Retromolar Route Access With and Without A Retromolar Gap

Study Overview
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Brief Summary
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Retromolar Intubation is a successful option for intubation in patients with an existing retromolar gap in the case that the conventional method fails. Therefore the investigators want to test if the retromolar gap is essential for performing the retromolar intubation technique.

Detailed Description
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For successful endotracheal intubation an optimal visualisation of the vocal cords is essential. A study comparing retromolar and conventional laryngoscopy showed in patients with an existing retromolar gap, that the retromolar technique is superior for endotracheal intubation especially in patients with a failed 'conventional' intubation attempt. The aim of the following study is to test if a retromolar gap at the right mandible is necessary for the successful performance of the retromolar laryngoscopy technique. Therefore, 20 patients with and 20 patients without a retromolar gap will be investigated. The anesthesiologist will visually determine the view of the vocal cords and score it according to Cormack & Lehane. For an improved view a backward, upward, right-ward pressure (BURP) will be performed, if needed, and scored again. Finally, endotracheal intubation will be performed by the 'conventional' intubation method. If, however, intubation is not possible, then the retromolar technique will be used. In the case that both methods fail, then any (other) intubation method will (can) be used.

Official Title
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Retromolar Route Access With and Without A Retromolar Gap - A Visualization Study Of The Vocal Cords

Conditions
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Airway Management

Intervention / Treatment
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* Procedure: Retromolar laryngoscopy and scoring of the visualisation of the vocal cords according to Cormack & Lehane


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI < 35kg/m2 Elective surgery Absence of at least one molar of the right mandible in arm I (20 patients) Exclusion Criteria: Emergency patients Prevalence of reflux disease Toothless patients Diaphragmatic hernia Patient is not sober Ventilation problems during induction of anaesthesia Patient with a tracheostomy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Patient with Retromolar Gap<br>20 patients with a retromolar gap between the last erupted molar and the ascending ramus at the right lower mandible. | Procedure: Retromolar laryngoscopy and scoring of the visualisation of the vocal cords according to Cormack & Lehane<br>* To facilitate the insertion of the straight blade laryngoscope (Miller #4) the head of the patient will be turned to the left side. The blade will be inserted and then pushed laterally rightwards until the retromolar space will be finally reached. Thereafter the epiglottis will be lifted up in order to achieve the best direct view to the vocal cords and scored according to Cormack & Lehane . This score will be assessed at least 2 minutes after muscle relaxation: Once without a backward, upward, rightwards pressure maneuver (=BURB) and immediately thereafter (i.e. 5-10 seconds later): If 100% visualization of the vocal cords is not possible a BURP maneuver will be performed and the scored again. Intubation will then be performed by the conventional method using a Macintosh blade #3. In the case that intubation with the conventional method is not successful the retromolar technique will be used.<br>|
| Other: Patient without a Retromolar Gap<br>20 patients without a retromolar gap between the last erupted molar and the ascending ramus at the right lower mandible. | Procedure: Retromolar laryngoscopy and scoring of the visualisation of the vocal cords according to Cormack & Lehane<br>* To facilitate the insertion of the straight blade laryngoscope (Miller #4) the head of the patient will be turned to the left side. The blade will be inserted and then pushed laterally rightwards until the retromolar space will be finally reached. Thereafter the epiglottis will be lifted up in order to achieve the best direct view to the vocal cords and scored according to Cormack & Lehane . This score will be assessed at least 2 minutes after muscle relaxation: Once without a backward, upward, rightwards pressure maneuver (=BURB) and immediately thereafter (i.e. 5-10 seconds later): If 100% visualization of the vocal cords is not possible a BURP maneuver will be performed and the scored again. Intubation will then be performed by the conventional method using a Macintosh blade #3. In the case that intubation with the conventional method is not successful the retromolar technique will be used.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cormack & Lehane score (without a backward, upward, rightwards pressure maneuver) | After ensuring sufficient bag-mask ventilation, the scoring of the vocal cords according to Cormack & Lehane will be performed at least 2 minutes after administration of the muscle relaxant rocuronium without a backward, upward, rightwards pressure maneuver (=BURB) | At least 2 minutes after muscle relaxation | 
| Cormack & Lehane score (with a backward, upward, rightwards pressure maneuver) | If the Outcome Measure 1 does not reveal a 100% visualization of the vocal cords, a backward, upward, rightwards pressure maneuver (BURP) maneuver will be applied and scored again according to Cormack & Lehane . Usually each of the two scoring procedures lasts approximately 5-10 seconds. | Approximately 5-10 seconds after the collection of the Outcome Measure 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Retromolar Intubation