The Effect Of Intraoperative Warming On Recovery Time And Effect Compartment Concentration Of Propofol In Elderly Patients Under General Anesthesia

Objective To investigate the effect of intraoperative warming measures on effectcompartment concentration of propofol in recovery time， postanesthesia recoveryperiod，time of extubation and the duration in PACU under general anesthesiaelderly patients undergoing gastrointestinal surgery.Methods44ASA Ⅰ~Ⅱ aged60yrs or older patients undergoing gastrointestinalsurgery were divided into two groups randomly: the experimental group(Group C)and the control group(Group N). All patients were under room temperature of22℃and were covered with quilts. All patients were injected cisatracuriumintermittent，usedpropofo（l2~4ug/ml）and remifentanil (4ng/ml) Target Control Infusion (TCI)during surgery．The BIS and TOF were montiored in both groups. The meanarterial pressure (MAP), heart rate (HR), pulse oxygen saturation (SPO2) andEsophagus temperature (T) were monitored in all patients. In the experimentalgroup, the fluid, blood products and flushing fluid were heated to40℃. In theexperimental group, all the patients were covered by a forced-air warming system（39℃）.The temperature,mean arterial pressure (MAP), heart rate (HR) and pulseoxygen saturation(SPO2)of before anesthesia (T0),30min after anesthesiainduced(T1),60min after anesthesia induced (T2),90min after anesthesia induced(T3),120min after anesthesia induced (T4),150min after anesthesia induced（T5）and the end of surgery(T6) were recorded. The TOF value at the moment ofT6(TOF1) and BIS≥80(TOF2) were recorded. The effect compartmentconcentration of propofol in TCI system when BIS≥80(Pce) was recorded. Thetime from stopping propofol to BIS≥80(S0),The time from stopping propofol toextubation of time (S1) and the recovery time in postanesthesia care unit(S2) wererecorded and compared. The correlations of T6with Pce, S0, S1and S2 were analyzed.Results There were no significant difference in HR, MAP and SPO2between thetwo groups. There were no significant differences in TOF1and TOF2between thetwo groups. The temperature at time of T2, T3, T4, T5and T6in group N wasobviously decreased compare to group C (P<0.05). The Pcein group N wassignificantly higher than group C (P<0.05). The S0, S1, and S2in group C weresignificantly decreased than group N (P<0.05).In PACU, there were2patientsdeveloped shivering in group C compared to8in group N.3patients felt cold ingroup C compared to10in group C. The blood loss in group C was obviouslydecreased compare to group C (P<0.05). There are high correlation between T6and Pce, S0, S1, S2.Conclusion Temperature monitoring during general anesthesia can maintain theelderly patients with intraoperative temperature,prevent the hypothermia.Temperature had effect on elderly patients`recovery in general anesthesia.Intraoperative maintain normal body temperature can accelerate the awakening ofpatients, shorten the time of extubation, reduce the recovery time and incidence ofrigors and patients`discomfort in PACU.