title: Effect of nitric oxide predilution on inhaled nitrogen dioxide concentrations.
abstract: We examined the possibility that predilution of a concentrated nitric oxide (NO) source with nitrogen, before contact with oxygen, can reduce the inspired nitrogen dioxide (NO2) concentration during administration of nitric oxide. A Manley Blease and a Siemens Servo 900 C ventilator delivered 10, 20, 40, 60 and 80 parts per million (ppm) NO using an NO source of 1000, 400 and 200 ppm. With the Manley Blease system, predilution from 1000 to 200 ppm NO reduced the inhaled NO2 concentration from 0.14 to 0.05 ppm (p < 0.01) at 10 ppm inhaled NO, and from 1.20 to 1.00 ppm (p < 0.01) at 40 ppm inhaled NO. With the Siemens Servo 900 C ventilator, inspiratory NO2 concentrations decreased from 0.21 to 0.11 ppm (p < 0.01) at 10 ppm inhaled NO, and from 1.49 to 1.16 ppm (p < 0.01) at 40 ppm NO. Predilution from 1000 to 400 ppm NO reduced the inspired NO2 concentrations by < 3% using either ventilator when the inspirated NO concentration was 80 ppm. Predilution of NO with nitrogen significantly reduced the inspired NO2 concentrations for nitric oxide concentrations between 10 and 40 ppm, but offered no clinically relevant advantage at higher NO concentrations.
authors.affiliation: Department of Anaesthesia, University Hospital, Gent, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Foubert
authors.forename: K
authors.initials: K
authors.lastname: Mareels
authors.forename: N
authors.initials: N
authors.lastname: den Blauwen
authors.forename: L
authors.initials: L
authors.lastname: Herregods
authors.forename: G
authors.initials: G
authors.lastname: Rolly
mesh_terms: D004334:Drug Administration Schedule; D006801:Humans; D008956:Models, Chemical; D009569:Nitric Oxide / Q000008:administration & dosage* / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D009585:Nitrogen Dioxide / Q000008:administration & dosage* / Q000737:chemistry; D010084:Oxidation-Reduction; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D014665:Vasodilator Agents; D009569:Nitric Oxide; D009584:Nitrogen; D009585:Nitrogen Dioxide