Prevalence of occult adrenal insufficiency and the prognostic value of a short corticotropin stimulation test in patients with septic shock

BACKGROUND: Corticosteroid insufficiency in acute illness can be difficult to discern clinically. Occult adrenal insufficiency (i.e., Δmax ≤9 μg/dL) after corticotropin may be associated with a high mortality rate. OBJECTIVE: To assess the prevalence of occult adrenal insufficiency and the prognostic value of short corticotropin stimulation test in patients with septic shock. MATERIALS AND METHODS: A total of 30 consecutive patients admitted in the adult intensive care unit of the Sheri Kashmir Institute of Medical Sciences who met the clinical criteria for septic shock were prospectively enrolled in the study. A low dose (1 μg) short corticotropin stimulation test was performed; blood samples were taken before the injection (T0) and 30 (T30) and 60 (T60) minutes afterward. RESULTS: The prevalence of occult adrenal insufficiency was 57%. The 28-day mortality rate was 60% and the median time to death was 12 days. The following seven variables remained independently associated with death: organ system failure scores, simplified acute physiology score II score, mean arterial pressure, low platelet count, PaO(2):FIO(2), random baseline cortisol (T0) >34 μg/dL, and maximum variation after test (Δmax) of ≤9 μg/dL. Three different mortality patterns were observed: (I) low (T0 ≤34 μg/dL and Δmax >9 μg/dL; a 28-day mortality rate of 33%),(II) intermediate (T0 >34 μg/dL and Δmax >9 μg/dL or T0 ≤34 μg/dL and Δmax ≤9 μg/dL; a 28-day mortality rate of 71%), and (III) high (T0 >34 μg/dL and Δmax ≤9 μg/dL; a 28-day mortality rate of 82%). CONCLUSION: A short corticotropin test using low-dose corticotropin (1 μg) has a good prognostic value. High basal cortisol and a low increase in cortisol on corticotropin stimulation test are predictors of a poor outcome in patients with septic shock.