EARLY RESPONSE TO INHALED NITRIC-OXIDE AND ITS RELATIONSHIP TO OUTCOME IN CHILDREN WITH SEVERE HYPOXEMIC RESPIRATORY-FAILURE

Objective: To examine whether the early response to inhaled nitric oxi de (iNO) is a measure of reversibility of lung injury and patient outc ome in children with acute hypoxemic respiratory failure (AHRF), Desig n: Retrospective review study. Setting: Pediatric ICUs. Patients: Thir ty infants and children, aged 1 month to 13 years (median, 7 months) w ith severe AHRF (mean alveolar arterial oxygen gradient of 568 +/- 9.3 mm Hg, PaO2/fraction of inspired oxygen of 56 +/- 2.3, oxygenation in dex [OI] of 41 +/- 3.8, and acute lung injury score of 2.8 +/- 0.1). E ighteen patients had ARDS. Interventions: The magnitude of the early r esponse to iNO was quantified as the percentage change in OI occurring within 60 min of initiating 20 ppm iNO therapy, This response was com pared to patient outcome data, Measurements and results: There was a s ignificant association between early response to iNO and patient outco me (Kendall tau B r=0.43, p<0.02), All six patients who showed <15% im provement in OI died; 4 of the 11 patients (36%) who had a 15 to 30% i mprovement in OI survived, while 8 of 13 (61%) who had a >30% improvem ent in OI survived. Overall, 12 patients (40%) survived, 9 with ongoin g conventional treatment including iNO, and 3 with extracorporeal supp ort, Conclusions: In AHRF in children, greater early response to iNO a ppears to be associated with improved outcome. This may reflect revers ibility of pulmonary pathophysiologic condition and serve as a bedside marker of disease stage.