Monitored anesthesia care (MAC) with continuous sedation for awake craniotomy allows rapid recovery but increases risks of hypoventilation and hypoxemia. In April 2019, our center replaced propofol-based sedation with dexmedetomidine-based protocols to improve respiratory safety. We evaluated the impact of this protocol change on respiratory and hemodynamic outcomes. This single-center retrospective before-after observational study analyzed all adult patients undergoing awake craniotomy between April 2017 and July 2021. The propofol group (April 2017-March 2019) received propofol-remifentanil sedation; the dexmedetomidine group (April 2019-July 2021) received dexmedetomidine-based sedation with supplemental low-dose propofol. Primary endpoints were hypoxemia (SpO2 < 92