PC3072: Factors Influencing the Risk of Intubation in Children with Critical Bronchiolitis

Background: Acute viral bronchiolitis is a leading cause of admission to pediatric intensive care units (PICU). Although use of non-invasive mechanical ventilation and high-flow nasal cannula have reduced the need for invasive mechanical ventilation (IMV), some children with bronchiolitis still require IMV. Currently, no guidance exists to help clinicians discern which patients will ultimately need IMV. The objective of this study was to determine predisposing factors for IMV requirement in children admitted to PICU with bronchiolitis.

Methods: We performed an IRB-approved retrospective chart review of children admitted to our tertiary PICU with viral bronchiolitis between 6/1/2016 and 4/1/2020. Exclusion criteria included intubation prior to arrival to the PICU, tracheostomy dependence, and a primary diagnosis that was not bronchiolitis. Data collected included demographics, length of stay, type and duration of respiratory support, causal viruses, and presence of risk factors, such as prior admissions, previous intubation for bronchiolitis, and history of prematurity, bronchopulmonary dysplasia, developmental delay, congenital heart disease, Down Syndrome, sickle cell disease, immunocompromised status, neuromuscular disease, and malignancy. Statistical analysis was performed comparing the groups of children who required IMV vs non-IMV using t-test (normal distribution) or Mann Whitney U test (non-normal distribution) for continuous variables and chi-square test or Fisher’s exact test for categorical variables. P-values less than 0.05 were considered statistically significant.

Results: A total of 623 charts were reviewed, with 381 patients meeting the inclusion criteria. Among 381 children treated for bronchiolitis, 33 children required IMV (8.6%). Younger age was associated with increased risk of requiring IMV, with median age of 3 months [IQR 2-5.5] in the IMV group and 6 months [IQR 3-14]in the non-IMV group (p=0.001). Respiratory syncytial virus (RSV) was the most common cause of bronchiolitis in both the IMV (67%) and non-IMV (56%) groups (p=0.27). Among other viral causes, only unknown virus (negative PCR assay) was found to be statistically significant, with 15% in IMV group and 5.7% in non-IMV group (p=0.05). Children in the IMV group required prolonged respiratory support with a median duration of 5 days [IQR 1-12] vs 2 days [IQR 1-4] in the non IMV group (p=0.005). Median duration of hospitalization in the IMV group was 11 days [IQR 8-15] vs 4 days [IQR 3-5] in the non-IMV group (p=0.000).

Conclusion: Younger age (median three months) and unknown viral cause were identified as significant predictors of IMV requirement in this single center retrospective study. The initiation of IMV is associated with significantly longer duration of respiratory support and hospital stay. Future studies should focus on determining risk factors or a predictive tool that could potentially reduce the need for IMV in children with critical bronchiolitis and in turn improve outcomes.