Airway assessment, management, tracheal intubation & difficult airway (adult)

Airway assessment, management, tracheal intubation & difficult airway (adult)

1) One-minute plan (what to do)

1. Assess & predict difficulty → make Plan A–D visible on the anaesthesia chart.

2. Pre-oxygenate well:

- Tight mask

- Head-elevated/ramped

- PEEP

- Consider HFNO in high risk

3. First attempt best attempt: 

- Video-laryngoscopy (VL) + bougie ready; 

- Low threshold to awake tracheal intubation (ATI) if predictors present. ([Difficult Airway Society][1])

4. Declare difficulty early, limit attempts, change something each time. 

- Have a timed path to supraglottic rescue → FONA (scalpel-bougie-tube) if “can’t intubate, can’t oxygenate.” ([Difficult Airway Society][1])

5. Confirm tube with continuous waveform capnography (gold standard) and document. 

- Use a planned extubation strategy if the airway was difficult (airway exchange catheter or staged approach). ([shanahq.com][2])

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2) Pre-op/bedside airway assessment (what matters)

* History

Prior anaesthetic notes, stridor, voice change, OSA (STOP-BANG), radiation/neck surgery, RA, goitre, tracheal pathology; in CT surgery: need for lung isolation (DLT vs blocker).

* Examination 

Inter-incisor distance (≥3 cm), Mallampati, thyromental/mandibular space, jaw protrusion, neck movement, dentition, beard, obesity.

* Risk synthesis

If multiple predictors or failure would be high-harm (critical AS/RV failure, tenuous gas exchange), plan ATI.

DAS explicitly lowers the threshold for ATI when predictors exist. ([Difficult Airway Society][3])

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3) Plan A–D framework (DAS/ASA aligned)

Plan A – Optimised intubation (asleep)

1. Setup: 

- Skilled assistant

- Suction

- VL primary, bougie out of packet, 2nd-gen supraglottic ready. 

- Head-elevated

- Preoxygenation 3–5 min with PEEP ± HFNO (High Flow Nasal Oxygen)

- Limit apnoea time. ([Difficult Airway Society][1])

2. Pharmacology:

- Standard RSI/induction tailored to haemodynamics

- Consider gentle ventilation in poor reserve

- Use short-acting agents where re-attempt likely.

3. Technique tips:

- External laryngeal manipulation

- Change blade/angle, use hyperangulated blade + stylet; 

- Change operator early if view is Cormack–Lehane grade 3 or above.

- DAS stresses early declaration and strategy change. ([Difficult Airway Society][1])

Plan B – Supraglottic airway (oxygen first)

- Insert 2nd-gen SGA to restore oxygenation

- Consider fiberoptic-Aintree or VL-through-SGA intubation if stable. ([Difficult Airway Society][1])

Plan C – Face-mask oxygenation

- Back to two-hand mask + OPA/NPA

- PEEP valve

- Optimize position

- Call for help

- Consider waking the patient if feasible. ([Difficult Airway Society][1])

Plan D – CICO → Front-of-neck access (FONA)

* Scalpel–bougie–tube is the DAS recommended default in adults 

- Vertical skin, horizontal cricothyroidotomy, bougie, 6.0 tube

- Have kit open; rehearse steps. ([Difficult Airway Society][1])

Why this discipline matters

NAP4 showed major airway harms (deaths/brain injury) were commonly due to repeated attempts, delayed help, and failure to perform timely FONA. ([The Royal College of Anaesthetists][4])

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4) Awake tracheal intubation (ATI) – when & how

Indications:

- Anticipated difficult laryngoscopy/ventilation,

- Aspiration risk when losing airway would be catastrophic (e.g., severe AS with fixed CO, mediastinal mass, prior failed GA intubation). 

- DAS 2019: consider ATI whenever predictors exist. ([Difficult Airway Society][3])

Steps (DAS 2019):

→ consent & briefing 

→ monitoring + antisialagogue 

→ meticulous topicalisation (lidocaine dosing within safe limits) 

→ minimal, titratable sedation (e.g., remifentanil or dexmedetomidine) maintaining spontaneous breathing 

→ oxygenation (HFNO or nasal cannula) 

→ flexible bronchoscope or VL-assisted awake 

→ confirm with waveform CO₂ 

→ secure and induce. 

