An interventional study of Video Laryngoscope and Direct Laryngoscope in Acute Respiratory Failure, sponsored by Vanderbilt University Medical Center. Completed at 12 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2024-08-19.
Sponsored by Vanderbilt University Medical Center · Not applicable, Interventional, and Treatment
Clinicians perform rapid sequence induction, laryngoscopy, and tracheal intubation for more than 5 million critically ill adults as a part of clinical care each year in the United States. Failure to intubate the trachea on the first attempt occurs in more than 10% of all tracheal intubation procedures performed in the emergency department (ED) and intensive care unit (ICU). Improving clinicians rate of intubation on the first attempt could reduce the risk of serious procedural complications.
In current clinical practice, two classes of laryngoscopes are commonly used to help clinicians view the larynx while intubating the trachea: a video laryngoscope (equipped with a camera and a video screen) and a direct laryngoscope (not equipped with a camera or video screen). For nearly all laryngoscopy and intubation procedures performed in current clinical practice, clinicians use either a video or a direct laryngoscope. Prior research has shown that use of a video laryngoscope improves the operator's view of the larynx compared to a direct laryngoscope. Whether use of a video laryngoscope increases the likelihood of successful intubation on the first attempt remains uncertain. A better understanding of the comparative effectiveness of these two common, standard-of-care approaches to laryngoscopy and intubation could improve the care clinicians deliver and patient outcomes.
Clinicians frequently perform tracheal intubation of critically ill patients in the emergency department (ED) or intensive care unit (ICU). In 10-20% of emergency tracheal intubations, clinicians are unable to intubate the trachea on the first attempt, which increases the risk of peri-intubation complications. Successful laryngoscopy and tracheal intubation requires using a laryngoscope to [1] visualize the larynx and vocal cords and [2] create a pathway through which an endotracheal tube can be advanced through the oropharynx and larynx and into the trachea.
In current clinical practice, two classes of laryngoscopes are commonly used by clinicians to view the larynx while intubating the trachea: a video laryngoscope (equipped with a camera and a video screen) and a direct laryngoscope (not equipped with a camera or video screen). Clinicians use either a video laryngoscope or a direct laryngoscope as standard of care for every laryngoscopy and intubation procedure performed in current clinical practice.
Direct Laryngoscope: The Macintosh direct laryngoscope consists of a battery-containing handle and a blade with a light source. The operator achieves a direct line of sight -from the operator's eye through the mouth to the larynx and trachea - by using the laryngoscope blade to displace the tongue and elevate the epiglottis.
Video Laryngoscope: Video laryngoscopes consist of a fiberoptic camera and light source near the tip of the laryngoscope blade, which transmits images to a video screen. The position of the camera near the tip of the laryngoscope blade facilitates visualization of the larynx and trachea.
Use of a video laryngoscope and use of a direct laryngoscope are both common, standard-of-care approaches the clinicians use to perform tracheal intubation in the ED and ICU in current clinical care.
Currently, it is unknown whether use of a video laryngoscope or use of a direct laryngoscope has any effect on successful intubation on the first attempt or any other outcome. Some prior research has raised the hypothesis that using a video laryngoscope would increase clinicians' rate of successful intubation on the first attempt by facilitating the view of the larynx. Some prior research has raised the hypothesis that using a direct laryngoscope would increase clinicians' rate of successful intubation on the first attempt by facilitating a clear pathway for placement of the tube through the mouth into the trachea.
To date, 8 small single-center randomized trials and one 371-patient multicenter randomized clinical trial have been conducted under waiver of or alteration of informed consent to compare use of a video vs a direct laryngoscope in the setting of emergency tracheal intubation in the ED or ICU. Two of these trials provide the most direct preliminary data for this proposal. The "Facilitating EndotracheaL intubation by Laryngoscopy technique and apneic Oxygenation Within the ICU (FELLOW)" randomized clinical trial, conducted under waiver of informed consent, compared these two standard-of-care approaches during 150 emergency tracheal intubations at Vanderbilt University Medical Center, finding no difference in the rate of successful intubation on the first attempt between use of a video and use of a direct laryngoscope. The "McGrath Mac Videolaryngoscope Versus Macintosh Laryngoscope for Orotracheal Intubation in the Critical Care Unit (MACMAN)" randomized clinical trial among 371 critically ill adults found no difference between use of a video vs direct laryngoscope in the rate of successful intubation on the first attempt. However, a hypothesis-forming post-hoc exploratory analysis of peri-intubation complications suggested that use of a video laryngoscope may be associated with a higher rate of complications than direct laryngoscope (9.5% vs 2.8%, respectively, p=0.01). These trials were underpowered to rule out small but clinically significant differences in first pass success, and were limited to intubations performed by inexperienced trainees in one practice setting (intensive care units), but they demonstrated hypothesis-generating findings requiring validation in larger trials that reflect the full spectrum of settings, operator specialties, and operator experience levels in which emergency tracheal intubation is routinely performed.
