Neonatal lung ultrasonography to evaluate need for surfactant or mechanical ventilation: a systematic review and meta-analysis

Context Lung ultrasonography (LUS) is increasingly used to identify various neonatal respiratory disorders. There is emerging evidence that it can identify infants with significant lung disease who need surfactant treatment or mechanical ventilation. Objective To systematically review the accuracy of LUS in determining the need for surfactant treatment or mechanical ventilation in infants with respiratory distress treated with nasal continuous positive airway pressure (NCPAP). Methods Database search include EMBASE, Medline, CINAHL and Cochrane central from inception until 17 October 2018. Included is diagnostic accuracy studies reporting LUS evaluating surfactant therapy/mechanical ventilation. Two authors extracted data independently and assessed quality. Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to determine the methodological quality. Results Six studies involving 485 infants included in the review. Three studies used LUS score, two used type 1 lung profile, and one used high-risk LUS to evaluate the outcome. The pooled sensitivity and specificity at LUS score cut-off >5-6 was 88% (95% CI 80% to 93%) and 82% (95% CI 74% to 89%), respectively. Infants with LUS score >5-6 were at significantly increased risk of surfactant treatment compared with infants with LUS score <5-6 (relative risk=7.51; 95% CI 4.16 to 13.58; two studies; participants=189; I-2=0%). The diagnostic accuracy of type 1 lung profile was better in younger preterm infants (sensitivity 88.9%, specificity 100%) compared with late preterm and term infants (sensitivity 100%, specificity 28%). Conclusions LUS, particularly LUS score, can be used accurately to determine the need for surfactant replacement treatment or mechanical ventilation in infants with respiratory distress treated with NCPAP support. The accuracy is better in younger preterm infants compared with late preterm and term infants.