Difficult intubation

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Definition[edit | edit source]

  • A condition where we need more than three attempts for routine laryngoscopy and intubation or it takes more than 10 minutes.
  • Difficult laryngoscopy: if the structures of the larynx visible during ordinary laryngoscopy are not visible or identifiable.
    • Incidence approximately 0.5-5%.
    • Evaluation using the Cormack and Lehane (1984) score of values ​​I–IV
      • Cormack I – vocal cords are clearly visible;
      • Cormack II – only posterior edge of glottis visible;
      • Cormack III – only epiglottis visible;
      • Cormack IV – only soft palate visible (epiglottis not visible).

When can we expect difficult intubation?[edit | edit source]

Difficult intubation is expected in patients with the following diagnoses and anatomical conditions:

  • Pregnancy,
  • limited mobility of the cervical spine (e.g. Morbus Bechtěrev, limited mobility of the cervical spine ),
  • monstrous goiter, elongated trachea,
  • overbite or promining incisors,
  • epiglottitis,
  • macroglossia and acromegaly,
  • small oral cavity (under 2 cm when maximally open),
  • anatomical variants, tumors in the neck area, injuries to the neck and face,
  • conditions after irradiation of the larynx,
  • burns.
Clinical assessment of difficult intubation during preoperative examination


  • Thorough anamnesis - focused on diseases or traumas in the neck and cervical spine and ENT area.
  • Previous successful or failed intubations in previous surgeries.
  • Evaluation according to Mallampati: aspect of the oral cavity and visibility of individual structures. Well visible are:
  1. soft palate, back wall of the pharynx, uvula, anterior and posterior palatine arch;
  2. soft palate, back wall of the pharynx, uvula;
  3. soft palate, base of uvula;
  4. soft palate only difficult to see.

Procedure for difficult intubation[edit | edit source]

Equipment for intubation, hose on top, air duct in the middle

If intubation is expected to be difficult we can perform elective fiberscopic intubation while conscious, or if the expected risk is lower, we can primarily prepare a video laryngoscope or other aids.

In case of unexpectedly difficult intubation, we can use the following procedures:

  • A maximum of two to three attempts – positioning the patient's head, using different laryngoscopic spoons, using a tube guide (buje), pressure on the thyroid cartilage (Sellick's maneuver). We should change something every time we try.
  • If we do not intubate the patient after three attempts, we continue to ventilate and call for the help of a more experienced colleague in time.
  • Avideolaryngoscope can be used for intubation.
  • If even a colleague fails, we will try to introduce a laryngeal mask or other device to secure the airways (we will assess whether it is appropriate to conduct the entire anesthesia with the pathways secured in this way; if so, we continue further, if not, we take the patient out of anesthesia).
    • It is also possible to try to insert an intubation cannula through the supraglottic device, either directly or with the help of a fiberscope.
  • Air ducts can be used when mask ventilation is difficult.
  • Can ventilate, can’t intubate if you can breathe with a mask, but you can't intubate, although it is necessary and the operation is urgent, we have to intubate with a flexible bronchoscope.
  • Cave!!!.png is an acute life-threatening condition, we cannot intubate the patient or ventilate with a mask (attempts to intubate and insert a laryngeal mask failed, the patient cannot be breathed even with a mask), we immediately call the team to perform a tracheotomy, or perform coniopuncture.

Links[edit | edit source]

related articles[edit | edit source]

External links[edit | edit source]

References[edit | edit source]

  • KRETZ, Franz-Josef – TEUFEL, Frank. Anästhesie und Intensivmedizin. 1. edition. Heidelberg : Springer, 2006. 695 pp. ISBN 3-540-62739-1.
  • HECK, Michael – FRESENIUS, Michael. Repetitorium Anästhesiologie. 5. edition. Heidelberg : Springer, 2007. 642 pp. ISBN 978-3-540-46575-1.