Comparison Study of Two Supraglottic Airway Devices Used for Patients Under General Anesthesia

Study Overview
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Brief Summary
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This study will compare two supraglottic airway devices currently on the market. Supraglottic airway devices are used during general anesthesia to provide a patent airway. They are inserted blindly into the mouth once the patient has lost consciousness and they cover the laryngeal inlet. The I-Gel and the Supreme laryngeal mask airway (LMA) are the two devices to be compared. The I-Gel has no inflatable cuff, which makes it different from all other supraglottic airway devices currently in use. The Supreme shares some characteristics of the other LMA devices, but it is disposable. Our main goal will be to compare the airway leak pressure and the peak airway pressure of each devices. We will also measure the time needed for insertion, number of attempts needed to secure the airway and side effects related to the airway (cough, dysphagia, trauma, hoarseness of voice, sore throat).

Detailed Description
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First of all, we will record the following demographic variables: age, sex, height, weight, BMI, surgery planned, American Society of Anesthesiology (ASA) status, dental state (good, bad, edentulous), tobacco use (none, ceased, active) and packs year, Mallampati score, thyromental distance and whether or not there is trauma on the tongue, teeth or lips prior to surgery. Induction of anesthesia will be standardized with Fentanyl 1-3 mcg/kiloGram(kG) and Propofol 1-3,5 mg/kG. The use of myorelaxant will be mandatory, but either succinylcholine or rocuronium will be used as long as complete disappearance of T1 is observed before attempting supraglottic airway insertion. Prior to insertion, ease of ventilation (yes/no) will be noted. The two airway devices will be used according to manufacturers instructions. The sizes of the devices will be chosen according to weight: I-Gel: 50-90 kG: #4 and 90 Kg and up: #5 LMA Supreme: 50-70 Kg: #4 and 70-100 Kg: #5. Patients will be randomized in either I-Gel or LMA Supreme group. Two insertions with the same device will be allowed before a crossover to the other device. If the third attempt fails, a standard endotracheal tube will be put in the trachea and blood in the oral cavity will be sought. After each failed attempt (no thoracic expansion, no carbon dioxide (CO2) square wave or leak at standardized volume. Blood on the devices will also be recorded. Since the LMA Supreme has a cuff, we will inflate it to 25 mL and then by intervals of 5 mL of air (max 45 mL) we will inflate it at a volume where no audible leak is heard at a standardized ventilation scheme of volume controlled 8 mL/kg X 10 breaths per minute. Once fixed with tape, we will measure peak and mean airway pressure for three breaths after 30 seconds of volume controlled breathing. Then the fresh gas flow will be fixed at 3 L/min of 50-50 air-oxygen blend and the Adjustable Pressure Limiting valve will be closed. We will look either for a plateau pressure at which a leak equal to the fresh gas flow or a pressure of 40 cm of water. We will sought adverse effect like bronchospasm, cough, regurgitation, desaturation, aspiration and deglutition movement. Ease of insertion will be score on a scale of 1 to 4. 1 being very easy and 4 being very hard. Endoscopic evaluation will take place afterwards. First in the ventilation tube. Scoring for laryngeal view: Vocal cords all visible; Partial view of the cords including arytenoids; View of the epiglottis only; Other (LMA or pharynx). Downfolding of the epiglottis will be sought. Then we will go through the oesophageal port and see if the oesophageal mucosa il visible. During surgery, we will check if airway manipulation and/or withdrawal was necessary and why. If traces of blood on the devices are present at the end of the intervention it will be noted. Two interviews will take place one at the post anesthesia care unit and another the following day by phone if the patient was having ambulatory surgery. Sore throat, cough, dysphagia and dysphonia will be asked to be graded: absent, mild, moderate or severe. Pulse and arterial pressure with the operating room's sphygmomanometer and oximeter will be written before induction, after induction before insertion and at 1 and 2 minutes post insertion.

Official Title
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Prospective Randomized Trial Comparing the Performance of Two Supraglottic Airway Management Devices: I-Gel and Supreme LMA

Conditions
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Anesthesia Airway Management

Intervention / Treatment
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* Device: I-Gel supraglottic airway device
* Device: LMA Supreme supraglottic airway device
* Device: Standard endotracheal tube


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Weight more than 50 kg; Body Mass Index less than 30; ASA I to III. Exclusion Criteria: Symptomatic gastro oesophageal reflux disease (GERD); Non fasted patients; Nasogastric tube in place; Intestinal obstruction; Ear, nose and throat surgery in the past or deformation of the airway; Known difficult airway (Cormack-Lehane grade 3-4); Oral cavity opening less than 3 cm; Pregnancy.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: I-Gel supraglottic airway device<br>Group in which the I-Gel will be used in the first and second attempts to secure the airway. If a third attempt is needed, the LMA Supreme will be used. If the third attempt fails, a standard endotracheal tube will be used. | Device: I-Gel supraglottic airway device<br>* 2 attempts to secure the airway will be tried. If they both fail, there will be a crossover with a Supreme LMA.<br>Device: Standard endotracheal tube<br>* In case both supraglottic airway devices fail, a standard endotracheal tube will be inserted<br>|
| Active Comparator: LMA Supreme supraglottic airway device<br>Group in which the LMA Supreme will be used in the first and second attempts to secure the airway. If a third attempt is needed, the I-Gel will be used. If the third attempt fails, a standard endotracheal tube will be used. | Device: LMA Supreme supraglottic airway device<br>* In the LMA Supreme group, the same interventions will be done as in the I-Gel group. The cuff of the LMA Supreme will be inflated with 25 mL of air and then by intervals of 5 mL until no leak is heard (max 45 mL). Leak pressure will also be measure at 45 mL. Once the leak test is done, the cuff will be deflated to initial volume necessary to avoid audible leaks.<br>Device: Standard endotracheal tube<br>* In case both supraglottic airway devices fail, a standard endotracheal tube will be inserted<br>|
| Active Comparator: Standard endotracheal tube<br>A Standard endotracheal tube will be inserted in case both other airway devices (LMA Supreme and iGel) devices fail to provide adequate ventilation. | Device: Standard endotracheal tube<br>* In case both supraglottic airway devices fail, a standard endotracheal tube will be inserted<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measure of the Airway Leak Pressure |  | After introduction of the supraglottic device before the beginning of the surgery. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measure of the Peak Airway Pressure |  | After introduction of the SAD before the beginning of the surgery. | 
| Time Needed to Secure the Airway |  | From opening of the mouth to thoracic expansion and presence of End Tidal CO2 up to five minutes. | 
| Number of Participants With Successful Attempts to Introduce the Devices |  | At the beginning of anesthesia before the beginning of the surgery. | 
| Adverse Effects After Anesthesia (Sore Throat, Cough, Dysphagia, Dysphonia) | Intent to treat assessment of adverse events, per intervention, was intended. The adverse effects were assessed by phone; or in person if patient in the hospital; on the following day. | On the day following surgery | 
| Airway Manipulation and Blood on Device at Removal |  | During and after anesthesia when the device is removed. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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supraglottic airway devices, I-Gel, Supreme Laryngeal mask airway, Airway leak pressure, peak airway pressure