The effect of cardiopulmonary bypass on the hypothalamic-pituitary-adrenal axis in children

Eric L Wald, Elizabeth Preze, Jens C. Eickhoff, Carl L Backer

Research output: Contribution to journalArticlepeer-review

31 Scopus citations

Abstract

Objective: 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. Design: Prospective cohort study. Setting: A children's hospital. Patients: Fifty-two pediatric heart surgery patients undergoing cardiopulmonary bypass. Intervention: Total cortisol and corticosteroid-binding globulin levels were obtained pre-and postoperatively and after a postoperative cosyntropin stimulation test. Free cortisol was calculated by using Coolens' method. Measurements And Main Results: Nine of 51 (17.6%) patients had low (<3 μg/dL) baseline postoperative total cortisol, median 1.6 μg/dL, yet all nine had normal (>9 μg/dL increase from postoperative baseline) stimulation tests. The corticosteroid-binding globulin levels declined from a mean of 29 mg/L preoperatively to 22 mg/L postoperatively (p <.001) and showed marked variability between patients. Patients with free cortisol δ >6 μg/dL (n = 18, 35%) had a longer length of stay (median 9 vs. 5 days; p =.002), higher inotrope scores (median 13.3 vs. 10.8; p =.05), greater fluid requirement (median 73.5 vs. 55.6 mL/kg; p =.007), and longer ventilator times (median 41.5 vs. 20 hrs; p =.013). Conclusions: 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.

Original languageEnglish (US)
Pages (from-to)190-196
Number of pages7
JournalPediatric Critical Care Medicine
Volume12
Issue number2
DOIs
StatePublished - Jan 1 2011

Keywords

  • adrenal insufficiency
  • cardiopulmonary bypass
  • congenital heart surgery
  • corticosteroid-binding globulin
  • free cortisol

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Critical Care and Intensive Care Medicine

Fingerprint Dive into the research topics of 'The effect of cardiopulmonary bypass on the hypothalamic-pituitary-adrenal axis in children'. Together they form a unique fingerprint.

Cite this