Airway Management
Conditions
Brief summary
This randomized crossover study evaluates the effects of left paratracheal pressure, cricoid pressure, and no pressure on glottic visualization during videolaryngoscopy in adult surgical patients. The primary endpoint is the Percentage of Glottic Opening (POGO) score assessed by blinded video review. Secondary endpoints include anatomical measures (glottic surface area, vertical and horizontal displacement of the glottic plane) and clinical outcomes (first-pass success, first-pass success without desaturation \<90%, intubation time, Intubation Difficulty Scale, hypoxemia, hemodynamic events, airway trauma, and postoperative sore throat or dysphonia). All outcomes are collected from routine anesthetic practice and video analysis, with no additional procedures.
Detailed description
This randomized crossover trial will compare three laryngoscopy conditions (no pressure, cricoid pressure, left paratracheal pressure) in adult surgical patients requiring general anesthesia with tracheal intubation. Each patient undergoes all three conditions in random order, with the intubation performed using the maneuver chosen by the operator. Anatomical outcomes (POGO, glottic surface area, vertical and horizontal displacement of the glottic plane) will be assessed from video recordings by blinded evaluators. Clinical outcomes (first-pass success, composite success without desaturation \<90%, intubation time, IDS, hypoxemia, hemodynamic changes, airway trauma, sore throat, dysphonia) will be collected from routine anesthetic records and PACU assessments. Statistical Analysis Plan: POGO: mixed-effects repeated measures model with patient as random effect, maneuver as fixed effect, adjusted for operator, BMI, and Mallampati. Anatomical outcomes: analyzed similarly with mixed models and planned contrasts (LPP vs CP). Clinical outcomes: analyzed as-treated, using logistic or linear regression with adjustments for baseline factors and operator as random effect. Mediation analysis will evaluate whether improvements in POGO explain clinical benefits (first-pass success, intubation time). Significance level set at α=0.05 (two-sided), with exploratory outcomes interpreted without multiplicity correction. Missing data (e.g., unusable videos, missing sore throat scores) will be reported; complete-case analysis will be primary, sensitivity analysis considered if \>5% missing.
Interventions
PROCEDURECricoid Pressure (30 N)
Manual application of posterior pressure on the cricoid cartilage at a standardized force of 30 newtons. The pressure is applied by a trained operator using one or two fingers, with the goal of compressing the esophagus against the cervical spine. The maneuver is performed after induction of general anesthesia and immediately before videolaryngoscopy. A still image of the glottic view is captured during pressure application.
PROCEDURELeft Paratracheal Pressure (30 N)
Manual application of pressure to the left paratracheal region, lateral to the trachea and inferior to the thyroid cartilage, at a standardized force of 30 newtons. The pressure is applied by a trained operator using the thumb or fingers. The maneuver is performed after induction of general anesthesia and immediately before videolaryngoscopy. A still image of the glottic view is captured during pressure application.
Sponsors
University of Liege
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age ≥ 18 years * Scheduled for elective surgery under general anesthesia requiring endotracheal intubation * ASA physical status I or II * Normal airway anatomy as assessed by the anesthesiologist (Mallampati I-II, no known or anticipated difficult airway) * Written informed consent obtained prior to inclusion
Exclusion criteria
* History of difficult intubation or anticipated difficult airway * Known upper airway anatomical abnormalities (e.g., tumors, tracheal deviation, cervical spine instability) * BMI \> 35 kg/m² * Gastroesophageal reflux disease or increased aspiration risk * Pregnancy * Emergency surgery * Allergy or contraindication to any anesthetic drugs used * Inability to provide informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Glottic Opening (POGO) score | During laryngoscopy, before tracheal intubation | POGO will be scored from video recordings of each condition (no pressure, cricoid, paratracheal) by blinded assessors (0-100%). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Vertical Displacement of the Glottic Plane | During laryngoscopy, before intubation | The vertical shift of the glottic plane relative to baseline will be measured on recorded videolaryngoscopic images under each condition, assessed by blinded reviewers. |
| Horizontal displacement of the glottic plane | During laryngoscopy, before intubation | The horizontal (lateral) shift of the glottic plane relative to baseline will be measured on recorded videolaryngoscopic images under each condition, assessed by blinded reviewers. |
| First-pass intubation success | From laryngoscope insertion to first confirmed capnography | Successful tracheal intubation at the first attempt with the maneuver chosen by the operator. |
| Time to intubation | From laryngoscope insertion to first confirmed capnography | Duration in seconds until successful tracheal intubation. |
| Intubation Difficulty Scale (IDS) | During intubation | Composite score including attempts, operators, optimization maneuvers, and force required. |
| Glottic surface area | During laryngoscopy, before intubation | Glottic surface area will be quantified from videolaryngoscopic images under each condition (no pressure, cricoid, paratracheal) using standardized image analysis by blinded reviewers. |
| Hypoxemia | From induction until confirmed intubation | Oxygen saturation \<92% recorded by pulse oximetry. |
| Hemodynamic events | From induction until confirmed intubation | Systolic blood pressure drop \>20% from baseline or heart rate \<50/min. |
| Airway trauma | Immediately after intubation | Blood on blade/stylet or visible lip/mucosal injury. |
| Postoperative sore throat | 30-60 minutes in PACU | Patient-reported throat pain on numeric scale (0-10). |
| First-attempt success without desaturation < 90% | From laryngoscope blade past the incisors until confirmed tracheal intubation (end-tidal CO₂ ≥ 5 mmHg for 3 breaths), typically up to 2 minutes. | Binary composite. Success = both (1) first-attempt intubation (tube placed without complete blade removal; optimizations allowed without blade withdrawal) and (2) no SpO₂ \< 90% for ≥ 5 s within the time frame. |
Countries
Belgium
Contacts
Primary ContactBenjamin Javillier, M.D.
Outcome results
None listed