Objective To explore the clinical application value of plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) in diagnosis and treatment of symptomatic patent ductus arteriosus (sPDA) in preterm infants. Methods A total of 107 preterm infants with gestational age of 28-32 weeks and birth weight less than 1500 g who were admitted to the neonatal intensive care unit from October 2013 to September 2014 were recruited. Plasma NT-proBNP were on 4th and 7th day after birth. The echocardiography examination was performed within 30 minutes after the blood was drawn. According to the echocardiography examination on 4th day after birth, the infants were divided into the patent ductus arteriosus (PDA) group (n?=?39) and the control group (n?=?68). According to whether there were signiifcant hemodynamics changes of ultrasonography and clinical symptoms, the PDA group were classiifed into the sPDA group (n?=?20) and the asymptomatic PDA group (asPDA, n?=?19). Then according to whether ibuprofen was taken, the sPDA group was further divided into treatment group (n?=?13) and non-treatment group (n?=?7). Results On the 4th day after birth, the level of plasma NT-proBNP in the sPDA group was signiifcantly higher than that in asPDA group, and the level of plasma NT-proBNP in asPDA group was signiifcantly higher than that in the control group (P??0.05). In the treatment group, the level of plasma NT-proBNP on the 7th day after birth was signiifcantly lower than that on the 4th day after birth (P??0.05). In PDA group, the level of plasma NT-proBNP on the 4th day after birth was positively correlated with ductus arteriosus (DA) diameter, ratio of the left atrium to aortic root diameter (LA/AO ratio) and transductal diameter-to-left pulmonary artery ratio (TDD/LPA) (r?=?0.498-0.670, respectively). The area under receiver operator characteristic (ROC) curve for prediction of sPDA by the plasma NT proBNP on the 4th day after birth was 0.969 (95%CI:0.938-1.000). When the NT-proBNP was 13964 pg/ml on the 4th day after birth, the sensitivity for diagnosis sPDA was 95%, the speciifcity was 95.4%. Conclusions The level of plasma NT-proBNP is signiifcantly higher in preterm infants with sPDA and is decreased after treatment. Plasma NT-proBNP on the 4th day after birth is a sensitive marker for predicting sPDA. Dynamic monitoring of plasma NT-proBNP has important clinical value in selection of the treatment strategy in preterm infants with PDA.

Objective To analyze the characteristics of blood loss for laboratory test of critically ill premature infants,and to seek feasible measures to reduce the blood loss.Methods Two hundred and forty-six cases of critically ill premature infants admitted to the neonatal intensive care unit from April 2012 to April 2013 were analyzed the blood loss for test during the hospitalization and the clinical features of blood loss with different gestational age,different weight within the first four weeks after admission.Then the application of blood loss according to test category was described.The blood volume demanded in theory was determined by the formula B =5 (∑ s + 0.1),then calculated the phlebotomy overdraw on the basis of the practical blood loss and analyzed the characteristics of overdraw per patients per day in first two weeks after admission.Results Among 246 patients,The median blood loss figure was 25.57 ml for each infants with the range between 7.10 ml ～ 119.20 ml,and the blood loss concentrated in first four weeks,which showed a decreasing trend with time.There was a statistically significant difference(P ＜0.05)that the smaller gestational age,the lower birth weight,the more daily blood loss per patient per day in first two weeks,but no significant differences(P ＞ 0.05) between the third and fourth week.The largest proportion of the blood samples was used for clinical chemical tests(31.49％),followed by blood gas analysis (19.03％),immunoassays (12.69％),blood cultures (12.63％),hematology (12.28％).The practical blood loss was about twice times of blood volume demanded for tests in theory,which the median was 7.8 times to the latter(25.57 ml vs 3.26 ml).It showed statistically significant difference(P ＜0.05) between blood overdraw per patients per day in the first week and the second week.Compared with different gestational age and birth weight,the difference of overdraw was also statistically significant(P ＜0.05).According to test category,blood culture was the most significant samples of phlebotomy overdraw,followed by biochemical,other,blood gas analysis,the percentage was 76％,64％,45％ and 41％ respectively.Conclusion The blood loss for laboratory test and the phenomenon of blood waste is serious in critically ill preterm infants.The smaller the gestational age is,the lower the weight is,the amount of blood loss and phlebotomy overdraw are more significantly.Biochemical and blood gas analysis are the main items of blood loss.

Objective To evaluate the level of plasma N－terminal pro－brain natriuretic peptide ( NT－proBNP ) in preterm infants with bronchopulmonary dysplasia ( BPD ) after dexamethasone administration and its correlation with the occurrence and severity of BPD.Method The preterm infants in NICU from December 2014 to October 2016 were enrolled in this prospective study.All of the infants were less than 32 weeks′gestational age (GA) and less than 1 500 g birth weight (BW) and they all underwent mechanical ventilation for severe ( stage Ⅲ－Ⅳ) respiratory distress syndrome ( RDS).The infants were assigned to weaning group and non－weaning group according to whether they underwent mechanical ventilation after 14 days of birth.Then the non－weaning group were assigned into the therapy group and control group according to whether treated by dexamethasone.By 14 and 28 days after birth, immunochromatography assay was used to detect the serum NT－proBNP respectively and the results were compared among the groups.Result A total of 157 preterm infants with severe RDS were included , 108 in the weaning group, the remaining 49 in the non－weaning group.(1)Compared with the non－weaning group, the weaning group had higher birth weight and lower plasma NT－proBNP level on day 14 ( P ＜0.05). (2)On day 28, all of the 30 infants in the dexamethasone treated group showed significantly lower plasma NT－proBNP level than the 19 infants in the control group [(2.42 ±0.47) pg/ml vs.(2.90 ±0.44) pg/ml] (P＜0.05).(3)Both of the occurrence of moderate to severe BPD and the plasma NT－pro BNP level on day 28 in the dexamethasone treated group were lower than that in the non－treated group (3/30 vs.8/19) and [(2.72 ±0.51) pg/ml vs.(3.09 ±0.30) pg/ml](P＜0.05).The plasma NT－proBNP level in the infants with BPD was higher than that in the infants without it and the difference was statistically significant ( P＜0.05).Conclusion Dexamethasone could reduce the incidence of BPD and the level of plasma NT －proBNP in infants with severe RDS.The plasma NT－pro BNP level was associated with the occurrence and severity of BPD, thus dynamic monitoring its change could be beneficial.