P2.I176: Decreasing Prolonged Inhaled Nitric Oxide Use in the NICU: A Quality Improvement Initiative

Background: Persistent Pulmonary Hypertension of the Newborn (PPHN) is a life-threatening condition afflicting neonates who fail to make a smooth transition from fetal to newborn circulation. Inhaled Nitric Oxide (iNO), has been established as a treatment for PPHN. Optimal weaning methods for iNO therapy remain unclear, which often leads to extended courses of treatment and increased side effects. Walid et al. demonstrated that implementation of an iNO weaning protocol led to a substantial reduction in iNO usage by 60%, with no significant adverse effects.

Methods: To understand the current iNO use in our Level IV NICU, we looked at the average duration of iNO, echocardiogram signs of PPHN, rebound hypoxia, and mortality rates with data collected from EMR. Data was compared by weaning style, gestational age, and birth weight to determine current practice and factors that increase the length of use.

Results: Performance evaluation showed that iNO was utilized for 52 infants at our center in 2023. The average iNO time was 256 hours.  3 different weaning styles were utilized. Weaning style A (20/15/10/5/4/3/2/1) had the highest rate of rebound hypoxia (81.8%), as well as the longest average iNO duration (451 hours). Weaning styles C (20/10/5/4/3/2/1) and D (20/5/4/3/2/1) showed similar iNO duration (254.2 and 281.5 respectively) but C showed the lowest rates of rebound hypoxia (33.3%). It also is notable that infants born at 34 WGA or older, had the shortest duration of iNO (184 hours), where infants 28-33 WGA averaged similar durations (249.75 hours and 243.6 hours respectively). In infants born at less than 28 WGA, the survival rate was 41%, 28-33 WGA was 56%, and infants born at greater than 34 WGA was 81%.

Conclusion: A notable increase in duration of therapy, as well as rebound hypoxia, was observed using weaning method A. Methods C and D have similar durations of therapy, though sample sizes differ too much to compare rates of rebound hypoxia. Based on this data, we plan to implement weaning style C as a protocol to try and decrease duration of iNO therapy in our NICU.
Currently, iNO is approved as a treatment for PPHN in infants over 34 WGA. In our center, iNO is often used in critically ill infants at all gestational ages as a last resort. These babies often have severe RDS and are difficult to both oxygenate and ventilate. In this situation, iNO is used as a pulmonary dilator to help improve oxygenation when ventilator settings are already maximized. When analyzing this data, notably, the survival rate in infants less than the approved gestational age shows that there is benefit to using iNO in this situation, as the survival rate in this population otherwise would likely be much lower.