Cardiopulmonary effects of nebulized sodium nitroprusside in term infants with hypoxic respiratory failure

Objective: To study whether nebulized nitroprusside (neb-NP) improves oxygenation in term infants with hypoxic respiratory failure (HRF). Study design: We studied 22 newborn term infants (gestational age, 39.7 ± 0.4 weeks [mean ± SEM]; birth weight, 3.6 ± 0.1 kg) with hypoxia (Pao₂ < 100 mm Hg) during mechanical ventilation (FIo₂ = 1.0). Sodium nitroprusside (5 mg followed by 25 mg) was nebulized into the inspiratory arm of the ventilator circuit. Vital signs and arterial blood gas values were recorded after 20 minutes at each dose and before and after initiation of inhaled nitric oxide (iNO). Results: Pao₂ increased significantly with 5 mg neb-NP (from 64.6 ± 5.6 to 90.1 ± 15.3 mm Hg, P = .04) and with 25 mg nebNP (113.2 ± 20.4 mm Hg, P = .009). Differences between mean Pao₂ at 5 mg versus 25 mg neb-NP were also statistically significant (P = .03). When comparing the effect of neb-NP to iNO, the treatment-induced increases in Pao₂ were similar (52.1 ± 18.7 vs 62.2 ± 18.2 mm Hg, respectively, P = not significant). Conclusions: Neb-NP causes a dose-dependent increase in oxygenation in term infants with HRF, similar in magnitude to iNO. Neb-NP may be beneficial in infants with HRF when iNO is not readily available.