Eosinophilia: An early marker of adrenal insufficiencyin critically ill patients with septic shock?

Adequate adrenocortical function is essential to survive critical illness. The goal of this study was to determine whether eosinophilia could serve as a useful and early marker of adrenal insufficiency in critically ill patients with severe septic shock. During a 1-year period, we prospectively studied 294 ICU patients.16 patients (5.4% of ICU admissions) with eosinophilia more than 3% of the white blood cell count and septic shock unresponsive to adequate fluid and vasopressor therapy, were included. A high dose (250 mcg i.v) corticotropin stimulation test was performed. Eosinophilia (>3%) was diagnosed in 16 patients with vasopressor-unresponsive septic shock. Eosinophilia was present 1.9±0.9d (range 8-96h) before the onset of septic shock. 11/16 patients failed to respond to corticotropin stimulation test above the critical level of 9 mcg/dL rise and 2/16 had baseline cortisol concentration <10 mcg/dL. Baseline cortisol level, maximal cortisol increase post-corticotropin administration and Eosinophils count (%) were higher in survivors (p≤0.05). A hydrocortisone infusion (300mg/d) treatment resulted in haemodynamic improvement in 12 of 16 patients (75%). The 28-day mortality (following the onset of septic shock) was 43.7%. Relative eosinophilia may be considered as a useful and early bioassay for adrenocortical function assessment in critically ill patients with septic shock and assumed adrenocortical depression.