This study assessed the association between findings of lung ultrasound (LUS) performed in the pediatric emergency department (PED) on infants with bronchiolitis and need for respiratory support.

An observational study was carried out in the PED during the epidemic seasons in two consecutive years. Infants diagnosed with bronchiolitis who fulfilled the inclusion criteria were evaluated. A group of six pediatricians performed LUS and classified lung findings into four groups: normal pattern (A), moderate interstitial pattern (B1), severe interstitial pattern (B2), and isolated consolidation (C). The relationship between LUS findings and need for respiratory support was explored. An expert sonographer, blinded to the results, reviewed the ultrasound studies to determine the interobserver reliability.

A total of 200 infants were included (mean age 5.7 months±4.4 SD); 65 (32.5%) obtained moderate clinical scores, while 23 (11.5%) needed respiratory support at admission and 34 (17.0%) at 48h. The ultrasound findings in the PED were the following: A=89 (44.5%), B1=55 (27.5%), B2=34 (17%), and C=22 (11%). Age less than 6 weeks and moderate bronchiolitis were correlated with abnormal LUS (P<0.005). The severity of interstitial ultrasound pattern has some correlation with an increased need for respiratory support. The interobserver concordance was high (0.95, confidence interval: 0.92–0.98).

LUS is a feasible tool that may help to confirm the clinical impression and assess the need for respiratory support in children with bronchiolitis, but further multicenter studies are needed.