title: Environmental monitoring of sevoflurane and nitrous oxide using the cuffed oropharyngeal airway.
abstract: We compared exposure to sevoflurane (SEV) and nitrous oxide (N(2)O) during ventilation using the cuffed oropharyngeal airway (COPA) with waste gas exposure using a conventional face mask (FM) without any additional airways or face straps and with the laryngeal mask airway (LMA). Trace concentrations of SEV and N(2)O were assessed by using a direct reading spectrometer during 33 surgical procedures under general anesthesia. Measurements were made at the patients' mouths and in the anesthesiologists' breathing zones. Mean +/- SD concentrations of SEV and N(2)O measured at the patients' mouths were comparable in the COPA (SEV, 8.1 +/- 12.2 ppm; N(2)O, 213.3 +/- 289.2 ppm) and LMA (SEV, 18.5 +/- 25.8 ppm; N(2)O, 283.4 +/- 361.0 ppm) groups but differed significantly from the FM group (SEV, 46.5 +/- 19.6 ppm; N(2)O, 750.7 +/- 308.3 ppm). These values resulted in a comparable contamination of the anesthesiologists' breathing zones (SEV, 0.5 +/- 0.2 ppm; N(2)O, 5.7 +/- 4.8 ppm) for the COPA group, compared with the LMA group (SEV, 1.0 +/- 0.9 ppm; N(2)O, 12.2 +/- 14.3 ppm). This differed significantly from the FM group (SEV, 2.2 +/- 0.9 ppm; N(2)O, 37.5 +/- 14.3 ppm). We conclude that the use of the COPA during short surgical interventions has an occupational safety comparable to that of the LMA and that both resulted in less contamination through waste anesthetic gases. Therefore, the COPA may be a valuable alternative to the conventional FM.
  
  
  CONCLUSIONS
  In this study, we have shown that the occupational exposure to waste anesthetic gases is comparable when using the cuffed oropharyngeal airway (COPA) and the laryngeal mask airway and is increased when using the face mask. Therefore, the COPA may be a valuable alternative to the conventional face mask during short surgical procedures.
authors.affiliation: Department of Anesthesia and Intensive Care B, Vienna General Hospital, University of Vienna, Austria.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Gustorff
authors.forename: Norbert
authors.initials: N
authors.lastname: Lorenzl
authors.forename: Laleh
authors.initials: L
authors.lastname: Aram
authors.forename: Claus G
authors.initials: CG
authors.lastname: Krenn
authors.forename: Brigitte P
authors.initials: BP
authors.lastname: Jobst
authors.forename: Klaus H
authors.initials: KH
authors.lastname: Hoerauf
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General / Q000379:methods*; D004784:Environmental Monitoring; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods*; D017214:Laryngeal Masks; D008738:Methyl Ethers / Q000032:analysis*; D008875:Middle Aged; D009609:Nitrous Oxide / Q000032:analysis*; D009960:Oropharynx; D000077149:Sevoflurane
chemical_list: D008738:Methyl Ethers; D000077149:Sevoflurane; D009609:Nitrous Oxide