Absolute and relative adrenal insufficiency in children with septic shock

Objective: Corticosteroid replacement improves outcome in adults with relative adrenal insufficiency and catecholamine-resistant septic shock. We evaluated the relationship of absolute and relative adrenal insufficiency to catecholamine-resistant septic shock in children. Design. Prospective cohort study. Setting. University hospital pediatric intensive care unit in Brazil. Patients. Fifty-seven children with septic shock. Children with HIV infection, those with a history of adrenal insufficiency, and those submitted to any steroid therapy or etomidate within the week before diagnosis of septic shock were excluded. Interventions: None. Measurements and Main Results., A short corticotropin test (250 mu g) was performed, and cortisol levels were measured at baseline and 30 and 60 mins posttest. Adrenal insufficiency was defined by a response <= 9 mu g/dL. Absolute adrenal insufficiency was further defined by a baseline cortisol < 20 mu g/dL and relative adrenal insufficiency by a baseline cortisol > 20 mu g/dL. Absolute adrenal insufficiency was observed in 18% of children, all of whom had catecholamine-resistant shock. Relative adrenal insufficiency was observed in 26% of children, of whom 80% had catecholamine-resistant and 20% had dopamine/dobutamine-responsive shock. All children with fluid-responsive shock had a cortisol response > 9 mu g/dL. Children with adrenal insufficiency had an increased risk of catecholamine-resistant shock (relative risk, 1.88; 95% confidence interval, 1.26-2.79). However, mortality was independently predicted by chronic illness or multiple organ failure (p <.05), not adrenal insufficiency. Conclusions: Absolute and relative adrenal insufficiency is common in children with catecholamine-resistant shock and absent in children with fluid-responsive shock. Studies are warranted to determine whether corticosterold therapy has a survival benefit in children with relative adrenal insufficiency and catecholamine-resistant septic shock.