Résumé
Objective:To study the clinical value of lung ultrasound score (LUSsc) within 2 h after birth for pulmonary surfactant (PS) use in preterm infants with respiratory distress syndrome (RDS).Methods:From July 2019 to May 2021, preterm infants with RDS hospitalized in our hospital and received pulmonary ultrasound within 2 h after birth were prospectively enrolled. 12-area LUSsc was calculated. The infants were assigned into <32 weeks group and 32-36 weeks group according to gestational age (GA). Simple random sampling was carried out in each group with 1/5 as the validation set and the other 4/5 as the training set. The infants were also assigned into PS group and non-PS group according to PS usage within 24 h after birth. Receiver operator characteristic (ROC) curve of LUSsc predicting PS usage was drawn and validated.Results:A total of 857 RDS infants were enrolled, including 313 in <32 weeks group and 544 in 32-36 weeks group. For <32 weeks group, area under curve (AUC) of LUSsc>8.5 predicting PS use was 0.779 (95% CI 0.722-0.837), with 76.4% sensitivity and 81.4% specificity. The accuracy of using LUSsc>8.5 as cut-off predicting actual clinical PS application was 82.3% (Kappa value 0.692, P<0.05, McNemar's test P>0.05).For 32-36 weeks group, AUC of LUSsc>9.5 predicting PS use was 0.785 (95% CI 0.723-0.848), with 71.1% sensitivity and 81.7% specificity. The accuracy of using LUSsc>9.5 as cut-off predicting actual clinical PS application was 92.6% (Kappa value 0.772, P<0.05, McNemar's test P>0.05). Conclusions:LUSsc within 2 h after birth is independent predictor of PS use in preterm infants with RDS. For <32 weeks group, LUSsc>8.5 suggests PS application and for 32-36 weeks group the cut-off is LUSsc>9.5.