Cerebral Oxygenation
Conditions
Keywords
Left Paratracheal Pressure, Cricoid Pressure, Near-Infrared Spectroscopy, NIRS, Regional Cerebral Oxygen Saturation, General Anesthesia
Brief summary
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.
Detailed description
Pulmonary aspiration of gastric contents remains a potentially serious complication of general anesthesia. Cricoid pressure has traditionally been used during induction of anesthesia to reduce the risk of regurgitation, although its effectiveness and its potential effects on airway management remain debated. Left paratracheal pressure (LPP) has been proposed as an alternative technique based on the frequent left-sided position of the cervical esophagus. Anatomical and clinical studies have suggested that LPP may provide effective esophageal compression while preserving airway management conditions. Previous work from the investigators also showed that application of LPP at 30 N did not significantly decrease left carotid blood flow. However, carotid blood flow is an indirect marker of cerebral perfusion, and the effect of LPP on cerebral oxygenation remains unknown. PARANIRS is a prospective, single-center, randomized, controlled crossover study designed to evaluate the effect of LPP on regional cerebral oxygen saturation during general anesthesia. Each participant will serve as their own control. After induction of general anesthesia, neuromuscular blockade, tracheal intubation, and hemodynamic stabilization, bilateral regional cerebral oxygen saturation will be continuously monitored using near-infrared spectroscopy. Measurements will be obtained during a baseline period without cervical pressure and during application of two cervical pressure maneuvers: left paratracheal pressure at 30 N and cricoid pressure at 30 N. The order of the two cervical pressure maneuvers will be randomized. Each maneuver will be applied for 60 seconds using a calibrated force-measuring device to ensure a constant force of 30 N, with a 60-second washout period between interventions. Hemodynamic and respiratory variables, including mean arterial pressure, heart rate, peripheral oxygen saturation, and end-tidal carbon dioxide, will also be continuously recorded. The study is intended to determine whether LPP produces a clinically relevant change in regional cerebral oxygenation and to compare its physiological effects with those of conventional cricoid pressure.
Interventions
PROCEDURELeft Paratracheal Pressure
A standardized cricoid pressure of 30 N will be applied for 45 seconds using a calibrated force-measuring device. Regional cerebral oxygen saturation, hemodynamic variables, and respiratory variables will be continuously recorded during the intervention.
PROCEDURECricoid Pressure
A standardized cricoid pressure of 30 N will be applied for 45 seconds using a calibrated force-measuring device. Regional cerebral oxygen saturation, hemodynamic variables, and respiratory variables will be continuously recorded during the intervention.
Sponsors
Clinique Saint-Luc
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Participants will undergo both cervical pressure interventions in a randomized crossover sequence. All participants will first undergo a baseline period without cervical pressure, followed by left paratracheal pressure (LPP) and cricoid pressure (CP) in randomized order, with a 60-second washout period between interventions.
Eligibility
Sex/Gender
ALL
Age
18 Years to 99 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Maximum Change in Left Regional Cerebral Oxygen Saturation During Left Paratracheal Pressure | During the 45-second application of left paratracheal pressure, compared with the preceding baseline period | Maximum absolute change in left regional cerebral oxygen saturation (rSO2), expressed in percentage points, during application of left paratracheal pressure at 30 N compared with the baseline value obtained without cervical pressure. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Maximum Change in Right Regional Cerebral Oxygen Saturation | During each 45-second cervical pressure intervention, compared with the preceding baseline period | Maximum absolute change in right regional cerebral oxygen saturation (rSO2), expressed in percentage points, during application of each cervical pressure maneuver compared with the baseline value obtained without cervical pressure. |
| Difference in Change in Left Regional Cerebral Oxygen Saturation Between LPP and Cricoid Pressure | During the two 45-second cervical pressure interventions | Within-participant difference in the maximum absolute change in left regional cerebral oxygen saturation (rSO2), expressed in percentage points, between left paratracheal pressure at 30 N and cricoid pressure at 30 N. |
| Difference in Regional Cerebral Oxygen Saturation Between the Left and Right Hemispheres | During baseline and each 45-second cervical pressure intervention | Difference in regional cerebral oxygen saturation (rSO2), expressed in percentage points, between the left and right cerebral hemispheres during baseline, left paratracheal pressure, and cricoid pressure. |
| Change in Mean Arterial Pressure | During baseline and each 60-second cervical pressure intervention | Change in mean arterial pressure (MAP), measured in mmHg, during left paratracheal pressure and cricoid pressure compared with baseline. |
| Change in Heart Rate | During baseline and each 45-second cervical pressure intervention | Change in heart rate, measured in beats per minute, during left paratracheal pressure and cricoid pressure compared with baseline. |
| Change in Peripheral Oxygen Saturation | During baseline and each 45-second cervical pressure intervention | Change in peripheral oxygen saturation (SpO2), expressed as a percentage, during left paratracheal pressure and cricoid pressure compared with baseline. |
| Change in End-Tidal Carbon Dioxide | During baseline and each 45-second cervical pressure intervention | Change in end-tidal carbon dioxide (EtCO2), measured in mmHg, during left paratracheal pressure and cricoid pressure compared with baseline. |
| Participants With Adverse Events Related to Cervical Pressure Maneuvers | From application of the first cervical pressure maneuver through completion of the second maneuver, approximately 3 minutes | Number and proportion of participants experiencing an adverse event considered related to left paratracheal pressure or cricoid pressure during the experimental study period. Events leading to premature interruption of either maneuver will also be recorded. |
| Participants Requiring Vasopressor Administration | From baseline measurement through completion of the second cervical pressure intervention, approximately 3 minutes | Number and proportion of participants requiring vasopressor administration during the experimental study period. |
Countries
Belgium
Contacts
CONTACTBenjamin Javillier, MD
PRINCIPAL_INVESTIGATORBenjamin Javillier, MD
Clinique Saint-Luc Bouge
Outcome results
None listed