Effects of Etomidate Combined With Dexmedetomidine on Adrenocortical Function in Elderly Patients: A Double-Blind Randomized Controlled Trial

Introduction Etomidate has been advocated to be used in anesthesia of the elderly and the critically ill patients due to its faint effect on cardiovascular system. But the dose-dependent suppression of etomidate on adrenal cortex function leads to the limitation of its clinical application. Clinical research shows that dexmedetomidine can reduce the dose requirements for intravenous or inhalation anesthetics and opioids, and the hemodynamics is more stable during the operation. The objective is to observe the effect of etomidate combined with dexmedetomidine on adrenocortical function in elderly patients. Methods 180 elder patients scheduled for elective ureteroscopic holmium laser lithotripsy were randomly allocated to PR group anesthetized with propofol- remifentanil, ER group anesthetized with etomidate-remifentanil, and ERD group anesthetized with dexmedetomidine combined with etomidate-remifentanil. Patients in each group whose operation time was less than or equal to 1h were incorporated into short time operation group (PR1 group, ER1 group and ERD1 group), and whose operation time was more than 1h were incorporated into long time operation group (PR2 group, ER2 group and ERD2 group). The values of SBP, DBP, HR and SpO2 were recorded at T0, T1, T2, T3, T4, T5, T6 and T7.The time of operation, the dosage of etomidate and remifentanil administrated during surgery, the time to spontaneous respiration, recovery and extubation, and the duration of stay in the PACU were recorded. The serum cortisol and ACTH concentration was measured at t0, t1, t2, t3, t4 and t5. Results The dosage of etomidate was significantly lower in ERD1 group and ERD2 group compared with ER1 group and ER2 group(P < 0.05), respectively. The SBP in ER2 and ERD2 group were higher at T1 and T3 compared to PR2 group (P < 0.05). The DBP in ER1 and ERD1 group were higher at T1compared to PR1 group (P < 0.05). The Serum cortisol concentration were higher at t1 ~ 2 in ERD1 group compared to ER1 group (P < 0.05). The Serum cortisol concentration were higher at t1 ~ 3 in ERD2 group compared to ER2 group (P < 0.05).The Serum ACTH concentration were lower at t1 ~ 2 in ERD1 group compared to ER1 group (P < 0.05). The Serum ACTH concentration were lower at t1 ~ 3 in ERD2 group compared to ER2 group (P < 0.05). Conclusion The administration of dexmedetomidine combined with etomidate can attenuate the inhibition of etomidate on adrenocortical function in elderly patients and maintain intraoperative hemodynamic stability.