Comparison of Two Novel Indirect Laryngoscopes to the Macintosh Laryngoscope in Patients With Cervical Spine Immobilization.

Study Overview
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Brief Summary
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It is essential that anaesthetists successfully perform orotracheal intubation in scenarios in which intubation is potentially more difficult, such as where the neck is immobilized. The Airtraq® Laryngoscope and the CMAC are new intubating devices. They are designed to provide a view of the glottis without alignment of the oral, pharyngeal and tracheal axes. These devices may be especially effective in situations where intubation of the trachea is potentially difficult. The efficacy of these devices in comparison to the traditional Macintosh laryngoscope in situations where the cervical spine is immobilized is not known. The investigators aim to compare the performances of the Airtraq® Laryngoscope and the CMAC to that of the Macintosh laryngoscope, the gold standard device, in patients in which the cervical spine has been immobilized by means of a Manual in-line stabilization of the spine. Hypothesis: The primary hypothesis is that, in the hands of experienced anaesthetists, time to intubation would be shorter using the indirect laryngoscopes, than using the Macintosh laryngoscope in simulated difficult laryngoscopy.

Conditions
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Immobilization

Intervention / Treatment
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* Device: intubate with the macintosh laryngoscope
* Device: intubate with the C-MAC laryngoscope
* Device: intubate with the Airtraq device


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA 1 - 3 Aged 18 - 85 years Written informed Consent No relevant drug allergies Mallampatti 1 - 2. Exclusion Criteria: Patients unable to cooperate with airway assessment (2) Patients with predicted difficult intubation Mallampatti III or IV Thyromental distance < 6cm Mouth opening < 3.5 cm Cervical spine disease Anteriorly protruding incisors Poor Dentition (2) Tumours, polyps or foreign bodies in the upper airway (2) Patients with documented difficult airways (2). Patients with history of or risk factors for gastric regurgitation (i.e. require rapid sequence induction of anaesthesia)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: macintosh<br> | Device: intubate with the macintosh laryngoscope<br>* intubate with the macintosh laryngoscope<br>|
| Active Comparator: C-MAC<br> | Device: intubate with the C-MAC laryngoscope<br>* intubate with the C-MAC laryngoscope<br>|
| Active Comparator: Airtraq<br> | Device: intubate with the Airtraq device<br>* intubate with the Airtraq device<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of successful placement of Tube in the Trachea a. Failed intubation defined as requiring greater than 60s or which resulted in Oesophageal Intubation. b. Successful intubation confirmed by an investigator. |  | immediately | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of Intubation attempt (successful Attempts only) a. Absolute time taken to perform successful tracheal intubation b. Number of successful intubations completed within 30 seconds. |  | immediatley | 
| Tracheal Intubation attempts. a. Overall number of attempts at Intubation. b. Number of successful intubations on first attempt |  | immediately | 
| Laryngeal View Obtained a. Cormac and Lehane Grading of Best Laryngeal View b. POGO score |  | immediately | 
| Intubation Difficulty Scale score |  | immediately | 
| Need for and number of optimisation Manoeuvres to aid tracheal intubation |  | immediately | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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airway, airway device, cervical spine immobilisation