A comparative study of two infusion doses of etomidate for induction vs standard induction dose of etomidate

In the search for the ideal intravenous induction drug, etomidate is in the forefront as it provides haemodynamic stability without compromising on the end point of induction. It has been established that slowing the rate of infusion of propofol decreases the dose required for induction. Even though etomidate provides good haemodynamic stability while inducing, there is concern about its cortisol suppressive function. This study has been designed, with entropy guidance, to establish whether induction by slowing the rate of infusion of etomidate will reduce the dose required for induction and simultaneously assess whether adverse effects are reduced.

Ninety-six patients were randomly allocated into three groups based on etomidate dose. Etomidate dose was given till both loss of eyelash reflex and entropy50 was achieved. Total dose of etomidate consumed, time taken for loss of eye lash reflex and time to reach entropy50 were recorded. Cortisol levels were measured at different intervals.

We observed that slowing the rate of infusion reduced the dose of etomidate for induction; however, it prolonged the time for induction of anaesthesia. Cortisol levels were suppressed in the first 6 h after induction in all three groups, but remained within normal limits and reached to pre induction levels by 24 h.

The slower the rate of infusion, the lesser the dose of etomidate used for induction, but prolongs the time taken to reach the end point of induction. Incidence of myoclonus might be avoided by infusing etomidate for induction at a lower rate.

Clinical Trials Registry of India, CTRI/2016/04/006879, www.ctri.nic.in/.