Abstract 148

The aim of the study was to assess cardiac output (CO) in premature neonates with respiratory distress syndrome (RDS) and symptomatic patent ductus arteriosus (PDA), and compare it with neonates without PDA. Study groups: We compared 61 premature neonates with symptomatic PDA treated with Indomethacin, mean BW: 1096±256g, mean GA: 28.7±2.9wga, and control group of 32 premature neonates without PDA, mean BW: 1123±229g and mean GA: 28.2±2.5wga. All of them in both groups had RDS. Methods: CO (ml/kg/min) was measured with noninvasive echocardiography based on calculations of stroke volume and heart rate (HR). Acuson 128XP was used to obtain all echocardiographic examinations. The measurements were performed in both groups in that same time point of life. First exam was done after confirmed diagnosis of PDA on 4th day of life for all neonates, followed by four others within 7 days from the enrollment to study. Student T test and ANOVA were used for statistical analysis. Results: Of 61 with PDA, 46 (75%) responded to treatment, 15 (25%) did not respond. We compared CO between all these three groups; group A (46) with PDA and responded to treatment, group B (15) with PDA and no response to treatment, and group C (32) control group, without PDA. We found: 1) in group A and B CO was over 50% higher than in group C on the first day of study (p<0.001), 2) successful closure with Indomethacine decreased CO to the normal values within 7 days after treatment, 3) in group B there was significant increase in CO in comparison to group C within 7 days from enrollment to study (p<0.001) (see table), 4) comparison of HR in groups A,B and C showed physiologic decrease in HR only in group A (to the level of group C), there was no decrease in HR in B. Conclusions: We conclude that increase in CO seen in infants with PDA was not due to increase in HR (as is usually thought), but change in stroke volume, since there was no increase in HR between the infants within and without PDA, HR=146±16 and 140±13 (p<0.05) respectively, prior to study.

Table 1 No caption available
Full size table

none