The Variation in Plasma Cortisol Levels in Response to Anesthetic Induction with Etomidate or Ketamine in Children Undergoing Intracardiac Repair of Tetralogy of Fallot on Cardiopulmonary Bypass

Objective: To compare the effect of a single induction dose of etomidate or ketamine on plasma cortisol levels in children with Tetralogy of Fallot (TOF) undergoing intra-cardiac repair on cardiopulmonary bypass (CPB). Design: A prospective randomized trial. Setting: Cardiac center of a tertiary care hospital. Participants: Thirty children with TOF undergoing intra-cardiac repair on CPB. Interventions: After random allocation of the children into two groups, the children either received etomidate 0.2 mg/kg or ketamine 2 mg/kg intravenously for anesthetic induction along with fentanyl 2 mcg/kg and midazolam 100 mcg/kg. Endotracheal intubation was accomplished with rocuronium bromide in the dose of 1 mg/kg. Anesthesia was maintained with sevoflurane in air-oxygen, titrated to response and supplemental vecuronium bromide for muscle relaxation, fentanyl chloride for pain relief. Serum cortisol was measured on three occasions, at preinduction, at the end of surgery and at 24 hours postoperatively. Measurements and Main Results: Baseline plasma cortisol (Normal 5 - 25 mcg/dl) in the etomidate group (19.91 ± 3.51 mcg/dl) decreased significantly at the end of surgery (5.78 ± 2.0 mcg/dl) and rose to significantly higher than baseline values at 24 hours (27.31 ± 8.30 mcg/dl). The baseline cortisol levels in the ketamine group (20.91 ± 3.19 mcg/dl) increased significantly at the end of surgery (44.02 ± 5.49 mcg/dl) and remained significantly higher than baseline at 24hours (45.93 ± 3.05 mcg/dl). Plasma cortisol levels in the etomidate group at end of surgery, and at 24 hours post-operatively, were significantly lower than the ketamine group. Conclusions: This study shows that etomidate is a suitable and safe agent for suppression of the increase in serum cortisol associated with the use of CPB in children with TOF undergoing intra-cardiac repair.