Oropharyngeal Space in Videolaryngoscopy

Oropharyngeal Space in Videolaryngoscopy: a Randomised Crossover Trial Measuring Remaining Space Adjacent to the Videolaryngoscope Blade

In this randomised crossover trial we measure the space between the right side of the laryngoscope blade and the right palatopharyngeal wall in a cohort of ASA I-III patients with a normal mouth opening. We compare the remaining spaces for seven different videolaryngoscopes and compare these to a classic Macintosh laryngoscope.

Intubation using indirect videolaryngoscopy has many advantages over classic direct laryngoscopy using the Macintosh laryngoscope. There are many different videolaryngoscopes available, and the blade differs largely between videolaryngoscopes. Different size and angles of blades may have an impact on the space available for insertion of the endotracheal tube. The space between the blade and the palatopharyngeal wall may be reduced significantly, so that there is less room in the mouth to insert an endotracheal tube. Positioning and manoeuvring of the endotracheal tube may consequently be more difficult and may traumatize the pharynx as was described in a few case reports, especially when an endotracheal tube with a rigid stylet inserted was used.

Inclusion Criteria:

• Informed patient consent
• ASA I - III
• Age > 18 years
• Elective surgery, other than head and/or neck surgery
• Pre-operative Mallampati I - III
• BMI < 35 kg/m2
• Fasted (≥6 hours)

Exclusion Criteria:

• No informed patient consent
• ASA ≥ IV
• Age < 18 year
• Emergency surgery, surgery of head and/of neck
• Locoregional anaesthesia
• Pre-operative Mallampati IV
• BMI > 35 kg/m2
• Fasted < 6 hours
• Pre-operative expected difficult airway (restrict neck movement, thyromental distance < 65mm, retrognathia)
• Bad, fragile dentition
• Dental crowns and/or fixed partial denture