Abstract:

Objective To investigate the application of a simplified 8-zone lung ultrasound examination method in predicting early postnatal respiratory support in late preterm and term neonates. Methods Late preterm and term infants who developed dyspnea within 4 hours after birth from June 1, 2019 to January 1, 2020 were included. The infants underwent lung ultrasound at any of the postnatal time points : 0.5 h, 1.0 h, 2.0 h, and 4.0 h. Among the lung ultrasound signs observed early postnatally, " isolated A-lines " and " scattered B-lines " were categorized as " low-risk " signs, while" coalescent B-lines " and " consolidation" were categorized as " high-risk " signs. The association between " high-risk " signs and lung disease was determined through logistic regression (odds ratio, OR). The accuracy of lung ultrasound and an existing symptom scoring tool (ACoRN score) in predicting respiratory support was compared using the receiver operating characteristic curve and area under the curve (AUC). The optimal sensitivity and specificity were calculated using the Youden index. Results A total of 310 newborns were included. Follow-up until 3 days postnatally found that 74 infants required respiratory support, while 236 did not. The AUC for " high-risk " signs predicting respiratory support in preterm infants was 0.93 (95 % CI: 0.85 - 1.00) with a cut-off value of 3; for full-term infants, it was 0.88 (95 % CI: 0.82 - 0.94) with a cut-off value of 2. Using clinical symptoms and signs (ACoRN score) for prediction, the AUC was 0.69 (95 % CI: 0.51 - 0.87) for preterm infants and 0.74 (95 % CI: 0.67 - 0.81) for full-term infants, significantly lower than the " high-risk " signs (P=0.006). Conclusion The simplified lung ultrasound method can be used to predict respiratory support in infants with early postnatal respiratory distress.

Key words: simplified lung ultrasound, respiratory support, neonates