INHALED NITRIC-OXIDE IN CONGENITAL HYPOPLASIA OF THE LUNGS DUE TO DIAPHRAGMATIC-HERNIA OR OLIGOHYDRAMNIOS

Objective. We determined whether inhaled nitric oxide (NO) could impro ve systemic oxygenation in human neonates with hypoplastic lungs. Meth ods. A multicenter nonrandomized investigation was performed to study the efficacy of short-term NO inhalation. Inhaled NO was administered at 80 ppm to nine neonates without evidence of structural cardiac dise ase by echocardiography. Lung hypoplasia was due to congenital diaphra gmatic hernia (CDH) in eight patients and to oligohydramnios in one pa tient. A total of 15 trials of NO inhalation were performed in these n ine patients. Eight trials in seven patients were performed before ext racorporeal membrane oxygenation ((ECMO); one patient had two trials) and seven trials were performed in five patients after decannulation f rom ECMO (two patients had two trials each). Results. NO inhalation be fore ECMO did not change postductal Pao(2) (42 +/- 3 mmHg vs 42 +/- 4 mmHg), oxygen saturation (Spo(2); 89% vs 88%) or oxygenation index (31 +/- 4 cm H2O/torr vs 31 +/- 4 cm H2O/torr) for the group. All patient s required ECMO support, which lasted from 5 to 17 days (mean 9). Afte r decannulation from ECMO, NO inhalation increased postductal Pao(2) f rom a median of 56 mm Hg (range 41 to 94) to a median of 113 mm Hg (ra nge 77 to 326), P < .05. It decreased the oxygenation index from a med ian of 23 cm H2O/torr (range 11 to 70) to a median of 11 cm H2O/torr ( range 4 to 21), P < .05. It increased Spo(2) from 91% to 96% (P < .05) and pH from 7.48 +/- .03 to 7.50 +/- .03. Conclusion. In our patients with hypoplastic lungs, inhaled NO was effective only after ECMO. Thi s could be due to maturational changes such as activating the endogeno us surfactant system. Inhaled NO may be effective in neonates with hyp oplastic lungs who have recurrent episodes of pulmonary hypertension a fter ECMO, even if they were previously unresponsive.