A Study On Pharmacokinetics Of Etomidate In Patients With Different Degrees Of Burn

Objective:The pharmacokinetics of etomidate in patients with varying degrees of burns was studied under BIS monitoring,so as to guide clinical medication.Methods:From September 2017 to February 2018,45 burn patients who underwent selective skin grafting under general anesthesia in the second affiliated hospital of Kunming Medical University were selected,ASA grades of all patients were level Ⅱ-III,and they were divided into three groups:group A was 15 patients with mild burns,group B was 15 patients with moderate burns,and group C was 15 patients with severe bums.No basic drugs such as sedatives and analgesics were used before surgery.After entering the operating room,percutaneous oxygen saturation,II conduction ecg monitoring,radial artery puncture catheter to measure invasive arterial pressure,CO,and BIS monitoring were performed.Anesthesia induction:All the 45 patients were given target controlled infusion of sufentanil(target blood concentration 0.4ng/ml).Intravenous infusion of etomidate began after 15 minutes(Tt15)of target-controlled infusion of sufentanil,the dosage of etomidate was 0.4mg/kg,and the pump infusion was set at the end of 2 minutes,after patient lose consciousnes,rocuronium was intravenously injected at 0.9mg/kg.After endotracheal intubation at TCI20(Tt20)time point,mechanical ventilation was performed with a spirally threaded tube of the anesthesia machine.Dexmedetomidine was continuously pumped intravenously at a dose of 0.4ug/kg/h while the concentration of sevoflurane was dynamically adjusted,BIS value was maintained between 40 and 60.Continuous target-controlled infusion of sufentanil(plasma effector chamber concentration 0.4ng/ml)was used for analgesia,no muscle relaxant was added during the operation.Before anesthesia(basis)、1min(Tti)、3min(Tt3)、5min(Tt5)、10min(Tt10)、15min(Tt15)、20min(Tt20)、30min(Tt30)、40min(Tt40)、50min(Tt50)、60min(Tt60)、90min(Tt90)、withdrawal(Stop)and withdrawal 1min(Stopl)、3min(Stop3)、5min(Stop5)、8min(Stop8)、1Omin(Stop10)、20 min(Stop20)and 30 min(Stop30).Recording elements:Bispectral index(BIS)、Hemodynamic parameter、body temperature(T),and collectedTt2o、Tt30、Tt40、Tt50、Tt60、Tt90、Stop、Stop1、Stop3、Stop5、Stop8、Stop10、Stop20、Stop30 points’s Arterial blood,determination of plasma concentration of etomidate(Cm).Finally,the pharmacokinetic parameters of each group were calculated.Results:1.General CaseAmong patients in groups A,B and C,all covariates,such as gender,age,height,body mass index(BMI),infusion volume,urine volume and etomidate dosage,were not significantly different between groups(P>0.05).There was no significant difference between groups A and B in preoperative albumin and ALT(P>0.05).The preoperative albumin content of group A and B was higher than that of group C(P<0.05).Preoperative ALT of group A and group B was lower than that of group C(P<0.05).The blood loss a in group C was higher than those in group A,B(P<0.05).There was no significant difference between group A and B(P>0.05).2.Vital signs during anesthesia:CO、SV、MAP、HR、BIS、TResults of numerical grouping comparison of CO,SV5 MAP and HR:After etomidate induction(Tt20、Tt30),there were no significant differences in CO,SV,MAP and HR(basic、Tt1、Tt3、Tt5、Tt10、T15)between groups A,B and C(P>0.05).Results of numerical grouping comparison of BIS:At Tt10 and Tti5,there were differences between group C and group A and B,all of which showed that group C was smaller than group A and B,but there was no statistical difference(P>0.05).Compared with group A and B,the Tt20 time point of group C was lower than that of group A and B,and the difference was statistically significant(P<0.05).There was no significant difference at other time points(P>0.05).Results of numerical grouping comparison of SV、T:There was no significant difference between groups A,B and C at the same time point(P>0.05).Results of numerical grouping comparison of CO、HR and MAP:There were statistically significant differences between group C and group A at the same time points in basis、Tt1.Tt3、Tt5、Tt10、Tt15、Tt20、Tt30、Tt40、Tt50、Tt60、Tt90、Stop、Stopl、Stop3、Stop5、Stop8、Stop10、Stop20 and Stop30(P<0.05),group C was larger than group A.The difference between group C and group B was statistically significant(P<0.05)at the same time points(basis、Tt1、Tt3、Tt5、Tt10、Tt30、Tt40、Tt50、Tt60、Tt90、Stop、Stop]、Stop3、Stop5、Stop8、Stop10、Stop20 and Stop30,group C was larger than group B.3.The actual measured plasma concentration of etomidateComparison of Cm in group C and group A at the same time points of Tt60、Tt90、Stop、Stopl、Stop3、Stop5、Stop8、Stop10、Stop20 and Stop30 showed that Cm in group C was greater than that in group A,and the difference was statistically significant(P<0.05).At the same time points of Tt90、Stop5、Stop8、Stop10、Stop20 and Stop30,Cm of group C was greater than that of group B,and the difference was statistically significant(P<0.05).There was no significant difference between group A and group B at the same time point(P>0.05),4.Pharmacokinetic parameters of etomidateK31、CL1、and CL3 ain group C were smaller than those in group A and group B,with significant difference(P<0.05).V3、T1/2r rof group C were greater than those of group A and B,with significant differences(P<0.05).There was no significant difference between group A and group B in V3、K31、T 1/2r、CL1、CL3。(P>0.05).Except the pharmacokinetic parameters of group A,group B and group C,the differences of other pharmacokinetic parameters between groups were small,and the differences were not statistically significant(P>0.05).Conclusion:1.BIS can be used to guide clinical individualized medication to maintain appropriate anesthesia depth,reduce the incidence of anesthesia complications,and improve the safety of anesthesia.2.In patients with burns,etomidate was used for anesthesia induction more well.When patients reached the depth of surgical anesthesia,no significant changes were observed in SV,CO and MAP,and the hemodynamics were stable.3.In patients with severe burns,when etomidate was used intraoperatively,K31 became smaller,V3 increased,CL1 and CL3 decreased,T1/2r was significantly prolonged,and pharmacological effects were enhanced,In clinical work,dosage can be appropriately reduced,so as to reduce the incidence of adverse reactions and complications,improve the quality of anesthesia,reduce the risk of anesthesia.