A 56-year-old woman is admitted to the ICU with septic shock from community-acquired pneumonia. She is intubated with etomidate and rocuronium, fluid resuscitated with 30 mL/kg of normal saline and treated with cefepime and levofloxacin. Despite treatment she becomes increasingly hypotensive requiring escalating vasopressor doses. A random cortisol level is sent to test for adrenal insufficiency.
Which of the following levels would be the lowest indicating an ADEQUATE adrenal response?A. 4 µg/dL
Correct Answer: C
Cortisol secretion normally exhibits a diurnal variation, with peak concentrations in the morning (around 8:00 am) correlating with waking and accelerating activity after sleeping. For outpatient testing, early morning “peak” measurements are typically used for diagnosing adrenal insufficiency. However, the timing of such testing is not always appropriate in the critical care setting. Providers can measure “random” cortisol levels as a gross test of hypothalamic-pituitary-adrenal axis integrity. Values below an established threshold indicate adrenal insufficiency that would respond to steroid administration. For critically ill patients, a lower bound of 20 to 25 µg/dL (depending on desired diagnostic sensitivity) is considered an adequate random cortisol. A level less than 5 µg/dL constitutes adrenal insufficiency with 100% specificity. In unstressed individuals (ie outpatients) a random cortisol >15 µg/dL is sufficient to rule out adrenal insufficiency. A level of 50 µg/dL would be considered adequate response in a critically ill patient.