Because of the imperative to optimize emergency tracheal intubation in clinical care, the common use of both video and direct laryngoscopes in current clinical practice, and the lack of definitive data from randomized trials to definitively inform whether use of a video laryngoscope or a direct laryngoscope effects the rate of successful intubation on the first attempt, examining whether one approach increases the odds of successful intubation on the first attempt represents an urgent research priority. To address this knowledge gap, the investigators propose to conduct a large, multicenter, randomized clinical trial comparing use of a video laryngoscope versus use of a direct laryngoscope with regard to successful intubation on the first attempt among critically ill adults undergoing tracheal intubation in the ED or ICU.
1,650 studies on the registry are indexed under Respiratory Insufficiency; 296 are open to participants now.
This study's enrollment of 1,420 is above the median of 55 across 1,043 interventional studies indexed under Respiratory Insufficiency.
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Exclusion Criteria:
For patients assigned to the video laryngoscope group, the operator will use a video laryngoscope on the first laryngoscopy attempt. A video laryngoscope will be defined as a laryngoscope with a camera and a video screen. Trial protocol will not dictate the brand of video laryngoscope.
Other: Video Laryngoscope
For patients assigned to the direct laryngoscope group, the operator will use a direct laryngoscope on the first laryngoscopy attempt. A direct laryngoscope will be defined as a laryngoscope without a camera or a video screen. Trial protocol will not dictate the brand of direct laryngoscope or the blade shape.
Other: Direct Laryngoscope
Laryngoscope with a camera and a video screen
Laryngoscope without a camera or a video screen
Number of Intubations With Successful Intubation on the First Attempt
The primary outcome is defined as placement of an endotracheal tube in the trachea with a single insertion of a laryngoscope blade into the mouth and EITHER a single insertion of an endotracheal tube into the mouth OR a single insertion of a bougie into the mouth followed by a single insertion of an endotracheal tube over the bougie into the mouth.
Time frame: Duration of procedure (minutes)
Number of Participants With Severe Complications of Tracheal Intubation
The secondary outcome is defined as the number of patients who experienced one or more of the following occurring between induction and 2 minutes after successful intubation: * Severe hypoxemia (lowest oxygen saturation measured by pulse oximetry \< 80%); * Severe hypotension (systolic blood pressure \< 65 mm Hg or new or increased vasopressor administration); * Cardiac arrest not resulting in death within 1 hour of intubation; or * Cardiac arrest resulting in death within 1 hour of induction
Time frame: from induction to 2 minutes following tracheal intubation
Duration of Laryngoscopy and Tracheal Intubation
The interval (in seconds) between the first insertion of a laryngoscope blade into the mouth and the final placement of an endotracheal tube or tracheostomy tube in the trachea.
Time frame: Duration of procedure (minutes)
Number of Laryngoscopy Attempts
Time frame: Duration of procedure (minutes)
Number of Attempts to Cannulate the Trachea With a Bougie or an Endotracheal Tube
Time frame: Duration of procedure (minutes)
Successful Intubation on the First Attempt Without a Severe Complication
This outcome reports the number of participants that experienced successful intubation on the first attempt without experiencing complications, a composite of two independent outcomes: successful intubation on the first attempt (the primary outcome of the trial) and severe complication (the secondary outcome of the trial).
Time frame: from induction to 2 minutes following tracheal intubation
Reason for Failure to Intubate on the First Attempt
Providers could give more than one reason for failure to intubate on the first attempt for each intubation (not mutually exclusive). In addition, data on the reason for failure to intubate on the first attempt was missing for 23 patients in the video laryngoscope group and 40 patients in the direct laryngoscope group. Reason for failure among those who did not meet the primary outcome (successful intubation on the first attempt): * Inadequate view of the larynx * Inability to intubate the trachea with an endotracheal tube * Inability to cannulate the trachea with a bougie * Attempt aborted due to change in patient condition (e.g., worsening hypoxemia, hypotension, bradycardia, vomiting, bleeding) * Technical failure of the laryngoscope (e.g., battery, light source, camera, screen) * Other * Not Reported
Time frame: Duration of procedure (minutes)
Operator-reported Aspiration
Time frame: from induction to 2 minutes following tracheal intubation
Esophageal Intubation
Time frame: from induction to 2 minutes following tracheal intubation
Injury to the Teeth
Time frame: from induction to 2 minutes following tracheal intubation
ICU-free Days in the First 28 Days
Time frame: 28 days
Ventilator Free Days in the First 28 Days
Time frame: 28 days
All-cause In-hospital Mortality
Time frame: 28 days
| Milestone | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Started | 707 | 713 |
| Completed | 705 | 712 |
| Not completed | 2 | 1 |
| Withdrew: After enrollment, discovered to be a person experiencing incarceration. | 2 | 1 |
The primary outcome is defined as placement of an endotracheal tube in the trachea with a single insertion of a laryngoscope blade into the mouth and EITHER a single insertion of an endotracheal tube into the mouth OR a single insertion of a bougie into the mouth followed by a single insertion of an endotracheal tube over the bougie into the mouth.
