Desflurane

Desflurane

Clinical data
ATC code	N01AB07 (WHO)
Pharmacokinetic data
Metabolism	Not metabolized
Biological half-life	Elimination dependent on minute ventilation
Identifiers
IUPAC name 2-(difluoromethoxy)-1,1,1,2-tetrafluoro-ethane
CAS Number	57041-67-5 Y
PubChem CID	42113
IUPHAR/BPS	7156
DrugBank	DB01189 Y
ChemSpider	38403 Y
UNII	CRS35BZ94Q
KEGG	D00546 Y
ChEBI	CHEBI:4445 Y
ChEMBL	CHEMBL1200733 N
ECHA InfoCard	100.214.382
Chemical and physical data
Formula	C3H2F6O
Molar mass	168.038 g/mol
3D model (Jmol)	Interactive image
SMILES FC(F)(F)C(F)OC(F)F
InChI InChI=1S/C3H2F6O/c4-1(3(7,8)9)10-2(5)6/h1-2H Y Key:DPYMFVXJLLWWEU-UHFFFAOYSA-N Y
NY (what is this?)

Desflurane (1,2,2,2-tetrafluoroethyl difluoromethyl ether) is a highly fluorinated methyl ethyl ether used for maintenance of general anesthesia. Like halothane, enflurane, and isoflurane, it is a racemic mixture of (R) and (S) optical isomers (enantiomers). Together with sevoflurane, it is gradually replacing isoflurane for human use, except in economically undeveloped areas, where its high cost precludes its use. It has the most rapid onset and offset of the volatile anesthetic drugs used for general anesthesia due to its low solubility in blood.

Some drawbacks of desflurane are its low potency, its pungency and its high cost. It may cause tachycardia and airway irritability when administered at concentrations greater than 10 vol%. Due to this airway irritability, desflurane is infrequently used to induce anesthesia via inhalation techniques.

Though it vaporises very readily, it is a liquid at room temperature. Anaesthetic machines are fitted with a specialized anaesthetic vaporiser unit that heats liquid desflurane to a constant temperature. This enables the agent to be available at a constant vapor pressure, negating the effects fluctuating ambient temperatures would otherwise have on its concentration imparted into the fresh gas flow of the anesthesia machine.

Desflurane, along with enflurane and to a lesser extent isoflurane, has been shown to react with the carbon dioxide absorbent in anesthesia circuits to produce detectable levels of carbon monoxide through degradation of the anesthetic agent. The CO₂ absorbent Baralyme, when dried, is most culpable for the production of carbon monoxide from desflurane degradation, although it is also seen with soda lime absorbent as well. Dry conditions in the carbon dioxide absorbent are conducive to this phenomenon, such as those resulting from high fresh gas flows.