Comparison Between the MacGrath MAC Videolaryngoscope and the MacIntosh Laryngoscope for Oro-tracheal Intubation for Patients With Less Than 2 Criteria of Difficult Intubation in Elective Surgery.

Tracheal intubation is a common procedure in the operating room to secure the airway in patients receiving muscle relaxants .

Two devices are currently used for this purpose with various indications: the French Society of Anesthesia and Resuscitation (SFAR) recommends a direct laryngoscopy with MacIntosh blade in first intention for patients with less than 2 criteria of difficult intubation (ID). The SFAR recommends first-line video laryngoscopy in patients with two or more criteria of difficult intubation. Video laryngoscopy improves glottic vision, difficult intubation score, and intubation success rate at the first attempt, compared to the direct laryngoscopy with a Macintosh blade.

Currently, it is estimated that 15% of direct laryngoscopies with a MacIntosh blade result in failure of orotracheal intubation (IOT) on first attempt, whereas tracheal intubation with a video laryngoscopy is a better solution to secure the airway.

Our hypothesis in this study is that the MacGrath MAC videolaryngoscope allows to intubate at the first laryngoscopy 91% of patients with less than 2 difficult intubation criteria, against the expected 85% with the MacIntosh blade.

Inclusion criteria

less than 2 criteria of difficult intubation admitted to the operating theater for scheduled surgery requiring orotracheal intubation after curarization - informed consent

Exclusion criteria

• pregnancy
• age < 18
• contraindication to oro-tracheal intubation
• emergency surgery
• thoracic surgery
• naso-tracheal intubation
• patient protected by law
• patient not affiliated to french social security
• BMI> 45kg / m²
• Predicted patient with difficult intubation

Patients considered to be predisposed to difficult intubation are those with a history of difficult intubation, or with 2 criteria among:

• Mallampati 3 or 4
• Thyroid-chin distance <65mm
• Mouth opening <35mm
• Spinal extension less than 90 °
• Retrognathism with Negative Lip Test
• Morbid obesity with BMI> 35kg / m²
• Obstructive Sleep Apnea Syndrome with choker> 45cm
• Diabetic with sign of the positive prior
• Head and Neck Pathology