Dexamethasone in bronchopulmonary dysplasia

Dose-related cardiac outcomes in response to postnatal dexamethasone treatment in premature lambs

BACKGROUND

Postnatal corticosteroids are used in the critical care of preterm infants for the prevention and treatment of bronchopulmonary dysplasia. We aimed to investigate the effects of early postnatal dexamethasone therapy and dose on cardiac maturation and morphology in preterm lambs.

METHODS

Lambs were delivered prematurely at ~128 days of gestational age and managed postnatally according to best clinical practice. Preterm lambs were administered dexamethasone daily at either a low-dose (n = 9) or a high-dose (n = 7), or were naïve to steroid treatment and administered saline (n = 9), over a 7-day time-course. Hearts were studied at postnatal Day 7 for gene expression and assessment of myocardial structure.

RESULTS

High-dose dexamethasone treatment in the early postnatal period led to marked differences in cardiac gene expression, altered cardiomyocyte maturation and reduced cardiomyocyte endowment in the right ventricle, as well as increased inflammatory infiltrates into the left ventricle. Low-dose exposure had minimal effects on the preterm heart.

CONCLUSION

Neonatal dexamethasone treatment led to adverse effects in the preterm heart in a dose-dependent manner within the first week of life. The observed cardiac changes associated with high-dose postnatal dexamethasone treatment may influence postnatal growth and remodeling of the preterm heart and subsequent long-term cardiac function.

Lower gastrointestinal tract perforation in preterm infants treated with dexamethasone for bronchopulmonary dysplasia

Two cases of ileal perforation in preterm infants treated with high-dose dexamethasone for bronchopulmonary dysplasia are described. Corticosteroid-induced gastroduodenal haemorrhage or perforation has been well documented, but less known to most clinicians is that the lower gastrointestinal tract can also be involved. Unlike previous reported cases in which affected infants deteriorated rapidly and became moribund within hours of onset of symptoms, "silent" perforations detected on routine radiograph or escaping clinical recognition until at an advanced stage can be the initial presentation. The need for greater vigilance and a low threshold for abdominal investigations are emphasised in preterm infants treated with dexamethasone.