Abstract.
To evaluate the cardiovascular effects of inhaled nitric oxide (NO) on the systemic and pulmonary circulations, 25 consecutive infants with severe persistent pulmonary hypertension of the newborn (PPHN) underwent serial echocardiographic evaluations before and during inhaled NO therapy. Estimation of the systolic pulmonary artery pressure (SPAP) was derived from measurement of a tricuspid regurgitant jet using Bernoulli's equation. We also derived a pulmonary/systemic pressure ratio to evaluate overall cardiopulmonary effects. Paired measurements of estimated SPAP decreased from 62.0 ± 3.8 mmHg to 44.7 ± 4.3 mmHg (p < 0.01) during inhaled NO therapy. The pulmonary/systemic pressure ratio decreased from 0.98 ± 0.06 to 0.59 ± 0.04 during NO therapy (p < 0.01), indicating a significant decline in the vascular resistance between the two circulations. These changes also correlated with changes in the extrapulmonary shunt patterns at the ductus arteriosus and foramen ovale seen during inhaled NO therapy. The decreased right-to-left shunting was accompanied by a parallel (64%) improvement in systemic oxygenation, with the alveolar–arterial oxygen gradient (A-a DO2) falling from 591 ± 14 mmHg to 380 ± 33 mmHg (p < 0.01). We found echocardiography to be a useful clinical tool for evaluating and monitoring pulmonary artery pressure in infants with PPHN. Measurement of the SPAP and the pulmonary/systemic pressure ratio gave a quantitative estimation of the severity of PPHN, and the extrapulmonary shunt flow patterns at the ductus arteriosus and foramen ovale gave qualitative estimates of its severity. Inhaled NO increased pulmonary blood flow and oxygenation and improved the systemic cardiopulmonary hemodynamics in this group of infants.
Similar content being viewed by others
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ochikubo, C., Waffarn, F., Turbow, R. et al. Echocardiographic Evidence of Improved Hemodynamics During Inhaled Nitric Oxide Therapy for Persistent Pulmonary Hypertension of the Newborn . Pediatr Cardiol 18, 282–287 (1997). https://doi.org/10.1007/s002469900175
Published:
Issue Date:
DOI: https://doi.org/10.1007/s002469900175