The Changes in Cortisol Levels during Cardiac Surgery: A Randomized Double-Blinded Study between Two Induction Agents Etomidate and Thiopentone

Abstract

Objective: To study the changes in cortisol levels during and after cardiac surgery after an inductive dose of either etomidate or thiopentone and their consequences.

Material and method: A prospective, randomized, double-blinded study was conducted in 26 patients undergoing elective cardiac surgery. They received either etomidate or thiopentone for induction. Serum cortisol levels were measured preoperatively, and then at 2-, 4-, 8-, and 24-hour All of the patients received standard anesthesia and surgery. The data also included patients perioperative management and outcome.

Results: There is no difference in patients' characteristics. The baseline plasma morning cortisols in the two groups were comparable (11.7 ± 7.5 mcg/dL in etomidate group vs. 12.0 ± 8.2 mcg/dL in thiopentone group). In both groups, during surgery, the cortisol levels rose to higher levels and reached peak levels at four to eight hours and related to surgical stress. At all times, the etomidate group had lower cortisol levels but only at 8-hour the etomidate group had significantly lower cortisol level (39.9 ± 14.2 vs. 65.9 ± 20.0 mcg/dL). At 24 hours, in both groups, cortisol levels were lower than at 8-hour but did not return to normal baseline levels. There were no differences in the dose of inotropic use and ICU stay. However surprisingly the etomidate group had shorter hospital stay.

Conclusion: A single dose of etomidate usedfor induction in elective cardiac patients can partially and reversibly inhibit of the cortisol synthesis for, at least, 24 hours, but its association with any hemodynamic consequences cannot be concluded.

Registration: ClinicalTrials.gov as NCT01495949.