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. Pharmacology
As of 2005 the exact mechanism of the action of general anaesthetics has not been delineated. Desflurane is known to act as a positive allosteric modulator of the GABAA and glycine receptors, and as a negative allosteric modulator of the nicotinic acetylcholine receptor, as well as affecting other ligand-gated ion channels. Stereochemistry
Desflurane medications are a racemate of two enantiomers. Physical properties
Global-warming potential
Desflurane is a greenhouse gas. The twenty-year global-warming potential, GWP(20), for desflurane is 3714, meaning that one tonne of desflurane emitted is equivalent to 3714 tonnes of carbon dioxide in the atmosphere, much higher than sevoflurane or isoflurane. In addition to global warming potentials, drug potency and fresh gas flow rates must be considered for meaningful comparisons between anesthetic gases. When a steady state hourly amount of anesthetic necessary for 1 minimum alveolar concentration (MAC) at 2 liters per minute (LPM) for Sevoflurane, and 1 LPM for Desflurane and Isoflurane is weighted by the GWP, the clinically relevant quantities of each anesthetic can then be compared. On a per-MAC-hour basis, the total life cycle GHG impact of desflurane is more than 20 times higher than Isoflurane and Sevoflurane (1 minimal alveolar concentration-hour).
One paper finds anesthesia gases used globally contribute the equivalent of 1 million cars to global warming. This estimate is commonly cited as a reason to neglect pollution prevention by anesthesiologists, however this is problematic. This estimate is extrapolated from only one U.S. institutions anesthetic practices, and this institution uses virtually no Desflurane. Researchers neglected to include nitrous oxide in their calculations, and reported an erroneous average of 17 kg CO2e per anesthetic. However, institutions that utilize some Desflurane and account for nitrous oxide have reported an average of 175–220 kg CO2e per anesthetic. Sulbaek-Andersons group therefore likely underestimated the total worldwide contribution of inhaled anesthetics, and yet still advocates for inhaled anesthetic emissions prevention. References
Further reading
Eger, Eisenkraft, Weiskopf. The Pharmacology of Inhaled Anesthetics. 2003. Rang, Dale, Ritter, Moore. Pharmacology 5th Edition. 2003. Martin Bellgardt: Evaluation der Sedierungstiefe und der Aufwachzeiten frisch operierter Patienten mit neurophysiologischem Monitoring im Rahmen der Studie: Desfluran versus Propofol zur Sedierung beatmeter Patienten. Bochum, Dissertation, 2005 (pdf)
Susanne Lohmann: Verträglichkeit, Nebenwirkungen und Hämodynamik der inhalativen Sedierung mit Desfluran im Rahmen der Studie: Desfluran versus Propofol zur Sedierung beatmeter Patienten. Bochum, Dissertation, 2006 (pdf Archived 2016-03-04 at the Wayback Machine)
Patel SS, Goa KL (1995). "Desflurane. A review of its pharmacodynamic and pharmacokinetic properties and its efficacy in general anaesthesia". Drugs. 50 (4): 742–67. doi:10.2165/00003495-199550040-00010. PMID 8536556. External links
"Desflurane". Drug Information Portal. U.S. National Library of Medicine.