title: Improvement in human tumour oxygenation with carbogen of varying carbon dioxide concentrations.
abstract: OBJECTIVE
  Carbogen (95%O2, 5%CO2) is being used in clinical trials as a hypoxic radiosensitiser. Tolerance to carbogen can be a problem, this study compares tumour oxygenation during inhalation of hyperoxic gas containing either 2% or 5% CO2.
  
  
  METHODS
  Tumour pO2 was measured in 16 patients using the Eppendorf pO2 histograph.
  
  
  RESULTS
  After breathing gas containing either 5% or 2% CO2 an increase in median pO2 was measured in every tumour, the frequency of low pO2 values ( < or = 10 mmHg) fell from 47% to 29% in the 5% group and from 55% to 17% in the 2% group.
  
  
  CONCLUSIONS
  This study confirms that breathing 2% CO2 and 98% O2 is well tolerated and effective in increasing tumour oxygenation.
authors.affiliation: CRC Tumour Biology and Radiation Research Group, Mount Vernon Hospital, Northwood, Middlesex, UK.
authors.forename: M E
authors.initials: ME
authors.lastname: Powell
authors.forename: D R
authors.initials: DR
authors.lastname: Collingridge
authors.forename: M I
authors.initials: MI
authors.lastname: Saunders
authors.forename: P J
authors.initials: PJ
authors.lastname: Hoskin
authors.forename: S A
authors.initials: SA
authors.lastname: Hill
authors.forename: D J
authors.initials: DJ
authors.lastname: Chaplin
mesh_terms: D000280:Administration, Inhalation; D002245:Carbon Dioxide / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000378:metabolism* / Q000532:radiotherapy; D010100:Oxygen / Q000008:administration & dosage* / Q000378:metabolism*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D011838:Radiation-Sensitizing Agents; D002245:Carbon Dioxide; C011700:carbogen; D010100:Oxygen