Lung ultrasound for prediction of respiratory support in infants with acute bronchiolitis: A cohort study

Abstract

Objective Respiratory tract infections are among the most common causes of morbidity and mortality worldwide. Acute bronchiolitis (AB) is the leading cause of hospital admission among infants. Clinical scores have proven to be inaccurate in predicting prognosis. Our aim was to build a score based on findings of lung ultrasound (LU) performed at admission, to stratify patients at risk of needing respiratory support (non‐invasive and invasive ventilation). Study design Prospective, multicenter study including infants <6 months of age admitted with AB. Point‐of‐care LU was performed on admission, and a score was calculated based on ultrasound findings (presence and localization of B lines, B line confluence and/or consolidations) and clinical data. Main outcome was need of respiratory support. Results A total of 145 patients were included in the study, with a median age of 1.7 months [IQR: 1.2‐2.8], 47.6% were female. Mean duration of symptoms prior to admission was 3.1 days (SD 1.8). Fifty‐six patients (39%) required non‐invasive ventilation (NIV), 14 (9.7%) were transferred to PICU, and 3 needed invasive ventilation (3/145). Identification of at least one posterior consolidation >1 cm was the main factor associated to NIV (RR 4.4; [CI95%1.8‐10.8]) The LU score built according to the findings on admission showed an AUC: 0.845(CI95%:0.78‐0.91). A score ≥3.5 showed a sensitivity of 89.1% (CI95%:78.2‐94.9%) and specificity of 56% (CI95%: 45.3‐66.1%) Conclusions Among infants below 6 months of age admitted with AB, point‐of‐care LU was a helpful tool to identify patients at risk of needing respiratory support.

Using lung ultrasound to quantitatively evaluate pulmonary water content

“…Currently, different LUS score protocols have been used to guide surfactant administration, respiratory support, and prognosis assessment . Our results suggest that the BLS is highly correlated with the PaO 2 /FiO 2 ratio, which is consistent with previous data revealing that the LUS score was significantly correlated with the oxygenation index in critical care patients .…”

“…Currently, different LUS score protocols have been used to guide surfactant administration, respiratory support, and prognosis assessment. 11,16,38 Our results suggest that the BLS is highly correlated with the PaO 2 /FiO 2 ratio, which is consistent with previous data revealing that the LUS score was significantly correlated with the oxygenation index in critical care patients. 39 These findings are also consistent with those reported by Bilotta et al 40 When the BLS ranged from 49 to 64 (infusion volume, 6-8 mL/kg) in our study, the PaO 2 /FiO 2 ratio decreased sharply ( Figure 12) but declined slowly when the BLS was < 49; these findings are in line with those of the pig model of acute lung injury induced by oleic acid, suggesting that the BLS increases before the decrease in the PaO 2 /FiO 2 ratio.…”

Acute Bronchiolitis: Is There a Role for Lung Ultrasound?

“…The total LUS score was in the range of 0-50 points, resulting from the sum of the scores for each individual zone (five areas: anterior parasternal, anterior axillary, posterior axillary, posterior paravertebral, posterior linea scapularis). The authors concluded that their results were consistent with the ones of the aforementioned studies [8,12] regarding the correlation with the clinical severity scores, and they confirmed the presence of a higher percentage of pulmonary anomalies in the posterior paravertebral and subscapular area, probably due to gravity or to the obligate supine position of the child.…”

“…An additional prospective, multicenter research trial has demonstrated that LUS could be a helpful tool to identify patients at risk for any type of respiratory support (non-invasive or invasive ventilation, except conventional low-flow oxygen through nasal sprongs) in the acute phase of bronchiolitis, starting from the idea that clinical scores have proven to be inaccurate in predicting prognosis. In fact, Bueno-Campaña et al [12] have analyzed the data of 145 infants < 6 months with the aim to build a score based on LUS findings (presence and localization of B-lines, B-lines confluence and/or consolidation) performed at admission, but also on clinical data (age < or > 1 month and Wood-Downes-Ferres Score, typically used for asthma). Their results were consistent with the ones of the previously described studies, especially regarding the increased association of NIV with posterior consolidations > 1 cm.…”

“…Their results were consistent with the ones of the previously described studies, especially regarding the increased association of NIV with posterior consolidations > 1 cm. Moreover, it was the first study to explore LUS usefulness as a predictive tool for the need of respiratory support other than supplemental oxygen in acute bronchiolitis [12].…”