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

ABSTRACT

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.