Nebulized nitroglycerin as an adjuvant drug in management of persistent pulmonary hypertension of newborns: a randomized controlled trial

The objective was to evaluate the effect of nebulized nitroglycerin (NNG) in neonates with persistent pulmonary hypertension (PPHN). The study focused on assessing changes in echocardiographic and clinical parameters following its administration. This is a randomized controlled trial that included 80 full-term newborns diagnosed with PPHN within 72 h after birth. Participants were randomized into two groups: the NNG group received nebulized nitroglycerin, while the control group did not receive it as adjunctive therapy to PPHN. Clinical parameters and echocardiographic measures were evaluated before intervention, and subsequently at 24 and 48 h. The primary outcome was the estimated systolic pulmonary artery pressure in both groups. Comparative analyses were conducted between the groups, along with repeated measures within each group. The NNG group exhibited a significant improvement in the oxygenation index and oxygen saturation index (OI&OSI) on days 2 and 3. There was a marked reduction in the systolic pulmonary artery pressure/systolic systemic pressure (SPAP/SSP) ratio, accompanied by a significant enhancement in biventricular systolic function and cardiac output. The myocardial performance index (MPI), as measured by tissue-Doppler echocardiography, was notably decreased in the NNG group on day 3. Furthermore, the requirements for ventilatory support and inotropic agents were significantly lower in the NNG group. Survival analysis indicated a more favorable weaning course in the NNG group.Conclusion: NNG was effective in managing neonates with PPHN and might be a promising, alternative therapy for PPHN, especially in settings where inhaled nitric oxide is unavailable.Trial registration: Clinical-Trial.gov identifier: NCT05741229 and was registered on February 14, 2023. URL: https://clinicaltrials.gov/study/NCT05741229 .