Tracheal Intubation Using Videolaryngoscope vs Fiberoptic Bronchoscope in Patients With Cervical Immobilization
Condition: Intubation, Intratracheal
Study type: Interventional

Summary: 
      In patients with suspected cervical spine injury, cervical immobilization, such as manual
      in-line stabilization or cervical collar has been adopted to prevent further neurologic
      injury due to cervical motion. In these patients, tracheal intubation with direct
      laryngoscopy is often challenging due to limited mouth opening, neck flexion, and head
      extension. In this situation, videolaryngoscope and fiberoptic bronchoscope have been used
      for tracheal intubation in such patients. In this study, the initial success rate of tracheal
      intubation and intubation time between the videolaryngoscope and fiberoptic bronchoscope will
      be compared.
    

Detailed description: 
      Patients entered the operating room without premedication. Airway-related parameters
      (modified Mallampati score, interincisior gap, thyromental distance, sternomental distance,
      and retrognathia) were evaluated in the sitting position. After changing to the supine
      position, thyromental height was measured and patients were monitored with
      electrocardiography, pulse oximetry, non-invasive blood pressure measurement, and processed
      electroencephalography. Cotton towels were placed below the patient's head for horizontal
      alignment of the external auditory meatus and the suprasternal notch. After sufficient
      preoxygenation for > 3 min, total intravenous anaesthesia was induced using a
      target-controlled infusion of propofol and remifentanil (effect site concentration: 4 µg/mL
      for propofol and 4 ng/mL for remifentanil). After confirming loss of consciousness,
      rocuronium (0.6-0.8 mg/kg) was administered to facilitate tracheal intubation, and mask
      ventilation was conducted. During mask ventilation, its difficulty was assessed and the use
      of the oropharyngeal airway was recorded. For invasive blood pressure measurement, a 20-gauge
      catheter was placed on the patient's radial artery. Thereafter, the patient's head was placed
      in the neutral position and an cervical collar was applied to minimise neck movement during
      intubation.

      About 90 s after administrating rocuronium, tracheal intubation was attempted by one of five
      attending anaesthesiologists with a collective history of more than 30 successful
      videolaryngoscopic and fiberscopic intubations. A reinforced tracheal tube was used in both
      groups. Orotracheal intubation was performed using a videolaryngoscope with a disposable
      Macintosh-typed blade and a malleable stylet in the videolaryngoscope group, and using a
      flexible fiberscope with an eyepiece in the fiberscope group. A tracheal tube was mounted on
      the stylet and flexible fiberscope in the videolaryngoscope and fiberscope groups,
      respectively. The stylet was angulated about 60° at the proximal margin of the cuff. Tracheal
      intubation was initially attempted without any assistance, including airway manoeuvres and
      devices. If additional airway manoeuvres including external laryngeal manipulation (ELM), jaw
      thrust, and tongue traction were required during intubation attempts, they were performed by
      an assistant and noted. After confirming the glottis, the percentage of glottic opening
      (POGO) score was recorded just before inserting the tracheal tube into the trachea. The
      tracheal tube was inserted into the trachea after removing the stylet and confirming the
      carina in the videolaryngoscope and fiberscope groups, respectively. Successful intubation
      was confirmed by waveform capnography. The time from oral insertion of the intubation device
      to obtainment of the glottis view (glottis visualisation time), to placement of the tracheal
      tube (tube placement time), and to detection of the waveform capnograph (capnograph detection
      time) were also measured.

      A maximum of three intubation attempts were allowed for the same anaesthesiologist, with a
      180-s time limit for each attempt. If the peripheral oxygen saturation (SpO2) decreased to
      below 90% during the intubation attempt, the attempt was considered to have failed, and
      rescue mask ventilation was conducted until SpO2 reached 100%. Cases where tracheal
      intubation was unsuccessful on all three attempts were recorded as intubation failure.

      After surgery, intubation-related airway complications were investigated. Airway injuries
      (blood in the oral cavity, blood staining on the tracheal tube, gum bleeding, and dental
      trauma) were assessed at the end of surgery. In addition, hoarseness and sore throat were
      evaluated at 1 h and 24 h after surgery. The severity of sore throat was measured using a
      numeric rating scale (NRS; 0: no pain, 10: worst pain imaginable).

      Mean blood pressure (MBP), heart rate (HR), SpO2, and bispectral index (BIS) were recorded
      just before the intubation attempt and at 1 min after successful intubation. Other
      perioperative data (demographic, anaesthetic, and surgical data) were collected from
      electronic medical records.
    

Intervention name(s): intubation with videolaryngoscope vs fiberoptic bronchoscope
Intervention type(s): Procedure
Intervention description(s): Tracheal intubation was performed using either videolaryngoscope or fiberoptic bronchoscope under cervical collar application according to the group allocations
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment