Lesson of the Week: Adrenocortical failure in intensive care

Diagnosis of acute adrenocortical failure in patients admitted to intensive care units is difficult as the clinical features are non-specific and may mimic those of other conditions. We report on a patient in whom the initial diagnosis of septic shock had to be amended later to acute adrenocortical failure. The criteria for laboratory diagnosis of adrenocortical failure in patients in intensive care may need to be modified as adrenocortical function is altered in patients with severe organ dysfunction. A 45 year old woman with myasthenia gravis was admitted to intensive care breathless and disoriented. She had a fever, with a temperature of 38°C, and had an arterial pressure of 60/40 mm Hg. Her serum concentration of sodium was 131 mmol/l and of potassium was 4.4 mmol/l. A full blood count showed a haemoglobin concentration of 148 g/l and leukocytosis, with a cell count of 18.9 x 109/l. Despite fluid resuscitation with 2000 ml 0.9% saline and 1000 ml gelatin (Haemaccel) she remained hypotensive. A pulmonary artery catheter was inserted, and the haemodynamic profile showed a normal mean pulmonary artery pressure of 15 mm Hg and cardiac index of 3.8 l/min/m2 but a low systemic vascular resistance index of 971 dyne.sec/cm5/m2 and left ventricular stroke work index of 20.7 g/m2/beat. A presumptive diagnosis of septic shock …