Introduction
hypoxia
HYPOXIA, ACUTE RESPIRATORY DISTRESS SYNDROME, COMPLICATIONS
The rate of utilization of low-flow (LF) anesthesia has gradually increased during the last decade, owing to some clinical advantages and cost savings. First suggested by Baum and AitkenheadActually, the most vulnerable organ to anesthesia-induced hypoxia is the brain. Thus, monitoring of cerebral oxygenation under various settings of general anesthesia is of paramount importance to prevent inadvertent hypoxia-related complications after surgery. Pulse oximeter saturation measurement may not always reflect the cerebral oxygen saturation. In this regard, methods measuring cerebral oxygenation are of value. Near-infrared spectroscopy (NIRS) measures regional cerebral oxygen saturationProne positioning (PP) is required in a number of surgical operations to be able to gain adequate access to the operation site. Moreover, PP is frequently used in the setting of acute respiratory distress syndrome thanks to its mechanistic advantages on gas exchanges in the lungsAlthough the impact of LF and MF anesthesia on cerebral oxygenation has been evaluated under various settings of general anesthesia