title: Sevoflurane degradation by carbon dioxide absorbents may produce more than one nephrotoxic compound in rats.
abstract: OBJECTIVE
  Degradation of sevoflurane by carbon dioxide absorbents produces compound A, a vinyl ether. In rats, compound A can produce renal corticomedullary necrosis. We tested whether other compounds produced by sevoflurane degradation also could produce corticomedullary necrosis.
  
  
  METHODS
  Two groups of rats were exposed for four hours to sevoflurane 2.5% delivered through a container filled with fresh Sodasorb and heated to 30 degrees C or to 50 degrees C, respectively. Compound A was added to produce an average concentration of 120 ppm in both groups. A third (control) group received 2.5% sevoflurane that did not pass through absorbent, and no compound A was added.
  
  
  RESULTS
  As determined by gas chromatography, the higher temperature produced more volatile breakdown products, including compound A. Median necrosis of the corticomedullary junction in the 50 degrees C group [10% (quartiles 1.0%-7.8%); n = 20] exceeded that in the 30 degrees C group [5% (6.5%-15%); n = 18; P < 0.02], and both exceeded the median necrosis in the control group [0% (0.0%-0.2%); n = 10; P < 0.02]. The respective mean +/- SD values for these three studies were: 12.8 +/- 16.7%, 5.3 +/- 4.4%, and 0.3 +/- 0.5%.
  
  
  CONCLUSIONS
  Degradation products of sevoflurane other than compound A can cause or augment the renal injury in rats produced by compound A.
authors.affiliation: Department of Anesthesia and Perioperative Care, and the Department of Pathology, University of California, San Francisco 94143, USA.
authors.forename: Caroline R
authors.initials: CR
authors.lastname: Stabernack
authors.forename: Edmond I
authors.initials: EI
authors.lastname: Eger
authors.forename: Uwe H
authors.initials: UH
authors.lastname: Warnken
authors.forename: Harald
authors.initials: H
authors.lastname: Förster
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Hanks
authors.forename: Linda D
authors.initials: LD
authors.lastname: Ferrell
mesh_terms: D000042:Absorption; D018685:Anesthetics, Inhalation / Q000737:chemistry*; D000818:Animals; D002245:Carbon Dioxide / Q000737:chemistry*; D004987:Ethers / Q000633:toxicity; D006845:Hydrocarbons, Fluorinated / Q000633:toxicity; D007668:Kidney / Q000187:drug effects*; D008297:Male; D008738:Methyl Ethers / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D000077149:Sevoflurane
chemical_list: 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