Risk factors of relative adrenocortical deficiency in intensive care patients needing mechanical ventilation.

OBJECTIVE

To study the factors associated with relative adrenocortical deficiency in mechanically ventilated, critically ill patients.

DESIGN AND SETTING

Prospective observational study in a multidisciplinary ICU of a university-affiliated teaching hospital.

PATIENTS

Sixty-two consecutive, acutely ill patients needing mechanical ventilation for more than 24 h.

MEASUREMENTS AND RESULTS

A high-dose short corticotropin test 24 h after endotracheal intubation. Relative adrenocortical deficiency ("nonresponder" group of patients) was defined by a rise in cortisol less than 90 microg/l after stimulation. Twenty-seven patients were classified as nonresponders and 35 as responders. On univariate analysis nonresponders were more often men, had lower mean arterial pressure, required vasoactive agents more often, had lower creatinine clearance, higher SAPS II, higher organ dysfunction scores, and received etomidate as a single bolus for endotracheal intubation more often than responders. On multivariate analysis, only etomidate administration was related to relative adrenocortical deficiency (OR 12.21; 95% CI 2.99-49.74) while female gender was protective (OR 0.13; 95% CI 0.03-0.57).

CONCLUSIONS

A single bolus infusion of etomidate could be a major risk factor for the development of relative adrenocortical deficiency in ICU patients for at least 24 h after administration. Female gender is an independent protective factor.