[Effect of etomidate and thiopental on ACTH and cortisol levels in serum. A prospective controlled comparative study in healthy probands].

A prospective controlled trial was carried out to determine the influence of etomidate and thiopentone on serum levels of cortisol and plasma levels of adrenocorticotrophic hormone (ACTH). There were two groups of nine healthy male volunteers: one group was given 0.3 mg/kg body wt. etomidate and the other 4 mg/kg body wt. thiopentone intravenously as a bolus. The hormone levels were measured before and every 30 min after injection of the anaesthetic over a period of 5 h. After thiopentone, cortisol levels dropped from a mean value of 13.2 micrograms/dl to a minimum of 9.0 micrograms/dl after 90 min and fluctuated between 9.2 and 10.9 micrograms/dl until the end of the experiment. Etomidate induced a more pronounced decrease in cortisol levels (from the 90th min the differences to the levels after thiopentone were statistically significant) from 13.9 micrograms/dl to a minimum of 5.0 micrograms/dl after 150 min. After 300 min cortisol levels had recovered only to 7.7 micrograms/dl. Plasma levels of ACTH were also different in the two groups. After thiopentone they decreased from 26.1 pg/ml to 18.2 pg/ml after 30 min, then increased to 30 pg/ml after 300 min. After etomidate, ACTH levels were as high at 30 min as before the injection and increased continuously to 67.1 pg/ml by the end of the experiment; from the 150th min on, the differences to the ACTH levels after thiopentone were statistically significant. We conclude from these hormone levels that a single intravenous bolus injection of thiopentone induces a slight but statistically significant and ACTH-independent decrease in adrenal cortisol secretion in healthy volunteers not stressed by an operation.(ABSTRACT TRUNCATED AT 250 WORDS)