Are convulsant gases also anesthetics?

Area of Science:

• Anesthesiology
• Pharmacology
• Neuroscience

Background:

• Anesthetic potency is often correlated with lipid solubility.
• The convulsant gas flurothyl's deviation from this correlation was investigated.
• Understanding this relationship is crucial for developing new anesthetic agents.

Purpose of the Study:

• To determine if flurothyl adheres to the anesthetic potency-lipid solubility correlation.
• To assess the anesthetic and convulsant properties of flurothyl and its isomer, iso-Indoklon.
• To investigate the interaction of flurothyl with isoflurane in dogs.

Main Methods:

• Determined the ED50 for convulsions and loss of righting reflex for flurothyl in mice.
• Measured the oil/gas partition coefficient for flurothyl.
• Assessed the Minimum Alveolar Concentration (MAC) of isoflurane in dogs with varying flurothyl concentrations.
• Evaluated the anesthetic properties of iso-Indoklon in mice and dogs.

Main Results:

• Flurothyl's ED50 for loss of righting reflex and its oil/gas partition coefficient yielded a product consistent with conventional anesthetics.
• Low concentrations of flurothyl increased isoflurane MAC in dogs, while higher concentrations decreased it.
• Iso-Indoklon demonstrated anesthetic properties without convulsant effects, and its potency also correlated with lipid solubility.

Conclusions:

• Flurothyl does not deviate from the anesthetic potency and lipid solubility correlation.
• Flurothyl exhibits dose-dependent effects on isoflurane MAC, suggesting both antagonistic and anesthetic properties.
• Iso-Indoklon also aligns with the anesthetic potency-lipid solubility correlation, reinforcing its anesthetic nature.