Forced Air and Intravenous Fluid Warmers in Gynecologic Laparoscopic Surgery

Perioperative hypothermia is a common problem. It has been defined as a core temperature below 36ºC. The reasons why patient undergoing gynecologic laparoscopic surgery has perioperative hypothermia because the reduced metabolic heat production, redistribution of heat from the core to the periphery and impaired thermoregulation (due to anesthetics), use of cool carbon dioxide gas insufflations and surgical irrigation solution, as well as heat loss due to the cool environment. This perioperative problem has been linked to adverse patient outcomes such as myocardial ischemia as hypothermia increases plasma catecholamine, surgical site infection as hypothermia diminishes wound tissue O2 tension and coagulopathy as hypothermia impairs platelet function.

It claims that perioperative heat loss occurs by radiation (60%), convection (25%) and evaporation (10%). This is caused by the difference between peripheral body and ambient temperature, air circulation around the body and vasodilatation.

In daily practice, most anesthesia personnel warm patient peri-operatively by using force air warmer and intravenous fluid warmer.

This study aimed to compare the difference of core and room temperature in patients undergoing gynecologic laparoscopic surgery by using forced air and intravenous fluid warmer

The study was approved from the Siriraj Institutional Review Board (Si-IRB), COA (Certificate of Analysis): Si201/2016 (18/03/2016), and was written informed consent was obtained from all subjects. The study was conducted at the Department of Siriraj Obstetrics and Gynecology.

A total of 90 patients were enrolled in the study between April 2016 and .....2017. All patients underwent general anesthesia for elective gynecologic laparoscopic surgery. Inclusion criteria were patients aged between 18 and 65, elective case, ASA (American Society of Anesthesiologist) physical status class I-III, BMI 25-30 kg/sq.m., surgical time \> 90 minutes. Exclusion criteria were the core temperature less than 36ºC or more than 38ºC. Withdrawal or termination criterion was the change of laparoscopic surgery to exploratory laparotomy.

On the day of surgery, participants signed the informed consent and were randomized equally into two groups: A = 45, receiving intraoperative forced air warming and B =45, having intraoperative intravenous fluid via a fluid warmer All patients underwent general anesthesia after application of standard monitors, anesthesia was induced with fentanyl 1-2 mcg/kg or morphine 0.1-0.2 mg/kg., propofol 1.5-2.5 mg/kg, nimbex 1-1.5 mg/kg or atracurium 0.6 mg/kg. Anesthesia was maintained with sevoflurane ,air,O2, supplemented with fentanyl or morphine.

Core temperatures were measured with an electronic thermometer via tympanic membrane. Intraoperatively, core temperatures and room temperatures were measured at 15 minute intervals until the end of surgery .

Postoperative data were measured at 15 minute intervals at the recovery room. Data consisted of vital sign, core temperature, room temperature, shivering, medication requirements and use of heating devices.

Eligibility Criteria:
Inclusion Criteria:

* ASA class 1-3, 18-65 years old, BMI 25-30 kg/sq.m., core temperature 36ºC-38ºC, operation more than 90 minutes

Exclusion Criteria:

* turn operation to exploratory laparotomy