Prevention of peroperative hypothermia in abdominal surgery

Abstract

It is important to reduce or prevent heat loss during anaesthesia, especially in patients with restricted cardiopulmonary reserves. To test a specially developed esophageal thermal tube (GK-esophageal thermal tube) for this purpose, 33 patients were randomly divided into two groups: Group A were given heat transferred to the central core during operation, using the GK-tube with circulating 41.7 degrees C warm water. Group B received no active warming. All patients were scheduled for major abdominal operation. In both groups there was a temperature fall in the induction phase. In Group B the temperature continued to fall slowly during operation, resulting in a median end-temperature of 34.9 degrees C. In Group A the temperature rose slowly after induction of heat via the tube, resulting in a median end-temperature of 36.8 degrees C in this actively warmed group. The temperature difference is significant (P less than 0.001). The median operating time was 3h 30 min in both groups. After 2 h of anaesthesia the median temperature in Group A was 36.1 degrees C and in Group B 35.0 degrees C. This difference is also significant (P less than 0.001). The described method was easy to use and without complications. We recommend this method to prevent peroperative hypothermia in all patients suspected to have limited cardiopulmonary reserves. The possible hazards and how to avoid these are described.

Efficacy of intraoperative heat administration by ventilation with warm humidified gases and an oesophageal warming system

“…There have been several clinical studies on the effects of different warming systems in preventing perioperative hypothermia with controversial results. Both heating of inspired gases and oesophageal warming have been demonstrated as either effective and ineffective in different studies [4][5][6][7][8][9][10][11] . The "within study" and "between studies" variability of the experimental conditions (patients, type of surgery, type of anaesthesia, fluid infusions, room temperature and relative humidity, etc.)…”

“…Several methods are commonly used to reduce body heat loss. Heating inspired gases [4][5][6][7][8] and oesophageal warming [9][10][11] are easily applied during surgery and have been proposed for providing (central) warming, which is probably more "physi-ological" than other methods which deliver heat peripherally (warming the operating room, warm mattresses, thermal blankets, infrared heating lamps, forced air warmers 1-2 12-18 ).…”

Forced‐air surface warming versus oesophageal heat exchanger in the prevention of peroperative hypothermia

“…It seems unclear whether the patients in that study had any thermal insulation applied to any part of the body. Further, in that study no comparison was made with other heating devices (3).…”

“…Forced-air warming with model 500 "Bair Hugger" (R) (Augustine Medical, Eden Prairie, MN, USA). Oesophageal heat exchanger CF1 (Granulab International BV, Amersfoort Netherlands), connected to an oesophageal, double-lumen, coaxical tube, circulated with warmed water in a closed system (3). Blood transfusions were given at 37°C through a heating device.…”

Clinical Evaluation of the Oesophageal Heat Exchanger in the Prevention of Perioperative Hypothermia

“…The oesophagus is a convenient site for core (central) warming in anaesthetized patients, being easily accessible and situated in close proximity to the major blood vessels, thus acting as a good conduit for heat transfer. An oesophageal thermal device has been designed and shown to be effective in delivering heat and in the prevention of perioperative hypothermia [2].…”