HWN Suggests

Halogenated Volatiles

During my anesthesiology residency and fellowship, I’ve used three major volatile agents...

Due to its relatively fast onset and minimal pungency, sevoflurane (Ultane) is often used as a potent bronchodilator and for mask inductions in pediatrics. Its metabolism generates fluoride and “compound A”, both of which have NOT been shown to translate to renal injury in humans.

Isoflurane (Forane) is the cheapest and most potent but has a relatively slow onset and recovery. This is the most common agent I use in cardiac surgery since it dilates the coronary vessels and tends to preserve cardiac output.

Desflurane (Suprane) is my favorite agent for non-cardiothoracic…

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Articles of Interest

Halogenated Hydrocarbon Anesthetics

Sevoflurane, desflurane, enflurane, isoflurane, halothane, and methoxyflurane are considered to be quite potent halogenated hydrocarbon anesthetics, since they pro-duce surgical levels of anesthesia at low inspired partial pressures. None of the halogenated hydrocarbons, how-ever, possess all of the pharmacological properties that are considered desirable for an anesthetic agent...

Hepatotoxicity of Halogenated Inhalational Anesthetics

For more than 50 years, halogenated inhalational anesthetics have been documented to be associated with liver injury. Chloroform the original halogenated anesthetic abandoned for a long period is indicated to be hepatotoxic by different studies (1, 2). Halothane, introduced in 1950s as a safer alternative for chloroform, causes a well-documented syndrome of acute hepatotoxicity as well. Enflurane and isoflurane are two halogenated anesthetics that followed halothane. These agents are also shown to cause similar injury, but less than halothane.

Inhalational Anaesthetics: An Update on Mechanisms of Action and Toxicity

All the currently used inhalative anaesthetics are halogenated hydrocarbons. Preferred halogenation of the ether derivatives with fluorine leads to improved stability and pharmacokinetic properties. Toxicity is reduced by this procedure. Isoflurane is halogenated with fluorine and chlorine. Desflurane and sevoflurane are exclusively halogenated with fluorine.

LiverTox:

The halogenated inhalational anesthetics have been linked to idiosyncratic liver injury for more than 50 years. These agents induce anesthesia by blocking CNS neurotransmission, although the exact mechanism of action is unknown. They are currently the most commonly used inhalational anesthetics in surgery. In the United States, the five halogenated anesthetics in current use are halothane, isoflurane, enflurane, desflurane, and sevoflurane. Halothane is now rarely used outside of pediatrics because of its potential to cause idiosyncratic severe liver injury, which is rare in children.

Resources

Desflurane

Desflurane administration is via the inhalational route. It has a pungent odor, making it difficult to use for the induction of general anesthesia. It is used most commonly for maintaining general anesthesia after induction with an IV or another inhalational agent.

Halothane

A nonflammable, halogenated, hydrocarbon anesthetic that provides relatively rapid induction with little or no excitement. Analgesia may not be adequate. nitrous oxide is often given concomitantly. Because halothane may not produce sufficient muscle relaxation, supplemental neuromuscular blocking agents may be required.

Isoflurane

Unlike enflurane, isoflurane is a non-flammable volatile anesthetic but carries a strong, pungent odor that makes it difficult to use for inhalational induction of general anesthesia.

Sevoflurane

Like other halogenated inhalational anesthetics, sevoflurane's precise mechanism to induce and maintain general anesthesia is unknown. There have been multiple attempts to identify a unitary hypothesis. However, no single proposed mechanism of action has fully explained their clinical effects.