Respiratory syncytial virus (RSV) is the main etiologic agent of bronchiolitis worldwide and RSV bronchiolitis seems to be a more severe disease than that caused by other viruses. The aim of our study is to observe the clinical, pulmonary function and bronchodilator responsiveness differences between respiratory syncytial virus (RSV) and non-RSV bronchiolitis.
Methods
96 bronchiolitis inpatients of Shengjing Hospital from November 2012 to March 2014 were enrolled. RSV detection was performed at enrollment and the patients were divided into RSV group and non-RSV group. Patient's information of demography, allergy and duration of onset were collected, infant pulmonary function, bronchial dilation test and serum total IgE were tested, and modified-Tal score and length of hospitalization were also recorded at admission.
Results
RSV bronchiolitis (n = 40 [46.17%]) were younger at hospitalization（5±3.97 vs 7.38±4.42 months，p=0.008）and disease severity defined by length of hospitalization and modified-Tal score was significantly worse in children with RSV bronchiolitis. There is no difference in sensitization between the two groups. The respiratory rate (RR) and respiratory system resistance (Rrs) were significantly increased, while the tidal volume per kilogram (VT/kg), ratio of time to peak tidal expiratory flow and total expiratory time (tPTEF/TE), ratio of volume to peak expiratory flow and total expiratory volume (VPTEF/VE), and respiratory system compliance per kilogram (Crs/kg) were significantly decreased as compared with those in non-RSV bronchiolitis. The plethysmographic functional residual capacity (FRCp) showed no statistically significant differences. With bronchodilators, VT/kg, tPTEF/TE and VPTEF/VE were significantly improved in RSV bronchiolitis. There were good correlations between disease severity and lung function.
Conclusions
In conclusion, this study supports that younger age is a risk factor for RSV bronchiolitis. The airway obstruction of RSV bronchiolitis seems to be more severe and have higher bronchodilator responsiveness. Infant pulmonary function may reflect disease severity, while we need to consider the affected factors when assessing the disease severity based on infant pulmonary function.