<p><strong>OBJECTIVES: </strong>To determine which patients with congenital diaphragmatic hernia (CDH) and pulmonary hypertension (PH) benefit from inhaled nitric oxide (iNO) treatment by comparing characteristics and outcomes of iNO responders to nonresponders.</p>

<p><strong>STUDY DESIGN: </strong>We performed a retrospective chart review of infants with CDH treated at our center between 2011 and 2016. In a subset of patients, iNO was initiated for hypoxemia or echocardiographic evidence of extrapulmonary right to left shunting. Initial post-treatment blood gases were reviewed, and patients were classified as responders (increased PaO &gt;20&nbsp;mm Hg) or nonresponders. Baseline characteristics, echocardiograms and outcomes were compared between groups with Fisher exact tests and Mann-Whitney t tests, as appropriate.</p>

<p><strong>RESULTS: </strong>During the study period, 95 of 131 patients with CDH (73%) were treated with iNO. All patients with pretreatment echocardiograms (n&nbsp;=&nbsp;90) had echocardiographic evidence of PH. Thirty-eight (40%) patients met treatment response criteria. Responders had significant improvements in PaO (51&nbsp;±&nbsp;3 vs 123&nbsp;±&nbsp;7&nbsp;mm Hg, P &lt; .01), alveolar-arterial gradient (422&nbsp;±&nbsp;30 vs 327&nbsp;±&nbsp;27&nbsp;mm Hg, P &lt; .01), and PaO to FiO ratio (82&nbsp;±&nbsp;10 vs 199&nbsp;±&nbsp;15&nbsp;mm Hg, P &lt; .01). Nonresponders were more likely to have left ventricular systolic dysfunction (27% vs 8%, P&nbsp;=&nbsp;.03) on echocardiogram. Responders were less likely to require extracorporeal membrane support (50 vs 24%, P&nbsp;=&nbsp;.02).</p>

<p><strong>CONCLUSIONS: </strong>iNO treatment is associated with improved oxygenation and reduced need for ECMO in a subpopulation of patients with CDH with PH and normal left ventricular systolic function.</p>

<p><strong>BACKGROUND/PURPOSE: </strong>Prostaglandin E1 (PGE) has been used to maintain ductus arteriosus patency and unload the suprasystemic right ventricle (RV) in neonates with congenital diaphragmatic hernia (CDH) and severe pulmonary hypertension (PH). Here we evaluate the PH response in neonates with CDH and severe PH treated with PGE.</p>

<p><strong>METHODS: </strong>We performed a retrospective chart review of CDH infants treated at our center between 2011 and 2016. In a subset, PGE was initiated for echocardiographic evidence of severe PH, metabolic acidosis, or hypoxemia. To assess PH response, we evaluated laboratory data, including B-type natriuretic peptide (BNP) and echocardiograms before and after PGE treatment. Categorical and continuous data were analyzed with Fisher's exact tests and Mann-Whitney t-tests, respectively.</p>

<p><strong>RESULTS: </strong>Fifty-seven infants were treated with PGE a mean 17 ± 2 days. BNP levels declined after 1.4 ± 0.2 days of treatment and again after 5.2 ± 0.6 days. After 6 ± 0.8 days of treatment, echocardiographic estimates of severe PH by tricuspid regurgitation jet velocity, ductus arteriosus direction, and ventricular septum position also improved significantly. Treatment was not associated with postductal hypoxemia or systemic hypoperfusion.</p>

<p><strong>CONCLUSIONS: </strong>In patients with CDH and severe PH, PGE is well tolerated and associated with improved BNP and echocardiographic indices of PH, suggesting successful unloading of the RV.</p>

<p><strong>TYPE OF STUDY: </strong>Treatment study.</p>

<p><strong>LEVEL OF EVIDENCE: </strong>Level III.</p>