Effect of Postop Steroids on Cardiovascular/Respiratory Function in Neonates Undergoing Cardiopulmonary Bypass

Open-heart surgery with cardiopulmonary bypass (CPB) induces an acute systemic inflammatory
response (SIRS) via synthesis and release of inflammatory mediators. These inflammatory
cascades may result in the development of capillary leak and generalized tissue edema, which
are associated with multiorgan dysfunction involving the myocardium, lungs, kidneys,
pancreas, and central nervous system. Neonates are especially susceptible to the injurious
effects of SIRS. In attempt to blunt post-bypass SIRS, most neonatal heart programs have
protocols in which patients receive preoperative and/or intraoperative steroids. Despite
this widespread use, studies have not demonstrated consistent benefit in this therapy, and
neonates often continue to suffer the deleterious effects of SIRS postoperatively. Only one
study was designed to evaluate the impact of prophylactic postoperative steroid
administration on outcomes after neonatal CPB. The early postoperative periods is a crucial
time during which attenuation of CPB-induced SIRS by exogenous steroids may lead to improved
clinical outcomes.

Adrenal insufficiency in neonates post-CPB may accentuate the harmful effects of SIRS by
diminishing the anti-inflammatory and hemodynamic stabilization benefits of endogenous
cortisol. Evidence suggests that neonates may suffer from inadequate cortisol activity
relative to the severity of illness post-CPB, in part related to immaturity of their
hypothalamic-pituitary-adrenal (HPA) axis. This so-called critical illness-related
corticosteroids insufficiency (CIRCI) may contribute to low cardiac output syndrome (LCOS),
respiratory dysfunction, and capillary leak in the postoperative period.

Much of the support for CIRCI as a contributor to LCOS after CPB originates from small
clinical studies that demonstrate benefit of exogenous steroid supplementation on various
short term clinical outcomes in patients with shock. Yet it is not clear if benefit from
exogenous steroids suggests by dysregulation of the HPA axis or whether these are merely
alternative effects of steroids. Investigators have recently begun to describe the cortisol
response in neonates post-CPB, but there is no consensus regarding the incidence of
clinically important adrenal insufficiency, its identification, or who should receive
exogenous steroids.

Inclusion Criteria:

1. Neonate (< 28 days old) undergoing correct cardiac surgery, or infants undergoing the
following surgery procedures: Norwood, Arterial Switch, Total Anomalous Pulmonary
Venous Return Repair, Interrupted Aortic Arch Repair, Truncus Arteriosus Repair

2. Successfully weaned off cardiopulmonary bypass after cardiac surgery

Exclusion Criteria:

1. requirement for extracorporeal membrane oxygenation (ECMO) in the operating room

2. Known immune deficiency

3. Having previously received systemic steroids (except for two routine preoperative
doses)

4. A current signed Do not resuscitate (DNR) or limitation of care order

5. Current enrollment in another interventional clinical study

6. Refusal of parental consent

7. Previous diagnosis of adrenal insufficiency

8. > 28 days old at time of surgery whose repair dose not require CPB