Zou Y, et al. - Researchers investigated the maximum tolerated dose (MTD, the dose of causing 10% respiratory depression) of intranasal sufentanil (SUF) and midazolam (MID) for sedation in thirty Chinese patients (18–65 years old) scheduled for gastroscopy, using continual reassessment method (CRM). The dose of MID (5 mg) was fixed, while the dose of SUF was increased progressively (six incremental doses ranging from 0–0.60 μg/kg). Based on CRM, 5 mg MID + 0.4 μg/kg SUF was defined as the MTD of intranasal MID and SUF for sedation during gastroscopy causing 10% respiratory depression.