Effects of etomidate combined with dexmedetomidine on adrenocortical function in elderly patients: a double-blind randomized controlled trial

Etomidate has been advocated to be used in anesthesia for 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 showed that dexmedetomidine could reduce the dose requirements for intravenous or inhalation anesthetics and opioids, and the hemodynamics was more stable during the operation. The objective was to observe the effect of etomidate combined with dexmedetomidine on adrenocortical function in elderly patients. 180 elderly 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 1 h were incorporated into short time surgery group (PR(1) group, ER(1) group and ERD(1) group), and whose surgical procedure time was more than 1 h were incorporated into long time surgery group (PR(2) group, ER(2) group and ERD(2) group). The primary outcome was the serum cortisol and ACTH concentration. The secondary outcomes were the values of SBP, DBP, HR and SpO(2), the time of surgical procedure, the dosage of etomidate and remifentanil administered during surgery, the time to spontaneous respiration, recovery and extubation, and the duration of stay in the PACU. The Serum cortisol concentration was higher at t(1~2) in ERD(1) group compared to ER(1) group (P < 0.05). The Serum cortisol concentration at t(1~3) was higher in ERD(2) group than in ER(2) group (P < 0.05). The Serum ACTH concentration was lower at t(1~2) in ERD(1) group compared to ER(1) group (P < 0.05). The Serum ACTH concentration at t(1~3) was lower in ERD(2) group compared to ER(2) group (P < 0.05). The SBP at T(1) and T(3) were higher in ER(2) and ERD(2) group than in PR(2) group (P < 0.05). The DBP in ER(1) and ERD(1) group were higher at T(1) compared to PR(1) group (P < 0.05). The dosage of etomidate was significantly lower in ERD(1) group and ERD(2) group than in ER(1) group and ER(2) group (P < 0.05), respectively. The administration of dexmedetomidine combined with etomidate can attenuate the inhibition of etomidate on adrenocortical function in elderly patients and maintain intraoperative hemodynamic stability.