Which Factors are Important in Determining the Length of Stay in Bronchiolitis?


Bronchiolitis is the most common lower respiratory infection in infancy1. Interventions may include hydration, oxygen therapy1,2 and, in selected cases, radiography2. Available data does not support the use of viral studies and blood tests to diagnose bronchiolitis2,3. We set out to determine whether investigations impact on the length of stay in infants with bronchiolitis.

We studied 217 infants (<13months) admitted between1/10/14 – 1/7/15. The mean (SD) age was 5.2 (3.5) months and the mean (SD) length of hospital stay (LOS) was 2.3 (2.0) days. Of 217 infants, 102 (47%) had blood tests including FBC and CRP; mean (SD) WCC 12.3 (4.7)x109/L, neutrophil 5.3 (4.0), lymphocyte5.2 (1.9) and CRP 17.1 (27.6) mg/L. Less than half of infants (97 of 217; 44.7%) underwent chest X-ray. This was reported normal in 27 (27.8%), however features consistent with a viral infection were suspected in 53 (54.6%) infants and consolidation was reported in 17 (17.5%). Nasopharyngeal aspirate (NPA) was performed in 176 of 217 [81%] infants, of which 115 (65.3%) were RSV, 11(6.3%) Human metapneumovirus and 2 (1.1%) Parainfluenza type 3 positive. No virus was isolated in 48 of 176(27.3%) infants. There was no significant correlation between LOS and age at presentation (p value = 0.11). Similarly, no significant association was found between LOS and WCC (p value= 0.3), neutrophil (p value =0.73, lymphocyte (p value = 0.69) or CRP (p value 0.97). In this group of patients, mean (SD) LOS did not differ significantly between infants with abnormal chest x-ray [1.96 (1.89) days], those with x-ray features suggestive of viral infection [2.51 (2.18)] and individuals with consolidation [1.94 (1.48)](p =0.39). Notably, there was a significant difference in LOS between infants with RSV infection [mean (SD) 2.75 (2.16) days] and those with negative NPA results [mean (SD) 1.79 (1.62) days] (p = 0.007). However, LOS did not differ between infants with non-RSV positive aspirates [mean (SD)2.31(1.32) days] and those with negative aspirates [mean (SD) 1.79 (1.62)] days (p= 0.29).

In conclusion, for infants presenting with clinically diagnosed bronchiolitis, FBC, CRP and chest X-ray do not impact on LOS. A significant association between RSV infection and prolonged LOS has been identified. These findings support current guidance recommending minimal investigations in managing bronchiolitis.



S Skirka, C Power, M Nadeem, P Greally

AMNCH, Tallaght, Dublin 24

Email: [email protected]




  1. American Academy of Pediatrics Subcommittee on Diagnosis and Management of Bronchiolitis. Diagnosis and management of bronchiolitis. Pediatrics 2006;118:1774-93
  2. B Jeremy, N Friedman, MJ Rieder, JM Walton. Bronchiolitis: Recommendations for diagnosis, monitoring and management of children one to 24 months of age. Paediatr Child Health 2014;19:485-91
  3. Agency for Healthcare Research and Quality. Management of Bronchiolitis in Infants and Children. Evidence Report/Technology number 69.AHRQ Publication No. 03-E014 January 2003.