Epiglottic Downfolding During Endotracheal Intubation

Usually videolaryngoscopy using a videolaryngoscope with a classic Macintosh design is performed with the blade in the vallecula and the epiglottis elevated from the vocal cords indirectly, as in direct laryngoscopy. However, during an audit of videolaryngoscopic practice we noticed that, in obtaining the best view, clinicians frequently and inadvertently advanced the blade into the vallecula to get a better view, such that the epiglottis was downfolded and elevated directly from the vocal cords. However, a better view does not necessarily lead to higher intubation success.

In this randomized, controlled trial, we want to determine the efficacy of videolaryngoscope-guided tracheal intubation using an alternative position for the blade in patients with normal airways.

Anaesthesia will be induced in the conventional matter. For patients randomized to the intervention group, when the anaesthesiologist considers the depth of anaesthesia to be sufficient, a C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany), will be placed into the patients mouth. The best possible view of the vocal cords will be obtained with the blade positioned normally in the vallecula anterior to the epiglottis. The epiglottis will be elevated from the vocal cords indirectly, identical with direct laryngoscopy. After this, the best possible view of the vocal cords will be obtained with the blade positioned alternatively in the vallecula posterior to the epiglottis, such that the epiglottis is downfolded and elevated directly from the vocal cords. Views will be scored in both positions using the Cormack and Lehane classification system. When correct laryngoscope positioning can't be achieved with a size 3 blade, a size 4 blade will be used.

For patients not randomized to the intervention group, anaesthesia will also be induced in the conventional matter. When the anaesthesiologist considers the depth of anaesthesia to be sufficient, a C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany), will be placed into the patients mouth. The best possible view of the vocal cords will be obtained with the blade positioned normally in the vallecula anterior to the epiglottis. The epiglottis will be elevated from the vocal cords indirectly, identical with direct laryngoscopy. The view will be scored in this position using the Cormack and Lehane classification system. After this, the patient will be intubated.

Patients will be interviewed 2 and 24 hours postoperatively about sore throat, dysphonia, dysphagia and coughing.

Eligibility Criteria:
Inclusion Criteria:

* Informed patient consent
* ASA I-III
* Age \> 18 years
* Elective surgery, other than head and/or neck surgery
* Elective surgery, duration \< 1 hour in supine position
* Pre-operative Mallampati I-II-III

Exclusion Criteria:

* No informed patient consent
* ASA IV
* Age \< 18 years
* Preoperative complaints of sore throat, dysphagia, dysphonia and coughing
* Emergency surgery, surgery of head and/of neck
* Surgery during \> 1 hour in other than supine position
* Locoregional anaesthesia
* Preoperative Mallampati IV
* Known difficult airway
* Bad dentition
* Dental crowns and/or fixed partial denture
* Risk of aspiration (fasted \< 6 hours, gastroesophageal reflux)