Postnatal diuretics, growth and home oxygen requirement in preterm infants

Abstract

<b>Introduction:</b> Diuretics are often used to treat infants with bronchopulmonary dysplasia (BPD), yet little evidence exists to suggest they improve pulmonary outcomes. <b>Aims:</b> To determine if diuretic use (&gt;7 consecutive days) was associated with poorer weight gain and lower need for home oxygen. <b>Methods:</b> Observational study of preterm infants (&lt;28wks) alive at discharge in all neonatal units in England over a 5-year period. Mahalanobis Kernel matching was based on gestational age, birthweight and sex. Efficacy was assessed using matched linear regression, adjusted for antenatal and postnatal steroids, duct ligation, mechanical ventilation, parenteral nutrition, BPD and length of stay. Treatment difference was summarized as the average treatment effect on the treated (ATT). <b>Results:</b> Of 9,457 neonates surviving discharge, 44.6% received diuretics. Logistic regression demonstrated selection bias for diuretic administration in the unmatched sample: 43% more for boys (p=0.004), 20% less for each additional week in gestational age (p=0.001) and 28% less for each additional standard unit in birthweight (p&lt;0.001). The matching algorithm yielded balanced groups, with identical means in gestation&nbsp;(25.7wks), birthweight (810g) and sex (56% boys). Diuretics were associated with an increased probability of home oxygen (ATT=0.14, p&lt;0.001), with a larger adverse effect for those who had postnatal corticosteroids (Coef=0.09; p=0.02). Postnatal growth was 2.5g per week greater in the diuretic group (p=0.01). <b>Conclusion:</b> Diuretic use was associated with increased supplemental oxygen on discharge and greater postnatal weight gain. Randomised trials are needed to determine long-term benefits and risks of diuretic treatment.