Combination of Inhaled Nitric Oxide with HFOV Reduces the Need for Extracorporeal Membrane Oxygenation (ECMO) in Infants with PPHN : Results from a Single Center Trial 980

Introduction: We examined whether inhaled nitric oxide (NO) improves oxygenation, mortality and the need for ECMO among infants with PPHN in a two-phase single center randomized controlled trial. In the first phase of this trial, in which combined use of inhaled NO and HFOV was prohibited, we reported significant improvement in oxygenation in infants treated with inhaled NO compared to the control group, but no reduction in mortality or ECMO utilization. We now report the outcomes of the second phase of our trial using inhaled NO in conjunction with HFOV. Methods: Forty one mechanically-ventilated infants ≥ 34 weeks gestation with echocardiographic and clinical evidence of pulmonary hypertension were enrolled. All were hypoxemic (PaO₂ ≤ 100 mm Hg on FiO₂ = 1.0) despite optimal medical management. Patients with congenital heart disease, diaphragmatic hernia, or other major anomalies were excluded. The initial inhaled NO dose of 40 ppm was reduced to 20 ppm after the first hour, followed by step-wise reduction of the dose as oxygenation improved. Adjunct therapies, including use of HFOV, were similar in the two groups of patients and ECMO was utilized as rescue treatment in both groups. Results: Baseline oxygenation and clinical characteristics were similar in the two groups of patients(Median baseline oxygenation index (OI)=30 in the inhaled NO group Vs 32 in the control group (p=0.98)). Infants in the inhaled NO group (n=21) had significantly better measures of oxygenation at 15 minutes and 1 hour following enrollment in the study than infants in the control group (n=20). ECMO utilization was significantly reduced among infants in the inhaled NO group compared to the control group. Mortality did not differ with treatment assignment (Table). Multivariate logistic regression analyses combining data from both phases of this trial (n=90) revealed significant reduction in ECMO utilization only among infants who received inhaled NO in combination with HFOV. Conclusion: Treatment with inhaled NO significantly improved oxygenation in infants with PPHN. However, only the combination of HFOV with NO treatment reduced the need for ECMO therapy.

Table 1 No caption available.