Bronchiolitis hospital admission in infancy is associated with later preschool ventilation inhomogeneity

Abstract

AbstractBackgroundRhinovirus (RV) positive bronchiolitis episodes in infancy confer a higher risk to develop asthma in later childhood with associated lung function impairments. We aimed to investigate the association between the type of virus causing a bronchiolitis hospitalization episode and lung ventilation inhomogeneities at preschool age.MethodsInfants hospitalized with a clinical diagnosis of moderate (ward admission) or severe (pediatric intensive care ward admission) bronchiolitis were prospectively followed‐up at preschool age to assess nitrogen (N2) multiple breath washout (MBW). Lung clearance index (LCI), functional residual capacity (FRC), and concentration normalized phase III slope analysis (SnIII) indices were reported from ≥2 technically acceptable trials. Differences between groups were calculated using logistic and linear regression and adjusted for confounders (sex, age at bronchiolitis admission, height at visit, maternal asthma, and doctor‐diagnosed asthma, including interaction terms between the latter three). An interaction term was included in a regression model to test for an interaction between RV bronchiolitis severity and MBW parameters at preschool age.ResultsOne hundred and thirty‐nine subjects attended preschool follow‐up, of which 84 out of 103 (82%) performing MBW had technically acceptable data. Children with a history of RV positive bronchiolitis (n = 39) had increased LCI (adjusted β‐coefficient [aβ] = 0.33, 95% confidence interval [CI] 0.02–0.65, p = 0.040) and conductive airways ventilation inhomogeneity [Scond] (aβ = 0.016, CI 0.004–0.028, p = 0.011) when compared with those with a RV negative bronchiolitis history (n = 45). In addition, we found a statistical interaction between RV bronchiolitis and bronchiolitis severity strengthening the association with LCI (aβ = 0.93, CI 0.20–1.58, p = 0.006).ConclusionChildren with a history of hospital admission for RV positive bronchiolitis in infancy might be at a higher risk of lung ventilation inhomogeneities at preschool age, arising from the peripheral conducting airways.