Videolaryngoscopy vs Direct Laryngoscopy for Intubation in Patients With Diabetes
Condition: Diabetes Mellitus
MeSH terms: Diabetes Mellitus
Study type: Interventional

Summary: 
      The use of videolarygoscopy (VL) as first choice for tracheal intubation versus direct
      laryngoscopy (DL) is a matter of debate. These two methods were compared in several studies.
      Videolaryngoscopes may reduce the number of failed intubations, particularly among patients
      presenting with a difficult airway. They improve the glottic view and may reduce airway
      trauma. DM is accepted as a risk factor for difficult intubation. The aim of this study is to
      compare VL to DL in adult patients requiring tracheal intubation for anesthesia, in terms of
      intubation success, glottic view quality, intubation failure, intubation time, conversion to
      another laringoscopy method and adverse outcomes related to tracheal intubation.
    

Detailed description: 
      The use of videolarygoscopy (VL) as first choice for tracheal intubation versus direct
      laryngoscopy (DL) is a matter of debate. These two methods were compared in several studies.
      First attempt intubation success and glottic visualization with VL versus DL by pediatric
      emergency medicine providers in simulated patients were evaluated and it was concluded that
      VL was associated with greater first-attempt success during intubation by pediatric emergency
      physicians on an adult simulator. The ease of viewing the glottis under direct vision during
      conventional laryngoscopy with the quality of indirectly viewing on a monitor during
      laryngoscopy with a Macintosh videolaryngoscope was compared in a multicenter study. The
      results were that VL can lead to better viewing conditions but in rare cases it may result in
      worse viewing conditions. The study evaluating the efficacy and safety of VL compared to DL
      in decreasing the time and attempts required and increasing the success rate for endotracheal
      intubation in neonates concluded that there was insufficient evidence to recommend or refute
      the use of VL for endotracheal intubation in neonates. Diverse videolaryngoscopes where also
      compared in patients undergoing tracheal intubation for elective surgery: the GlideScope
      Ranger (GlideScope, Bothell, WA), the V-MAC Storz Berci DCI (Karl Storz, Tuttlingen,
      Germany), and the McGrath (McGrath series 5, Aircraft medical, Edinburgh, UK) and tested
      whether it is feasible to intubate the trachea of patients with indirect videolaryngoscopy
      without using a stylet. The authors concluded that the trachea of a large proportion of
      patients with normal airways can be intubated successfully with certain VL blades without
      using a stylet, although the three studied VL's clearly differ in outcome. The Storz VL
      displaces soft tissues in the fashion of a classic Macintosh scope, affording room for
      tracheal tube insertion and limiting the need for stylet use compared with the other two
      scopes. Although VL's offer several advantages, including better visualization of the glottic
      entrance and intubation conditions, a good laryngeal view does not guarantee easy or
      successful tracheal tube insertion. Three different videolarygoscope devices were compared to
      direct laringoscopy in obese patients undergoing bariatric surgery: Video Mac and GlideScope
      required fewer intubation attempts that DL and Video Mac provide shorter intubation times and
      improved glottis view compared to DL. A recent metanalysis stated that videolaryngoscopes may
      reduce the number of failed intubations, particularly among patients presenting with a
      difficult airway. They improve the glottic view and may reduce laryngeal/airway trauma.
      However currently, no evidence indicates that use of a VLS reduces the number of intubation
      attempts or the incidence of hypoxia or respiratory complications, and no evidence indicates
      that use of a VL's affects time required for intubation. DM is accepted as a risk factor for
      difficult intubation.

      The aim of this study is to compare VL to DL in adult diabetic patients requiring tracheal
      intubation for anesthesia, in terms of intubation time, intubation success, glottic view
      quality, intubation failure, conversion to another laringoscopy method and adverse outcomes
      related to tracheal intubation.

      METHODS After obtaining ethical approval and written informed patient consent, consecutive
      patients having diabetes mellitus (DM) and requiring elective intubation for anesthesia will
      be randomly allocated to either the videolaryngoscopy (Group VL) or the direct larngoscopy
      (Macintosh laryngoscope) (Group DL). Age, gender, body mass index, American Society of
      Anesthesiologists (ASA) physiologic classification, the duration of DM will be recorded. The
      patients will be evaluated for difficult airway predictors and the following parameters will
      be recorded: Malampati class, thyromental distance, sternomental distance, mandibulohyoid
      distance, interincisor distance, neck circumference, the ability of upper lip overbite and
      lower lip overbite, the presence of limited neck extension. Fentanyl-propofol-rocuronium will
      be used for anesthesia induction. After subsequent positive-pressure ventilation using a face
      mask and an oxygen-air-sevoflurane mixture for 3 min, the trachea will be intubated according
      to group allocation using either DL (Macintosh laryngoscope) or VL (CMAC). During intubation,
      the following data will be documented: intubation time, number of intubation attempts, use of
      extra tools to facilitate intubation, conversion to another laryngoscopy method,intubation
      difficulty and the quality of the view of the glottis will be assessed according to the
      Cormack and Lehane scoring system and the percentage of glottic opening. Adverse events
      related to tracheal intubation will be also evaluated: desaturation (SPO2<94), hypercabia
      (ETCO2>35), hypertension (mean arterial pressure >20% above baseline values), tachycardia
      (heart rate >20% above baseline values), new onset arrhythmia, laryngospasm, bronchospasm,
      airway trauma and sore throat in PACU). The primary outcome measure is the time to
      intubation; first-attempt intubation success and ease of intubation, secondary outcome
      measures are the glottic view guality, conversion to another laryngoscopy method and adverse
      outcomes related to tracheal intubation.
    

Intervention name(s): Videolaryngoscopy; Direct laryngoscopy
Intervention type(s): Device; Device
Intervention description(s): Patients will be intubated with the video laryngoscope; Patients will be intubated with the direct laryngoscope
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Prospective randomised
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Direct laryngoscopy; Videolaryngoscopy; Diabetes Mellitus; Intubation; Anesthesia