Dynamic Monitoring Of The Change In Hemodynamics In Preterm Infants Developing Bronchopulmonary Dysplasia

Objective:To investigate the change in hemodynamics and its significance in preterm infants developing bronchopulmonary dysplasia(BPD).Methods: Selected from september 2018 to june 2019 and nineteen 59 premature infants with NICU gestational age less than 32 weeks and birth weight less than 1800 g in the Department of Newborn medicine,the Affiliated Hospital of Southwest Medical University,excluding congenital heart disease(CHD),congenital chromosomal abnormalities,congenital lung bronchogenic abnormalities.According to the diagnostic and grading criteria for BPD,59 preterm infants who met the inclusion criteria were divided into non-BPD group with 27 infants,mild BPD group with 9 infants,moderate BPD group with 13 infants,and severe BPD group with 10 infants.A noninvasive cardiac output monitor was used for dynamic monitoring of hemodynamic parameters on days 1,7,and 28 after birth,and the correlation of these parameters with brain natriuretic peptide(BNP)concentration on day 28 after birth was analyzed in preterm infants developing BPD.The hemodynamic indexes include :1.blood flow index: heart rate(heart rate,HR),stroke output/pastoral output index(stroke volume/index,SV/SI),cardiac output/cardiac index(cardiac output/index,CO/CI);2.cardiac contractility index: myocardial contractility index(Index of Contractility,ICON),left ventricular ejection time(left ventricular ejection time,LVET),systolic time ratio(systolic Time ratio,STR);3.fluid status: pleural fluid level(thoracic fluid content,TFC).The data were analyzed using spss 19.0 software for statisticalanalysis,the measured data were expressed by SX ?,the qualitative data were expressed by rate(%);A repeated ANOVA was used to compare the mean of quantitative data in many groups at different time points,and LSD test was used to compare the hemodynamic indexes between groups according to the homogeneity of variance.The correlation between hemodynamic index and plasma BNP concentration in BPD group was analyzed by linear regression analysis,P <0.05 indicated that the difference was statistically significant.Results: Compared with the non-BPD group,the values of cardiac output/cardiac index(CO/CI)of each group were decreased in 1d,14 d and 28 d after birth,and the difference was statistically significant(p <0.05),.Compared with the mild and moderate BPD group,the CO/CI values of the severe BPD group were decreased in 1d,7d and 28 d after birth,and the difference was statistically significant(p <0.05),there were no significant difference in the CO/CI values of among the above groups at each time point(p >0.05).Compared with the non-BPD group,the values of stoke volume/index(SV/SI)of each BPD group was lower in1 d and 28 d after birth,and the difference was statistically significant in the other groups(p<0.05).the SV/SI values of the severe BPD group were decreased in 1d,7d and 28 d after birth,and the difference was statistically significant(p<0.05)compared with the non-BPD,mild and moderate BPDgroup.there were no significant difference in the SV/SI values of among the above groups at each time point(p >0.05).Compared with the non-BPD group,mild and moderate BPD group,the left ventricular ejection time(LVET)values of the severe BPD group were decreased at 7d and 28 d after birth,and the difference was statistically significant(p <0.05).there were no significant difference in the LVET values of among the above groups at each time point(p >0.05).Compared with the non-BPD group,the systolic time ratio(STR)of the moderate and severe BPD group wereincreased in the 28 d after birth,and the difference was statistically significant(p< 0.05).Compared with each other of the rest groups at various time points,and the difference was not statistically significant(p>0.05).Compared with the non-BPD group,the heart rate(HR),thoracic fluid content(TFC)and Index of Contractility(ICON)of the BPD groups were not significantly different in 1d,7d and 28 d after birth(p>0.05).Compared with the non-BPD group,the Plasma BNP concentration in BPD group was increased in 28 d after birth,the difference was statistically significant(p<0.05),and the concentration of BNP negatively correlated with changes in CO/CI(r=-0.714,P <0.05),SV/SI(r=-0.4,P <0.05)in28d and positively correlated with changes in STR(r=0.722,P<0.05).Conclusion: There are different degree of hemodynamic changes in the process of developing bronchopulmonary dysplasia in preterm infants,and the dynamic monitoring of cardiac output parameters is beneficial to early evaluation of cardiac function changes in preterm infants with BPD using Non-invasive cardiac output monitor.