[Reaction products of sevoflurane with new soda lime-A under various conditions]

Sevoflurane is reported to react with sodalime, a common carbon dioxide absorber which resolves into several products. We measured the reaction products of sevoflurane when this anesthetic reacted with sodalime-A, a new carbon dioxide absorber under various conditions. Analysis of reaction products was done by gas chromatography using a 2 m column packed with DOP. Six peaks including sevoflurane were detected on the gas chromatogram of sevoflurane after reaction with sodalime-A and five reaction products were obtained. These peaks were from P1 with the shortest retention time to P5 with the longest retention time. When sevoflurane was sealed with sodalime-A in a test tube at room temperature, 40 degrees C and 45 degrees C, only P1 was detected and two reaction products of P3 and P5 were identified when the test tube was heated at 50 degrees C. Sodalime contains Ca(OH)2, NaOH, KOH and silicon dioxide, and sodalime-A contains Ca(OH)2 and NaOH only. We reported previously that sevoflurane reacted with KOH to produce P1 to P5 even at room temperature and KOH was the most contributing factor to produce these reaction compounds. Reaction products of sevoflurane with two types of carbon dioxide absorber were checked with gas chromatography. Degradation products except P1 with sodalime-A was less than with conventional sodalime at any conditions. P1 production was about twice to three times more than that with sodalime.