King Vision Video Laryngoscope Versus Glidescope Video Laryngoscope: A Comparative Study in Ambulatory Surgery Center Patients
Phase: NA
Conditions: Difficult Intubation
Sponsor: Vanderbilt University

1 
 
King Vision Video Laryngoscope vs. Glidescope Video 
Laryngoscope:  A Comparative Study in Ambulatory Surgery 
Center Patients 
 
Revision Date: April 4, 2013 
 
NCT02324465 
 
 
 

 
King Vision Video Laryngoscope vs. Glidescope Video 
Laryngoscope:  A Comparative Study in Ambulatory Surgery 
Center Patients 
 
Revision Date: April 4, 2013 
 
Douglas Hester, M.D. 
Principal Investigator 
Assistant Professor of Anesthesiology 
Vanderbilt University Medical Center 
Department of Anesthesiology 
 
Nashville, TN  37232-5614 
 
Paul St. Jacques, M.D. 
Associate Professor of Anesthesiology 
Vanderbilt University Medical Center 
Department of Anesthesiology 
 
Nashville, TN  37232-5614 
 
Michael S Higgins, M.D. 
 Professor of Anesthesiology 
Vanderbilt University Medical Center 
Department of Anesthesiology, Division of Multi-Specialty 
 
Nashville, TN  37232-5614 
 
 
Stuart McGrane, M.D. 
Assistant Professor of Anesthesiology 
Vanderbilt University Medical Center 
Department of Anesthesiology 
 
Nashville, TN  37232-5614 
 
 
 

3 
 
 
 
Confidential 
 
 
 
 
 
Table of Contents: 
 
1.0 
Background 
2.0 
Rationale and Specific Aims 
3.0 
Inclusion Criteria 
4.0 
Exclusion Criteria 
5.0 
Enrollment 
6.0 
Study Method 
7.0 
Reporting of Adverse Events or Unanticipated Problems involving Risk to 
Participants or Others 
8.0 
Statistical Considerations 
9.0 
Privacy/Confidentiality Issues 
10.0 Follow-up and Record Retention 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
1.0 
Background 
 
Both the King Vision and Glidescope video laryngoscopes are advanced airway devices 
that are relatively low cost and are designed to improve the efficiency of both routine and 
difficult intubation. Both systems use disposable blades, which eliminates the need for 
blade sterilization and may minimize the risk of infectious exposure to patients and 
improve cost and efficiency associated with the sterilization processing of non-disposable 
laryngoscopes. The Glidescope has been commercially available longer than the King 
Vision, and has been more frequently studied.  
 
Although similar in many respects, the King Vision and Glidescope systems have 
differing designs which may result in differences in speed and success in the management 
of routine and/or difficult airways. 
 
2.0 
Rationale and Specific Aims 
 
We plan to conduct a randomized trial comparing the intubation success rate and time of 
the King Vision VL to the Glidescope VL in order to demonstrate the comparability of 
the devices.  
 
Hypothesis 
 
The King Vision VL with the disposable “guided tract blade” has comparable intubation 
success rates and times to intubation as the Glidescope VL. 
 
Primary Aim 
 
Determine if the KingVision VL offers comparable intubation success rates and times to 
intubation as compared to the Glidescope VL. 
 
3.0 
Inclusion Criteria 
 
 Adult patients scheduled for elective, ambulatory surgery requiring general 
anesthesia and endotracheal intubation.  
 
4.0 
Exclusion Criteria 
 
 Patients who require rapid sequence induction and intubation or fiberoptic 
intubation. 
 Pregnancy 
 
5.0 
Enrollment 
 

5 
 
Sample size calculation was done via inference of means, and using time parameter 
estimates from prior studies. We will enroll 122 subjects in our pilot study as determined 
by our sample size calculation for a no difference study on the primary outcome of 
intubation time whereby a 10 second difference would be considered clinically 
significant (alpha 0.05, power 0.90).   
 
6.0 
Study Method 
 
1. Patients would be identified who meet inclusion/exclusion criteria.  After obtaining 
written informed consent, airway assessment and baseline vital signs would be 
documented.  
 
2. Information regarding the experience level of the resident/anesthetist assigned to 
perform the intubation as well as number of prior VL experiences would be collected.   
 
3. The patient would be randomized to one of two groups: intubation via use of the  
    Glidescope VL then King Vision VL, or the King Vision VL then Glidescope VL.  
 
4. Before the intubations, one of the investigators will educate the airway provider about 
proper use of the device.   
 
5.  In the operating room, patients would undergo application of monitors and induction 
of anesthesia per routine. 
 
6. Patients would then be intubated with the devices in random order. 
 
7. The intubation time will be recorded as the time from the introduction of the VL into 
the oral cavity to ETT reaching the glottic aperture. The actual intubation would occur 
during the second device.  
 
8. An attempt failure will be defined as the inability to visualize the glottis and/or 
successfully pass the endotracheal tube within 90 seconds or before the oxygen 
saturation falls below 90%. 
 
9. When an attempt is deemed to have failed the patient will receive mask ventilation and 
will then be intubated with standard direct laryngoscopy or other method at the 
discretion of the anesthesia team. 
 
10. 
Additional data collected will include: 
 
 
 Lowest pulse oximetry saturation value reading during intubation 
 Assistance required during the intubation (larngeal manipulation, head lift, etc.) 
 Notation of any injury to lips, teeth, soft tissue. 
 
 

 
 
7.0     Reporting of Adverse Events or Unanticipated Problems involving Risk to 
Participants or Others 
 
Information regarding AEs will be obtained by examining the patients and questioning 
them postoperatively in the recovery room. All new complaints and symptoms (i.e., those 
not existing prior to signing of informed consent) must be recorded on the AE CRF.  All 
AEs must be characterized in terms of their start and stop dates, start and stop times, 
intensity, action taken, relationship to research study, subject outcome and whether or not 
the AE led to an SAE. 
 
8.0 Statistical Considerations 
 
Statistics including means, medians, and variances will be calculated on variables of 
interest.  
 
All individual data (including any relevant derived variables) will be stored in a password 
protected electronic database.  
 
9.0  Privacy/Confidentiality Issues 
 
All reasonable efforts will be made to keep a patient’s protected health information (PHI) 
private and confidential.  There will be limited access to medical records and de-
identification of all records.  Federal privacy guidelines will be followed when using or 
sharing any protected health information.  
 
10.0 
 Follow-up and Record Retention 
 
The study will be completed after the participation of 122 patients. This data will be used 
to draw conclusions about use of the King Vision VL as compared with the Glidescope 
VL. 
 
The investigator will keep a record (i.e., Master Subject Log) relating the names of the 
subjects, date informed consent was signed, subject status, and date when subject 
completed the trial.