Inhaled Nitric Oxide(INO) is the one of the most potent selective pulmonary vasodilators described. Although several multi-center studies have been reported, these suffer from inherent inter-institutional biases. We report here our single center experience of 182 neonates with pulmonary hypertension(PH) treated with INO. 87% of the babies were referred from other hospitals. INO was commenced when there was severe hypoxemia despite optimal conventional ventilation and/or high frequency oscillation. PH was confirmed by echocardiography. None of the infants were hyperventilated and no attempts were made to induce alkalosis. Mean gestational age was 38 weeks (range 24-42). Underlying diagnoses are tabulated below. INO was tolerated well, without obvious side effects, median duration of ventilation being 6 days. Responses were categorised as per criteria described by Goldman (Pediatrics 98:706-713,1996) and are tabulated below. Median Oxygenation Index prior to commencing INO was 49.8(range 14-180) and dropped to 19.9(2-88)within 12 hours. Overall survival was 75%.

We conclude that INO is an effective and well tolerated therapy for PH in the neonate despite not treating them with a regimen utilising hyperventilation or alkalosis. Patients with MAS and PPHN were found to have the best response to INO. Table

Table 1 No caption available.
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