Background: Bronchiolitis is a viral respiratory illness affecting children younger than one year of age, and its accurate prognosis in the emergency department (ED) is often difficult. Lung ultrasound (LUS) has been shown to be useful in risk stratification with respect to the likelihood of being admitted to the hospital or high-intensity care units, receiving supplemental oxygen, or non-invasive ventilation (NIV). Our aim is to evaluate the predictive value of point-of-care lung ultrasound performed in a pediatric ED, especially regarding hospitalization, need for oxygen therapy and NIV.

Methods: Observational prospective monocentric study including 109 patients with bronchiolitis younger than 12 months presenting to the ED. Both clinical and LUS scores were assigned at the time of medical examination, then main data regarding admission, need for oxygen supply and NIV were collected.

Results: Comparing patient who required hospital care (admission, oxygen supply or NIV) or not, we found a higher median LUS score for patients requiring hospital care (4 vs 1 p < .001 for hospital admission, 4 vs 2 p < .001 for oxygen supply, 5 vs 3 p < .001 for NIV); furthermore, setting the threshold of LUS score at 3.5 as a predictive marker, the ROC AUC for hospital admission, need for oxygen supply or NIV was 0.78, 0.75 and 0.8, respectively. A logistic regression analysis evaluated the risk associated with LUS score: an increase in score affects the risk of hospital admission, need for oxygen supplementation and NIV (OR 1.4, 95%CI 1.04-1.78, p < .05; OR 1.4, 95%CI 1.10-1.78, p < .05; OR 1.6, 95%CI 1.17-2.06, p < .05, respectively).

Conclusions: LUS has demonstrated to be a useful tool to help clinician in the process of risk stratification for bronchiolitis, although further (multicentric) studies would be advisable to strengthen this result.