The Effects of Patent Ductus Arteriosus on Pulmonary Function in Infants with Respiratory Distress Syndrome

PURPOSE: Patent ductus arteriosus (PDA) is a common problem in infants with respiratory distress syndrome (RDS). The reported effects of closure of ductus on pulmonary function are variable. The purpose of this study was to compare the respiratory indices between infants with RDS with and without PDA and in infants with PDA, between before and after closure of PDA. METHODS: The respiratory indices, settings of mechanical ventilation and arterial blood gas analysis were investigated in 31 infants who were admitted to Seoul National University Hospital NICU from June 1998 to May 1999 with a diagnosis of RDS. The respiratory parameters were compared between infants with and without PDA. In the infants with PDA, the parameters were compared before and after closure of PDA with administration of indomethacin. The diagnosis of a significant PDA was made by cardiovascular distress scoring of greater than 3 and echocardiographic confirmation of ductal shunt. RESULTS: Nineteen infants (61.3%) were diagnosed with PDA and 4 infants were excluded due to failure of closure. Infants with PDA showed lesser pre-surfactant PaCO2 (32.5+/-10.5 vs 43.5+/-8.5, P<0.05) and lesser total pulmonary compliance (0.65+/-0.20 vs 1.05+/-0.17, P<0.01), tidal volume (4.78+/-1.53 vs 7.19+/-2.02, P<0.05) and higher airway resistance (435+/-44 vs 301+/-49, P<0.01) at 12 hours after surfactant treatment than infants without PDA. In infants with PDA, oxygenation index (7.27+/-9.84 vs 3.29+/-6.21, P<0.05) and airway resistance(439+/-45 vs 291+/-93, P<0.05) were decreased and total pulmonary compliance (0.55+/-0.21 vs 1.35+/-0.48, P<0.05) were increased after closure of PDA. CONCLUSIONS: The pulmonary functions were poor in infants with PDA and closure of the ductus with indomethacin lead into a significant improvement in pulmonary function.

Predictors of Clinical Outcome in the Newborns of Persistent Pulmonary Hypertension Treated with Inhaled Nitric Oxide

PURPOSE: Inhaled nitric oxide (iNO) has been known to improve oxygenation in newborns with persistent pulmonary hypertension (PPHN). This study was performed to evaluate the predictors of clinical outcome in the newborn infants with PPHN treated with iNO. METHODS: Between September 1998 and August 2002, 23 newborn infants with PPHN treated with iNO were enrolled in this study. Reduction of oxygenation index (OI) and AaDO2 to 30% or more were defined as clinical response. Accoding to the response time within or after 12 hours, the clinical response was sub-categorized as early or delayed response, respectively. RESULTS: The mean gestational age and birth weight of 23 newborn infants were 36.7+/-4.4 weeks and 2,644+/-907 g. The mean baseline OI and AaDO2 were 22.20+/-13.63 and 477.16+/-127.96. There were ten non-responsders, eight early responsders and five delayed responders. Eleven neonates showed sustained response for 24 hours. The mean AaDO2, and PaO2 were decreased after 12 hours (P<0.05), while there was no difference in oxygenation index, arteral pH and PaCO2. The mortality rates of non-responders or not- sustained responders were higher than those of responders or sustained responders (P< 0.05). The birth weight of death group was lower than that of survival group and AaDO2, and OI at 12 hours after iNO therapy in survival group were lower than those in death group. CONCLUSION: Predictors of the clinical outcome of iNO therapy were clinical response patterns after iNO therapy, time taken until clinical response, duration of response and change of oxygenation at 12 hours after iNO therapy.

Predictors of Clinical Outcome in the Newborns of Persistent Pulmonary Hypertension Treated with Inhaled Nitric Oxide

PURPOSE: Inhaled nitric oxide (iNO) has been known to improve oxygenation in newborns with persistent pulmonary hypertension (PPHN). This study was performed to evaluate the predictors of clinical outcome in the newborn infants with PPHN treated with iNO. METHODS: Between September 1998 and August 2002, 23 newborn infants with PPHN treated with iNO were enrolled in this study. Reduction of oxygenation index (OI) and AaDO2 to 30% or more were defined as clinical response. Accoding to the response time within or after 12 hours, the clinical response was sub-categorized as early or delayed response, respectively. RESULTS: The mean gestational age and birth weight of 23 newborn infants were 36.7+/-4.4 weeks and 2,644+/-907 g. The mean baseline OI and AaDO2 were 22.20+/-13.63 and 477.16+/-127.96. There were ten non-responsders, eight early responsders and five delayed responders. Eleven neonates showed sustained response for 24 hours. The mean AaDO2, and PaO2 were decreased after 12 hours (P<0.05), while there was no difference in oxygenation index, arteral pH and PaCO2. The mortality rates of non-responders or not- sustained responders were higher than those of responders or sustained responders (P< 0.05). The birth weight of death group was lower than that of survival group and AaDO2, and OI at 12 hours after iNO therapy in survival group were lower than those in death group. CONCLUSION: Predictors of the clinical outcome of iNO therapy were clinical response patterns after iNO therapy, time taken until clinical response, duration of response and change of oxygenation at 12 hours after iNO therapy.