([associationofanaesthetists-publications.onlinelibrary.wiley.com][5])

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5) Tracheal tube confirmation & ventilation

Mandatory continuous waveform capnography to confirm and during anaesthesia/ICU—the ASA 2022 update emphasises capnography to verify gas exchange. ([shanahq.com][2])

For lung isolation (thoracics): 

- Confirm DLT/bronchial blocker position with bronchoscopy

- Re-check after turning lateral. 

(Standard thoracic practice; consistent with DAS/ASA principles.) ([shanahq.com][2])

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6) Extubation strategy for the (potentially) difficult airway

Plan extubation as carefully as intubation (DAS/ASA): 

- Optimise patient (awake, warmed, reversible factors)

- Skilled staff, and equipment for rapid re-intubation. 

- Consider airway exchange catheter or SGA-assisted strategies

- Choose location (theatre vs ICU). 

- Document the plan and communicate handover. 

([database.das.uk.com][6])

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7) Cardiac/CT-specific pearls

1. Haemodynamic fragility:

- use gentle induction (avoid long apnoeas); VL first-line to maximise first-pass success.

2. After sternotomy/mediastinal masses:

- anticipate airway shift/compression—strongly consider ATI if symptoms postural or imaging concerning. ([PMC][7])

3. Anticoagulation:

- if FONA is plausible (redo sternotomy airway risk, obesity), ensure FONA kit ready before heparinisation.

4. ICU re-intubation risk:

- use checklists for tube security and sedation holds; 

- if prior difficulty, extubate over an exchange catheter and keep difficult-airway cart in room. ([shanahq.com][2])

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8) Safety rules to audit against (from DAS/ASA/NAP4)

1. Limit attempts

- Each attempt must change something substantive. ([Difficult Airway Society][1])

2. Prioritise oxygenation over intubation; 

- Move to SGA early. ([Difficult Airway Society][1])

3. Do FONA without delay in CICO. ([Difficult Airway Society][1])

4. Waveform capnography for every intubation and during maintenance/retrieval. ([shanahq.com][2])

5. Plan the extubation

- Document and hand over. ([database.das.uk.com][6])

6. Learn from NAP4

- Avoid repeated attempts & cognitive fixation

- Call for help early. 

([The Royal College of Anaesthetists][4])

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Key references (quick cite)

* DAS 2015 Unanticipated difficult intubation in adults. ([Difficult Airway Society][1])

* DAS 2019 Awake tracheal intubation guideline. ([Difficult Airway Society][3])

* ASA 2022 Difficult airway practice guideline (extubation, capnography emphasis). ([shanahq.com][2])

* DAS Extubation guidance. ([database.das.uk.com][6])

* NAP4 airway major complications (RCoA). ([The Royal College of Anaesthetists][4])

[1]: https://das.uk.com/guidelines/das_intubation_guidelines/?utm_source=chatgpt.com "DAS guidelines for management of unanticipated difficult ..."

[2]: https://www.shanahq.com/main/sites/default/files/shana_library/2022%20ASA%20Practice%20Guidelines%20for%20Management%20of%20the%20Difficult%20Airway.pdf?utm_source=chatgpt.com "2022 ASA Practice Guidelines for Management of the ..."

[3]: https://das.uk.com/guidelines/das-guidelines-for-awake-tracheal-intubation-ati-in-adults/?utm_source=chatgpt.com "DAS guidelines for awake tracheal intubation (ATI) in adults"

[4]: https://www.rcoa.ac.uk/research/research-projects/national-audit-projects-naps/nap4-major-complications-airway-management?utm_source=chatgpt.com "NAP4: Major Complications of Airway Management in ..."

[5]: https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/10.1111/anae.14904?utm_source=chatgpt.com "Difficult Airway Society guidelines for awake tracheal ..."

[6]: https://database.das.uk.com/guidelines/das-extubation-guidelines1?utm_source=chatgpt.com "DAS extubation guidelines"

[7]: https://pmc.ncbi.nlm.nih.gov/articles/PMC9463628/?utm_source=chatgpt.com "Awake tracheal intubation - PMC"