We can conclude that a sedative dose of propofol and fentanyl before induction of general anesthesia inhibits redistribution hypothermia during general anesthesia.