title: [Monitoring expired oxygen fraction in preoxygenation of patients with chronic obstructive pulmonary disease].
abstract: OBJECTIVE
  To compare the rate of preoxygenation before induction of anesthesia in patients with no lung disease and in patients with chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  End-tidal fractional oxygen concentration (FEO2) was monitored using a paramagnetic oxygen analyzer, during a 5 minute-period of preoxygenation (tidal breathing of 100% oxygen) in 16 control patients (control group) and in 15 patients with COPD. COPD was defined and its severity was characterized by clinical criteria and by respiratory functional tests. FEO2 increase was compared between groups using Anova.
  
  
  RESULTS
  The increase in FEO2 was slower in the COPD group than in control group (p < 0.05). After 2 and 3 minutes of preoxygenation, FEO2 was significantly lower in COPD group as compared to control group, but was not different at 5 minutes. Mean time to reach a FEO2 equal to 0.90 was significantly longer in COPD than in control group (COPD: 261 +/- 130 s; control: 165 +/- 90 s, p < 0.05). SpO2 measured during room air breathing was moderately lower in COPD group, but this difference was no more significant after 30 s of preoxygenation (SpO2 after 30 s: control: 98.8 +/- 1.0%; COPD: 98.2 +/- 1.9%, NS).
  
  
  CONCLUSIONS
  These results suggest that preoxygenation monitoring may be useful in patients with COPD, to ensure adequate preoxygenation is achieved.
authors.affiliation: Service d'anesthésie-réanimation, hôpital Beaujon, Assistance Publique-Hôpitaux de Paris, UFR Xavier Bichat, université Paris VII, 100, bd du Général Leclerc, 92118 Clichy, France. emmanuel.samain@bjn.ap-hop-paris.fr
authors.forename: E
authors.initials: E
authors.lastname: Samain
authors.forename: M
authors.initials: M
authors.lastname: Biard
authors.forename: E
authors.initials: E
authors.lastname: Farah
authors.forename: S
authors.initials: S
authors.lastname: Holtzer
authors.forename: D
authors.initials: D
authors.lastname: Delefosse
authors.forename: J
authors.initials: J
authors.lastname: Marty
mesh_terms: D000758:Anesthesia; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D011300:Preoperative Care; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology; D012129:Respiratory Function Tests
chemical_list: D010100:Oxygen