Inhaled nitric oxide for the early treatment of persistent pulmonary hypertension of the term newborn: a randomized, double-masked, placebo-controlled, dose-response, multicenter study. The I-NO/PPHN Study Group. Inhaled nitric oxide in full-term and nearly full-term infants with hypoxic respiratory failure. Inhaled nitric oxide in term infants with hypoxemic respiratory failure. A randomized trial of early versus standard inhaled nitric oxide therapy in term and near-term newborn infants with hypoxic respiratory failure. Inhaled nitric oxide in the treatment of moderate persistent pulmonary hypertension of the newborn: a randomized controlled, multicenter trial. Inhaled nitric oxide and persistent pulmonary hypertension of the newborn. The Inhaled Nitric Oxide Study Group. Acute response to inhaled nitric oxide in newborns with respiratory failure and pulmonary hypertension. Low-dose nitric oxide therapy for persistent pulmonary hypertension of the newborn. Clinical Inhaled Nitric Oxide Research Group. Randomized, controlled trial of low-dose inhaled nitric oxide in the treatment of term and near-term infants with respiratory failure and pulmonary hypertension. Early compared with delayed inhaled nitric oxide in moderately hypoxaemic neonates with respiratory failure: a randomised controlled trial. The Franco-Belgium Collaborative NO Trial Group. Randomized, multicenter trial of inhaled nitric oxide and high-frequency oscillatory ventilation in severe, persistent pulmonary hypertension of the newborn. Inhaled nitric oxide and hypoxic respiratory failure in infants with congenital diaphragmatic hernia. The Neonatal Inhaled Nitric Oxide Study Group (NINOS). Inhaled nitric oxide reduces the need for extracorporeal membrane oxygenation in infants with persistent pulmonary hypertension of the newborn.
To assess the dose-related effects of inhaled nitric oxide (I-NO) as a specific adjunct to early conventional therapy for term infants with persistent pulmonary hypertension (PPHN), with regard to neonatal outcome, oxygenation, and safety.
                Randomized, placebo-controlled, double-masked, dose-response, clinical trial at 25 tertiary centers from April 1994 to June 1996. The primary endpoint was the PPHN Major Sequelae Index ([MSI], including the incidence of death, extracorporeal membrane oxygenation (ECMO), neurologic injury, or bronchopulmonary dysplasia [BPD]). Patients required a fraction of inspired oxygen [FIO2] of 1.0, a mean airway pressure >/=10 cm H2O on a conventional ventilator, and echocardiographic evidence of PPHN. Exogenous surfactant, concomitant high-frequency ventilation, and lung hypoplasia were exclusion factors. Control (0 ppm) or nitric oxide (NO) (5, 20, or 80 ppm) treatments were administered until success or failure criteria were met. Due to slowing recruitment, the trial was stopped at N = 155 (320 planned).
                The baseline oxygenation index (OI) was 24 +/- 9 at 25 +/- 17 hours old (mean +/- SD). Efficacy results were similar among NO doses. By 30 minutes (no ventilator changes) the PaO2 for only the NO groups increased significantly from 64 +/- 39 to 109 +/- 78 Torr (pooled) and systemic arterial pressure remained unchanged. The baseline adjusted time-weighted OI was also significantly reduced in the NO groups (-5 +/- 8) for the first 24 hours of treatment. The MSI rate was 59% for the control and 50% for the NO doses (P = .36). The ECMO rate was 34% for control and 22% for the NO doses (P = .12). Elevated methemoglobin (>7%) and nitrogen dioxide (NO2) (>3 ppm) were observed only in the 80 ppm NO group, otherwise no adverse events could be attributed to I-NO, including BPD.
                For term infants with PPHN, early I-NO as the sole adjunct to conventional management produced an acute and sustained improvement in oxygenation for 24 hours without short-term side effects (5 and 20 ppm doses), and the suggestion that ECMO use may be reduced. Neonates with pulmonary hypertension have been treated with inhaled nitric oxide because of studies suggesting that it is a selective pulmonary vasodilator. We conducted a randomized, multicenter, controlled trial to determine whether inhaled nitric oxide would reduce mortality or the initiation of extracorporeal membrane oxygenation in infants with hypoxic respiratory failure.
                Infants born after a gestation of > or =34 weeks who were 14 days old or less, had no structural heart disease, and required assisted ventilation and whose oxygenation index was 25 or higher on two measurements were eligible for the study. The infants were randomly assigned to receive 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 response to 80-ppm nitric oxide or control gas.
