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 (FIO 2 ) >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 [CI 1.461-7.292]) but not in infants with HRF who were treated with iNO (OR = 1.626 [CI 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.