Effects Of Propofol With Or Without Dexmedetomidine On Patient's Temperature At Different Sedation Level

Background:Core body temperature is normally tightly regulated to within a few tenths of a degree.General anesthetics greatly impair thermoregulation,synchronously reducing the thresholds for vasoconstriction and shivering.Consequently,unwarmed anaesthetized patients become hypothermic,typically by 1–2°C.Hypothermia results initially from an internal redistribution of body heat from the core to the periphery,followed by heat loss exceeding metabolic heat production.Complications of perioperative hypothermia include coagulopathy and increased transfusion requirement,surgical site infection,delayed drug metabolism,prolonged recovery,shivering,and thermal discomfort.Objective:To investigate the effect of Propofol with or without dexmedetomidine on patient's temperature at different anesthesia depth.Methods:A total of 80 patients undergoing elective abdominal surgery with general anesthesia were randomized into 4 groups,namely group P1(BIS40-50 by propofol),group P2(BIS 50-60 by propofol),group D1(BIS50-60 by propofol and dexmedetomidine)and D2(BIS 50-60 by propofol and dexmedetomidine).The patients' nasopharynx temperature were recorded respectively before anesthesia,5 min after induction,30 min after induction,1h after induction,2h after induction,3h after induction,and extubation.Results:Compared to temperature before induction,follow-up times decreased significantly(P <0.05).There were no obvious differences in serum levels of P1?D1 and P2?D2 on their hypothermia and shivering incidence(P > 0.05);However,patients maintained by propofol and dexmedetomidine temperature decreased more and shivering lease compared to patients maintained by propofol.Conclusions:Maintenance of anesthesia by simple propofol or complex with dexmedetomidine both can reduce the core temperature of patients undergoing abdominal surgery.Dexmedetomidine maylead to more temperature decrease and more hypothermia during perioperative period.But the depth of anesthesia may not have discernible effect on hypothermia.