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Completed

NCT Number: NCT05228288

Conventional vs. Video-Assisted Laryngoscopy for Perioperative Endotracheal Intubation

COVALENT is a randomized, controlled, multi-center study that aims to evaluate the clinical routine practice of endotracheal intubation in an operative setting comparing video-assisted laryngoscopy to direct laryngoscopy.

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Key information

Conditions

Endotracheal Intubation

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University Hospital Wuerzburg

Würzburg, Germany

About this study

Data on the routine use of video-assisted laryngoscopy in peri-operative intubations are rather inconsistent and ambiguous, in part due to small study populations and non-uniform outcome measures in past trials. Failed or prolonged intubation procedures are a reason for relevant morbidity and mortality. This study aims to determine whether video-assisted laryngoscopy (irrespective of the shape of the blade) is non-inferior to the standard method of direct laryngoscopy with respect to the first-pass success rate. Furthermore, validated tools from the field of human factors will be applied to examine within-team communication and task load during this critical medical procedure.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult, legally competent patients
  • Scheduled for elective, non-cardiac surgical procedure
  • Need for endotracheal intubation as determined during the premedication visit
  • Informed consent
  • Care providers performing the intubation have at least one year of training in anesthesiology and experience in the use of VAL

Exclusion criteria

  • Lack of ability to give consent
  • Previous participation in this study
  • Pregnancy
  • Need for fiberoptic intubation
  • Patients scheduled for bariatric surgery
  • Any circumstance that will lead the anesthesiologist(s) in charge to believe that random assignment of a laryngoscopy instrument may compromise patient safety during induction of anesthesia

Treatment and study plan

Conventional direct laryngoscopy (CDL)

Procedure

This procedure is considered the gold standard for endotracheal intubation and is routinely used in the peri-operative setting as well as in intensive care and emergency medicine.

Other names: conventional direct laryngoscopy, conventional laryngoscopy

Video assisted laryngoscopy with Macintosh-shaped blade (M-VAL)

Procedure

This device is implemented in most german hospitals and used when conventional direct laryngoscopy is not sufficient. By positioning the camera at the tip of the blade, the achievable field of view onto the glottic plane is improved.

Other names: video assisted laryngoscopy with Macintosh-shaped blade

Video assisted laryngoscopy with hyper-angulated blade (H-VAL)

Procedure

The hyper-angulated blades are often used as a backup instrument when a view of the glottic plane cannot be achieved with the Macintosh blade due to anatomic abnormalities, even with a video-assisted laryngoscope.

Other names: video assisted laryngoscopy with hyper-angulated blade

Primary outcomes

  1. Successful intubation

    Time frame: During the period of intubation (as soon as the laryngoscope blade passes the teeth row of the patient until the first capnographic end-expiratory carbon dioxide [CO2] detection is possible)

    The primary endpoint is the successful intubation at first attempt as a dichotomous (successful/unsuccessful) event. The first attempt begins with the laryngoscope spatula passing the patient's row of teeth. The attempt is considered unsuccessful if a complete retraction of the laryngoscope or the endotracheal tube from the oropharynx is necessary for any reason (need for bag ventilation, change of device, change of patient position, change in the curvature of the stylet, etc.). Maneuvers that can be performed during laryngoscopy, such as BURP (backward, upward, rightward pressure) or reclining the head, which end with successful intubation, count towards the first attempt.

Secondary outcomes

  1. Parameters regarding the duration of the intervention

    Time frame: During the period of intubation (as soon as the laryngoscope blade passes the teeth row of the patient until the first capnographic end-expiratory CO2 detection is possible)

    Time to intubation and time to glottis view (as announced by the anesthesist)

  2. Cormack & Lehane grade

    Time frame: During the period of intubation (as soon as the laryngoscope blade passes the teeth row of the patient until the first capnographic end-expiratory CO2 detection is possible)

    Grade 1 (full view of glottis), Grade 2a (partial view of glottis), Grade 2b (view only of posterior extremity of glottis or arytenoid cartilages), Grade 3 (view of epiglottis, none of the glottis), Grade 4 (neither view of glottis nor epiglottis)

  3. Intubation success

    Time frame: During the period of intubation (as soon as the laryngoscope blade passes the teeth row of the patient for the first time until the first capnographic end-expiratory CO2 detection is possible)

    Total number of attempts. Number of attempts using the randomized device. Success rate of intubation attempts regarding the respective device.

  4. Influence of the device on human factors during the intervention

    Time frame: During the period of intubation and maintenance of anesthesia

    Mayo High Performance Teamwork Scale, NASA-TLX (National Aeronautics and Space Administration's Task Load Index)

  5. Complications: occurrence of one or more of the following

    Time frame: During the period of intubation (as soon as the laryngoscope blade passes the teeth row of the patient for the first time until the first capnographic end-expiratory CO2 detection is possible)

    Drop of SpO2 (oxygen saturation) below 90%. Regurgitation as announced by the anesthetist. Need for bronchoscopy due to suspected aspiration. Dental injury or dental clicks upon contact with the blade. Soft tissue injuries as detected by blood on the blade. Visible swelling. Bleeding or other injury of the lips. Need for resuscitation (administration of adrenalin, chest compressions, defibrillation or any combination thereof). Death. Occurence of any adverse event (AE) or serious adverse event (SAE).

  6. Need for auxiliary devices or switch of laryngoscopy device

    Time frame: During the period of intubation (as soon as the laryngoscope blade passes the teeth row of the patient for the first time until the first capnographic end-expiratory CO2 detection is possible)

    Manœuvres to optimize intubation conditions after the first attempt at intubation has started. Switch to alternate laryngoscopy device. Switch of the anesthetists. Switch of airway device

  7. Relevant vital parameters during the intervention

    Time frame: During the period of intubation (as soon as the laryngoscope blade passes the teeth row of the patient for the first time until the first capnographic end-expiratory CO2 detection is possible)

    Baseline SpO2 and lowest SpO2

  8. Post-operative sore throat, coughing or hoarseness

    Time frame: End of surgery until two hours after the end of surgery

    Post-operative sore throat, coughing or hoarseness, according to the "Scoring System for Sore Throat, Cough, and Hoarseness" by Park et al. This outcome will not be assessed in patients who continue to be invasively ventilated > 2 hours after surgery.

Sponsors and collaborators

Lead sponsor

Wuerzburg University Hospital

Other

Collaborators

  • University Hospital, Aachen
  • University Hospital, Bonn

Registry information

Acronym: COVALENT

Important dates

Study start
2022
Primary completion
2025
Study completion
2025
First posted
Feb 8, 2022
Registry last updated
Apr 3, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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