| Participants | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Number of Intubations With Successful Intubation on the First Attempt | 600 | 504 |
The secondary outcome is defined as the number of patients who experienced one or more of the following occurring between induction and 2 minutes after successful intubation: * Severe hypoxemia (lowest oxygen saturation measured by pulse oximetry \< 80%); * Severe hypotension (systolic blood pressure \< 65 mm Hg or new or increased vasopressor administration); * Cardiac arrest not resulting in death within 1 hour of intubation; or * Cardiac arrest resulting in death within 1 hour of induction
| Participants | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Number of Participants With Severe Complications of Tracheal Intubation | 151 | 149 |
The interval (in seconds) between the first insertion of a laryngoscope blade into the mouth and the final placement of an endotracheal tube or tracheostomy tube in the trachea.
| Seconds | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Duration of Laryngoscopy and Tracheal Intubation | 38 (26 to 60) | 46 (30 to 83) |
| Participants | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Number of times a laryngoscope entered the patient's mouth (reported by observer) - 1 | 636 | 546 |
| Number of times a laryngoscope entered the patient's mouth (reported by observer) - 2 | 54 | 127 |
| Number of times a laryngoscope entered the patient's mouth (reported by observer) - 3+ | 14 | 33 |
| number of events | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Endotracheal Tube - 1 | 646 | 620 |
| Endotracheal Tube - 2 | 43 | 66 |
| Endotracheal Tube - 3+ | 15 | 19 |
| Bougie - 0 | 364 | 330 |
| Bougie - 1 | 316 | 317 |
| Bougie - 2 | 19 | 33 |
| Bougie - 3+ | 6 | 27 |
This outcome reports the number of participants that experienced successful intubation on the first attempt without experiencing complications, a composite of two independent outcomes: successful intubation on the first attempt (the primary outcome of the trial) and severe complication (the secondary outcome of the trial).
| Participants | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Successful Intubation on the First Attempt Without a Severe Complication | 484 | 420 |
Providers could give more than one reason for failure to intubate on the first attempt for each intubation (not mutually exclusive). In addition, data on the reason for failure to intubate on the first attempt was missing for 23 patients in the video laryngoscope group and 40 patients in the direct laryngoscope group. Reason for failure among those who did not meet the primary outcome (successful intubation on the first attempt): * Inadequate view of the larynx * Inability to intubate the trachea with an endotracheal tube * Inability to cannulate the trachea with a bougie * Attempt aborted due to change in patient condition (e.g., worsening hypoxemia, hypotension, bradycardia, vomiting, bleeding) * Technical failure of the laryngoscope (e.g., battery, light source, camera, screen) * Other * Not Reported
| Participants | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Inadequate view of the larynx | 26 | 123 |
| Inability to intubate the trachea with an endotracheal tube | 44 | 32 |
| Inability to cannulate the trachea with a bougie | 7 | 19 |
| Attempt aborted due to change in patient condition | 2 | 14 |
| Technical failure of the laryngoscope (e.g., battery, light source, camera, screen) | 2 | 4 |
| Other | 13 | 10 |
| Not Reported | 23 | 40 |
| Participants | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Operator-reported Aspiration | 7 | 12 |
| Participants | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Esophageal Intubation | 6 | 9 |
| Participants | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Injury to the Teeth | 3 | 2 |
| days | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| ICU-free Days in the First 28 Days | 20 (0 to 25) | 19 (0 to 24) |
| days | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| Ventilator Free Days in the First 28 Days | 24 (0 to 26) | 23 (0 to 26) |
| Participants | Video Laryngoscope Group | Direct Laryngoscope Group |
|---|---|---|
| All-cause In-hospital Mortality | 184 | 191 |
Collected over 28 days. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Video Laryngoscope Group | 184/705 (26.1%) | 0/705 (0%) | 0/705 (0%) |
| Direct Laryngoscope Group | 191/712 (26.8%) | 0/712 (0%) | 0/712 (0%) |
| Age, Continuous(years) | Video Laryngoscope Group | Direct Laryngoscope Group | Total |
|---|---|---|---|
| Median | 54 (36 to 66) | 55 (39 to 67) | 55 (38 to 67) |
| Sex: Female, Male(Participants) | Video Laryngoscope Group | Direct Laryngoscope Group | Total |
|---|---|---|---|
| Female | 240 | 258 | 498 |
| Male | 465 | 454 | 919 |
| Race/Ethnicity, Customized(Participants) | Video Laryngoscope Group | Direct Laryngoscope Group | Total |
|---|---|---|---|
| Race or ethnic group — Non-Hispanic White | 360 | 346 | 706 |
| Race or ethnic group — Non-Hispanic Black | 166 | 167 | 333 |
| Race or ethnic group — Hispanic | 101 | 94 | 195 |
| Race or ethnic group — Other | 61 | 84 | 145 |
| Race or ethnic group — Not reported | 17 | 21 | 38 |
| Region of Enrollment(participants) | Video Laryngoscope Group | Direct Laryngoscope Group | Total |
|---|---|---|---|
| United States | 705 | 712 | 1417 |
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes — Following publication, individual patient data will be made available for sharing to researchers with 1) a signed data access agreement, 2) research testing a hypothesis, 3) a protocol that has been approved by an institutional review board, and 4) a proposal that has received approval from the principal investigator.
Supporting information: Study protocol, Sap
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