RESUMO
Objective To evaluate the value of serum aminoterminal pro-brain natriuretic peptide (NT-proBNP) and interleukin(IL)-6 levels in diagnosis and severity assessment of the preterm infants with respiratory distress syndrome(RDS).Methods Totally 150 preterm infants with RDS who were hospitalized in our center from August 2016 to March 2018 were enrolled in this study as the RDS group. These infants were further divided into grades 1,2,3,and 4 according to chest radiography. In addition,158 preterm infants without RDS hospitalized in our center during the same period were included as the controls (control group). Serum NT-proBNP and IL-6 levels were measured by ELISA on days 1,3,and 7 after birth,and their pulmonary arterial pressure (PAP) was monitored as well.Results Serum NT-proBNP and IL-6 levels in RDS group were significantly higher than those in control group on day 1 (t=-91.04,P=0.000;t=-11.03,P=0.000),day 3 (t=-89.10,P=0.000;t=-9.909,P=0.000),and day 7 (t=-87.91,P=0.000;t=-8.548,P=0.000). There were significant differences in NT-proBNP levels among grades 1,2,3,and 4 on day 1 (F=50.89,P=0.000),day 3 (F=49.16,P=0.000),and day 7 (F=45.45,P=0.000),showing an increasing trend. Serum IL-6 levels showed no significant difference among grades 1,2,3,and 4 on day 1 (F=0.89,P=0.448),day 3 (F=0.76,P=0.518),and day 7 (F=0.85,P=0.469). The PAP of the RDS group on days 1,3,and 7 was (49.3±3.7),(40.1±5.4),and (39.0±2.6)mmHg (1 mmHg=0.133 kPa),which were significantly higher than those of the control group (35.0±2.7)mmHg (t=-90.01,P=0.000),(30.0±3.1)mmHg (t=-81.90,P=0.000),(26.0±3.0)mmHg (t=-88.89,P=0.000). Thus,there was a positive correlation between NT-proBNP and IL-6 levels (r=0.876,P=0.000) and a positive correlation between NT-proBNP and PAP (r=0.916,P=0.000) in preterm infants with RDS.Conclusion Monitoring serum NT-proBN contributes to early diagnosis and disease severity assessment in preterm infants with RDS.