Efficacy of inhaled nitric oxide under different oxygenation indexes in neonatal pulmonary hypertension

Objectives To analyze the efficacy of inhaled nitric oxide (iNO) in the treatment of neonatal pulmonary hypertension under different oxygenation indexes (OI). Methods In this retrospective analysis, 51 neonates diagnosed with PPHN and treated with invasive mechanical ventilation at The Second People's Hospital of Nanning and Maternal and Child Health Hospital of Nanning from January 1, 2021, to December 31, 2023, were selected as the study subjects. According to different values of OI, the neonates were divided into three groups; subjects with OI ≤ 12 were categorized into group A (n = 20), 12 < OI ≤ 16 into group B (n = 16), and OI > 16 into group C (n = 15). The OI, oxygen saturation (SaO ₂ ), pulmonary artery pressure (PAP), duration of iNO treatment, and the time and cure rate of invasive mechanical ventilation were compared between groups A, B, and C after treatment. Results Comparison of OI between the three groups indicated significant changes in group A at 6 h and 24 h after treatment; whereas, there were no significant changes in group B and C at 6 h after treatment, and changes were visible only 24 h after treatment. Among the three groups, the degree of decrease of OI in group A was the highest, followed by group B, and group C was the least, with the differences being statistically significant ( P  < 0.05). Moreover, there were no significant differences in PAP and SaO ₂ in the three groups before treatment; whereas, after treatment, group A showed the greatest decrease in PAP and the greatest increase in SaO ₂ , followed by groups B and C, and the differences were statistically significant ( P  < 0.05). Furthermore, a comparison of the durations of NO treatment, mechanical ventilation, and prognosis of children in groups A, B, and C revealed that children in group A needed iNO and mechanical ventilation for the lowest time, followed by those in group B, while children in group C needed iNO and mechanical ventilation for the longest time, with the differences being statistically significant ( P  < 0.05). The cure rate of group A was 85.0%, that of group B was 75.0%, and group C was 46.7% (x ^{2 =} 6.161; P  < 0.05). Conclusions Under different OI conditions, iNO treatment for pulmonary hypertension may produce different curative effects. When OI ≤ 12, iNO treatment can timely improve SaO ₂ , reduce PAP, improve the cure rate, shorten the time on the machine, and decrease the treatment cost. When OI > 12, iNO treatment cannot increase SaO ₂ significantly or decrease PAP and PaCO ₂ timely; mortality rates increased significantly, and the time needed on a ventilator was longer. Therefore, when the OI of children with PPHN reaches 12, iNO should be used as soon as possible to improve the cure rate.