Initial Increase in Cuff Pressure in Anterior Cervical Spinal Surgery
Condition: Pressure Injury; Dysphonia; Dysphagia
MeSH terms: Dysphonia; Hoarseness; Crush Injuries
Study type: Interventional

Summary: 
      When the retractor blades oped and is positioned to provide the surgical access in the
      anterior cervical spine surgery, it cause the trachea to deviate laterally and pose pressure
      on the tissue between the retractor and the trachea. This is convincible as revealed by the
      increase of cuff pressure of endotracheal tube. The study aims to investigate differences in
      the increase of cuff pressure after retractor is positioned between nasotracheal and
      orotracheal intubation.
    

Detailed description: 
      When the retractor blades oped and is positioned to provide the surgical access in the
      anterior cervical spine surgery, it cause the trachea to deviate laterally and pose pressure
      on the tissue between the retractor and the trachea. The most important structure is the
      recurrent laryngeal nerve. This is convincible as revealed by the increase of cuff pressure
      of endotracheal tube. The pressure created by the retractor may be related to postoperative
      dysphonia and dysphagia. In view of minimizing the pressure created by the retractors, some
      neurosurgeons advocate to deflate then to inflate the cuff of ETT tube after the retractor is
      on, while some advocate monitoring of cuff pressure and keep below 25 mmHg. Nasotracheal or
      orotracheal tube can both be applied to general anesthesia for the anterior cervical spine
      surgery. The option depends on the surgeons' preference. Though both approaches end at the
      trachea, the nasotracheal tube is fixed at the nostril, and orotracheal tube, at the mouth
      angle, on the opposite side of surgical approach. The investigators hypothetize this
      difference in location results in different degree of deviation and increase of cuff
      pressure. The study aims to investigate differences in the increase of cuff pressure after
      retractor is positioned between nasoendotracheal and oroendotracheal intubation.

      Apfelbaum and colleagues indicated the asymmetric position of the oroETT within the larynx as
      being fixed distally by the cuff and proximally by taping at the mouth angle. The asymmetry
      of the tube shaft and cuff may contribute to unilateral vocal palsy. When the retractors are
      set up for ACCS, the deviation of cuff towards the retractors increases ETCP and creates a
      extrusion compression of tissues in between the cuff and the retractor blade. Nasotracheal
      intubation follows a more natural trajectory into the trachea. In theory, a nasoETT is more
      centrally located and less asymmetric in the thyroid cartilage and trachea; thus pressure
      from this tube may be relatively evenly distributed, and the pressure on the surrounding
      tissues is lower. Therefore, we hypothesised lower degree of tissue compression with a
      nasoETT, even during retractor splay. The effect may be reflected in intraoperative ETCP or
      post-ACCS dysphonia. This randomised controlled clinical trial assessed the differences in
      the tracheal intubation mode on the maximal ETCP during retractor splay (primary endpoint)
      and post-ACSS dysphonia (secondary endpoint).
    

Intervention name(s): nasotracheal intubation; orotracheal intubation
Intervention type(s): Procedure; Procedure
Intervention description(s): The participants either receive intubation via nasal route.; The participants either receive intubation via oral route.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants are randomly allocated into one of the two group: nasoendotracheal and oroendotracheal group
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Prevention
Keywords: anterior cervical spine surgery; endotracheal cuff pressure; endotracheal tracheal intubation; dysphonia