Drug-Induced Sleep Endoscopy for the Optimisation of Treatment of Patients With Obstruction Sleep Apnoea
Condition: Obstructive Sleep Apnoea; Sleep-Disordered Breathing
MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive
Study type: Interventional

Summary: 
      The main diagnostic challenge in patients with OSA (obstructive sleep apnea) is to determine
      the location of obstruction of the upper airway during sleep. This is so, because the
      otorhinolaryngology examination, which states probable site of obstruction of upper airways,
      is performed in the awake status. Therefore, drug-induced sleep endoscopy (DISE) has been
      introduced in the diagnostic algorithm of OSA patients during the last decade. The advantage
      of DISE is, that the collapse of upper airways, which is not visible during the awake status
      can be observed and targeted therapy according to the location and degree of obstruction of
      the upper airway can be applied. As a result, higher treatment success in patients with OSA
      can be reached.
    

Detailed description: 
      Materials and Methods The study was approved by the Institutional Ethics Committee and
      performed in accordance with the Declaration of Helsinki, good clinical practice, and
      applicable regulatory requirements. Informed written consent was obtained from all
      participants before initiation of any procedure.

      • History, otorhinolaryngology examination, polysomnography Patient history will be taken
      with emphasis on snoring and OSA symptoms. Daytime sleepiness will be assessed using the
      Epworth Sleepiness Scale. Moreover, patients will be asked to grade the severity of snoring
      on a 10-point Visual Analogue Scale (0 = no snoring, 10 = extreme snoring). The body mass
      index (BMI) will be calculated.

      Otorhinolaryngology examination, focusing on nasal, pharyngeal and laryngeal pathologies
      (enlargement of uvula, soft palate webbing, enlargement of palatal tonsils, base of the
      tongue hypertrophy, visibility of vallecula, pathology of epiglottis), will be performed.

      Thereafter, each patient will undergo polysomnography and patients will be divided according
      to the severity of OSA into three groups (mild OSA - 5 < AHI ≤ 15, moderate OSA 15 < AHI ≤
      25, and severe OSA with AHI > 25 events per hour of sleep).

      According to history, otorhinolaryngology examination and polysomnography, presumably site of
      obstruction will be stated and therapeutic plan will be designated. Patients with severe OSA
      will be sent for CPAP (continuous positive airway pressure) treatment, whereas surgery will
      be recommended for patients with mild and moderate OSA.

      • Drug-Induced sleep endoscopy

      - Indication and contraindication to DISE DISE will be indicated in patients with mild and
      moderate OSA and in those with severe OSA who will fail or refuse CPAP treatment. All these
      patients will be potentially planned for surgery and will have to agree with the surgical
      treatment.

      Patients with ASA (American Society of Anesthesiology) score above 4, as well as patients
      with central apnea and propofol or midazolam allergies, will be excluded from the study.

        -  Premedication Patients will be pre-medicated with a combination of 5 mg midazolam and
           0,5 mg atropine intramuscularly 30 minutes before DISE.

        -  Procedure Patients will be lying in a supine position on an operation table, the lights
           will be dimmed and the room quiet to minimize awaking stimuli. Patients will be
           standardly monitored: ECG (electrocardiogram), blood oxygen saturation, non-invasive
           blood pressure, and depth of anesthesia will be monitored by bispectral index (BIS).
           Local anesthesia of nasal cavity will be performed by Lidocaine 10%, 2 sprays into each
           nostril.

      Anaesthesia will be induced by intravenous bolus of propofol 1 mg per kg of ideal body
      weight, and maintained by repeated boluses of propofol 10-20 mg every 3-5 minutes for the
      target BIS (Bispectral Index) value of 50-70. Once the patient reaches a satisfactory level
      of sedation, a flexible fiber optic. Intubation scope 3.7mm x 65cm coated with anti-condense
      will be introduced into the nasal cavity. The nasal passage, nasopharynx, velum, oropharynx
      (including tonsils), tongue base, epiglottis, and larynx will be observed. The length of
      examination will be 15 minutes minimal in order to detect the obstruction. DISE findings will
      be reported using the VOTE classification system according to Kezirian. Accordingly,
      localization of upper airways obstructions will be done.

      At the end of endoscopy a jaw thrust (or Esmarch maneuver) will be performed. The mandible
      will be gently advanced up to 5 mm. The manoeuver will be evaluated as successful when the
      enlargement of upper airway will be observed and disappearance of apnea mimicking the effect
      of mandibular repositioning appliance (MRA).

      After finishing of endoscopy, patients will be awakened to full consciousness in the
      operating room and then transferred to recovery room for 1-hour observation.

      • Evaluation of changes in indication for site of surgery Indication for surgery made
      according to otorhinolaryngology examination before DISE and after DISE will be compared.
      Changes will be noted and the number of patients will be calculated using percentage.
    

Intervention name(s): Short-time diagnostic anaesthesia
Intervention type(s): Procedure
Intervention description(s): Patients will undergo a short-time general anaesthesia in order to diagnose Obstructive Sleep Apnoea when relaxed.
Intervention MeSH terms: Anesthetics
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: drug-induced sleep endoscopy; obstructive sleep apnoea; VOTE classification; AHI; BMI