Pediatr Crit Care Me
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Pediatr Crit Care Me · Mar 2011
The effect of cardiopulmonary bypass on the hypothalamic-pituitary-adrenal axis in children.
The pathophysiology of low-cardiac-output syndrome after cardiopulmonary bypass is incompletely understood, but adrenal insufficiency has been proposed as a contributing factor. Our objective was to examine the effect of cardiopulmonary bypass on the hypothalamic-pituitary-adrenal axis, specifically adrenal responsiveness, in patients with congenital heart disease undergoing surgery. We hoped to correlate bound and free cortisol values both postoperatively and after adrenocorticotropic hormone stimulation, in conjunction with corticosteroid-binding globulin levels, with clinical outcomes to determine whether these variables are sensitive indicators of adrenal axis function. ⋯ Although hypothalamic-pituitary-adrenal axis dysfunction may play a role in low-cardiac-output syndrome among children undergoing congenital heart surgery, using total cortisol to investigate such dysfunction may be inadequate. Decreased corticosteroid-binding globulin levels and marked free cortisol increase after stimulation were associated with worse clinical outcomes. Further investigation into the cortisol-corticosteroid-binding globulin complex and its relationship to free cortisol is necessary to examine the problem of adrenal insufficiency from a more integrated perspective.