INHALED NITRIC-OXIDE IN FULL-TERM AND NEARLY FULL-TERM INFANTS WITH HYPOXIC RESPIRATORY-FAILURE

Background Neonates with pulmonary hypertension have been treated with inhaled nitric oxide because of studies suggesting that it is a selec tive pulmonary vasodilator. We conducted a randomized, multicenter, co ntrolled trial to determine whether inhaled nitric oxide would reduce mortality or the initiation of extracorporeal membrane oxygenation in infants with hypoxic respiratory failure, Methods Infants born after a gestation of greater than or equal to 34 weeks who were 14 days old o r less, had no structural heart disease, and required assisted ventila tion and whose oxygenation index was 25 or higher on two measurements were eligible for the study. The infants were randomly assigned to rec eive nitric oxide at a concentration of 20 ppm or 100 percent oxygen ( as a control). Infants whose partial pressure of arterial oxygen (PaO2 ) increased by 20 mm Hg or less after 30 minutes were studied for a re sponse to 80-ppm nitric oxide or control gas, Results The 121 infants in the control group and the 114 in the nitric oxide group had similar base-line clinical characteristics. Sixty-four percent of the control group and 46 percent of the nitric oxide group died within 120 days o r were treated with extracorporeal membrane oxygenation (P=0.006). Sev enteen percent of the control group and 14 percent of the nitric oxide group died (P not significant), but significantly fewer in the nitric oxide group received extracorporeal membrane oxygenation (39 percent vs. 54 percent, P=0.014). The nitric oxide group had significantly gre ater improvement in PaO2 (mean [+/-SD] increase, 58.2+/-85.2 mm Hg, vs . 9.7+/-51.7 mm Hg in the controls; P<0.001) and in the oxygenation in dex (a decrease of 14.1+/-21.1, vs, an increase of 0.8+/-21.1 in the c ontrols; P<0,001). The study gas was not discontinued in any infant be cause of toxicity. Conclusions Nitric oxide therapy reduced the use of extracorporeal membrane oxygenation, but had no apparent effect on mo rtality, in critically ill infants with hypoxic respiratory failure. ( C) 1997, Massachusetts Medical Society.