Background                                       
Patients undergoing gynecologic laparoscopic surgery frequently experience with hypothermia . This can cause myocardial ischemia, surgical site infection  and coagulopathy. The reasons why patient has this event are the reduced metabolic heat production, redistribution of heat from the core to the periphery, impaired thermoregulation (due to anesthetics), use of cool insufflations carbon dioxide gas and surgical irrigation solution, as well as heat loss due to the cool environment.  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

Material and Method                              
A prospective experimental study was conducted with 90 patients who underwent elective gynecologic laparoscopic surgery. All patients were randomized into two groups, in group A, patients were actively warmed after induction period by forced air-warming at 43 0C, group B received intravenous fluid warmer at 41 0C by Ranger warmer. Core temperature (tympanic membrane) and room temperature were recorded every 15 minute after the induction period.

Results: Interim analysis ( group A : 29, group B : 23)                          
Intra-operative tympanic membrane temperature were higher in the active warming (Group A) compared with intravenous fluids warmer (Ranger warmer) at 15 minutes interval after induction of anesthesia.  In the recovery room, the core temperature was higher in group A than that of group B. Nevertheless, there were insignificant differences in  temperature between groups.Discussion                                                                                    
The demographic data of both groups were similar. After induction, group A and B insignificantly showed to decrease in temperature and appeared to maintain at steady stage throughout the procedure with a little bit higher in Group A. This might due to the forced air warmer yielded a circulating, temperature flow; while, warmed intravenous fluid lost heat en route to the patients. Therefore, in a cool operating theatre, the distance between administered fluid and site of intravenous cannulation should be short as much as possible. Nevertheless, the core temperature of both groups showed insignificant differences in the recovery room, as all participants were covered by blanket in a warmed atmosphere.

Conclusion                                                                                   
The active warming with forced air warmer might be more efficient than  intravenous fluids warmer (Ranger warmer). However intergroup differences were unremarkable.

Comparison between forced air and intravenous fluid Warmer in gynecologic laparoscopic surgery: an interim analysis