Response categorization and outcomes in extremely premature infants born at 22–26 weeks gestation that received inhaled nitric oxide for hypoxic respiratory failure

Objective To evaluate the outcomes of extremely premature infants who received inhaled nitric oxide(iNO) for hypoxic respiratory failure(HRF). Study design Retrospective analysis of 107 infants born 22–26 weeks gestation who received iNO for HRF at a single institution. Infants were categorized as positive, negative, or no responders based on change in FiO 2 or OI. Underlying physiology was determined using Echocardiography/Radiography/Biochemistry. Results 63% of infants had a positive response; they received iNO earlier and were more likely to have acute pulmonary hypertension(PH). Positive response correlated with decreased incidence of death or grade 3 BPD at 36 weeks postmenstrual age, as compared to a negative response. Conclusions Extremely premature infants have a positive response rate to iNO comparable to term infants when used for PH in the transitional period. Infants with a negative response to iNO had worse outcomes, necessitating the determination of the underlying physiology of HRF prior to iNO initiation.