Which inhaled agent has the least hepatic metabolism?

Which inhaled agent has the least hepatic metabolism?

• A. Halothane
• B. Isoflurane
• C. Sevoflurane
• D. Desflurane

Answer: (D)

Understanding how much an inhaled anesthetic is metabolized by the liver helps predict hepatic load during anesthesia. Desflurane is biotransformed by the liver to a negligible extent—roughly 0.02–0.04% of the dose—so nearly all of it is exhaled unchanged. This means minimal hepatic exposure, making it the agent with the least hepatic metabolism among the common options. Halothane, by contrast, is heavily metabolized (around 20%), which is linked to hepatic toxicity in some cases. Isoflurane has very low metabolism, about 0.2%, and sevoflurane is a bit higher, roughly 2–5%. Therefore, desflurane has the least hepatic metabolism.

Understanding how much an inhaled anesthetic is metabolized by the liver helps predict hepatic load during anesthesia. Desflurane is biotransformed by the liver to a negligible extent—roughly 0.02–0.04% of the dose—so nearly all of it is exhaled unchanged. This means minimal hepatic exposure, making it the agent with the least hepatic metabolism among the common options. Halothane, by contrast, is heavily metabolized (around 20%), which is linked to hepatic toxicity in some cases. Isoflurane has very low metabolism, about 0.2%, and sevoflurane is a bit higher, roughly 2–5%. Therefore, desflurane has the least hepatic metabolism.