DAS 2025 Difficult Airway Algorithm: Plans A–D Explained

The DAS 2025 difficult-airway algorithm uses Plans A–D: tracheal intubation, supraglottic airway ventilation, final face-mask ventilation, then emergency front-of-neck access when oxygenation fails. The aim is safe oxygenation, with the best possible first attempt and a clear decision to move on when a technique fails.

This EDAIC revision guide explains the sequence, attempt limits and reasoning traps in the 2025 adult guideline. Use the official DAS algorithms alongside it; paediatric, obstetric and anticipated difficult-airway pathways require their own guidance.

What matters in the 2025 update?

Videolaryngoscopy should be first line whenever possible. Preparation, continuous oxygen delivery, waveform capnography and team communication are central. The adult rescue sequence remains A–D. For emergency front-of-neck access, a vertical skin incision is the default when membrane palpability has not been established or remains uncertain. Read the 2025 BJA guideline.

For revision, keep three questions beside the algorithm: what is the current goal, what would count as success, and what triggers the next plan? Knowing the letters without those transitions leaves the reasoning unfinished.

The four plans at a glance

The Plans A–D sequence can be held in your head as one sentence: optimise the laryngoscopy, then rescue oxygenation with a supraglottic device, then fall back to face-mask oxygenation, and — if you can neither intubate nor oxygenate — perform surgical front-of-neck access.

Running through every plan are the constants: call for help early, maintain oxygenation throughout, limit your attempts, and declare each transition aloud so the whole team shares the mental model.

Plan A — optimise the first-line intubation attempt

Plan A is tracheal intubation, done well. The emphasis is on getting the best possible attempt rather than repeating a poor one. That means optimal head-and-neck positioning, adequate neuromuscular blockade, the best available laryngoscope, a bougie or stylet ready, and external laryngeal manipulation when it helps.

Crucially, Plan A caps the number of attempts. The principle is a maximum of three attempts, with a fourth permitted only by a more experienced colleague. Each additional attempt risks airway trauma, bleeding and oedema — turning a difficult airway into an impossible one. The limit is a ceiling, not a target: clinical deterioration can require an earlier transition.

This is also where the modern shift toward videolaryngoscopy lives. The 2025 recommendation is first-line videolaryngoscopy whenever possible, not simply keeping it as a rescue device. For the EDAIC, remember the nuance: a better view does not always mean an easier tube delivery, so a bougie or hyperangulated-blade-compatible stylet still matters.

If Plan A fails after optimised attempts, you declare failed intubation and move on. You do not keep trying.

Plan B — rescue oxygenation with a supraglottic airway

The mental gear-change at Plan B is the single most important concept in the whole algorithm: the goal is no longer intubation; it is oxygenation. You insert a supraglottic airway device — a second-generation device — to re-establish oxygenation.

SAD insertion attempts are limited to three; failure of oxygenation can require moving on sooner. If the SAD restores oxygenation, you have bought time. You then stop, think and communicate. If proceeding is not essential, wake the patient. If tracheal intubation is essential, consider one flexible-bronchoscope-guided attempt through the SAD or front-of-neck access; blind intubation through a SAD is not recommended.

Plan C — final face-mask ventilation and the wake-up option

If the SAD fails, Plan C is a final, optimised attempt at face-mask ventilation using adjuncts: oral and nasopharyngeal airways, two-person technique, full muscle relaxation (full neuromuscular block is part of optimisation), and maximal jaw thrust.

If face-mask ventilation succeeds, stop and reassess with senior input: the options include waking the patient or front-of-neck access, according to the clinical situation. Plan C is the last chance to recover the situation non-invasively. If oxygenation cannot be achieved through Plans A, B and C, you have arrived at the emergency the whole algorithm exists to prevent.

Can't intubate, can't oxygenate: the CICO emergency

A cannot intubate, cannot oxygenate (CICO) emergency occurs when tracheal intubation has failed, supraglottic rescue has failed, and face-mask ventilation has failed. Effective oxygenation has not been achieved; hypoxic injury is an immediate concern. Failed intubation alone is not CICO if ventilation and oxygenation remain effective.

A central reasoning trap is denial and delay — clinicians fixate on re-attempting intubation instead of declaring CICO and acting. The DAS answer is unambiguous: declare the emergency out loud, give 100% oxygen, ensure full neuromuscular blockade, and proceed to front-of-neck access without further delay. Saying the words "this is a can't intubate, can't oxygenate situation" is itself a recognised, recommended step because it breaks fixation and mobilises the team.

For study, explain the transition from failed rescue oxygenation to emergency access in full. A three-word slogan is not a substitute for recognising the trigger, mobilising the team and having trained in the technique.

Plan D — emergency front-of-neck access

Plan D is emergency front-of-neck access to restore oxygenation. The adult DAS approach uses scalpel–bougie–tube equipment. Learn the current illustrated technique from the official guideline and algorithm in supervised training; a blog summary cannot teach the motor skill.

The 2025 incision qualification above matters when reviewing older notes. Do not automatically carry forward a 2015 “palpable versus impalpable” shorthand without checking how the current guideline handles uncertainty. Paediatric emergency airway access is a separate topic.

