Oropharyngeal Space in Videolaryngoscopy

Study Overview
=================
Brief Summary
-----------------
In this randomised crossover trial we measure the space between the right side of the laryngoscope blade and the right palatopharyngeal wall in a cohort of ASA I-III patients with a normal mouth opening. We compare the remaining spaces for seven different videolaryngoscopes and compare these to a classic Macintosh laryngoscope.

Detailed Description
-----------------
Intubation using indirect videolaryngoscopy has many advantages over classic direct laryngoscopy using the Macintosh laryngoscope. There are many different videolaryngoscopes available, and the blade differs largely between videolaryngoscopes. Different size and angles of blades may have an impact on the space available for insertion of the endotracheal tube. The space between the blade and the palatopharyngeal wall may be reduced significantly, so that there is less room in the mouth to insert an endotracheal tube. Positioning and manoeuvring of the endotracheal tube may consequently be more difficult and may traumatize the pharynx as was described in a few case reports, especially when an endotracheal tube with a rigid stylet inserted was used.

Official Title
-----------------
Oropharyngeal Space in Videolaryngoscopy: a Randomised Crossover Trial Measuring Remaining Space Adjacent to the Videolaryngoscope Blade

Conditions
-----------------
Abrasion of Soft Palate, Intubation Complication

Intervention / Treatment
-----------------
* Device: C-MAC ® videolaryngoscope
* Device: Coopdech® videolaryngoscope
* Device: McGrath® Series 5 videolaryngoscope
* Device: Glidescope® Cobalt videolaryngoscope
* Device: King Vision® videolaryngoscope
* Device: Venner® videolaryngoscope
* Device: McGrath® MAC


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Informed patient consent ASA I - III Age > 18 years Elective surgery, other than head and/or neck surgery Pre-operative Mallampati I - III BMI < 35 kg/m2 Fasted (≥6 hours) Exclusion Criteria: No informed patient consent ASA ≥ IV Age < 18 year Emergency surgery, surgery of head and/of neck Locoregional anaesthesia Pre-operative Mallampati IV BMI > 35 kg/m2 Fasted < 6 hours Pre-operative expected difficult airway (restrict neck movement, thyromental distance < 65mm, retrognathia) Bad, fragile dentition Dental crowns and/or fixed partial denture

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Coopdech® videolaryngoscope<br> | Device: Coopdech® videolaryngoscope<br>* Coopdech® videolaryngoscope<br>* Other names: Coopdech® videolaryngoscope (Daiken Medical, Osaka, Japan);|
| Other: C-MAC® videolaryngoscope<br> | Device: C-MAC ® videolaryngoscope<br>* C-MAC ® videolaryngoscope<br>* Other names: C-MAC ® videolaryngoscope (Karl Storz, Tuttlingen, Germany);|
| Other: McGrath® Series 5 videolaryngoscope<br> | Device: McGrath® Series 5 videolaryngoscope<br>* McGrath® Series 5 videolaryngoscope<br>* Other names: McGrath® Series 5 (Aircraft Medical, Edinburgh, UK);|
| Other: Glidescope® Cobalt videolaryngoscope<br> | Device: Glidescope® Cobalt videolaryngoscope<br>* Glidescope® Cobalt videolaryngoscope<br>* Other names: Glidescope® Cobalt (Verathon, Bothell, USA);|
| Other: King Vision® videolaryngoscope<br> | Device: King Vision® videolaryngoscope<br>* King Vision® videolaryngoscope<br>* Other names: King Vision® videolaryngoscope (King Systems, Noblesville, IN, USA);|
| Other: Venner® videolaryngoscope<br> | Device: Venner® videolaryngoscope<br>* Venner® videolaryngoscope<br>* Other names: Venner® videolaryngoscope (Venner Medical, Singapore, Republic of Singapore);|
| Other: McGrath MAC® videolaryngoscope<br> | Device: McGrath® MAC<br>* McGrath® MAC (Aircraft Medical, Edinburgh, UK)<br>* Other names: McGrath® MAC (Aircraft Medical, Edinburgh, UK);|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Palatopharyngeal distance | Two laryngoscopes (one classic direct laryngoscope and one indirect videolaryngoscope) will subsequently be inserted into the patient's mouth at random order. With each laryngoscope the horizontal distance between the laryngoscope blade and mid-palatopharyngeal fold will be measured using an mm ruler. | Participants will be followed during induction of anesthesia, an expected average of 10 min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in palatopharyngeal distance between videolaryngoscope and classic Macintosh laryngoscope | Investigating how this space differs from the space that remains on the right side of the blade of the classic Macintosh laryngoscope and the palatopharyngeal wall in the same cohort of patients. | Participants will be followed during induction of anesthesia, an expected average of 10 min | 
| Difference in palatopharyngeal distance between videolaryngoscopes | Comparing the difference in remaining palatopharyngeal space between the different videolaryngoscopes. | Participants will be followed during induction of anesthesia, an expected average of 10 min | 
| Cormack-Lehane score | Registering difficulty of intubation (Cormack-Lehane score) | Participants will be followed during induction of anesthesia, an expected average of 10 min | 
| Successful intubation | Registering the number of successful intubations. | Participants will be followed during induction of anesthesia, an expected average of 10 min | 
| Use of rigid stylet | Use of rigid stylet during intubation | Participants will be followed during induction of anesthesia, an expected average of 10 min | 
| Number of attempts | Number of intubation attempts | Participants will be followed during induction of anesthesia, an expected average of 10 min | 
| Time until picking up endotracheal tube | Time until picking up endotracheal tube | Participants will be followed during induction of anesthesia, an expected average of 10 min | 
| Epiglottic down-folding | Occurrence of epiglottic down-folding | Participants will be followed during induction of anesthesia, an expected average of 10 min | 
| Complications | Any complication that occurs during intubation will be registered. | Participants will be followed during induction of anesthesia, an expected average of 10 min | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Videolaryngoscopy, Palatopharyngeal distance, Trauma