Background: Inhaled nitric oxide (iNO) reduces pulmonary vascular resistance by preferential vasodilaton on ventilated lung units. In experimental animals, iNO also reduces airway resistance by smooth muscle relaxation. Hence, there may be a therapeutic role for iNO in evolving bronchopulmonary dysplasia (BPD). Objective: To evaluate the acute effects of low-dose iNO on lung mechanics, ventilation distribution, oxygenation, and cardiac function on preterm infants with evolving BPD. Methods: Measurements of lung compliance (CL), airway resistiance (RL), ventilation-distribution (N2 clearance in multiple-breath washout), oxygenation (SpO2), left ventricular ejection fraction (LVEF) and right ventricular shortening fraction were abtained before and during 2 hours of iNO (10 ppm) nin a group of ventilated preterm infants with evolving BPD. Results: A total of 13 preterm infants with (mean±SD) BW: 663.8±116 g, GA: 24.9±1.2 weeks, age: 32±14 days, mean airways pressure: 6.7±0.9 cmH2O and fraction of inspired oxygen: 0.35±0.06 were studied. iNO did not affect CL, RL or N2 clearance. There was a small increase in LVEF. Mean SpO2 remained unchanged, but the duration of spontaneous hyoxemic episodes increased during iNO. Conclusion: Low-dose iNO had no acute effects on lung function, cardiac function and oxygenation in evolving BPD.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Obstetrics and Gynecology