                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 or were treated with extracorporeal membrane oxygenation (P=0.006). Seventeen 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 greater improvement in PaO2 (increase, 58.2+/-85.2 mm Hg, vs. 9.7+/-51.7 mm Hg in the controls; P<0.001) and in the oxygenation index (a decrease of 14.1+/-21.1, vs. an increase of 0.8+/-21.1 in the controls; P<0.001). The study gas was not discontinued in any infant because of toxicity.
                Nitric oxide therapy reduced the use of extracorporeal membrane oxygenation, but had no apparent effect on mortality in critically ill infants with hypoxic respiratory failure. To determine whether inhaled nitric oxide (NO) administered during conventional mechanical ventilation could produce improvements in oxygenation and reduce the incidence of meeting extracorporeal membrane oxygenation (ECMO) criteria in infants with hypoxemia.
                Prospective, randomized, controlled trial. Enrolled infants were assigned to conventional treatment with or without adjunctive inhaled NO. Control infants meeting failure criteria (partial pressure of arterial oxygen (PaO2)<80 mm Hg (10.7 kPa)) were allowed to cross over. Caregivers were not masked to group assignment.
                Neonatal intensive care units at the University of Alabama Hospital and the Children's Hospital of Alabama, October 1993 to May 1994.
                Newborn infants, both term and near-term, with PaO2 less than 100 mm Hg (13.3 kPa) who were receiving mechanical ventilation with 100% oxygen. Exclusion criteria included major congenital anomalies, diaphragmatic hernia, profound asphyxia, and significant bleeding.
                Inhaled NO was initiated in the NO group at a dose of 20 to 40 ppm and advanced stepwise to 80 ppm if PaO2 remained less than 100 mm Hg (13.3 kPa).
                Primary outcome variables were treatment failure and meeting of ECMO criteria before crossover. Improvement in oxygenation and ultimate use of ECMO or high-frequency oscillatory ventilation were secondary outcome variables.
                Seventeen neonates with hypoxemia were enrolled; 16 had echocardiographic evidence of pulmonary hypertension, and eight had extrapulmonary shunting. At 1 hour of treatment, two infants in the NO group responded with increases in PaO2 of more than 100 mm Hg (13.3 kPa); after crossover, two had increases in PaO2 of more than 10 mm Hg (1.3 kPa) and one control infant had an increase in PaO2 of more than 10 mm Hg (1.3 kPa). All control infants met failure criteria and crossed over to receive NO; two had increases in PaO2 of more than 10 mm Hg (1.3 kPa) with NO treatment. Despite initial responses, all subjects in both groups eventually met failure criteria. There were no differences between groups in primary outcome variables.
                Although inhaled NO produced a transient improvement in oxygenation in some infants, it did not reduce the incidence of meeting ECMO criteria in this population. Inhaled nitric oxide (iNO) reduces the use of extracorporeal membrane oxygenation (ECMO)/incidence of death in term and near-term neonates with severe hypoxic respiratory failure. We conducted a randomized, double masked, multicenter trial to determine whether administration of iNO earlier in respiratory failure results in additional reduction in the incidence of these outcomes.
                Neonates who were born at > or =34 weeks' gestation were enrolled when they required assisted ventilation and had an oxygenation index (OI) > or =15 and <25 on any 2 measurements in a 12-hour interval. Infants were randomized to early iNO or to simulated initiation of iNO (control). Infants who had an increase in OI to 25 or more were given iNO as standard therapy.
                The trial enrollment was halted after 75% of target sample size was reached because of decreasing availability of eligible patients. The 150 infants who were given early iNO and 149 control infants had similar baseline characteristics. Arterial oxygen tension increased by >20 mm Hg in 73% of early iNO and 37% of control infants after study gas initiation. Control infants received standard iNO and deteriorated to OI >40 more often than infants who were given early iNO. The incidence of death (early iNO, 6.7% vs control, 9.4%), ECMO (10.7% vs 12.1%), and their combined incidence (16.7% vs 19.5%) were similar in both groups.
                iNO improves oxygenation but does not reduce the incidence of ECMO/mortality when initiated at an OI of 15 to 25 compared with initiation at >25 in term and near-term neonates with respiratory failure. Inhaled nitric oxide (iNO) improves oxygenation and reduces the need for extracorporeal membrane oxygenation in infants with severe persistent pulmonary hypertension of the newborn (PPHN). The effectiveness of iNO in the treatment of moderate PPHN has not been adequately defined. We therefore conducted a randomized, prospective multicenter study to assess whether iNO in patients with moderate PPHN would improve arterial p(a)O(2), prevent progression to severe PPHN, and improve outcomes.
