Which statement is true regarding sevoflurane in relation to isoflurane potency?

Which statement is true regarding sevoflurane in relation to isoflurane potency?

• A. They are equally potent
• B. Sevoflurane is less potent than isoflurane
• C. Sevoflurane is more potent than isoflurane
• D. Sevoflurane is not used in anesthesia

Answer: (B)

Potency is reflected by the MAC—the minimum alveolar concentration needed to prevent movement in 50% of patients. A lower MAC means higher potency. Isoflurane has a lower MAC than sevoflurane, so it achieves anesthesia at a lower concentration. Sevoflurane requires a higher alveolar concentration (MAC roughly 2.3–2.6% vs about 1.1–1.3% for isoflurane in many species), meaning it is less potent than isoflurane. The other statements don’t fit because matching potency would imply similar MAC values, sevoflurane is widely used in anesthesia, and it is not more potent than isoflurane.

Potency is reflected by the MAC—the minimum alveolar concentration needed to prevent movement in 50% of patients. A lower MAC means higher potency. Isoflurane has a lower MAC than sevoflurane, so it achieves anesthesia at a lower concentration. Sevoflurane requires a higher alveolar concentration (MAC roughly 2.3–2.6% vs about 1.1–1.3% for isoflurane in many species), meaning it is less potent than isoflurane. The other statements don’t fit because matching potency would imply similar MAC values, sevoflurane is widely used in anesthesia, and it is not more potent than isoflurane.