The safety and efficacy of nitric oxide therapy in premature infants

Objectives To assess the safety-efficacy balance of low-dose inhaled nitric oxide (iNO) in hypoxemic premature infants because no sustained beneficial effect has been demonstrated clearly and there are concerns about side effects. Study design Eight hundred and sixty infants < 32 weeks were randomized at birth to receive 5 ppm iNO or placebo when they presented with hypoxemic respiratory failure (HRF) defined by a requirement for mechanical ventilation, fraction of inspired oxygen (FIO2) > 40%, and arterio-alveolar ratio in oxygen (aAO(2)) < 0.22. The primary end point was intact survival at 28 days of age. Results Sixty-one of 415 infants presented with HRF and were compared with 84 of 445 controls who presented with HRF. There was no difference in the primary end point (61.4% in infants [23% with HRF who were treated with iNO] vs 61.1% in controls [21.4% in controls with HRF]; P = .943). For the infants with HRF who were treated with iNO, there was no significant difference from controls for intraventricular hemorrhage (IVH) (6% vs 7%), necrotizing enterocolitis (8% vs 6 %), or patent ductus arteriosus (PDA) (34% vs 37%). Compared with nonhypoxemic infants, the risk of bronchopulmonary displasia (BPD) increased significantly in HRF controls (OR = 3.264 [Cl 1.461-7.292]) but not in infants with HRF who were treated with iNO (OR = 1.626 [Cl 0.633-4.178]). Conclusions iNO appears to be safe in premature infants but did not lead to a significant improvement in intact survival on day 28.