Abstract: ObjectiveTo explore the value of neonatal pulmonary ultrasound in the evaluation of pulmonary infection in premature infants. 
MethodsIn total, 80 preterm infants with pulmonary infection were selected as the observation group, and 80 preterm infants without pulmonary infection were selected as the control group. All of them were given neonatal pulmonary ultrasound examination. The pulmonary ultrasound score, oxygenation index and respiratory index of the two groups were compared. The pulmonary ultrasound score, oxygenation index and respiratory index of the children with different conditions and prognosis in the observation group were compared, and the correlation between the pulmonary ultrasound score, oxygenation index and respiratory index was analyzed. 
ResultsThe pulmonary ultrasound score and oxygenation index of the observation group were lower than those of the control group, and the respiratory index was higher than that of the control group(P＜0.05). In the observation group, the pulmonary ultrasound score and oxygenation index of extremely critical children were lower than those of critical and non-critical children, and the respiratory index was higher than that of critical and non-critical children. The pulmonary ultrasound score and oxygenation index of critical children were lower than those of non-critical children, while the respiratory index was higher than that of non-critical children, suggesting significant differences(P＜0.05). The pulmonary ultrasound score was negatively correlated with respiratory index(r=-0.455, P＜0.05) and positively correlated with oxygenation index(r=0.470, P＜0.05). In the observation group, the pulmonary ultrasound score and oxygenation index of the dead children were lower than those of the surviving children, and the respiratory index was higher than that of the surviving children, with a significant difference(P＜0.05). The area under receiver operating characteristic(ROC) curve of pulmonary ultrasound score for predicting prognosis of children was 0.874, which was higher than that of respiratory index and oxygenation index(P＜0.05). When the cutoff value was 20 points, the sensitivity and specificity were 88.50% and 75.00% respectively. 
ConclusionNeonatal pulmonary ultrasound has a good effect in the evaluation of premature infants with pulmonary infection, which is worthy of clinical application.

Key words: infant, premature, pneumonia, ultrasonography