                Infants > or = 34 weeks gestation with moderate pulmonary hypertension (alveolar-arterial oxygen gradient (AaDO(2)) 500-599 Torr) were randomly assigned to continue standard medical therapy (control group) or standard medical therapy plus iNO (iNO group). For each patient in the iNO group, iNO concentration was increased in steps of 10-20 ppm every 30 minutes until there was no further improvement in arterial p(a)O(2). This concentration of iNO was then maintained while all other ventilatory support, including inspired oxygen concentration, was weaned according to a predefined protocol.
                In all, 27 of 40 control patients (58%) compared to six of 40 infants (15%) in the iNO group failed assigned therapy and developed severe PPHN (p<0.0005). Arterial p(a)O(2) improved from 112+/-48 to 133+/-100 (p=0.132) in control infants compared to an increase from 101+/-29 to 208+/-118 (p<0.0005) in iNO-treated patients. For the first 36 hours after study, entry AaDO(2) levels and ventilatory support were significantly lower in iNO-treated infants compared to control patients.
                In patients with moderate PPHN, treatment with iNO improves arterial p(a)O(2), reduces the amount of ventilatory support needed, and prevents progression to severe PPHN. Persistent pulmonary hypertension of the newborn causes systemic arterial hypoxemia because of increased pulmonary vascular resistance and right-to-left shunting of deoxygenated blood. Inhaled nitric oxide decreases pulmonary vascular resistance in newborns. We studied whether inhaled nitric oxide decreases severe hypoxemia in infants with persistent pulmonary hypertension.
                In a prospective, multicenter study, 58 full-term infants with severe hypoxemia and persistent pulmonary hypertension were randomly assigned to breathe either a control gas (nitrogen) or nitric oxide (80 parts per million), mixed with oxygen from a ventilator. If oxygenation increased after 20 minutes and systemic blood pressure did not decrease, the treatment was considered successful and was continued at lower concentrations. Otherwise, it was discontinued and alternative therapies, including extracorporeal membrane oxygenation, were used.
                Inhaled nitric oxide successfully doubled systemic oxygenation in 16 of 30 infants (53 percent), whereas conventional therapy without inhaled nitric oxide increased oxygenation in only 2 of 28 infants (7 percent). Long-term therapy with inhaled nitric oxide sustained systemic oxygenation in 75 percent of the infants who had initial improvement. Extracorporeal membrane oxygenation was required in 71 percent of the control group and 40 percent of the nitric oxide group (P=0.02). The number of deaths was similar in the two groups. Inhaled nitric oxide did not cause systemic hypotension or increase methemoglobin levels.
                Inhaled nitric oxide improves systemic oxygenation in infants with persistent pulmonary hypertension and may reduce the need for more invasive treatments. Systemic oxygenation is improved by inhaled nitric oxide therapy in some newborns with respiratory failure and pulmonary hypertension. Our results with inhaled nitric oxide were reviewed to determine factors associated with an acute improvement in systemic oxygenation.
                Newborns with oxygenation indices of 25 to 40 were prospectively randomized to receive conventional therapy with or without 20 ppm inhaled nitric oxide. All newborns with oxygenation indices greater than 40 were treated with inhaled nitric oxide. Hemodynamic, blood gas, and Doppler ultrasound measurements were performed before and after 30 to 60 minutes of observation or therapy. The severity of lung disease was classified by the chest radiograph as: (1) normal or focal disease; (2) moderate diffuse disease-diffuse lung disease with well-defined heart borders; or (3) severe diffuse disease-diffuse lung opacification with indistinct heart borders.
                Heart rate, blood pressure, and ductal diameters did not change. Blood gases and ductal shunting acutely improved only in patients treated with inhaled nitric oxide. Patients with normal lung fields or focal disease had the greatest degree of improvement in systemic oxygenation. Changes in oxygenation were not influenced by gestational age, baseline blood gases, the proportion of right-to-left ductal shunting, prior treatment with a surfactant, or the use of conventional or high-frequency jet ventilation. Collectively, blood gases and ductal shunting did not improve with inhaled nitric oxide in patients with lung hypoplasia or severe diffuse lung disease. Sustained improvement in oxygenation occurred in 87% of patients with oxygenation indices greater than 40 in whom oxygenation indices less than 40 acutely developed after exposure to nitric oxide, whereas 90% of patients in whom oxygenation indices less than 40 did not acutely develop were treated with extracorporeal membrane oxygenation or ultimately died.