For a written answer, distinguish the trigger for rescue, the named technique, and how successful ventilation is confirmed. These are different questions. Being able to recite equipment does not demonstrate that you recognised when to change plans.

Decision points and common reasoning traps

Use these points to interrogate an unfamiliar scenario rather than simply recognising the algorithm’s name:

• Attempt limits matter. Plan A: three attempts, with a fourth and final attempt only by a more experienced colleague. Each plan has a deliberate ceiling — the algorithm is built to stop you persevering with a failing technique.
• Oxygenation, not intubation, is the priority from Plan B onward. A statement that "the aim of Plan B is to intubate" is false.
• Paralysis helps, both for mask ventilation in Plan C and for the surgical airway in Plan D. Reaching for sugammadex to wake a paralysed patient is not the reflex during CICO.
• Declare each step aloud. Verbalising "failed intubation" and "CICO" is part of the algorithm, not just good manners.
• Waveform capnography confirms ventilation and supports confirmation of tracheal placement; oxygenation must also be assessed.
• Videolaryngoscopy is first-line whenever possible, but a good view still needs a plan for tube delivery.
• Human factors matter, alongside anatomy and physiology — fixation error, loss of situational awareness and poor team communication are repeatedly cited causes of preventable harm.

Because these distinctions hinge on reading each statement independently, they reward disciplined exam technique. If you are still refining how you handle five-part stems, our guide to answering MTF questions strategically and the reminder that there is no negative marking, so you answer every statement are worth a read before you sit the paper.

How to actually remember the algorithm

Stepwise algorithms are perfect candidates for spaced repetition: short, frequent self-testing on the order, limits and triggers beats re-reading the guideline once. Turning each decision point into a question — "What is the goal of Plan B?", "How many intubation attempts before declaring failure?" — and revisiting them on a schedule is far stickier than passive review. Our piece on the spaced-repetition memory method explains how to build that into your routine.

It also helps to use the algorithm in scenario practice rather than memorising it in isolation. Working CICO and difficult-airway stems inside a question bank forces you to apply the order under time pressure, and exposes gaps that are easy to miss while reading. If you are mapping out your revision, slot airway management into a structured timetable using our effective EDAIC study plan, and gauge where airway sits among the topics most worth your hours in our overview of what makes the EDAIC difficult and what to expect.

Original revision exercise: identify what changed

Compare two fictional statements:

1. “The tube has not been placed, but ventilation through the SAD is effective.”
2. “The tube has not been placed, and rescue ventilation has not restored oxygenation.”

The first sentence describes failed intubation with successful rescue ventilation. The second describes a different, escalating problem. Do not use the same answer just because both sentences begin with failed intubation.

Now write three lines: the current plan, the evidence for success or failure, and the next decision. Compare your reasoning with the current official algorithm. This is a revision exercise, not a complete clinical scenario or a patient-management instruction.

Frequently Asked Questions

What is the difference between Plans A, B, C and D?

Plan A is optimised tracheal intubation (limited attempts, videolaryngoscope and bougie ready). Plan B switches the goal to oxygenation using a supraglottic airway device. Plan C is a final optimised face-mask ventilation attempt, with senior reassessment if it succeeds. Plan D is front-of-neck access — the surgical rescue when you can neither intubate nor oxygenate.

How many intubation attempts are allowed before declaring failure?

The DAS principle is a maximum of three attempts at tracheal intubation, with a fourth permitted only by a more experienced colleague. Each repeated attempt risks trauma, bleeding and oedema, which can convert a difficult airway into an impossible one — hence the deliberate limit.

What does "can't intubate, can't oxygenate" mean and what do I do?

CICO means tracheal intubation, supraglottic rescue and face-mask ventilation have all failed, so effective oxygenation has not been achieved. The response is to declare the emergency aloud, deliver 100% oxygen, ensure full neuromuscular blockade, and perform front-of-neck access without delay — most commonly a scalpel–bougie–tube cricothyroidotomy.

Is videolaryngoscopy now the first choice for intubation?

Yes: the 2025 adult guideline recommends videolaryngoscopy first line whenever possible. Remember the caveat for the exam: a better view does not guarantee easier tube delivery, so keep a bougie or appropriate stylet ready.

Should I quote a specific edition of the guideline in the exam?

This article refers to DAS 2025. Name the version when contrasting recommendations with older notes, and check the official DAS website for subsequent updates. Use the current guideline, local protocols and supervised training in clinical practice.

Continue your revision

Practise the airway algorithm through its decisions — by recalling the order, the limits and the triggers under pressure, not by re-reading the guideline once. Create a free AnesCORE account to start, then drill difficult-airway and CICO scenarios alongside the rest of your revision in our EDAIC question bank, with explanations that help you revisit the reasoning behind each statement.

Primary sources

• Difficult Airway Society: official 2025 adult intubation algorithms.
• Difficult Airway Society 2025 guidelines for management of unanticipated difficult tracheal intubation in adults. British Journal of Anaesthesia.

Updated with AI assistance on 6 November 2026. Key 2025 recommendations checked against the official DAS material and primary guideline. This educational summary is not a clinical protocol or a substitute for hands-on airway training.