title: Low levels of nitric oxide as contaminant in hospital compressed air: physiologic significance?
abstract: OBJECTIVE
  To determine whether the levels of nitric oxide found in hospital compressed air have a clinically relevant effect on oxygenation in intubated patients with normal lungs.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Cardiothoracic and surgical intensive care unit in a university hospital.
  
  
  METHODS
  Twelve postoperative patients receiving mechanical ventilation.
  
  
  METHODS
  Pure nitrogen and oxygen were substituted for hospital compressed air as a source of blending for correct FIO2.
  
  
  RESULTS
  Hemodynamics and PaO2 were measured in nitrogen and oxygen used for blending oxygen during stable FIO2 levels. Inhaled nitric oxide was measured with a nitric oxide-chemiluminescence detector. There was no clinically relevant change in systemic hemodynamics. However, the PaO2 decreased significantly when nitrogen was used for blending. Inhaled nitric oxide levels varied from 2 to 550 parts per billion during use of hospital compressed air; no nitric oxide was detectable during use of nitrogen.
  
  
  CONCLUSIONS
  The low concentration of nitric oxide in hospital compressed air improves oxygenation in patients with normal lungs receiving mechanical ventilation.
authors.affiliation: Department of Anesthesiology/Critical Care Medicine, University of Pittsburgh Medical Center, PA 15261, USA.
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
authors.forename: P S
authors.initials: PS
authors.lastname: Tan
authors.forename: P
authors.initials: P
authors.lastname: Rico
authors.forename: E
authors.initials: E
authors.lastname: Delgado
authors.forename: J A
authors.initials: JA
authors.lastname: Kellum
authors.forename: M R
authors.initials: MR
authors.lastname: Pinsky
mesh_terms: D001784:Blood Gas Analysis; D003422:Critical Care; D004780:Environment, Controlled; D006439:Hemodynamics; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D008176:Lung Volume Measurements; D009569:Nitric Oxide; D009584:Nitrogen; D010100:Oxygen; D011446:Prospective Studies; D012121:Respiration, Artificial
chemical_list: D009569:Nitric Oxide; D009584:Nitrogen; D010100:Oxygen