                Inhaled nitric oxide acutely improves systemic oxygenation in many newborns with respiratory failure and pulmonary hypertension. The diagnosis and chest radiograph are helpful in identifying patients who will have favorable acute responses to therapy. In patients with severe hypoxemia, the need for invasive support with extracorporeal membrane oxygenation may be determined by an acute trial of inhaled nitric oxide. Inhaled nitric oxide improves gas exchange in neonates, but the efficacy of low-dose inhaled nitric oxide in reducing the need for extracorporeal membrane oxygenation has not been established.
                We conducted a clinical trial to determine whether low-dose inhaled nitric oxide would reduce the use of extracorporeal membrane oxygenation in neonates with pulmonary hypertension who were born after 34 weeks' gestation, were 4 days old or younger, required assisted ventilation, and had hypoxemic respiratory failure as defined by an oxygenation index of 25 or higher. The neonates who received nitric oxide were treated with 20 ppm for a maximum of 24 hours, followed by 5 ppm for no more than 96 hours. The primary end point of the study was the use of extracorporeal membrane oxygenation.
                Of 248 neonates enrolled, 126 were randomly assigned to the nitric oxide group and 122 to the control group. Extracorporeal membrane oxygenation was used in 78 neonates in the control group (64 percent) and in 48 neonates in the nitric oxide group (38 percent) (P=0.001). The 30-day mortality rate in the two groups was similar (8 percent in the control group and 7 percent in the nitric oxide group). Chronic lung disease developed less often in neonates treated with nitric oxide than in those in the control group (7 percent vs. 20 percent, P=0.02). The efficacy of nitric oxide was independent of the base-line oxygenation index and the primary pulmonary diagnosis.
                Inhaled nitric oxide reduces the extent to which extracorporeal membrane oxygenation is needed in neonates with hypoxemic respiratory failure and pulmonary hypertension. Recent reports indicate that inhaled nitric oxide (iNO) causes selective pulmonary vasodilation, increases arterial oxygen tension, and may decrease the use of extracorporeal membrane oxygenation (ECMO) in infants with persistent pulmonary hypertension of the newborn (PPHN). Despite these reports, the optimal dose and timing of iNO administration in PPHN remains unclear.
                To test the hypotheses that in PPHN 1) iNO at 2 parts per million (ppm) is effective at acutely increasing oxygenation as measured by oxygenation index (OI); 2) early use of 2 ppm of iNO is more effective than control (0 ppm) in preventing clinical deterioration and need for iNO at 20 ppm; and 3) for those infants who fail the initial treatment protocol (0 or 2 ppm) iNO at 20 ppm is effective at acutely decreasing OI.
                A randomized, controlled trial of iNO in 3 nurseries in a single metropolitan area. Thirty-eight children, average gestational age of 37.3 weeks and average age <1 day were enrolled. Thirty-five of 38 infants had echocardiographic evidence of pulmonary hypertension. On enrollment, median OI in the control group, iNO at 0 ppm, (n = 23) was 33.1, compared with 36.9 in the 2-ppm iNO group (n = 15).
                Initial treatment with iNO at 2 ppm for an average of 1 hour was not associated with a significant decrease in OI. Twenty of 23 (87%) control patients and 14 of 15 (92%) of the low-dose iNO group demonstrated clinical deterioration and were treated with iNO at 20 ppm. In the control group, treatment with iNO at 20 ppm decreased the median OI from 42.6 to 23.8, whereas in the 2-ppm iNO group with a change in iNO from 2 to 20 ppm, the median OI did not change (42.6 to 42.0). Five of 15 patients in the low-dose nitric oxide group required ECMO and 2 died, compared with 7 of 23 requiring ECMO and 5 deaths in the control group.
