Prognostic Implication of Adrenocortical Response during the Course of Critical Illness

BACKGROUND: Critical illness-related corticosteroid insufficiency (CIRCI) and adrenocorticotropic hormone (ACTH)-cortisol dissociation are hormonal conditions frequently observed in patients in the intensive care unit (ICU). The aim of this study was to evaluate the association between ACTH-cortisol dissociation and clinical outcomes of critically ill patients. METHODS: We retrospectively reviewed the medical records of 94 ICU patients who underwent two rapid cosyntropin tests during hospital admission and compared the clinical aspects of patients with and without ACTH-cortisol dissociation. ACTH-cortisol dissociation was defined as plasma ACTH and serum cortisol concentrations of <22 pmol/L and >600 nmol/L, respectively. RESULTS: Dissociation was present in 30 of the 94 patients (31.9%). Patients with ACTH-cortisol dissociation in the initial test had significantly higher hospital mortality rate than those in the control group (55% vs. 25.7%, P=0.013) There was no difference in hospital mortality between patients classified as having CIRCI and those who were not. In multivariate adjusted Cox regression analysis, the mortality risk was higher in the group with ACTH-cortisol dissociation (hazard ratio, 2.98; 95% confidence interval, 1.34 to 6.63; P=0.007). Patients with dissociation in two consecutive stimulation tests showed the highest hospital mortality rate among groups classified according to stimulation test results (100% vs. 31.3%). CONCLUSIONS: The hospital mortality was higher in ICU patients diagnosed with ACTH-cortisol dissociation. It is clinically feasible to evaluate the presence of ACTH-cortisol dissociation by analyzing rapid ACTH stimulation test results in critically ill patients.