Exploring Risk Factors Associated With Intensive Care Unit Admission in a Retrospective Cohort of 631 Children With Bronchiolitis.

Aim: Examine the trends and epidemiological features of acute hospitalized bronchiolitis cases among children aged 28 days to 2 years, both before and after the COVID-19 pandemic. Furthermore, evaluate their need for intensive care unit (ICU) admission and identify primary risk factors associated with severe bronchiolitis.

Methods: A retrospective analysis was conducted on the medical records of paediatric patients admitted to Meyer Children's Hospital in Florence (Italy) from September 2019 to March 2023, with the diagnosis of bronchiolitis.

Results: Between 2019 and 2023, bronchiolitis hospitalizations grew by 76%, going from 131 to 230 cases, after the historical minimum of 14 cases in the 2020-2021 season. Respiratory syncytial virus (RSV) infection emerged as the predominant etiological agent, contributing to 76% of hospitalizations in both 2021-2022 and 2022-2023 seasons. Coinfection cases increased fivefold from 2019 to 2023, accounting for 23% of hospitalizations in 2022-2023. In addition, the ICU admission rate increased from 13% in 2019-2020 to 31% of bronchiolitis hospitalizations in 2022-2023. Univariate and multivariate analysis data show that infants below 2 months of age, preterm births, comorbidities and RSV infections were correlated with a higher risk for ICU admission.

Conclusion: The growing trend in ICU admissions for acute bronchiolitis in hospitalized children represents a substantial health challenge. Addressing the bronchiolitis epidemic necessitates a strategic focus on RSV prevention through interventions such as vaccines and monoclonal antibodies. Urgent implementation of preventive initiatives, together with continuous surveillance and the establishment of national databases, is imperative and cannot be further deferred.