Enflurane

Enflurane

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Enflurane is a halogenated ether used as an inhalational anesthetic. It was first synthesized in 1963 by Ross Terrell and introduced into clinical practice in the early 1970s. Enflurane is known for its rapid onset and recovery times, making it a popular choice for general anesthesia.

Chemical Properties

Enflurane is chemically designated as 2-chloro-1-(difluoromethoxy)-1,1,2-trifluoroethane. It is a clear, colorless, and volatile liquid at room temperature. The molecular formula of enflurane is C₃H₂ClF₅O, and it has a molecular weight of 184.5 g/mol.

Pharmacology

Enflurane works by depressing the central nervous system, leading to a reversible loss of consciousness and sensation. It is believed to act on GABA receptors, enhancing the inhibitory effects of the neurotransmitter gamma-aminobutyric acid. Enflurane also affects other ion channels, including NMDA receptors and potassium channels.

Clinical Use

Enflurane is administered via inhalation using a vaporizer. It is often used in combination with other anesthetic agents such as nitrous oxide and muscle relaxants. The typical concentration for induction ranges from 2-4%, while maintenance concentrations are usually between 0.5-2%.

Advantages

• Rapid induction and recovery
• Minimal metabolism, reducing the risk of toxic metabolites
• Good muscle relaxation properties

Disadvantages

• Potential for seizure activity, especially at high concentrations
• Cardiovascular depression, leading to hypotension and bradycardia
• Respiratory depression

Side Effects

Common side effects of enflurane include:

• Nausea and vomiting
• Shivering
• Hypotension
• Respiratory depression

Rare but serious side effects include:

• Seizures
• Malignant hyperthermia
• Hepatotoxicity

History

Enflurane was developed as an alternative to earlier anesthetics like halothane and ether. Its introduction marked a significant advancement in the field of anesthesiology, offering a safer and more controllable option for general anesthesia.

Discontinuation

Due to the development of newer anesthetics with better safety profiles, such as isoflurane and sevoflurane, the use of enflurane has declined significantly. It is now rarely used in clinical practice.

See Also

• Isoflurane
• Sevoflurane
• Desflurane
• Halothane
• General anesthesia