Background: Patients with obstructive jaundice have increased sensitivity to inhaled anesthetics. In rodent brain, bilirubin can enhance γ-aminobutyric acid A/glycinergic synaptic transmission. Etomidate is a nonbarbiturate hypnotic that induces sedation through γ-aminobutyric acid A receptors in the central nervous system. We tested the hypothesis that patients with obstructive jaundice have an altered sensitivity to etomidate.
Methods: The study design was a comparison of etomidate requirements to reach a Bispectral Index of 50 in patients with obstructive jaundice versus patients with chronic cholelithiasis and normal bilirubin levels. Etomidate was infused at 30 μg/kg/min until this end point was reached.
Results: The etomidate requirement in the obstructive jaundice group was lower than that in the control group (150±46 μg/kg vs 206±74 μg/kg, P=0.007). The average decrease in etomidate requirement was 56 μg/kg (95% confidence interval: 16-96 μg/kg). In addition, we found a significant negative correlation between serum total bilirubin and etomidate requirement with Pearson r of -0.545, and 95% confidence interval for r value (-0.791 to -0.148). All subjects were hemodynamically stable during the study.
Conclusions: Etomidate requirements to reach a level of anesthesia defined by a Bispectral Index of 50 are reduced in patients with obstructive jaundice.