Sevoflurane degradation by carbon dioxide absorbents may produce more than one nephrotoxic compound in rats.
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.
Stabernack
Caroline R
CR
Department of Anesthesia and Perioperative Care, and the Department of Pathology, University of California, San Francisco 94143, USA.
Eger
Edmond I
EI
Warnken
Uwe H
UH
Förster
Harald
H
Hanks
Douglas K
DK
Ferrell
Linda D
LD
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
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