Adrenal insufficiency in neonates undergoing cardiopulmonary bypass and postoperative hypothalamic-pituitary-adrenal function after prophylactic glucocorticoids.

OBJECTIVES

Determine incidence of preoperative adrenal insufficiency in neonates >35 weeks gestation with congenital heart disease undergoing cardiothoracic surgery with bypass and effects of prophylactic methylprednisolone on postoperative hypothalamic-pituitary-adrenal function and hemodynamic stability.

DESIGN

Prospective observational study in 36 neonates with preoperative adrenocorticotrophic hormone stimulation tests and serial total cortisol and adrenocorticotrophic hormone measurements before and after surgery. Data analyses: analysis of variance and regression.

RESULTS

Baseline circulating adrenocorticotrophic hormone and cortisol were unchanged 4-20 days postnatal (P > 0.1); however, cortisol levels rose with increasing adrenocorticotrophic hormone, P = 0.02. Ten neonates (29%) demonstrated preoperative adrenal insufficiency (∆cortisol ≤9 µg/dl); one had postoperative hemodynamic instability. Growth-restricted neonates had lower baseline cortisol, but normal stimulation tests and responded well to surgical stresses. Seventy-five percent of neonates receiving perioperative methylprednisolone demonstrated postoperative hypothalamic-pituitary-adrenal inhibition.

CONCLUSION

Adrenal insufficiency appears common in neonates >35 weeks gestation with congenital heart disease, but did not contribute to postoperative hemodynamic instability despite hypothalamic-pituitary-adrenal inhibition.