title: [Low alkali-hydroxide content in soda limes does not lead to reduction of compound A formation from sevoflurane during low-flow anesthesia].
abstract: The alkali hydroxide content in soda lime induces Compound A formation from Sevoflurane (Sevo). This study was designed to answer the question if the use of potassium hydroxide-free Soda Lime (SL) would lead to lower Compound A levels as compared to Sodasorb (SO). A total of 30 patients scheduled for elective laparoscopic cholecystectomy received Sevo anaesthesia under low-flow conditions (0.8 l/min fresh gas flow). Each absorbent was used in 15 patients, but 3 patients of the SO group were excluded due to technical problems with Compound A analysis. Hemodynamic parameters, parameters of ventilation and gas concentrations were documented. Compound A concentrations were measured by gas chromatography from gas samples before Sevo application and 20, 40, 60, 90 and 120 min after low-flow start. Mean endtidal Sevo concentrations were 1.94 +/- 0.17 (SO) and 1.97 +/- 0.15 (SL) vol %, the total anaesthetic exposition was 1.52 +/- 0.36 (SO) and 1.64 +/- 0.47 (SL) MAC-h (n.s). The maximum Compound A concentration was significantly higher in SL group (19.6 +/- 2.8 vs. 11.7 +/- 4.1 ppm, p < 0.001). Therefore, elimination of potassium hydroxide from carbon dioxide absorbents alone did not lead to a reduction of Compound A formation during low-flow anaesthesia.
authors: Klinik für Anästhesiologie, Ludwig-Maximilians-Universität München, Klinikum Grosshadern, Marchioninistrasse 15, 81366 München. florian.reichle@ana.med.uni-muenchen.de
authors: F M
authors: FM
authors: Reichle
authors: P
authors: P
authors: Conzen
authors: S
authors: S
authors: Czerner
authors: G
authors: G
authors: Gröger
authors: K
authors: K
authors: Peter
mesh_terms: D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D002245:Carbon Dioxide / Q000032:analysis; D017081:Cholecystectomy, Laparoscopic; D002849:Chromatography, Gas; D004987:Ethers / Q000737:chemistry*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry; D008738:Methyl Ethers / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D000077149:Sevoflurane; D012972:Sodium Hydroxide / Q000737:chemistry*
chemical_list: D018685:Anesthetics, Inhalation; D017610:Calcium Compounds; D004987:Ethers; D006845:Hydrocarbons, Fluorinated; D006878:Hydroxides; D008738:Methyl Ethers; D010087:Oxides; D002245:Carbon Dioxide; D000077149:Sevoflurane; C004569:soda lime; D012972:Sodium Hydroxide; C078742:fluoromethyl 2,2-difluoro-1-(trifluoromethyl)vinyl ether