Etomidate adverse effects

Effects on respiration are similar to those of thiopental at usual anesthetic doses. However, propofol causes a marked decrease in systemic blood pressure during induction of anesthesia, primarily through decreased peripheral resistance. In addition, propofol has greater negative inotropic effects on the heart than etomidate and thiopental. Apnea and pain at the site of injection are common adverse effects of bolus administration. Muscle movements, hypotonus, and (rarely) tremors have also been reported following its use. Clinical infections due to bacterial contamination of the propofol emulsion have led to the addition of antimicrobial adjuvants (eg, ethylenediaminetetraacetic acid and metabisulfite). 

In 104 patients, the freqnency of pain on injection of etomidate was 32-53% and was severe in 5-20% of patients (5). The freqnency of involnntary movements was 15-35%. The freqnency of both pain and involuntary muscle movements was least when fentanyl 2.5 pg/kg was given before etomidate. There was no significant relation between pain and muscle movement. A medium-chain triglyceride and soya bean emulsion formulation has been used for anesthetic induction, in an attempt to reduce the unwanted adverse effects of pain on injection and thrombophlebitis (6). 

The main adverse effects with etomidate are pain on injection and muscle twitching during induction, both of which can be reduced by using an opioid analgesic. It also causes suppression of the adrenal cortex. 

Kosarek L, Hart SR, Schultz L, DiGiovanni N. Increase in venous complications associated with etomidate use during a propofol shortage an example of clinically important adverse effects related to dmg substitution. Ochsner J 2011 11(2) 143-6. 

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