title: Inhaled nitric oxide in children with severe lung disease: results of acute and prolonged therapy with two concentrations.
abstract: OBJECTIVE
  To evaluate the acute effects of 11 and 60 parts per million (ppm) inhaled nitric oxide on the pulmonary vascular resistance and systemic oxygenation of children with severe lung disease, and to compare the outcome of prolonged therapy with approximately 10 and 40 ppm inhaled nitric oxide.
  
  
  METHODS
  Prospective, randomized study.
  
  
  METHODS
  A 26-bed pediatric intensive care unit in a tertiary children's hospital.
  
  
  METHODS
  Nineteen patients (median age 11 yrs, range 7 months to 16 yrs) with acute bilateral lung disease requiring a positive end-expiratory pressure (PEEP) of > 6 cm H2O and an FIO2 of > 0.5 for > 12 hrs were treated with inhaled nitric oxide. One patient was treated twice during the same hospitalization.
  
  
  METHODS
  Acute hemodynamic and blood gas effects of 11 and 60 ppm inhaled nitric oxide were studied, while delivering these concentrations in random order for intervals of 20 to 30 mins. Each interval was preceded by an interval of 20 to 30 mins without nitric oxide. Patients were then randomized and treated for a prolonged period with approximately 10 or 40 ppm inhaled nitric oxide independent of their initial acute responses to 11 and 60 ppm. Nitric oxide was discontinued when ventilatory support was decreased to a PEEP of < or = 6 cm H2O and an FIO2 of < or = 0.5.
  
  
  RESULTS
  Inhaled nitric oxide selectively decreased pulmonary vascular resistance and improved systemic oxygenation. Acute hemodynamic and blood gas effects of 11 and 60 ppm nitric oxide were similar. Systemic oxygenation improved to a greater extent in patients with radiographic evidence of residual aerated lung regions than in patients with diffuse bilateral lung disease. Maximum methemoglobin concentrations were greater in patients treated for a prolonged period with 40 ppm nitric oxide. The mortality and duration of therapy were similar for patients treated with 10 and 40 ppm inhaled nitric oxide.
  
  
  CONCLUSIONS
  Pulmonary vascular resistance and systemic oxygenation are acutely improved to a similar extent by 11 and 60 ppm inhaled nitric oxide, and concentrations in excess of 10 ppm are probably not needed for prolonged therapy of children with severe lung disease.
authors.affiliation: Division of Pediatric Cardiology, Primary Children's Medical Center, Salt Lake City, UT, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Day
authors.forename: M
authors.initials: M
authors.lastname: Guarín
authors.forename: J M
authors.initials: JM
authors.lastname: Lynch
authors.forename: D D
authors.initials: DD
authors.lastname: Vernon
authors.forename: J M
authors.initials: JM
authors.lastname: Dean
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D001784:Blood Gas Analysis; D002648:Child; D002675:Child, Preschool; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007223:Infant; D008171:Lung Diseases / Q000097:blood / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D008297:Male; D009569:Nitric Oxide / Q000008:administration & dosage*; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D011652:Pulmonary Circulation / Q000187:drug effects*; D013997:Time Factors; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D009569:Nitric Oxide