Forced Air and Intravenous Fluid Warmers in Gynecologic Laparoscopic Surgery
Condition: Hypothermia; Anesthesia
MeSH terms: Hypothermia
Study type: Interventional

Summary: 
      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
    

Detailed description: 
      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.
    

Intervention name(s): Forced Air warmer; Intravenous Fluid Warmer
Intervention type(s): Procedure; Procedure
Intervention description(s): record room temperature
record core temperature (tympanic membrane)
General anesthesia
using forced air warmer (bair hugger)
Intravenous fluid at room temperature
room temperature and core temperature q15 minutes
anesthesia finish, stop bair hugger
record core temperature before recovery room; record room temperature
record core temperature (tympanic membrane)
General anesthesia
using ranger warmer
Intravenous fluid at room temperature
room temperature and core temperature q15 minutes
anesthesia finish, stop ranger warmer
record core temperature before recovery room
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Health Services Research
Keywords: hypothermia; Shivering; Gynecologic laparoscopic surgery; Warming; General anesthesia