Comparing Full vs. Partial Glottis View Using CMAC D-Blade Video Laryngoscope in Simulated Cervical Injury Patient
Condition: Intubation; Difficult or Failed; Airway Complication of Anesthesia
Study type: Interventional

Summary: 
      Direct laryngoscope requires proper alignment of the oro-pharyngeal-laryngeal axis to provide
      an optimal glottic view for intubation. However, in cervical spine patients, this alignment
      is not possible thus resulting in an increased risk of fail intubations.

      D-blade comes with an elliptically tapered blade shape rising at the distal end to provide
      better glottic visualization in comparison with direct laryngoscopes. Hence, CMAC D-blade is
      preferred in simulated cervical spine injury where intubator needs to maintain a neutral neck
      position. However, intubation time may be significantly longer due to difficulty in
      negotiating the endotracheal tube pass vocal cord and impingement of endotracheal tube to the
      anterior wall of trachea.

      There is a study published Glidescope which is also a hyperangulated videolaryngoscope
      suggested that obtaining a partial glottic view of larynx may facilitate a faster and easier
      tracheal intubation when compare to a full glottis view. The aim of this study is to
      clinically evaluate the time of tracheal intubation in relation to the full glottic view vs.
      partial glottic view which is deliberately obtained when using CMAC D-blade video
      laryngoscopy in simulated cervical spine injury.
    

Detailed description: 
      Direct laryngoscope requires proper alignment of the oro-pharyngeal-laryngeal axis to provide
      the best laryngeal view for intubation. In cervical spine patients, this alignment is not
      possible resulting in an increased risk of failed intubations. Difficult intubation and
      failed tracheal intubation are among the major causes of morbidity and mortality associated
      with anesthesia.

      In recent years, video laryngoscope has played an increasingly important role in the
      management of patients with unanticipated difficult or failed endotracheal intubation. When
      compared with a direct laryngoscope, the video laryngoscope achieved a better view of the
      glottis and a high rate of successful intubation.

      On comparing the C-MAC with the conventional Macintosh blade, a conventional C-MAC Macintosh
      blade 3 and D-blade have a blade angulation of 18° and 40° in the D-blade respectively. In
      addition, with D-blade is an elliptically tapered blade-shaped rising to distal.

      This highly angulated C-MAC D blade provides a better glottic visualization in comparison to
      the direct laryngoscopes and in simulated cervical spine injury. This resulted in successful
      intubation in routine induction of anesthesia and rescue intubation in patients with
      difficult airway with C-MAC D Blade. But in terms of intubation time, study has shown a
      significantly shorter time with C-MAC D Blade compared with other indirect laryngoscopes.
      This may be due to a common problem seen in indirect video laryngoscopy whereby a good
      glottic view does not always allow advancing the tube into the trachea.

      A study has been conducted on Glidescope which is also a hyperangulated blade suggested that
      obtaining a partial glottic view of larynx may facilitate a faster and easier tracheal
      intubation when compare to a full glottis view. Randomised controlled trial also showed that
      GlideScope and C-MAC D blade video laryngoscope using manual inline axial stabilization
      (MIAS) for tracheal intubation in patients with cervical spine injury/pathology were equally
      efficacious.

      The aim of this study is to clinically evaluate the time of tracheal intubation in relation
      to deliberately obtained full glottic view vs. partial glottic view when using CMAC D-blade
      video laryngoscopy in simulated cervical spine injury.
    

Intervention name(s): CMAC D-blade videolaryngoscope with full or partial glottic view
Intervention type(s): Device
Intervention description(s): Deliberate achieving full or partial glottic view on C MAC D-blade video laryngoscope and comparing time and ease of intubation with both arms
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Glottic view; Intubation time; C MAC D- blade