Sevoflurane breakdown produces flammable concentrations of hydrogen. Anesthesiology 2007 Jan;106(1):144-8
Date
01/02/2007Pubmed ID
17197856DOI
10.1097/00000542-200701000-00023Scopus ID
2-s2.0-33845942153 (requires institutional sign-in at Scopus site) 13 CitationsAbstract
BACKGROUND: Fires, explosions, and extreme heat production may occur when sevoflurane reacts with desiccated barium hydroxide lime. The identity of the flammable gas has not previously been published, although carbon monoxide, methanol, formaldehyde, and methyl formate have been identified in low quantities.
METHODS: The authors reacted sevoflurane with excess desiccated barium hydroxide lime or soda lime at 55 degrees, 100 degrees, 200 degrees, 300 degrees, and 400 degrees C. Formaldehyde, methanol, sodium formate, and hexafluoroisopropanol were reacted with barium hydroxide lime at 300 degrees or 400 degrees C. The authors measured hydrogen production by gas chromatography with a thermal conductivity detector and calculated the molar yield of hydrogen produced.
RESULTS: Up to 3 moles of hydrogen were produced per mole of sevoflurane degraded. Each mole of formaldehyde produced up to 2 moles of hydrogen at 400 degrees C. Formate and hexafluoroisopropanol produced up to 1 mole of hydrogen each at 400 degrees C. More than 2 moles of hydrogen were produced by methanol at 400 degrees C. Soda lime and barium hydroxide lime produced similar amounts of hydrogen from sevoflurane above 200 degrees C, but barium hydroxide lime produced more than soda lime at lower temperatures. The temperature above which large amounts of hydrogen were produced seemed to be 300 degrees C.
CONCLUSIONS: Up to 3 moles of hydrogen are produced by the chemical reaction of sevoflurane with heated, desiccated absorbent. The high yield, ease of ignition, and low tissue solubility of hydrogen make it the most likely fuel in anesthesia machine fires due to the reaction of sevoflurane with desiccated absorbent.
Author List
Dunning MB 3rd, Bretscher LE, Arain SR, Symkowski Y, Woehlck HJAuthor
Harvey J. Woehlck MD Professor in the Anesthesiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Anesthetics, InhalationBarium Compounds
Desiccation
Fires
Hot Temperature
Hydrogen
Methyl Ethers