title: Reducing the oxygen concentration of gases delivered from anaesthetic machines unadapted for medical air.
abstract: High fractional concentrations of inspired oxygen (FiO(2)) delivered over prolonged periods produce characteristic histological changes in the lungs and airway of exposed animals. Modern medical anaesthetic machines are adapted to deliver medical air (FiO(2)=0.21) for the purpose of reducing FiO(2); anaesthetic machines designed for the veterinary market have not been so adapted. Two inexpensive modifications that allow medical air to be added to the gas flow from veterinary anaesthetic machines are described. The advantages and disadvantages of each modification are discussed.
authors.affiliation: Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, Easter Bush, Roslin, Midlothian, EH25 9RG, UK. e.clutton@ed.ac.uk
authors.forename: R E
authors.initials: RE
authors.lastname: Clutton
authors.forename: G
authors.initials: G
authors.lastname: Schoeffmann
authors.forename: M
authors.initials: M
authors.lastname: Chesnil
authors.forename: R
authors.initials: R
authors.lastname: Gregson
authors.forename: F
authors.initials: F
authors.lastname: Reed
authors.forename: H
authors.initials: H
authors.lastname: Lawson
authors.forename: M
authors.initials: M
authors.lastname: Eddleston
mesh_terms: D000388:Air / Q000032:analysis; D000769:Anesthesia, Inhalation / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D010100:Oxygen / Q000008:administration & dosage* / Q000009:adverse effects; D014730:Veterinary Medicine / Q000295:instrumentation* / Q000379:methods*
chemical_list: D010100:Oxygen