Virologic testing in bronchiolitis: does it change management decisions and predict outcomes?

The aim of this study was to evaluate the clinical, therapeutic, laboratory, and radiological differences between respiratory syncytial virus (RSV) and non-RSV bronchiolitis in order to assess if the prior knowledge of viral etiology changed management decisions and would be able to predict outcomes. Medical charts of children <1 year admitted to the emergency department with bronchiolitis during two RSV seasons (2010–2012) were reviewed. We analyzed 221 episodes of bronchiolitis. The percentage of exams performed (95 % confidence interval (CI) 0.74–2.52), abnormal laboratory and radiological findings (95 % CI 0.53–16.89) did not differ between groups. RSV bronchiolitis had a more severe clinical course. However, virologic testing for RSV had low specificity in identifying at-risk patients for hospitalization, longer hospital length of stay, and need of oxygen therapy and nasogastric tube (44, 40, 42, and 35 %, respectively), and while statistically significant, the positive likelihood ratios were only slightly greater than 1. Conclusion: Although RSV bronchiolitis has a more severe clinical course, virologic testing does not help in management decisions, and at an individual level, as a performance test, it seems insufficient to precisely predict outcomes.