523 What is the impact of preterm birth for children admitted to PICU with bronchiolitis? – A systematic review

Abstract

<h3>Aims</h3> There are approximately 60,000 preterm births each year in the UK. Respiratory complications following preterm birth can cause long-term sequelae and predisposition to respiratory tract infection. Bronchiolitis, a viral lower respiratory tract infection affecting infants, is a common cause of hospitalisations, and require admission to a paediatric intensive care unit (PICU) for respiratory support. In the United Kingdom 12.5% of PICU admissions are due to bronchiolitis.¹ We conducted a systematic review of existing literature examining the proportion and outcomes of children born preterm among patients admitted to PICU with bronchiolitis. <h3>Methods</h3> We conducted a primary search of MEDLINE, Embase, and Scopus using relevant terms for prematurity and paediatric intensive care. Studies were included that compared children born preterm and at term admitted for care in a PICU, aged 0-18 years, published after the year 2000, in high income countries. <h3>Outcomes</h3> • Primary outcome: percentage of children born preterm among those admitted to PICU with bronchiolitis • Secondary outcomes: requirement for invasive mechanical ventilation and mortality within PICU RevMan was used for data extraction and meta-analysis. A subset of papers were screened for inclusion by a second reviewer. Study quality was assessed using JBI Critical Appraisal tools. <h3>Results</h3> 5355 results were obtained through primary search. Following exclusions, 30 studies were included that examined RSV and/or bronchiolitis in PICU, comparing children born preterm and at term. 27 papers reported between 8 and 49% of patients were born preterm within the cohort of children admitted to PICU with bronchiolitis. Five papers reported that between 1 and 11% were born extremely preterm (&lt;28 weeks gestational age). A random effects model was used for meta-analysis. Figure 1 shows a Forest plot of invasive mechanical ventilation for children born preterm. The relative risk was 1.57 (95% CI 1.25 to 1.97), significantly higher. Figure 2 shows a Forest plot of mortality within PICU for children born preterm. The relative risk was 1.10 (95% CI 0.70 to 1.72), indicating a higher, but non-significant, risk of mortality in those born preterm. There was considerable variation across published studies in the inclusion criteria for age, exclusion of comorbidities, and definition of prematurity used. The majority of studies were at high risk of bias, for example due to failure to describe confounding factors, or failing to specify the definition of prematurity used. <h3>Conclusion</h3> Children born preterm are over-represented within PICU admissions for bronchiolitis and require significant healthcare resources. Within PICU they appear to have increased risk of requiring invasive ventilation compared to those born at term, but do not have significantly increased risk of mortality. While there are many studies examining the impact of children who were born preterm within PICU, many are small or at high risk of bias. Use of large datasets to examine this population could provide important information for healthcare professionals within neonatal and paediatric intensive care, and families of children born preterm. <h3>Reference</h3> Almossawi O, et al. A study of sex difference in infant mortality in UK pediatric intensive care admissions over an 11-year period. <i>Sci Rep</i>. 2021;11(1):21838.