Effects Of Active Warming On Core Temperature And Recovery Time In Patients Undergoing Laparotomy

Objective:To investigate the active heat preservation effectiveness of adult underbody forced-air warming blanket on patients undergoing laparotomy under general anesthesia and to observe the correlation between nasopharynx temperature and tympanic membrane temperature in patients under general anesthesia.Methods:Choose 100 patients undergoing laparotomy,aged >18 years old,ASAI-II,received total intravenous anesthesia(TIVA).Randomly divided the patients into group E(experimental group)and group C(control group),50 cases in each group.Based on the used of sterile sheets and quilts,add a adult underbody forced-air warming blanket under each patient for active heat preservation in group E,and just used of sterile sheets and quilts only for conventional insulation in group C.Controlled the ambient temperature with 24±1 ℃ and relative humidity with50%-70%.The tympanic temperature(TMT)and nasopharyngeal temperature(NT)were measured as core temperatures.Controlled the depth of anesthesia by BIS.Using a infrared thermometer to monitored the TMT according to the following points:before anesthesia induction(T0),15 minutes(T1),30 min(T2),60 min(T3),90 min(T4),120 min(T5),150 min(T6),min(T7),210 min(T8),240(T9)after the induction,at the end point of operation(T10)and the time left PACU(T11).Monitored the NT at T1 to T10 by NTC thermistor temperature sensor.First,merged the two groups as a group,and Compared TMT and NT in all patients at different time points;then,Observed the change of TMT and NT respectively in two groups in perioperative period,recorded the hypothermia incidence,postoperative shivering incidence,the value of BIS when drug withdrew,recovery time and extubation time in recovery period.Results: 1.There were no statistically significant between two groups with demographics and the general situation of operation(P>0.05).2.The variation trend of TMT and NT of all patients were similar during the perioperative period.They are highly postitive and the correlation coefficient r=0.874;TMT was higher than NT,the average difference was 0.46 ± 0.26℃,95% confidence interval [0.44,0.48].3.The changed of TMT:Compared within the two groups,the TMT was significantly decreased from T1 to T11 compared withbaseline values(T0)in each group(P<0.05).4.Compared between the two groups,there were no significant difference of TMT from T0 to T10 between group E and group C(P>0.05)and had statistical significance at T11(P<0.05).The TMT changed in both groups were the same tendency:at first,it descended rapidly within 1 hour after anesthesia inducion,then decreased slowly and maintained a relatively stable condition.During this period,the TMT in group E and group C fell with no significantly differents and they reduced by 0.98±0.40℃ and 1.02±0.47℃respectively(P>0.05).Some times later,it began to rise gradually.During this period,The TMT in group E rebounded more rapidly than group C,and they rose significantly difference by 0.76±0.40℃and 0.54±0.40℃respectively(P<0.05).5.The changed of NT:Compared within the two groups,the NT was significantly declined from T2 to T10 compared with T1(P<0.05).Compared between the two groups,there were no significant difference from T1 to T7 and T9 between group E and group C(P>0.05),and had significant difference at T8 and T10(P<0.05).The tendency of the NT was the same as the TMT:at first,it descended rapidly within 1 hour after anesthesia inducion,then decreased slowly and maintained a relatively stable condition,some times later,it began to rise gradually.6.There were no statistically significant between two groups with the hypothermia incidence,there were 19.14% and 27.08%(P>0.05)in group E and group C with TMT as the standard,while 36.17% and 52.08%(P>0.05)respectively in each group with NT as the standard.7.The difference was not statistically significant of the postoperative shivering incidence:with 4.25% in group E and 12.5% in group C(P>0.05).8.When the drug withdrew,the BIS in group E and group C were50.3±7.2 and 52±5.9respectively(P>0.05);The recovery time in group E and group C were 17.1±5.3min 和 19.0±6.5min respectively(P>0.05),the extubation time in group E and group C were 22.2±6.1min 和 24.6±5.6min respectively(P>0.05).Conclusion: 1.The underbody forced-air warming blanket is conducive to the recovery of decreased body temperature in patients undergoing abdominal surgery under general anesthesia.2.The tympanic membrane temperature is higher than the nasopharynx temperature in patients undergoing abdominal surgery under general anesthesiaand and there is good correlation between them.