Effectiveness and Safety of the Levitan Scope for Laryngoscopy and Tracheal Intubation With a Simulated Difficult Airway

Study Overview
=================
Brief Summary
-----------------
A laryngoscope is a medical instrument that is used to get a view of the voice box and the space in between the vocal cords. A laryngoscope is used to place a breathing tube into the trachea (windpipe or airway) to protect the patient's airway and provide a way to help a person breathe during surgery; this is called intubation.

Detailed Description
-----------------
A laryngoscope is a medical instrument that is used to get a view of the voice box and the space in between the vocal cords. A laryngoscope is used to place a breathing tube into the trachea (windpipe or airway) to protect the patient's airway and provide a way to help a person breathe during surgery; this is called intubation. The placement of a breathing tube into the windpipe is a skill that is not easily mastered. In fact, the placement is difficult or impossible using the usual technique in 1-3 of every 100 patients. The ease of placing this breathing tube depends in part on how easily and how much of the vocal cords are able to be seen directly using a laryngoscope. In a small number of patients, the Levitan First Pass Success (FPS) Scope has been shown to be more effective and easier to insert even in patients who have difficult airways. This study will evaluate the use of the LFS compared to the other conventional laryngoscope in subjects with a simulated difficult airway. The goal of this study is to determine the effectiveness and safety of the LFS in a large number of patients with simulated airway difficulties. The results obtained during the study may provide useful information to health care providers who cannot place a breathing tube in patients that are either in operating rooms or in emergency situations requiring intubation by paramedics. An example would be a trauma situation where a paramedic is having difficulty attempting an intubation when a patients c-spine is being protected from any movements. The LFS is an affordable and transportable device, which makes this an attractive asset for health providers in smaller community settings or in paramedic vehicles which may not have the capacity to stock or ability to afford a variety of different scopes and must choose a more limited selection.

Official Title
-----------------
Effectiveness and Safety of the Levitan FPS Scope for Laryngoscopy and Tracheal Intubation With a Simulated Difficult Airway in Surgical Subjects Under General Anesthesia

Conditions
-----------------
Airway Complication of Anaesthesia

Intervention / Treatment
-----------------
* Device: Laryngoscopy order: 1) MAC, 2) Levitan
* Device: Laryngoscopy order: 1) Levitan, 2) MAC


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: American Society of Anesthesiologists (ASA) physical status I or II (healthy or mild systemic disease, ex. asthma, high blood pressure) Elective surgery requiring endotracheal intubation English speaking Age 16 - 75 years Exclusion Criteria: Significant gastroesophageal reflux disease (GERD) that may require alternate induction/intubation techniques Prior history of a difficult intubation requiring an awake tracheal intubation Clinical predictors of a potentially difficult intubation requiring an awake intubation BMI > 45 kg/m2 (Obesity is a common and important risk factor for difficult intubation)

Ages Eligible for Study
-----------------
Minimum Age: 16 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
Female

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

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

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Laryngoscopy order: 1) MAC, 2) Levitan<br>Levitan FPS Intubation | Device: Laryngoscopy order: 1) MAC, 2) Levitan<br>* Laryngoscopy with MAC, then Levitan<br>Device: Laryngoscopy order: 1) Levitan, 2) MAC<br>* Laryngoscopy with Levitan, then MAC<br>|
| Experimental: Laryngoscopy order: 1) Levitan, 2) MAC<br>Macintosh Intubation | Device: Laryngoscopy order: 1) MAC, 2) Levitan<br>* Laryngoscopy with MAC, then Levitan<br>Device: Laryngoscopy order: 1) Levitan, 2) MAC<br>* Laryngoscopy with Levitan, then MAC<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cormack-Lehane Grade | The anesthesiologist graded the laryngeal view after induction of anesthesia using Cormack-Lehane Scale. Grade 1 = full view of glottis Grade 2a = partial view of glottis Grade 2b = Only posterior extremity of glottis seen or only arytenoid cartilages Grade 3 = Only epiglottis seen, none of glottis seen Grade 4 = Neither glottis nor epiglottis seen | intraoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Intubation Attempts | Number of intubation attempts was recorded after intubation was completed. | intraoperative | 
| Operator Rating of Difficulty | The attending anesthesiologist rated the difficulty in using each technique to intubate the larynx using an 11-point numeric rating scale and a 4-point visual rating scale. | intraoperative | 
| Time to Successful Intubation | Time to successful intubation was documented during the second laryngoscopy and defined as the time from the insertion of the Macintosh laryngoscope into the oral cavity to its removal. | intraoperative |