Amsorb Plus and Drägersorb Free, two new-generation carbon dioxide absorbents that produce a low compound A concentration while providing sufficient CO2 absorption capacity in simulated sevoflurane anesthesia.
OBJECTIVE
The properties of two new-generation CO(2) absorbents, Amsorb Plus (Armstrong Medical, Coleraine, UK) and Drägersorb Free (Drager, Lubeck, Germany), were compared with those of Amsorb (Armstrong Medical) and Sodasorb II (W.R. Grace, Lexington, MA, USA).


METHODS
The concentration of compound A produced by each absorbent was determined in a low-flow circuit containing sevoflurane, and the CO(2) absorption capacity of the absorbent was measured. The circuit contained 1000 g of each absorbent and had a fresh gas (O(2)) flow rate of 1 l.min(-1) containing 2% sevoflurane. CO(2) was delivered to the circuit at a flow rate of 200 ml.min(-1).


RESULTS
The maximum concentrations of compound A were 2.2 +/- 0.0, 2.3 +/- 0.3, 2.2 +/- 0.2, and 23.5 +/- 1.5 ppm (mean +/- SD) for Amsorb Plus, Drägersorb Free, Amsorb, and Sodasorb II, respectively. The maximum concentration of compound A for Sodasorb II was significantly higher than those for the other absorbents (P < 0.01). The CO(2) absorption capacities (time taken to reach an inspiratory CO(2) level of 2 mmHg) were 1023 +/- 48, 1074 +/- 36, 767 +/- 41, and 1084 +/- 54 min, respectively, and the capacity of Amsorb was significantly lower than that of the other absorbents (P < 0.01).


CONCLUSIONS
The new-generation carbon dioxide absorbents, Amsorb Plus and Drägersorb Free, produce a low concentration of compound A in the circuit while showing sufficient CO(2) absorption capacity.
Kobayashi
Shunji
S
Department of Anesthesiology and Intensive Care, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu 431-3192, Japan.
Bito
Hiromichi
H
Morita
Koji
K
Katoh
Takasumi
T
Sato
Shigehito
S
D000042:Absorption; D000758:Anesthesia; D018685:Anesthetics, Inhalation / Q000493:pharmacokinetics; D002122:Calcium Chloride; D002126:Calcium Hydroxide; D002245:Carbon Dioxide / Q000493:pharmacokinetics*; D004987:Ethers / Q000493:pharmacokinetics; D006845:Hydrocarbons, Fluorinated / Q000493:pharmacokinetics; D008738:Methyl Ethers; 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