Risk Factors of Paternt Ductus Arteriosus in Very Low Birth Weight infants

ABSTRACT

PURPOSE: Hemodynamically significant patent ductus arteriosus (PDA) may increase the mortality of premature infants who received ventilator care by aggravating hypoxia, acidosis, pulmonary edema and hypotension. The risk factors for PDA in premature infants are low gestational age, infusion of excessive fluid, and severity of neonatal respiratory distress syndrome. We studied the risk factors of PDA in very low birth weight infants (VLBW) to establish a guideline for the treatment. METHODS: VLBW infants who were born at Severance Hospital, Yonsei Medical Center from January, 1989 through December, 1995 and survived for at least 5 days with ventilator care were recruited for this study. Patent ductus arteriosus was diagnosed according to the clinical diagnostic criteria of Yeh (Yeh et al, 1981b). Thirty six infants had diagnosed as PDA (PDA group), and thirty seven infants who had not PDA were selected as control. Both groups of infants received restrictive fluid therapy. RESULTS: 1) Gestational age, sex, Apgar score, administration of surfactant, mode of delivery, toxemia and use of antenatal dexamethasone were similar between PDA and control infants. 2) In PDA group, ventilatory index and duration of vetilator care were significantly greater (P<0.05), and a/ApO2 was significantly lower than control group (P<0.05). There was no difference in peak inspiratory pressure at initial setting, the highest peak inspiratory pressure and mean airway pressure during ventilator care. 3) During the first 3 days of life, the urine output was similar between groups. On the 4th and 5th days of life, PDA group had significantly reduced urine ouput compared with control (on day 4; 2.6+/-1.1 ml/kg/h vs. 3.2+/-1.2ml/kg/h, P<0.05; on day 5, 2.9+/-1.4ml/kg/h vs. 3.6+/-1.6ml/kg/h, P<0.05) . 4) The percent weight loss compared to birth weight was siginificantly lower in PDA group (12.5% vs. 15.1%, P<0.05). 5) The PDA group had higher incidences of bronchpulmonary dysplasia and intraventricular hemorrhage (P<0.05). CONCLUSION: Among Vlnfants who received restrictive fluid therapy during the first 5 days of life, infants with PDA had reduced urine output and percent weight loss than control group.