Adrenocortical function and outcome in critically ill patients

Objective

To assess the value of measuring adrenocortical function parameters in predicting outcome and mortality in critically ill patients.

Methods

Prospective clinical investigation with no therapeutic interventions in which were involved 63 consecutive patients admitted to the medical intensive care unit. Adrenocortical function was assessed by plasma cortisol and dehydroepiandrosterone sulfate (DHEA-S) levels on days 1, 3 and 7 and by the short synthetic ACTH stimulation test performed within 24 h of admission to the ICU. Individual variables were compared with severity scores, biological data and outcome. Statistical analysis: Student test, Mann-Whitney U test P < 0.05 was considered significant.

Results

Mean age 57 ± 19, APACHE II score at admission 20 ± 7, there were 37 (54.4%) septic patients. In hospital mortality rate 43.1%. Busal cortisol concentrations were increased with a mean value of 32.22 ± 19.3. Of overall cortisol determinations 94% were above 15 μg/dl. No correlations were found between these levels and factors such as APACHE II score, MODS score, haemodynamic measurements, amount of vassopresor support neither mortality. Cortisol levels on day 3 correlated with the use of dopamine (p:.03) and noradrenaline (p:.02) and were able to discriminate between survivors and non-survivors (median 13.65 vs 30.3, P < 0.005). The response to ACTII test had a mean value of 45.4 ± 18 with a mean difference with basal cortisol levels of 13.85 ± 10. No one of these measurements did show any relationship with clinical variables of outcome. Global basal concentrations of DHEA-S were lower (median 65, range: 1–447) than normal values (r: 120–240) and showed a marked tendency to decrease over the time (median 30 on days 3 and 7). Levels of DHEA-S on day 1 showed a weak correlation with APACHE II score (r. 0.33; P = 0.039) DHE-S on day 3 was much higher in survivors than in non-survivors patients (median 41.1 vs 20.7; P = 0.002).

Two patterns of adrenocortical function were identified. In surviving patients plasma cortisol levels were normal or increased and gradually decreased whereas levels of DHEA-S showed an opposite pattern. In the other hand, in non-survivors cortisol levels persisted elevated and DHEA-S decreased. The ratio DHEA-S/cortisol on day 3 was a good indicator of final outcome with a median value of 1.92 in survivors and 0.79 in non-survivors (P = 0.009).

Conclusion

In critically ill patients the basal adrenocortical function is characterized by high plasma cortisol and low DHEA-S levels. The DHEA-S/cortisol plasma concentrations on day 3 might be used as a prognostic marker for identifying final outcome in this population.