Emergency · Adult · Reference card

Difficult Intubation Rescue

DAS 2015 unanticipated difficult intubation — Plan A to D, the stop-and-think options, and emergency front-of-neck access.

Draft — not yet clinically verified. Distilled from the DAS 2015 guidelines for management of unanticipated difficult intubation in adults (Frerk et al, BJA 2015). A memory aid — in the event, use the DAS algorithm poster / your QRH. Adult guideline; obstetric and paediatric algorithms differ.

Priority — oxygenation, not intubation

Declare each failure · limit attempts · call for help early

Plan A · Laryngoscopy

3 + 1 attempts max

Fourth only by a more experienced colleague.

Plan B · SAD

3 insertion attempts max

2 with preferred 2nd-gen device + 1 alternative. A size change counts.

Waking on rocuronium

16 mg/kg sugammadex

Must be immediately available. Does not guarantee a patent airway.

Plan D · eFONA

Scalpel–bougie–tube

No. 10 blade · coudé bougie · cuffed 6.0 tube.

A Mask ventilation & tracheal intubation
Maximise first-attempt success

Preoxygenate every patient; ramp / head-up in the obese (align external auditory meatus with the suprasternal notch). Nasal O₂ up to 15 l/min for apnoeic oxygenation in high-risk patients.
Full neuromuscular block before further attempts if intubation is difficult — never persist without it.
Each new attempt must change something: position, device or blade, bougie/stylet, depth of block, external laryngeal manipulation, personnel.
All anaesthetists should be skilled with a videolaryngoscope; have one available.
Remove cricoid pressure if intubation is difficult.
Maximum 3 attempts (+1 by a senior) — then declare failed intubation and move to Plan B.

Failed intubation — declare it

B Maintain oxygenation — SAD
Second-generation device

Insert a second-generation SAD (e.g. i-gel, ProSeal). Maximum 3 attempts; remove cricoid pressure (if applied) during insertion.
Confirm ventilation clinically and with capnography.
Ventilation working? Stop and think — see the four options below.
No effective oxygenation after 3 attempts → declare failed SAD ventilation, Plan C.

S+TSAD in, oxygenating — stop and think

1 · Wake

The default. If surgery is not immediately life-threatening, wake the patient — full antagonism of block.

2 · Fibreoptic

Intubate through the SAD under fibreoptic vision (e.g. Aintree catheter). Blind techniques are not recommended.

3 · Proceed

Continue surgery on the SAD — high-risk, for life-threatening situations only, with senior input.

4 · FONA

Rarely — proceed directly to tracheostomy or cricothyroidotomy.

Patient factors, urgency and operator skill set drive the choice — the principle is oxygenation while minimising aspiration risk.

Failed SAD ventilation — declare it

C Final attempt — face-mask ventilation
Two-person technique, adjuncts

Optimise: two-person mask technique, oro/nasopharyngeal airways, 100% O₂.
Ventilation adequate → wake the patient in all but exceptional circumstances. Fully antagonise the block (sugammadex 16 mg/kg after rocuronium).
Ventilation impossible → ensure complete paralysis before critical hypoxia — the last chance of rescue without front-of-neck access.
Still can't oxygenate → declare CICO and start Plan D immediately. Hypoxic injury follows if this is delayed.

CICO — declare it

D Emergency front-of-neck access
Scalpel cricothyroidotomy — "stab, twist, bougie, tube"

Equipment: scalpel with No. 10 blade (broad), bougie with coudé tip, cuffed 6.0 mm tube.
Complete neuromuscular block is essential before FONA. If sugammadex was given, use a non-steroidal agent (not rocuronium/vecuronium).
Extend the neck — pillow under the shoulders or drop the head of the table. Continue 100% O₂ to the upper airway (SAD / mask / nasal) throughout.

CrCricothyroid membrane palpable

Laryngeal handshake — stabilise the larynx between thumb and middle finger, index finger palpates the cricothyroid membrane.
Stab — transverse incision through skin and membrane, cutting edge towards you.
Twist — turn the blade 90° so the sharp edge points caudally; swap hands and pull gently towards you, handle vertical.
Bougie — slide the coudé tip down the far side of the blade into the trachea; rotate, align and advance gently 10–15 cm. Remove the scalpel.
Tube — railroad the lubricated 6.0 cuffed tube, rotating as it advances; avoid endobronchial intubation.
Remove the bougie, inflate the cuff, confirm with capnography, secure the tube.

ImMembrane impalpable — scalpel, finger, bougie

8–10 cm vertical midline incision, caudad to cephalad; blunt dissection with the fingers to identify and stabilise the larynx, then proceed as above.
Bougie hold-up at <5 cm suggests a pre-tracheal position.
A smaller cuffed tube (incl. Melker) is acceptable if it fits over the bougie.

Why scalpel, not cannula?

Scalpel cricothyroidotomy is the fastest, most reliable emergency technique: a cuffed tube protects against aspiration, allows normal minute ventilation on a standard circuit and gives EtCO₂ monitoring.
Narrow-bore (<4 mm) cannulae need a high-pressure source — significant risk of barotrauma, kinking and displacement.

Frerk C, et al. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. Br J Anaesth 2015;115:827–48 (Tables 1–4, Figs 2–4).