Inhaled nitric oxide in newborn and paediatric patients with pulmonary hypertension and moderate to severe impaired oxygenation: Effects of doses of 3-100 parts per million

Objective: To assess the effects of inhaled nitric oxide (INO) 3-100 ppm on oxygenation in both newborn and paediatric patients with pulmonary hypertension and impaired gas exchange. Design: Open, prospective, multicentre study. Setting: Tertiary neonatal and paediatric intensive care units in university referral centres. Patients: Newborn (age less than or equal to 7 days; n = 26) and paediatric (age 8 days-7 years; n = 16) patients with pulmonary hypertension verified by echocardiography and an oxygenation index of (OI) 15-40 were included in the study. Interventions: The patients were subjected to stepwise increases in doses of INO (0, 3, 10, 30, 60, 100 ppm). Measurements and results: The effect on oxygenation was measured by repeated blood gas analysis. A positive response to INO was defined as a reduction in OI of greater than or equal to 25 % compared to baseline (0 ppm). INO was found to improve oxygenation in both newborn (p < 0.0001) and paediatric (p = 0.015) patients and the response rate was 77 and 50 %, respectively. A marked interindividual difference in the magnitude of the response was found between patients (change in OI compared to baseline: - 90 to 15 %). Only 2 of 28 responding patients required doses in excess of 30 ppm in order to show a positive response. Conclusions: INO is capable of improving oxygenation in both newborn and paediatric patients with pulmonary hypertension and impaired gas exchange, although the magnitude of the individual response can vary greatly. Doses in excess of 30 ppm are only rarely required in order to achieve a reduction in the oxygenation index of greater than or equal to 25 %.