title: Compound A concentration in the circle absorber system during low-flow sevoflurane anesthesia: comparison of Drägersorb Free, Amsorb, and Sodasorb II.
abstract: OBJECTIVE
  To determine compound A concentrations in a low-flow circuit containing Drägersorb Free (Dräger, Lübeck, Germany), Amsorb (Armstrong, Coleraine, Northern Ireland), and Sodasorb II (W. R. Grace, Lexington, MA).
  
  
  METHODS
  Randomized study.
  
  
  METHODS
  Hamamatsu University Hospital.
  
  
  METHODS
  24 ASA physical status I and II patients scheduled for general anesthesia greater than 3 hours' duration.
  
  
  METHODS
  Patients were allocated to three groups of eight patients each to receive either using either Drägersorb Free, Amsorb, or Sodasorb II. Immediately before anesthesia induction, 1 kg of fresh absorbent was placed in the anesthesia canister. Anesthesia was maintained with sevoflurane (end-tidal concentration 1% to 3%) in oxygen and nitrous oxide (FIO(2) > 0.3) at a total flow of 1 L/min.
  
  
  METHODS
  Inspiratory compound A concentration in the circuit was measured once every hour.
  
  
  RESULTS
  Maximum compound A concentrations for Drägersorb Free, Amsorb, and Sodasorb II were 2.4 +/- 0.8 (mean +/- SD) ppm, 3.1 +/- 0.5 ppm, and 28.0 +/- 10.0 ppm (p < 0.01 vs. Drägersorb Free and Amsorb). Concentrations with Drägersorb Free and Amsorb remained at less than 4 ppm throughout the study.
  
  
  CONCLUSIONS
  Because compound A concentrations in the circuit with Drägersorb Free and Amsorb were negligible, sevoflurane can be used at a fresh gas flow of 1 L/min with these two absorbents.
authors.affiliation: Department of Anesthesiology and Intensive Care, Hamamatsu University School of Medicine, Japan. je2fbw@hama-med.ac.jp
authors.forename: Shunji
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Bito
authors.forename: Yukako
authors.initials: Y
authors.lastname: Obata
authors.forename: Takasumi
authors.initials: T
authors.lastname: Katoh
authors.forename: Shigehito
authors.initials: S
authors.lastname: Sato
mesh_terms: D000042:Absorption; D000328:Adult; D000769:Anesthesia, Inhalation / Q000295:instrumentation*; D018685:Anesthetics, Inhalation; D002122:Calcium Chloride / Q000737:chemistry*; D002126:Calcium Hydroxide / Q000737:chemistry*; D002245:Carbon Dioxide / Q000032:analysis; D004987:Ethers / Q000032:analysis*; D005260:Female; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000032:analysis*; D008297:Male; D008738:Methyl Ethers; D008875:Middle Aged; D000077149:Sevoflurane
chemical_list: C400293:Amsorb; D018685:Anesthetics, Inhalation; D004987:Ethers; D006845:Hydrocarbons, Fluorinated; D008738:Methyl Ethers; D002245:Carbon Dioxide; D000077149:Sevoflurane; C078742:fluoromethyl 2,2-difluoro-1-(trifluoromethyl)vinyl ether; D002122:Calcium Chloride; D002126:Calcium Hydroxide