Adrenal insufficiency in hemodynamically unstable neonates after open-heart surgery

Congenit Heart Dis. 2010 Sep-Oct;5(5):422-9. doi: 10.1111/j.1747-0803.2010.00447.x.

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.

Design: 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.

Setting: Tertiary care referral center.

Patients: 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.

Outcome measures: 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.

MeSH terms

  • Adrenal Cortex Function Tests
  • Adrenal Insufficiency / complications*
  • Adrenal Insufficiency / diagnosis
  • Adrenal Insufficiency / drug therapy
  • Adrenal Insufficiency / physiopathology
  • Adrenocorticotropic Hormone
  • Arkansas
  • Biomarkers / blood
  • Cardiac Surgical Procedures* / adverse effects
  • Cardiopulmonary Bypass* / adverse effects
  • Critical Illness
  • Female
  • Heart Defects, Congenital / complications
  • Heart Defects, Congenital / surgery*
  • Hemodynamics*
  • Humans
  • Hydrocortisone / blood
  • Hydrocortisone / therapeutic use
  • Infant, Newborn
  • Male
  • Predictive Value of Tests
  • Reproducibility of Results
  • Retrospective Studies
  • Time Factors
  • Treatment Outcome

Substances

  • Biomarkers
  • Adrenocorticotropic Hormone
  • Hydrocortisone