Persistent Pulmonary Hypertension of the Newborn: Experience in a Single Institution

Abstract

Persistent pulmonary hypertension of the newborn (PPHN) remains one of the most challenging situations in the neonatal intensive care unit, and it is associated with high mortality and morbidity. The optimal treatment for PPHN is controversial. We report our 9-year experience in the management of PPHN through a retrospective review of 29 neonates with persistent pulmonary hypertension. The diagnosis of PPHN is made by echocardiography and/or preductal and postductal oxygen tension difference . The treatment modalities include supportive medical care, vasodilator therapy, mechanical ventilation and correction of underlying conditions. The wide diversity of etiologies of PPHN, the complications of vasodilator therapy, the management of assisted ventilation, the mortality and the morbidity are evaluated. There are 29 patients enrolled in this study, including 18 male and 11 female babies. Twenty- two patients (72%) are referred from other hospitals. The mean birth body weight is 2707 +/- 693 grams (range: 1450- 4100 grams) and the mean gestational age is 37.1 +/- 3 .1 weeks (range: 31-41 weeks). The underlying clinical conditions include meconium aspiration syndrome (n = 8), perinatal asphyxia (n = 7), respiratory distress syndrome (n = 5), sepsis and/or pneumonia (n = 4), congenital diaphragmatic hernia (n = 3) and idiopathic persistent fetal circulation (n = 2). In addition to supportive medical care and correction of underlying clinical conditions, most of the patients receive vasodilator therapy (Tolazoline) and nonhyperventilation respirator management. The overall mortality rate is 27.6% (8/29). The duration on ventilator therapy in the survival group (9.3 +/- 8.6 days) is not significantly different from in the mortality group (6.0 +/- 7.1 days) (p = 0.13). There is also no statistically significant difference between these two groups both in the maximal alveolar-arterial oxygen tension difference (594 +/- 53 mmHg and 613 +/- 37 mmHg, p = 0.145) and in the maximal oxygenation index (49.7 +/- 29.6 and 61.1 +/- 36.9, p = 0. 172) before vasodilator therapy. However, twenty-four hours after treatment, these two parameters change significantly with the former changes to 426 + /- 198 mmHg and 643 +/- 7 mmHg, respectively (p < 0.001), and the latter changes to 21 .6 +/- 15.8 and 82.3 +/- 54.8, respectively (p < 0.001). Skin rash, gastrointestinal hemorrhage, hypotension and hyponatremia are the most common complications of Tolazoline therapy. Eight patients have pulmonary complications including pneumothorax (n = 5) and pulmonary interstitial emphysema (n = 3). Two patients develop chronic lung disease . Three patients have neurodevelopmental handicap. In conclusion, we achieve a survival rate of nearly 75% in PPHN mainly with the administration of Tolazoline therapy and the nonhyperventilation respirator approach. Further well- controlled and multicenter studies with newer treatment modalities are crucial for the improvement of survival of PPHN in Taiwan.