This session will cover:
The rationale for difficult airway algorithms
The DAS Algorithm
The Vortex Approach
Emergency Intubation Checklists
Critically ill patients are at a substantially increased risk of life-threatening complications during airway management.
Tracheal intubation can lead to severe adverse events, including hypoxemia, regurgitation, dysrhythmias, and cardiac arrest. Data from the Fourth National Audit Project (NAP4) underscore this risk, revealing that patients in the intensive care and emergency departments face a 70-fold increased risk of death during airway management compared to patients in the controlled environment of an operating theatre.
Furthermore, the incidence of these complications rises directly with the number of intubation attempts.
To help mitigate these formidable challenges, the CCAM advocates for the tandem use of a structured algorithm—the UK Difficult Airway Society (DAS) algorithm—and a powerful cognitive aid, the Vortex approach.
Effective airway management is not solely a matter of technical proficiency; it is profoundly influenced by a set of skills known as “non-technical skills” or “human factors.”
These encompass a team’s ability to maintain situational awareness, make sound decisions, communicate effectively, and lead or follow in a crisis.
Elaine and Martin Bromiley
The tragic case of Elaine Bromiley gives us compelling evidence for the importance of human factors in health care. This 37-year-old mother died following anaesthesia for routine surgery in 2005. The Difficult Airway Society algorithm was not followed when it proved difficult to intubate her trachea or ventilate her lungs.
The independent review which followed Elaine’s death concluded that the technical skills of the anaesthetists concerned, facilities and staffing levels were all more than adequate and that human factors such as poor situational awareness, decision making and communication skills, and a lack of adherence to a difficult airway algorithm were responsible for her death.
Elaine Bromiley’s husband, Martin, an airline pilot and human factors trainer for the airline industry, responded to this tragedy by founding the Clinical Human Factors Group, an independent organisation that
brings together experts, clinicians and enthusiasts who have an interest in placing the understanding of human factors at the heart of improving patient safety.
If you have not seen it, please watch Martin’s video below for an account of Elaine’s case, and how Martin suggests we respond.
The UK Difficult Airway Society (DAS) publishes evidence-based, peer-reviewed guidelines for managing unanticipated failed intubation.
The DAS algorithm outlines a linear sequence of relatively simple skills and places a heavy emphasis on pre-procedural planning. This planning involves establishing Plans B (supraglottic airway device, or SAD), C (facemask ventilation), and D (neck rescue) in advance, so they can be executed swiftly if the primary plan (Plan A, tracheal intubation) fails.
The DAS algorithm’s core tenet is that oxygenation takes precedence over all other objectives, and it explicitly prompts the team to seek the best available help at the first sign of difficulty.
A key feature is the “Stop, Think and Communicate” box, which provides a moment to reconsider the plan; however, it is important to note that the option to “wake the patient up” is often not feasible in critically ill patients, thereby committing the team to a clear progression toward a neck rescue if all else fails.
The Vortex cognitive aid facilitates decision making by prompting actions to optimise attempts at three broad airway management techniques: oxygenation via a face mask (FMV), supraglottic airway device (SAD) or tracheal intubation (TI).
The optimisation strategies (on the right of the cognitive aid) are the same for each technique, and once they have been performed, constituting a best effort, the technique is abandoned
A maximum of three attempts at each technique is suggested. Once best efforts at FMV, SAD and TI have been completed, neck rescue is therefore the logical next step.
If optimisation strategies have been completed efficiently, neck rescue may occur when the oxygen saturations are still normal
Optimisation Strategies for each Lifeline
Manipulations: of head and neck (e.g. head lift, jaw thrust); larynx (bimanual laryngoscopy); and device (e.g. re-insertion of laryngoscope to improve tongue control)
Adjuncts: (e.g. oropharyngeal airway for FMV, laryngoscope for SAD, bougie for TI)
Size and type: of face mask, SAD, tracheal tube or laryngoscope
Suction: this is especially important for FMV and SAD after attempts at laryngoscopy
Muscle Tone: consider increasing neuromuscular blockade
The Vortex approach therefore guards against a loss of situational awareness and task fixation, whereby multiple attempts are made at one technique without changing how it is implemented.
This failure to change technique and progress towards neck rescue has long been recognised to be a problem in difficult airway management, resulting in patient harm.
The Green Zone
The Vortex approach introduces the concept of the “Green Zone,” a name for the situation when alveolar oxygenation is successfully occurring via any of the three lifelines.
