Prevention of adrenal crisis: cortisol responses to major stress compared to stress dose hydrocortisone delivery.

CONTEXT: Patients with adrenal insufficiency require increased hydrocortisone cover during major stress to avoid life-threatening adrenal crisis. However, current treatment recommendations are not evidence-based. OBJECTIVE: To identify the most appropriate mode of hydrocortisone delivery in patients with adrenal insufficiency exposed to major stress. DESIGN AND PARTICIPANTS: Cross-sectional study: 122 unstressed healthy subjects and 288 subjects exposed to different stressors (major trauma [N=83], sepsis [N=100], and combat stress [N=105]). Longitudinal study: 22 patients with preserved adrenal function undergoing elective surgery. Pharmacokinetic study: 10 patients with primary adrenal insufficiency undergoing administration of 200mg hydrocortisone over 24 hours in four different delivery modes (continuous intravenous infusion; six-hourly oral, intramuscular or intravenous bolus administration). MAIN OUTCOME MEASURE: We measured total serum cortisol and cortisone, free serum cortisol and urinary glucocorticoid metabolite excretion by mass spectrometry. Linear pharmacokinetic modelling was used to determine the most appropriate mode and dose of hydrocortisone administration in patients with adrenal insufficiency exposed to major stress. RESULTS: Serum cortisol was increased in all stress conditions, with the highest values observed in surgery and sepsis. Continuous intravenous hydrocortisone was the only administration mode persistently achieving median cortisol concentrations in the range observed during major stress. Linear pharmacokinetic modelling identified continuous intravenous infusion of 200mg hydrocortisone over 24 hours, preceded by an initial bolus of 50-100mg hydrocortisone, as best suited for maintaining cortisol concentrations in the required range. CONCLUSIONS: Continuous intravenous hydrocortisone infusion should be favored over intermittent bolus administration in the prevention and treatment of adrenal crisis during major stress.