Desflurane

Desflurane is a volatile inhalational anesthetic used for the maintenance of general anesthesia in adults and older children. It is a halogenated ether delivered through a desflurane-specific vaporizer on anesthesia machines, usually with oxygen or air and sometimes with nitrous oxide. Because it is highly pungent, desflurane is generally not used for inhalational induction and may provoke airway irritation, coughing, or laryngospasm in susceptible patients.

Pharmacokinetics and metabolism are characterized by very low blood-gas solubility, reflected in a rapid onset and offset of anesthesia (rapid emergence when the concentration is reduced). The minimum alveolar concentration (MAC) in adults is about 6%. Desflurane undergoes minimal hepatic metabolism (roughly 0.02%), with the majority excreted unchanged through the lungs. Trace fluoride ion production occurs but is far less than with some other agents.

Pharmacodynamically, desflurane produces dose-dependent hypnosis and anesthesia, with vasodilation that can reduce systemic blood pressure. Its rapid changes in inspired concentration can trigger sympathetic responses, including tachycardia, if concentration is increased quickly or airway irritation occurs. Cerebral effects include a decrease in cerebral metabolic rate with associated changes in cerebral blood flow. It is generally favored for maintenance due to rapid recovery, facilitating postoperative assessment.

Safety and adverse effects include the potential to trigger malignant hyperthermia in susceptible individuals. Perioperative monitoring is essential, and dantrolene is the treatment. Emergence may be rapid, but airway management and hemodynamic stability should be monitored, especially in patients with reactive airways or cardiovascular risk.