Effect of initial nitric oxide concentration on outcome in infants with persistent pulmonary hypertension of the newborn

A randomized nonblinded comparison of two treatment groups was performed to determine whether treatment of infants with persistent pulmonary hypertens ion of the newborn using a continuous 6-ppm dose of inhaled nitric oxide (i NO) changes the likelihood of death or utilization of extracorporeal membra ne oxygenation (ECMO) when compared to infants treated with 20 ppm iNO for 4 h followed by 6 ppm. Twenty-nine infants with a gestational age > 34 week s and a diagnosis of persistent pulmonary hypertension of the newborn were enrolled during the 3-year study period. The relative risk (20/6 vs. 6 ppm) for treatment with ECMO was 3.11 (p = 0.02), for death it was 2.80 (p = 0. 32), and for either death or ECMO it was 3.42 (p = 0.006). There was no app arent advantage of treatment with a higher dosage of iNO at the initiation of therapy in the reduction of death or utilization of ECMO. These data sug gest that a continuous lower dose of iNO results in a comparable improvemen t in oxygenation as a short exposure of higher dose iNO at the initiation o f therapy.