Effect on thermoregulatory responses in patients undergoing a tympanoplasty in accordance to the anesthetic techniques during PEEP: a comparison between inhalation anesthesia with desflurane and TIVA

Abstract

BackgroundIt has been known that positive end-expiratory pressure (PEEP) increases the vasoconstriction threshold by baroreceptor unloading. We compared the effect on the thermoregulatory responses according to anesthetic techniques between an inhalation anesthesia with desflurane and a total intravenous anesthesia (TIVA) with propofol and reminfentanil when PEEP was applied in patients undergoing tympanoplasty.MethodsForty-six patients with a scheduled tympanoplasty were enrolled and the patients were divided in two study groups. Desflurane was used as an inhalation anesthetic in group 1 (n = 22), while TIVA with propofol and remifentanil was used in group 2 (n = 24). PEEP was applied by 5 cmH2O in both groups and an ambient temperature was maintained at 22-24℃ during surgery. The core temperature and the difference of skin temperature between forearm and fingertip were monitored for about 180 minutes before and after the induction of general anesthesia.ResultsThe final core temperature was significantly higher in group 2 (35.4 ± 0.7℃) than in group 1 (34.9 ± 0.5℃). Peripheral thermoregulatory vasoconstriction was found in 5 subjects (23%) in group 1 and in 21 subjects (88%) in group 2. The time taken for reaching the thermoregulatory vasoconstriction threshold was 151.4 ± 19.7 minutes in group 1 and 88.9 ± 14.4 minutes in group 2.ConclusionsWhen PEEP will be applied, anesthesia with TIVA may have more advantages in core temperature preservation than an inhalation anesthesia with desflurane.

Effects of positive end-expiratory pressure on intraoperative core temperature in patients undergoing posterior spine surgery: prospective randomised trial

“…Numerous previous reports have indicated that peripheral vasoconstriction by PEEP-induced baroreceptor unloading effectively prevents intraoperative hypothermia. 10 , 11 , 13 , 14 Although the present study revealed the beneficial effect of PEEP on thermoregulatory reactions (a high threshold and rapid onset of peripheral vasoconstriction), there were no significant differences in the core temperature changes over time between the two groups. This discrepancy regarding the effects of PEEP on intraoperative core temperature may be explained in part by the cold environment and prone positioning in our experimental setting.…”

“…Thermoregulatory vasoconstriction was evaluated with the same method used in several previous studies. 11 , 13 , 14 The difference in skin temperature between the forearm and fingertip was also calculated. A forearm–fingertip skin temperature difference of <0°C was defined as peripheral vasodilation.…”

“… 10 – 12 Several studies have shown that in patients undergoing lower abdominal surgery or tympanoplasty, the extent of intraoperative hypothermia can be effectively attenuated by applying PEEP of 5 to 10 cmH 2 O. 10 , 11 , 13 , 14 However, the effect of PEEP on intraoperative thermoregulation in the prone position has not been investigated. The prone position is associated with relative intravascular volume depletion due to a decrease in venous return by compression of the inferior vena cava and increased abdominal pressure, 15 – 17 which may enhance the effect of PEEP on intraoperative thermoregulation.…”

Preoperative interscalene brachial plexus block aids in perioperative temperature management during arthroscopic shoulder surgery

“…First, cervical sympathetic involvement from IBPB might cause vasodilation of the upper extremity, head, and neck of the ipsilateral side of the block, affecting temperature measurement on the ipsilateral side of block before induction of anesthesia and in the PACU. A skin temperature thermometer on the upper extremity might be helpful to determine whether peripheral vasodilation or constriction developed [ 19 ]. Second, additional rocuronium was administered for the prevention of any patient movement during arthroscopic surgery with the appearance of clefts in the capnogram.…”

“…Third, a forced-air warming device should have been applied to patients whenever body temperatures fell below 36.5℃ during the operation and below 36℃ in the PACU according to the National Institute for Health and Care Excellence (NICE) clinical guideline 65. This study adopted a lower temperature than that suggested in the NICE guideline before active warming measures, referring to other studies [ 2 3 19 21 ].…”