Retrospective study of preterm infants exposed to inhaled nitric oxide in Kaiser Permanente Southern California: morbidity, mortality and follow-up.

ABSTRACT

OBJECTIVE: Describe characteristics of preterm infants exposed to inhaled nitric oxide (iNO) in Kaiser Permanente Southern California. STUDY DESIGN: Case review of preterm infants <34-weeks exposed to iNO during 2010-2020 including respiratory and echocardiographic status, NICU course, and 12-month follow-up. RESULTS: 270 infants, 2.63% of births<34 weeks, (median, range 26.1, 225/7-336/7 weeks gestation) were exposed to iNO. Median FiO2 at iNO initiation was 1.0 (IQR 0.94-1.0). Pulmonary hypertension (PH) was not associated with risk-adjusted 2 h oxygenation response or improved survival. Mortality to NICU discharge was 37.4%. Median cost of iNO was $7,695/patient. Discharged survivors experienced frequent rehospitalization (34.9%), use of supplemental oxygen, sildenafil, diuretics, bronchodilators, and steroids. Four infants had persistent PH. Five infants died after NICU discharge. CONCLUSIONS: Preterm infants receiving iNO have high mortality and 1st year morbidity. As currently used, iNO may be an indicator of respiratory disease severity rather than mediator of improved outcomes.