Efficacy of inhaled nitric oxide in children with ARDS.

STUDY OBJECTIVE Data concerning inhaled nitric oxide (iNO) on pediatric ARDS is rare. We investigated the effects of iNO on pediatric ARDS in order to examine the ability to predict a response to iNO, the optimal concentration of iNO, the effects of < or = 1 ppm nitric oxide (NO), and the effect of iNO on PaCO2. SETTING ICU at Kumamoto (Japan) University Hospital. PATIENTS AND INTERVENTIONS Seven children with ARDS. The initial responses to 16 ppm NO and the dose-response effects of 0.13 to 16 ppm NO were assessed. MEASUREMENTS AND RESULTS Sixteen ppm of iNO improved oxygenation in all seven children. The use of iNO significantly increased the ratio of arterial oxygen tension to the fraction of inspired oxygen (PaO2/FIO2). A correlation between the NO-induced increase in PaO2/FIO2 and the baseline PaO2/FIO2 was observed (r=0.93, p<0.01). Dose-response tests showed that the optimal concentration of iNO was < or = 4 ppm, improvements in PaO2/FIO2 could be observed with concentrations of < or = 1 ppm NO, and iNO induced a slight decrease in PaCO2. CONCLUSIONS In children with ARDS, iNO frequently improves oxygenation and induces a slight decrease in PaCO2, with the baseline PaO2/FIO2 functioning as a predictor of all NO response. Improvements of PaO2 and PaCO2 were observed with concentrations of iNO of < or = 1 ppm, a level in which the risk of a toxic reaction in children is minimal. Effects on outcome need verification in larger controlled trials.