Hypothalamic-pituitary-adrenal axis response to the severity of illness in non-critically ill patients: does relative corticosteroid insufficiency exist?

OBJECTIVE: Relative corticosteroid insufficiency may be common in critically ill patients and is associated with a poor outcome; however, the response of the hypothalamic-pituitary-adrenal (HPA) axis in nursed patients is not known. Our aim was to evaluate the response of HPA axis to the severity of illness in non-critically ill nursed (NCIN) patients and the clinical outcome. SUBJECTS AND METHODS: Fifty-six nursed patients who were divided into four groups (stroke, mild disease, sepsis and severe sepsis) as well as a control group (n=15) were studied. At admission (day 1), cortisol and ACTH were measured and a low-dose (1 microg) corticotrophin test was performed, followed 2 h later by a standard-dose (250 microg) corticotrophin test. Diurnal variation of cortisol was obtained on day 2. A second identical set of low-dose and standard-dose corticotrophin tests were performed on day 5 or 6 (recovery phase). Results In patients with stroke and severe sepsis, cortisol had the highest values and its diurnal variation was abolished. Dissociation of ACTH and cortisol was found in all patients. The Delta(max) of cortisol after the 1-microg corticotrophin test did not differ among the groups, while after the 250-microg corticotrophin test, it was borderline higher in controls. The ratio of responders (Delta(max) of cortisol >or=9 microg/dl) to non-responders after 1- or 250-microg corticotrophin test did not differ among patients and controls. All patients had a good outcome without glucocorticoid treatment.
CONCLUSIONS: Depending on the severity of illness, mild alterations in the HPA axis occurred. However, relative corticosteroid insufficiency was not confirmed in NCIN patients.