                In infants with PPHN, iNO 1): at 2 ppm does not acutely improve oxygenation or prevent clinical deterioration, but does attenuate the rate of clinical deterioration; and 2) at 20 ppm acutely improves oxygenation in infants initially treated with 0 ppm, but not in infants previously treated with iNO at 2 ppm. Initial treatment with a subtherapeutic dose of iNO may diminish the clinical response to 20 ppm of iNO and have adverse clinical sequelae. Inhaled nitric oxide improves oxygenation in severely hypoxaemic term neonates, which lessens the need for extracorporeal-membrane oxygenation. Improvement in other relevant outcomes remains unknown, and safety of inhaled nitric oxide is uncertain in preterm neonates. We did a randomised controlled trial to assess use of inhaled nitric oxide in preterm and near-term neonates.
                We randomly assigned 204 preterm (< 33 weeks) and near-term (> or = 33 weeks) neonates with oxygenation indices from 12.5 to 30.0 and 15 to 40, respectively, 10 parts per million (ppm) inhaled nitric oxide (n=105) or control ventilation therapy without nitric oxide (n=99). The primary endpoint was the oxygenation index at 2 h. Analysis was done by intention to treat.
                12 neonates were excluded, leaving 97 (45 preterm) in the nitric-oxide group and 95 (40 preterm) in the control group. The decline in oxygenation index at 2 h was greater in the nitric-oxide group than in the control group (median 6.2 (IQR 8.4)) [corrected] vs -2.9 [12.4], p=0.005), but was significant only in near-term neonates (p=0.03). Survivors assigned nitric oxide spent fewer days on mechanical ventilation and in the neonatal intensive-care unit, but this was also significant only in near-term neonates (6 [3] vs 7 [3] days, p=0.05, and 9 [6] vs 12 [9] days, p=0.02, respectively).
                Low-dose inhaled nitric oxide early in the course of neonatal respiratory failure improves oxygenation and shortens duration of mechanical ventilation and the length of stay in intensive care. Inhaled nitric oxide was not, however, significantly beneficial in preterm neonates. Although inhaled nitric oxide (iNO) causes selective pulmonary vasodilation and improves oxygenation in newborn infants with persistent pulmonary hypertension, its effects are variable. We hypothesized (1) that the response to iNO therapy is dependent on the primary disease associated with persistent pulmonary hypertension of the newborn (PPHN) and (2) that the combination of high-frequency oscillatory ventilation (HFOV) with iNO would be efficacious in patients for whom either therapy alone had failed.
                To determine the relative roles of iNO and HFOV in the treatment of severe PPHN, we enrolled 205 neonates in a randomized, multicenter clinical trial. Patients were stratified by predominant disease category: respiratory distress syndrome (n = 70), meconium aspiration syndrome (n = 58), idiopathic PPHN or pulmonary hypoplasia (excluding congenital diaphragmatic hernia) ("other": n = 43), and congenital diaphragmatic hernia (n = 34); they were then randomly assigned to treatment with iNO and conventional ventilation or to HFOV without iNO. Treatment failure (partial pressure of arterial oxygen [PaO2] < 60 mm Hg) resulted in crossover to the alternative treatment; treatment failure after crossover led to combination treatment with HFOV plus iNO. Treatment response with the assigned therapy was defined as sustained PaO2 of 60 mm Hg or greater.
                Baseline oxygenation index and PaO2 were 48 +/- 2 and 41 +/- 1 mm Hg, respectively, during treatment with conventional ventilation. Ninety-eight patients were randomly assigned to initial treatment with HFOV, and 107 patients to iNO. Fifty-three patients (26%) recovered with the initially assigned therapy without crossover (30 with iNO [28%] and 23 with HFOV [23%]; p = 0.33). Within this group, survival was 100% and there were no differences in days of mechanical ventilation, air leak, or supplemental oxygen requirement at 28 days. Of patients whose initial treatment failed, crossover treatment with the alternate therapy was successful in 21% and 14% for iNO and HFOV, respectively (p = not significant). Of 125 patients in whom both treatment strategies failed, 32% responded to combination treatment with HFOV plus iNO. Overall, 123 patients (60%) responded to either treatment alone or combination therapy. By disease category, response rates for HFOV plus iNO in the group with respiratory syndrome and the group with meconium aspiration syndrome were better than for HFOV alone or iNO with conventional ventilation (p < 0.05). Marked differences in outcomes were noted among centers (percent death or treatment with extracorporeal membrane oxygenation = 29% to 75%).
                We conclude that treatment with HFOV plus iNO is often more successful than treatment with HFOV or iNO alone in severe PPHN. Differences in responses are partly related to the specific disease associated with PPHN. We designed and conducted a randomized, double-masked, controlled multicenter study to determine whether inhaled nitric oxide (INO) in term and near-term infants with congenital diaphragmatic hernia (CDH) would reduce the occurrence of death and/or the initiation of extracorporeal membrane oxygenation (ECMO).
