Inhaled Anesthetics Have Hyperalgesic Effects at 0.1 Minimum Alveolar Anesthetic Concentration

Abstract

The inhaled anesthetics isoflurane, halothane, nitrous oxide, and diethyl ether produce antianalgesia at subanesthetic concentrations, with a maximal effect at approximately one-tenth the concentration required for anesthesia. This effect may enhance perception of pain when such small concentrations are reached during recovery from anesthesia.