title: Total and free cortisol responses and their relation to outcomes after cardiopulmonary bypass in infants.
abstract: Hypothalamic-pituitary-adrenal (HPA) axis dysfunction may be partially responsible for the hemodynamic instability experienced by infants after cardiopulmonary bypass (CPB). We report the full spectrum of the HPA response surrounding CPB for infant congenital cardiac surgery.
  
  
  
  We enrolled 84 infants who received 1 mg/kg of dexamethasone before initiation of CPB. Total cortisol (TC), free cortisol (FC), adrenocorticotropic hormone (ACTH), and corticosteroid-binding globulin (CBG) were measured at 3 time points: immediately before CPB (TP1), on intensive care unit arrival (TP2), and at 24 hours after surgery (TP3). A 1-μg ACTH stimulation test was performed at each time point to evaluate adrenal responsiveness.
  
  
  
  Sixty-eight infants completed all study procedures. Levels of TC, FC, CBG, and ACTH decreased significantly between the preoperative and 24-hour postoperative measurements. There were no significant associations between preoperative FC responses and clinical outcomes after adjusting for weight and Risk-Adjusted Scores for Congenital Heart Surgery. Infants with subnormal TC responses to ACTH stimulation (<9 μg/dL) at TP2 had greater fluid requirements (P < .001) and greater chest tube output (P < .001) during the first 24 hours, as well as longer length of stay (LOS) (P = .007). Except for LOS, these differences persisted for infants with subnormal stimulation tests at TP3.
  
  
  
  We observed a significant decline in all aspects of the HPA axis throughout the first 24 hours after infant CPB. TC and FC levels were not associated with clinical outcomes. Subnormal (Δ <9 μg/dL) TC response to cosyntropin stimulation during the postoperative period was associated with increased fluid resuscitation and greater LOS.
authors.affiliation: Divisions of Critical Care and Cardiology, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, Ill. Electronic address: Ewald@luriechildrens.org.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Wald
authors.affiliation: Division of Cardiovascular-Thoracic Surgery, Department of Surgery, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, Ill.
authors.forename: Carl L
authors.initials: CL
authors.lastname: Backer
authors.affiliation: Division of Cardiothoracic Surgery, Mayo Clinic, Rochester, Minn.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Dearani
authors.affiliation: Division of Statistics, Mayo Clinic, Rochester, Minn.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, Minn.
authors.forename: William C
authors.initials: WC
authors.lastname: Oliver
authors.affiliation: Division of Pediatric Critical Care, Department of Pediatrics and Adolescent Medicine, Mayo Clinic, Rochester, Minn.
authors.forename: Sheri S
authors.initials: SS
authors.lastname: Crow
mesh_terms: D000302:Adrenal Cortex / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D000304:Adrenal Cortex Function Tests; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D002675:Child, Preschool; D003366:Cosyntropin / Q000008:administration & dosage; D003907:Dexamethasone / Q000008:administration & dosage; D005260:Female; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D011446:Prospective Studies; D013997:Time Factors; D014156:Transcortin / Q000378:metabolism; D016896:Treatment Outcome; D014481:United States
chemical_list: D015415:Biomarkers; C534935:SERPINA6 protein, human; D003366:Cosyntropin; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D014156:Transcortin; D006854:Hydrocortisone
keywords: adrenal insufficiency; cardiopulmonary bypass; clinical outcomes; congenital heart surgery; cortisol