Endotracheal IntubationCOVALENTNCT05228288
Conventional vs. Video-Assisted Laryngoscopy for Perioperative Endotracheal Intubation
A study testing Conventional direct laryngoscopy (CDL), Video assisted laryngoscopy with Macintosh-shaped blade (M-VAL) and Video assisted laryngoscopy with hyper-angulated blade (H-VAL) in people with Endotracheal Intubation, run by Wuerzburg University Hospital at 1 site in Germany.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Endotracheal Intubation
- What is being tested?
- Conventional direct laryngoscopy (CDL), Video assisted laryngoscopy with Macintosh-shaped blade (M-VAL) and Video assisted laryngoscopy with hyper-angulated blade (H-VAL)
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 2,855 participants
- Where
- 1 siteGermany
- Study dates
- 28 Mar 2022to 18 Feb 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
About this study
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.
Read the detailed description
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.
- Conditions
- Endotracheal Intubation
- Being tested
- Conventional direct laryngoscopy (CDL), Video assisted laryngoscopy with Macintosh-shaped blade (M-VAL), Video assisted laryngoscopy with hyper-angulated blade (H-VAL)
- Keywords
- anesthesiology, laryngoscopy, video-assisted laryngoscopy, intubation, airway management, patient safety, human factors, conventional laryngoscopy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Conventional direct laryngoscopy (CDL)Procedure or surgery
Also called conventional direct laryngoscopy, conventional laryngoscopy
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.
Video assisted laryngoscopy with Macintosh-shaped blade (M-VAL)Procedure or surgery
Also called video assisted laryngoscopy with Macintosh-shaped blade
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.
Video assisted laryngoscopy with hyper-angulated blade (H-VAL)Procedure or surgery
Also called video assisted laryngoscopy with hyper-angulated blade
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.
| Study group | Role | What they receive |
|---|---|---|
| CDL | Active comparator | Conventional direct laryngoscopy using a Macintosh blade Receives: Procedure: Conventional direct laryngoscopy (CDL) |
| M-VAL | Experimental | Video assisted laryngoscopy with a Macintosh-shaped blade Receives: Procedure: Video assisted laryngoscopy with Macintosh-shaped blade (M-VAL) |
| H-VAL | Experimental | Video assisted laryngoscopy with a hyper-angulated blade Receives: Procedure: Video assisted laryngoscopy with hyper-angulated blade (H-VAL) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Successful intubation
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.
Measured: 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)
Secondary outcomes (8)
Parameters regarding the duration of the intervention
Time to intubation and time to glottis view (as announced by the anesthesist)
Measured: 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)
Cormack & Lehane grade
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)
Measured: 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)
Intubation success
Total number of attempts. Number of attempts using the randomized device. Success rate of intubation attempts regarding the respective device.
Measured: 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)
Influence of the device on human factors during the intervention
Mayo High Performance Teamwork Scale, NASA-TLX (National Aeronautics and Space Administration's Task Load Index)
Measured: During the period of intubation and maintenance of anesthesia
Complications: occurrence of one or more of the following
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).
Measured: 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)
Need for auxiliary devices or switch of laryngoscopy device
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
Measured: 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)
Relevant vital parameters during the intervention
Baseline SpO2 and lowest SpO2
Measured: 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)
Post-operative sore throat, coughing or hoarseness
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.
Measured: End of surgery until two hours after the end of surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Feb 2022
- Study start28 Mar 2022
- Primary completion17 Feb 2025
- Study completion18 Feb 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Endotracheal IntubationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- In this randomized, controlled, three-armed parallel group design, multi-center trial, a total of more than 2500 adult patients scheduled for perioperative endotracheal intubation will be randomized. In equally large arms, video-assisted laryngoscopy with a Macintosh-shaped or a hyperangulated blade will be compared to the standard of care (direct laryngoscopy with Macintosh blade).
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 2,855 participants (actual)
Sponsor and investigators
- Lead sponsor
- Wuerzburg University Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- University Hospital, Aachen, University Hospital, Bonn
- Responsible party
- Sponsor
- Investigators
- Benedikt Schmid, MD, PhD, Principal investigator, Department of Anaesthesiology, Medical Faculty Würzburg
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05228288
- Sponsor's protocol ID
- COVALENT
- Acronym
- COVALENT
- Status last verified
- Mar 2025
- First submitted
- 7 Feb 2022
- Last updated
- 3 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Park SY, Kim SH, Lee AR, Cho SH, Chae WS, Jin HC, Lee JS, Kim YI. Prophylactic effect of dexamethasone in reducing postoperative sore throat. Korean J Anesthesiol. 2010 Jan;58(1):15-9. doi: 10.4097/kjae.2010.58.1.15. Epub 2010 Jan 31.
PubMed 20498806Schmid B, Grusser L, Muller L, Wittmann M, Delis A, Dinc Dogan T, Werdehausen R, Neuhaus C, Paal P, Claassen C, Helmer P, Fischer P, Kranke P, Meybohm P, Massoth G; German Society of Anaesthesiology and Intensive Care (GSAIC) Trials Group. Conventional vs Video-Assisted Laryngoscopy for Perioperative Endotracheal Intubations: A Randomized Clinical Trial. JAMA Netw Open. 2026 Aug 3;9(8):e2625965. doi: 10.1001/jamanetworkopen.2026.25965.
