title: Adrenal insufficiency in hemodynamically unstable neonates after open-heart surgery.
abstract: OBJECTIVE
  To investigate if the low dose (1 µg) ACTH stimulation test appropriately assesses adrenal responsiveness in neonates undergoing open-heart surgery requiring cardio-pulmonary bypass.
  
  
  METHODS
  In this retrospective study, adrenal axis response was assessed on the first post-operative day with the low-dose (1 µg) ACTH stimulation test. Age, gender, weight, RACHS category, inotrope score, and baseline and post-stimulation cortisol levels were collected. The association between basal serum cortisol levels and degree of response to the ACTH stimulation test was also investigated.
  
  
  METHODS
  Tertiary care referral center.
  
  
  METHODS
  Twenty-one neonates who underwent neonatal cardiac surgery on cardiopulmonary bypass and underwent an ACTH stimulation test. Interventions.  Hydrocortisone 50 mg/m(2) bolus in four divided doses daily.
  
  
  METHODS
  Response to the low dose (1 µg) ACTH stimulation was assessed.
  
  
  RESULTS
  All neonates with hemodynamic instability in the immediate post-operative period had low basal serum cortisol levels. The basal mean serum cortisol level for the 21 patients who underwent the low dose ACTH stimulation test was 7.3 µg/dL (median 2.2, range 0.7-42). The mean serum cortisol level increased after the ACTH stimulation test in the 21 patients to 39.6 µg/dL (median 38, range 79-17). The mean inotrope score in the first 24 hours after surgery was 24 (median 17.5, range 7-76.5) and decreased to 17 (median 14, range 5-52.3) 24-48 hours after surgery. At 48 hours post-surgery the mean arterial pressure in the groups with a serum cortisol increase after ACTH stimulation (<30 µg/dL vs. >50 µg/dL) was significantly different (P value 0.026).
  
  
  CONCLUSIONS
  The low dose (1 µg) ACTH stimulation test is a valid test to assess adrenal responsiveness among neonates after open heart surgery requiring CPB. Traditionally used basal serum cortisol level cutoff of <20 µg/dL used to define relative adrenal insufficiency may not be applicable in neonates undergoing open heart surgery on CPB thus indicating the need for re-defining adrenal insufficiency in this patient population.
authors.affiliation: Pediatric Critical Care Medicine, College of Medicine, University of Arkansas Medical Sciences, Arkansas Children's Hospital, Little Rock, Ark 72202, USA. garciaxiomara@uams.edu
authors.forename: Xiomara
authors.initials: X
authors.lastname: Garcia
authors.forename: Adnan T
authors.initials: AT
authors.lastname: Bhutta
authors.forename: Umesh
authors.initials: U
authors.lastname: Dyamenahalli
authors.forename: Michiaki
authors.initials: M
authors.lastname: Imamura
authors.forename: Robert D B
authors.initials: RD
authors.lastname: Jaquiss
authors.forename: Parthak
authors.initials: P
authors.lastname: Prodhan
mesh_terms: D000304:Adrenal Cortex Function Tests; D000309:Adrenal Insufficiency / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology; D000324:Adrenocorticotropic Hormone; D001131:Arkansas; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D016638:Critical Illness; D005260:Female; D006330:Heart Defects, Congenital / Q000150:complications / Q000601:surgery*; D006439:Hemodynamics; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000627:therapeutic use; D007231:Infant, Newborn; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone