title: Degradation products of different water content sevoflurane in carbon dioxide absorbents by gas chromatography-mass spectrometry analysis.
abstract: BACKGROUND
  Sevoflurane is currently used as a volatile inhalation anesthetic with many clinical advantages. A representative degradation product, compound A, was quantitatively measured to investigate whether there are different reactions between two kinds of water content sevoflurane formulations with different carbon dioxide (CO2) absorbents.
  
  
  METHODS
  A closed-circle breathe bag with the Dräger Fabius GS anesthesia apparatus was used as an artificial rubber lung. The experiments were grouped according to different sevoflurane formulations: group A: higher-water sevoflurane (Ultane); group B: lower-water sevoflurane (Sevoness). During the experiment, CO2 (200 ml/min) was continually perfused to keep the end-tidal pressure of CO2 (P(ET)CO2) at 35 - 45 mmHg. The artificial ventilation was set to 6 L/min, and the breathing rate at 12 breaths/min. The circuit was operated with constant fresh gas flow rate (1 L/min) and the sevoflurane concentration was kept at 1.0 minimum alveolar concentration (MAC) for 240 minutes. At 0, 10, 20, 30, 60, 90, 120, 180 and 240 minutes, gas was collected from the Y-piece. Gas chromatography/mass spectrometry (GC/MS) was used to quantify the major degradation product, compound A, with different water content sevoflurane. PETCO2 and sevoflurane concentration, and the temperature of the canister were continuously monitored during the experiment.
  
  
  RESULTS
  There were no significant differences in P(ET)CO2 and sevoflurane concentrations between the two groups. Drägersorb 800 plus produced the highest concentrations of compound A compared with other sodalimes, and Sevoness in Drägersorb 800 plus generated more compound A than Ultane (P < 0.05). There were significant differences in the peak and average compound A concentrations between Ultane and Sevoness with Drägersorb 800 plus (P < 0.05), while the compound A concentration produced by Sodasorb grase and sofonolime in the two groups showed no significant difference (P > 0.05). In the same group, the peak and average of compound A concentration produced by Sodasorb grase and sofonolime showed significant difference with Drägersorb 800 plus (P < 0.05).
  
  
  CONCLUSIONS
  The water content of sevoflurane and potassium hydroxide in CO2 absorbent can influence compound A production.
authors.affiliation: Department of Anesthesiology, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.forename: Yi-Cong
authors.initials: YC
authors.lastname: Li
authors.forename: Yi-Nan
authors.initials: YN
authors.lastname: Zhang
authors.forename: Shu-Jie
authors.initials: SJ
authors.lastname: Liu
authors.forename: Yan-Mei
authors.initials: YM
authors.lastname: Zhou
authors.forename: Chang-Song
authors.initials: CS
authors.lastname: Wang
authors.forename: Yu-Lei
authors.initials: YL
authors.lastname: Gong
authors.forename: En-You
authors.initials: EY
authors.lastname: Li
mesh_terms: D000042:Absorption; D002245:Carbon Dioxide / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry; D008738:Methyl Ethers / Q000737:chemistry*; D000077149:Sevoflurane
chemical_list: D004987:Ethers; D006845:Hydrocarbons, Fluorinated; D008738:Methyl Ethers; D002245:Carbon Dioxide; D000077149:Sevoflurane; C078742:fluoromethyl 2,2-difluoro-1-(trifluoromethyl)vinyl ether