Compound A concentration in the circle absorber system during low-flow sevoflurane anesthesia: comparison of Drägersorb Free, Amsorb, and Sodasorb II.
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.
Kobayashi
Shunji
S
Department of Anesthesiology and Intensive Care, Hamamatsu University School of Medicine, Japan. je2fbw@hama-med.ac.jp
Bito
Hiromichi
H
Obata
Yukako
Y
Katoh
Takasumi
T
Sato
Shigehito
S
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
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