A Single Adrenocorticotropic Hormone Stimulation Test Does Not Reveal Adrenal Insufficiency in Septic Shock

In Brief The diagnosis of adrenocortical insufficiency in critically ill patients is complex. The adrenocorticotropic hormone (ACTH) stimulation test is a widely accepted method for assessing the adequacy of adrenal function in intensive care units, but it is possible that there may be wide variations in responses to the test over a short period of time. In this prospective study, we investigated the reproducibility of the ACTH stimulation test in 20 patients with sepsis, in 20 patients with septic shock, and in 20 critically ill patients without sepsis. Two consecutive ACTH stimulation tests were performed within 24 h after intensive care unit admission or at the onset of sepsis. In patients without sepsis there was good correlation between ACTH responses on days 1 and 2 (Pearson's correlation coefficient, 0.689; P = 0.001). In contrast, in patients with septic shock no correlation was observed between the two ACTH responses (Pearson's correlation coefficient, 0.401; P = 0.080). We conclude that the results of the ACTH stimulation tests are poorly reproducible in septic shock and a single ACTH stimulation test may not be the best method to diagnose adrenal insufficiency in these patients. IMPLICATIONS: In this prospective study two consecutive adrenocorticotropic hormone (ACTH) stimulation tests were performed in 60 critically ill patients. In a subgroup of septic shock patients the test results were poorly reproducible. This suggests that the ACTH stimulation test is not a sensitive method to diagnose adrenal insufficiency in septic shock patients.