[Anemia, a new severity factor in young infants with acute viral bronchiolitis?]

INTRODUCTION: The role of anemia is raised as a risk of low respiratory infection of the child, but there are no data on anemia as a severity factor in acute viral bronchiolitis (AVB) in infants.

METHODS: All infants less than 16 weeks old admitted to Montpellier University Hospital from 2015/10/01 to 2016/04/01 for AVB were included in a retrospective observational study. The primary objective was to determine whether the hemoglobin (Hb) concentration on admission was an independent factor of clinical severity, judged by the modified Wood's clinical asthma score (m-WCAS). The secondary objective was to assess the impact of Hb level on the characteristics of hospitalization, including the type and duration of respiratory support.

RESULTS: The m-WCAS was used at least once during hospitalization in 180 out of 220 patients (82%), making it possible to distinguish patients with mild AVB (maximum m-WCAS<2, n=81) from patients with severe AVB (maximum m-WCAS>2, n=99). A logistic regression model indicated that the Hb concentration, for every 1g/dL decrement, was an independent factor of AVB severity (OR 1.16 [1.03-1.29], P=0.026). A level under 10g/dL on admission was associated with a higher use of continuous positive airway pressure (P<0.001), as well as a longer duration of respiratory support (P=0.01).

CONCLUSION: This study suggested that anemia may influence the clinical expression of AVB in young infants.