Objective: To analyze data from a registry of Japanese neonates with hypoxic respiratory failure associated with pulmonary hypertension (PH) to compare the effectiveness of inhaled nitric oxide (iNO) in neonates born <34 weeks vs. ≥34 weeks gestational age (GA).
Materials and methods: iNO was administered according to approved Japanese product labeling. Study data were collected before iNO administration and at predefined intervals until discontinuation.
Results: A total of 1,114 neonates were included (n=431, <34 weeks GA; n=675, ≥34 weeks GA; n=8, missing age data). Mean decrease from baseline oxygenation index (OI) was similar in both age groups. OI reduction was more pronounced in the <34 weeks subgroups with baseline OI ≥25. Survival rates were similar in the <34 weeks GA and ≥34 weeks GA groups stratified by baseline OI (OI<15, 89% vs. 93%; 15≤OI<25, 85% vs. 91%; 25≤OI≤40, 73% vs. 79%; OI>40, 64% vs. 66%).
Conclusion: iNO improved oxygenation in preterm neonates as effectively as in late preterm and term neonates, without negative impact on survival. If clinically significant PH is present, as measured by pulse oximetry or echocardiography, a therapeutic trial of iNO might be indicated for preterm neonates.
Keywords: Hypoxic respiratory failure; inhaled nitric oxide; preterm neonate; pulmonary hypertension.