Effects of acute normovolemic hemodilution on target-controlled infusion of etomidate blood concen-trations and adrenocortical function
Objective To observe the effects of acute normovolemic hemodilution(ANH)on target-controlled infusion(TCI)of etomidate blood drug concentration and adrenal cortical function.Methods Sixty patients who undergo elective multisegmental spine surgery,35 males and 25 females,aged 30-60 years,BMI 20-25 kg/m2,ASA physical status Ⅰ or Ⅱ,were divided into two groups using random number table method:ANH group and control group,30 patients in each group.Both groups used a target-controlled infusion of etomidate for anesthesia induction and anesthesia maintenance.In the ANH group,ANH was performed after steady anesthesia induction,ideal Hct 28%to 30%,and transfused within 1 hour after surgery;the control group was routinely treated.The dosage of etomidate was recorded.Liquid chroma-tography-tandem mass spectrometry(LC-MS/MS)was used to detect etomidate blood concentrations at the immediate postoperative,10,20,and 30 minutes postoperative periods in the two groups,and the immedi-ate moment autologous blood collected into the storage bag,preserved in the storage bag for 1 hour,and the immediate moment transfused back in the ANH group.Plasma concentrations of cortisol(Cor),adrenocorti-cotropic hormone(ACTH),and aldosterone(ALD)were measured by chemiluminescence immunoassay(CLIA)before the induction of anesthesia,immediately after the operation,and at 1 day and 2 days postop-eratively.Results There was no significant difference in the total dosage of etomidate between the two groups.Compared with the immediate postoperative period,the plasma etomidate concentration was signifi-cantly decreased 10,20,and 30 minutes after surgery(P<0.05).Compared with the control group,the concentration increased significantly 10 minutes after surgery in the ANH group(P<0.05).The plasma concentrations of etomidate were(547.8±119.4)ng/ml at the immediate moment autologous blood collected into the storage bag,(536.7±107.8)ng/ml at the preserved in the storage bag for 1 hour,and(522.8±91.7)ng/ml at theimmediatemoment transfusedbackinthe ANHgroup.Comparedwithbeforein-duction of anesthesia,the concentration of Cor and ALD immediately after the operation decreased signifi-cantly(P<0.05)and the concentration of ACTH was significantly higher(P<0.05).There were no sta-tistically significant differences in the concentrations of Cor,ALD,and ACTH between the two groups before induction of anesthesia 1 day and 2 days postoperatively.Conclusion In the orthopedic surgery of TCI eto-midate,return transfusion of collected autologous blood transiently(about 10 minutes)increases etomidate blood concentrations,the function of adrenal cortical will recover to the preoperative level within 24 hours after the operation.
EtomidateAcute normovolemic hemodilutionAdrenocortical functionBlood drug concentration