Bronchiolitis prevalence rates in Congenital Diaphragmatic Hernia: a systematic review and meta-analysis

Abstract

<b>Background:</b> The seasonality of Respiratory Syncytial Virus (RSV) epidemics have been disrupted by Covid19 ‘lockdowns’. Debate exists with regard to Palivizumab (RSV prophylaxis) to protect infants with Congenital Diaphragmatic Hernia (CDH) who may be vulnerable due to lung hypoplasia and pulmonary hypertension. <b>Aim:</b> To evaluate (1) if CDH infants have higher risk of admission with RSV bronchiolitis than infants in the general population;(2) if Palivizumab may reduce this risk. <b>Methods:</b> We included all studies examining the risk of RSV-positive bronchiolitis needing hospitalisation in (1) unvaccinated CDH index cases vs infants in the general population, or (2) vaccinated vs unvaccinated CDH infants. Primary outcome was the risk of admission with RSV bronchiolitis. Results are reported descriptively and synthesised when appropriate. <b>Results:</b> We included 4 retrospective cohorts and 1 case series: none compared RSV admission rates in CDH infants vs the normal population; 2 compared RSV hospitalisation rates in CDH patients who had Palivizumab vs those that did not and found no benefit (Fig 1). Study quality was poor. <b>Conclusion:</b> Whether CDH infants are at particular risk of severe bronchiolitis is unknown. There is no evidence CDH infants should receive Palivizumab. Multicentre interventional and observational studies are needed. <b>Figure 1:</b> Admission with RSV bronchiolitis in vaccinated vs unvaccinated CDH infants