PubMed 42545700Schmid B, Eckert D, Meixner A, Pistner P, Malzahn U, Berberich M, Happel O, Meybohm P, Kranke P. Conventional versus video-assisted laryngoscopy for perioperative endotracheal intubation (COVALENT) - a randomized, controlled multicenter trial. BMC Anesthesiol. 2023 Apr 18;23(1):128. doi: 10.1186/s12871-023-02083-3.
PubMed 37072702
Study at a glance
From the registry record, last updated by the sponsor on 3 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Conventional vs. Video-Assisted Laryngoscopy for Perioperative Endotracheal Intubation
- ClinicalTrials.gov ID
- NCT05228288
- Acronym / sponsor ID
- COVALENT / COVALENT
- Conditions
- Endotracheal Intubation
- Keywords
- anesthesiology, laryngoscopy, video-assisted laryngoscopy, intubation, airway management, patient safety, human factors, conventional laryngoscopy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 2,855 participants (actual)
- Lead sponsor
- Wuerzburg University HospitalUniversity, hospital or other
- Collaborators
- University Hospital, Aachen, University Hospital, Bonn
- Study start
- 28 Mar 2022 (actual)
- Primary completion
- 17 Feb 2025 (actual)
- Study completion
- 18 Feb 2025 (actual)
- First posted
- 8 Feb 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 3
- Model description
- In this randomized, controlled, three-armed parallel group design, multi-center trial, a total of more than 2500 adult patients scheduled for perioperative endotracheal intubation will be randomized. In equally large arms, video-assisted laryngoscopy with a Macintosh-shaped or a hyperangulated blade will be compared to the standard of care (direct laryngoscopy with Macintosh blade).
| Arm | Type | Receives |
|---|---|---|
| CDL | Active comparator | Procedure: Conventional direct laryngoscopy (CDL)Conventional direct laryngoscopy using a Macintosh blade |
| M-VAL | Experimental | Procedure: Video assisted laryngoscopy with Macintosh-shaped blade (M-VAL)Video assisted laryngoscopy with a Macintosh-shaped blade |
| H-VAL | Experimental | Procedure: Video assisted laryngoscopy with hyper-angulated blade (H-VAL)Video assisted laryngoscopy with a hyper-angulated blade |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- 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
Key exclusion criteria (6 listed)
- Lack of ability to give consent
- Previous participation in this study
- Pregnancy
- Need for fiberoptic intubation
- Patients scheduled for bariatric surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Conventional direct laryngoscopy (CDL)Also: conventional direct laryngoscopy, conventional laryngoscopyThis 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. | Procedure or surgery | CDL |
| Video assisted laryngoscopy with Macintosh-shaped blade (M-VAL)Also: video assisted laryngoscopy with Macintosh-shaped bladeThis 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. | Procedure or surgery | M-VAL |
| Video assisted laryngoscopy with hyper-angulated blade (H-VAL)Also: video assisted laryngoscopy with hyper-angulated bladeThe 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. | Procedure or surgery | H-VAL |
Primary outcome
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.
8 secondary outcomes
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)
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)
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)
Influence of the device on human factors during the intervention
Time frame: During the period of intubation and maintenance of anesthesia
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)
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)
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)
Post-operative sore throat, coughing or hoarseness
Time frame: End of surgery until two hours after the end of surgery
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Apr 2025.
- Background: PubMed 20498806Park SY, Kim SH, Lee AR, Cho SH, Chae WS, Jin HC, Lee JS, Kim YI. Prophylactic effect of dexamethasone in reducing postoperative sore throat. Korean J Anesthesiol. 2010 Jan;58(1):15-9. doi: 10.4097/kjae.2010.58.1.15. Epub 2010 Jan 31.
- Derived from this study: PubMed 42545700Schmid B, Grusser L, Muller L, Wittmann M, Delis A, Dinc Dogan T, Werdehausen R, Neuhaus C, Paal P, Claassen C, Helmer P, Fischer P, Kranke P, Meybohm P, Massoth G; German Society of Anaesthesiology and Intensive Care (GSAIC) Trials Group. Conventional vs Video-Assisted Laryngoscopy for Perioperative Endotracheal Intubations: A Randomized Clinical Trial. JAMA Netw Open. 2026 Aug 3;9(8):e2625965. doi: 10.1001/jamanetworkopen.2026.25965.
- Derived from this study: PubMed 37072702Schmid B, Eckert D, Meixner A, Pistner P, Malzahn U, Berberich M, Happel O, Meybohm P, Kranke P. Conventional versus video-assisted laryngoscopy for perioperative endotracheal intubation (COVALENT) - a randomized, controlled multicenter trial. BMC Anesthesiol. 2023 Apr 18;23(1):128. doi: 10.1186/s12871-023-02083-3.
- covalent WebsiteLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Benedikt Schmid, MD, PhD principal investigator
Department of Anaesthesiology, Medical Faculty Würzburg
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Conventional direct laryngoscopy (CDL), Video assisted laryngoscopy with Macintosh-shaped blade (M-VAL) and Video assisted laryngoscopy with hyper-angulated blade (H-VAL) in people with Endotracheal Intubation, run by Wuerzburg University Hospital at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 3 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05228288, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Apr 2025.