Airway management

Airway assessment and preparation (anatomical and physiological)

Reviewed Nov 2026·5 references
New· views rounded down, updated weekly

Before every ICU intubation, score anatomical difficulty (MACOCHA), identify physiological risks (hypoxaemia, hypotension, acidosis, RV failure), and run a checklist with a team brief and a stated Plan A-B-C-D.

At the bedside

Timed steps
  1. 1

    Is intubation needed now?

    Decide

    Failure to protect airway, oxygenate or ventilate; anticipated course; procedural need. Call a senior early for predicted difficulty.

  2. 2

    Anatomical risk: MACOCHA

    Score

    Mallampati III-IV (5), OSA (2), reduced cervical mobility (1), mouth opening < 3 cm (1), coma (1), severe hypoxaemia SpO2 < 80% (1), non-anaesthetist operator (1). Score ≥ 3 predicts difficult intubation.

  3. 3

    Physiological risk

    Score

    Hypoxaemia, hypotension (SBP < 90, shock index > 0.9), severe metabolic acidosis, RV failure/pulmonary hypertension, raised ICP, full stomach.

  4. 4

    Resuscitate before induction

    Optimise

    Preoxygenate (next topic); start noradrenaline if hypotensive or shock index high; consider bicarbonate/ventilation plan in severe acidosis (match minute ventilation after intubation).

  5. 5

    Equipment (STOP MAID / checklist)

    Prepare

    Suction ×2, oxygen sources, BVM with PEEP valve, video and direct laryngoscopes, bougie, 2 tube sizes (7.0-8.0), second-generation SGA, scalpel-bougie-tube FONA kit, waveform capnography connected, drugs drawn and labelled.

  6. 6

    Brief

    Team

    Roles (intubator, drugs, airway assistant with cricoid/BURP, monitor watcher, runner), verbalise Plan A (VL + bougie), Plan B (SGA), Plan C (face mask), Plan D (FONA) and the 'call out' SpO2.

  7. 7

    Ramp and head up

    Position

    Ear-to-sternal notch alignment; 20-30° head-up (reverse Trendelenburg if spine precautions) improves preoxygenation and reduces aspiration.

MACOCHA score

FactorPoints
Mallampati III or IV5
Obstructive sleep apnoea syndrome2
Reduced mobility of cervical spine1
Limited mouth opening < 3 cm1
Coma1
Severe hypoxaemia (SpO2 < 80%)1
Non-anaesthesiologist operator1
Total 0-12; ≥ 3 = predicted difficult

Physiologically difficult airway: risk and response

RiskBefore inductionDuring and after
HypoxaemiaNIV or HFNC preoxygenation, PEEP, head upApnoeic oxygenation, bag-mask ventilation between induction and laryngoscopy
Hypotension / shockNoradrenaline running, fluid if responsive, reduced-dose inductionPush-dose vasopressor ready; avoid big PEEP and high rates immediately
Severe metabolic acidosisAvoid apnoea; consider bicarbonate or delay if possibleSet high minute ventilation matching pre-intubation breathing; ABG early
RV failure / pulmonary hypertensionNoradrenaline or vasopressin first, avoid hypoxia and hypercapniaLow PEEP and Vt; inhaled vasodilator if available
Red flag · call your senior now
MACOCHA ≥ 3 or known difficult airway: most experienced operator, awake or double set-up plan.
Red flag
SBP < 90 mmHg before induction: vasopressor running first.
Red flag
Severe metabolic acidosis with compensatory hyperventilation: apnoea can trigger arrest.
Pitfall
Intubating 'quickly' without a checklist at night.
Pitfall
No capnography in the room.
Pearl
INTUBE (29 countries, Indian centres included): 45% of ICU intubations had a major adverse event, mostly cardiovascular instability; cardiac arrest in 3%.
Pearl
AIDAA recommends announcing 'Code D' (difficult airway emergency code) to summon help.

References

  1. 1

    De Jong A, Molinari N, Terzi N, et al. Early identification of patients at risk for difficult intubation in the intensive care unit: development and validation of the MACOCHA score. Am J Respir Crit Care Med. 2013;187(8):832-839

  2. 2

    Russotto V, Myatra SN, Laffey JG, et al. Intubation practices and adverse peri-intubation events in critically ill patients from 29 countries (INTUBE). JAMA. 2021;325(12):1164-1172

  3. 3

    Higgs A, McGrath BA, Goddard C, et al. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth. 2018;120(2):323-352

  4. 4

    Myatra SN, Ahmed SM, Kundra P, et al. The All India Difficult Airway Association 2016 guidelines for tracheal intubation in the Intensive Care Unit. Indian J Anaesth. 2016;60(12):922-930

  5. 5

    Tracheal intubation in critically ill adults with a physiologically difficult airway. An international Delphi study. Intensive Care Med. 2024

Test yourself

Module quiz · score 70% to complete the module

Next

Preoxygenation and apnoeic oxygenation

Educational reference for trained clinicians. Check doses against your hospital protocol and the patient in front of you.