Decomposition of enflurane in soda lime

Area of Science:

• Anesthesiology
• Chemical Engineering
• Toxicology

Background:

• Volatile anesthetics like enflurane are critical in medical procedures.
• Soda lime is commonly used to absorb carbon dioxide during anesthesia.
• Potential degradation of anesthetics by absorbent materials requires investigation.

Purpose of the Study:

• To investigate the stability of enflurane when in contact with soda lime.
• To identify any decomposition products of enflurane in the presence of soda lime.
• To determine the factors influencing enflurane decomposition.

Main Methods:

• Gas chromatography-mass spectrometry (GC-MS) was used for compound identification.
• Enflurane reactions with soda lime and individual alkali hydroxides were performed.
• Anesthesia circle system with a model lung was utilized to simulate clinical conditions.

Main Results:

• A specific decomposition product, 1-chloro-1,2-difluorovinyl difluoromethyl ether, was identified.
• This compound was formed only in the presence of soda lime or its constituent hydroxides.
• Decomposition rate increased with elevated time and temperature.

Conclusions:

• Enflurane decomposes to 1-chloro-1,2-difluorovinyl difluoromethyl ether when exposed to soda lime.
• The reaction is dependent on temperature and contact duration.
• Findings highlight a potential safety concern regarding enflurane degradation in anesthesia circuits.