Effect of Left Paratracheal Pressure on Cerebral Oxygenation During General Anesthesia

Left paratracheal pressure (LPP) has been proposed as an alternative to cricoid pressure to reduce the risk of regurgitation during induction of general anesthesia. Previous studies suggest that LPP can effectively compress the esophagus without significantly reducing left carotid blood flow. However, its effect on cerebral oxygenation has not yet been evaluated. The aim of this prospective randomized crossover study is to assess whether application of LPP affects regional cerebral oxygen saturation measured by near-infrared spectroscopy (NIRS) during general anesthesia. Seventy adult patients undergoing elective surgery under general anesthesia with tracheal intubation will be included. After induction of anesthesia and stabilization, cerebral oxygen saturation will be continuously measured under three conditions: no cervical pressure, left paratracheal pressure at 30 N, and cricoid pressure at 30 N. The order of the two pressure maneuvers will be randomized. The primary objective is to determine the change in left regional cerebral oxygen saturation during LPP compared with baseline without cervical pressure.

Inclusion Criteria: * Age ≥18 years * Scheduled for elective surgery requiring general anesthesia with orotracheal intubation * American Society of Anesthesiologists (ASA) physical status I to III * Ability to understand the study information * Written informed consent obtained before study procedures Exclusion Criteria: * Refusal to participate * Known or suspected pregnancy * Emergency surgery * Inability to provide informed consent * History of stroke or transient ischemic attack within the previous 6 months * Known severe carotid artery stenosis (\>70%) or previous carotid surgery * Known intracranial hypertension * Cervical malformation or previous cervical surgery preventing correct application of left paratracheal pressure or cricoid pressure * Technical inability to correctly position the NIRS sensors * Any condition considered by the investigator to be incompatible with study participation