Cao Y, Zhang L, Peng X, et al. - Researchers compared the hypnotic potency of sevoflurane between patients with sleep disorders vs patients with normal sleep habits. They analyzed 38 patients, comprising 19 individuals with normal sleep habits and 19 individuals with sleep disorders. According to the Dixon ‘up-and-down’ design, sevoflurane was administered at preselected concentrations starting at 1.0 vol%. They performed a verbal command for testing awakening following a steady-state period. Based on the negative or positive response to the verbal command, the concentration of sevoflurane was decreased or increased by 0.2 vol% in the next patient accordingly. Measurement of plasma orexin-A was also done before observation. Mild-aged women of breast surgery with sleep disorders exhibited higher MACawake (minimum alveolar concentration of awake) of sevoflurane compared with those with normal sleep habits. Changes of orexin-A levels may explain the increased anesthetic requirement. Findings here suggest the possibility of a potential impact of sleep on clinical anesthesia, including changes of sensitivity to anesthetics or postoperative complications.