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Difficult airway
The goal is oxygenation, not intubation: predict difficulty in advance, preoxygenate well, limit attempts and move on in time from plan A to the next plan, up to front-of-neck access (FONA).
Why it matters in the exam
Exam questions ask what predicts difficult intubation and what predicts difficult mask ventilation, what the next step is when intubation fails, and when to choose awake intubation. A favourite is the "cannot intubate, cannot oxygenate" (CICO) scenario — and the answer is a scalpel cricothyroidotomy, not another laryngoscopy. Candidates are also asked how tube position is confirmed (waveform capnography) and what preoxygenation aims for.
The pre-anaesthetic assessment looks at mouth opening, the Mallampati class, the thyromental distance, neck mobility, obesity, obstructive sleep apnoea, a beard, neck radiotherapy and airway obstruction. When difficulty is expected with both intubation and ventilation, or the aspiration risk is high, the safe choice is awake intubation with a fibreoptic scope or a videolaryngoscope. When difficulty is unexpected, the team works through plans A to D and announces every change of plan aloud.
When practising for the exam, read every case through three fixed questions: is the patient oxygenating right now, is difficulty expected with mask ventilation and not only with intubation, and is there a risk of aspiration. The answers decide whether to induce at all, whether to keep spontaneous breathing, and which backup plan is ready before starting. In theatre the principle is the same: a videolaryngoscope, a bougie, a supraglottic device and a cricothyroidotomy kit are prepared in advance, and the whole team knows who does what when the plan changes.
Key points
- The aim of airway management is oxygenation; intubation is only a means.
- Predictors: small mouth opening, high Mallampati class, short thyromental distance, stiff neck, obesity and obstructive sleep apnoea.
- Anticipated difficult ventilation and intubation → awake intubation.
- Unanticipated difficulty: plans A (up to 3+1 attempts), B (supraglottic device), C (mask), D (cricothyroidotomy).
- Tube position is confirmed with waveform capnography.
Summary table
| Plan | What is done | Limit | If it fails |
|---|---|---|---|
| A — intubation | Preoxygenation, optimal position, videolaryngoscope or bougie | Up to 3 attempts, plus 1 by the most experienced | Declare failed intubation and move to B |
| B — supraglottic device | Second-generation device (with a gastric channel) to oxygenate | Up to 3 attempts | If oxygenating: stop and think; if not — C |
| C — face mask | Two-handed ventilation with an airway adjunct, full paralysis | Last attempt | If oxygenating: wake the patient; if not — D |
| D — CICO | Cricothyroidotomy: scalpel, bougie and a 6.0 tube | As soon as saturation falls with no oxygenation | No further attempt from above |
| Anticipated difficulty | Awake intubation (fibreoptic or videolaryngoscope) | When difficult ventilation and intubation are both expected | Plan FONA in advance |
A free exam question
בזמן אינטובציה ניתן לראות רק את ה epiglottis- ואי-אפשר לראות את ה- arytenoids . לפי Cormack & Lehane ?מהי דרגת הראייה (the question as examined, in Hebrew)
- א. Cormack- Lehane Grade 2A
- ב. Cormack- Lehane Grade 2B
- ג. Cormack- Lehane Grade 3
- ד. Cormack- Lehane Grade 4
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Sources
- ASA Practice Guidelines for Management of the Difficult Airway, 2022 — Difficult airway algorithm for adult patients
- Difficult Airway Society guidelines for management of unanticipated difficult intubation in adults, 2015 — Plans A–D
- Miller's Anesthesia, 9th edition (2020) — Airway Management in the Adult
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.