                Infants of 34 weeks gestation or more, <14 days of age with CDH, without known structural heart disease, requiring assisted ventilation for hypoxemic respiratory failure with two oxygenation indices (OIs) of 25 or more at least 15 minutes apart, were eligible for this trial. Infants were centrally randomized and then received masked treatment with 20 ppm NO or 100% oxygen as control. Infants with less than a full response to 20 ppm NO (increase in PaO2 > 20 Torr) after 30 minutes were evaluated at 80 ppm NO/control study gas.
                The 28 control and 25 treated infants enrolled by the 13 participating centers were not significantly different at randomization for any of the measured variables including prerandomization therapies and initial OIs (45.8 +/- 16.3 for controls, 44.5 +/- 14.5 for INO). Death at <120 days of age or the need for ECMO occurred in 82% of control infants compared with 96% of INO infants (ns). Death occurred in 43% of controls and 48% of the INO group (ns), and ECMO treatment was used for 54% of control and 80% of INO-treated infants. There was no significant improvement in PaO2 (delta PaO2 7.8 +/- 19.8 vs 1.1 +/- 7.6 Torr, ns) nor significant reduction in OI (-2.7 +/- 23.4 vs 4.0 +/- 14.8, ns) associated with INO treatment. Mean peak nitrogen dioxide (NO2) concentration was 1.9 +/- 1.3 ppm and the mean peak methemoglobin was 1.6 +/- 0.8 mg/dL. No infant had study gas discontinued for toxicity. There were no differences between the control and INO groups for the occurrence of intracranial hemorrhage, specific grades of intracranial hemorrhage, periventricular leukomalacia, brain infarction, and pulmonary or gastrointestinal hemorrhages.
                Although the immediate short-term improvements in oxygenation seen in some treated infants may be of benefit in stabilizing responding infants for transport and initiation of ECMO, we conclude that for term and near-term infants with CDH and hypoxemic respiratory failure unresponsive to conventional therapy, inhaled NO therapy as used in this trial did not reduce the need for ECMO or death. We previously reported improved oxygenation, but no change, in rates of extracorporeal membrane oxygenation (ECMO) use or death among infants with persistent pulmonary hypertension of the newborn who received inhaled nitric oxide (NO) with conventional ventilation, irrespective of lung disease. The goal of our study was to determine whether treatment with inhaled NO improves oxygenation and clinical outcomes in infants with persistent pulmonary hypertension of the newborn and associated lung disease who are ventilated with high-frequency oscillatory ventilation (HFOV).
                Single-center, prospective, randomized, controlled trial.
                Newborn intensive care unit of a tertiary care teaching hospital.
                We studied infants with a gestational age of > or =34 wks who were receiving mechanical ventilatory support and had echocardiographic and clinical evidence of pulmonary hypertension and hypoxemia (PaO2 < or =100 mm Hg on FIO2 = 1.0), despite optimal medical management Infants with congenital heart disease, diaphragmatic hernia, or other major anomalies were excluded.
                The treatment group received inhaled NO, whereas the control group did not. Adjunct therapies and ECMO criteria were the same in the two groups of patients. Investigators and clinicians were not masked as to treatment assignment, and no crossover of patients was permitted.
                Primary outcome variables were mortality and use of ECMO. Secondary outcomes included change in oxygenation and duration of mechanical ventilatory support and supplemental oxygen therapy. Forty-two patients were enrolled. Baseline oxygenation and clinical characteristics were similar in the two groups of patients. Infants in the inhaled NO group (n = 21) had improved measures of oxygenation at 15 mins and 1 hr after enrollment compared with infants in the control group (n = 20). Fewer infants in the inhaled NO group compared with the control group were treated with ECMO (14% vs. 55%, respectively; p = .007). Mortality did not differ with treatment assignment.
                Among infants ventilated by HFOV, those receiving inhaled NO had a reduced need for ECMO. We speculate that HFOV enhances the effectiveness of inhaled NO treatment in infants with persistent pulmonary hypertension of the newborn and associated lung disease.
On the evidence presently available, it appears reasonable to use inhaled nitric oxide in an initial concentration of 20 ppm for term and near term infants with hypoxic respiratory failure who do not have a diaphragmatic hernia.