The Green Zone is confirmed by either stable or rising oxygen saturations (of any value*) AND the presence of a capnography (ETCO2) trace (of any quality).
*This is obviously very context dependent. We might tolerate lower a SpO2 in a patient with chronic lung disease, for example. Ask yourself, ‘Is this patient likely to suffer harm from hypoxia if this SpO2 level persists for the next 15 minutes?’ If so, optimise or change your technique.
This moment of relative stability is not a time for complacency; rather, it serves as a reminder to the team that they have achieved success with a technique and prompts them to STOP and THINK. This will inevitably lead to better decision making.
Not all green zones are the same
The Vortex in a three-dimensional structure with many Green Zones, getting closer to neck rescue as the funnel is descended.
This focuses the team on the likelihood that neck rescue will occur, an important part of priming (see below).
Planning in the Green Zone
When the airway team lands in the Green Zone there is time to think, plan, mobilise resources and consider what will be done if the next plan fails.
The Green Zone Planning Tool prompts the team to optimise the patient, mobilise resources and come up with a strategy (a series of plans) to proceed.
The team should consider all the situational, airway, patient and team factors before deciding to maintain their current technique, perform and conversion (such as bronchoscopic conversion of a SAD to a tracheal tube) or replace the current technique.
The cognitive aid ensures that all factors are considered and improves decision making.
Priming for Success
The term ‘priming’ refers to the stepwise escalation in readiness to perform neck rescue when difficult airway management occurs.
This escalation includes physical and mental preparation to perform neck rescue, and occurs in parallel with attempts to get back into the Green Zone.
The priming process also allows team members time for mental rehearsal, so that procedures occur calmly and efficiently.
When a best effort at a lifeline has been completed, the team should declare “Priming Status Ready”: senior help should be called, the neck rescue kit should be brought to the bedside and a proceduralist allocated
When another lifeline is exhausted, the Priming Status is escalated to “Set” and further preparation occurs.
When best efforts at all 3 lifelines are exhausted, the team leader is empowered to declare “Go” so that the team proceeds to Neck Rescue.
I am the Gamechanger – help!
The Vortex approach suggests that a maximum of three attempts should be made as any of FMV, SAD or TI (with optimisation of each attempt), but a fourth attempt is permitted if a ‘gamechanger’ arrives.
A gamechanger is a person (e.g. a senior clinician), or piece of equipment (e.g. a videolaryngoscope)
If you find yourself in the position of being the gamechanger, you need to understand the crisis as quickly as possible. So rather than asking for an ISBAR handover, ask The Vortex Gamechanger Questions:
Question 1: If the team is in the Vortex, you must try and get back into the Green Zone.
Question 2: The quickest way to achieve a Green Zone is to return to one the team has been in previously.
Question 3 and Question 4: Establish how many best efforts have occurred and that the Priming Status is appropriately elevated (or one step ahead).
Question 5: Discuss the team’s Green Zone strategy and how that might change now that you have arrived.
If the team has not been in a Green Zone, use Vortex optimisation strategies in the current lifeline, then alternative techniques until a Green Zone is achieved or neck rescue occurs.
This video depicts the simulated clinical use of the Vortex Approach in a team setting. The intention of the video is to illustrate the implementation of airway management using the Vortex.
The CCAM team believes that the DAS algorithm and the Vortex cognitive aid should be used in tandem: DAS to plan the airway strategy; the Vortex to implement it.
We have combined them in the cognitive aid below.
One of the strongest recommendations from NAP 4 was the introduction of intubation checklists to ensure all personnel and equipment is available and to create a shared mental model of the airway plan.
When used as part of safety bundles, checklists have been shown to be beneficial.
Intubation checklists are designed to be used as a final check before the induction drugs are given, like an operating theatre ‘Time out’.
When used in this way, the checklist should take less than a minute to complete.
An Emergency Intubation Checklist
Effective airway management in critical care requires a comprehensive strategy that transcends mere technical skill.
By integrating the linear planning of the DAS algorithm with the adaptive, problem-solving framework of the Vortex approach, clinicians can navigate high-stakes scenarios with greater precision and confidence.
These algorithms, when combined with a keen awareness of non-technical skills, a commitment to pre-procedural planning, and the use of cognitive aids like checklists and the Green Zone Planning Tool, empower the clinical team to prioritize oxygenation, avoid task fixation, and ensure that the right rescue strategy is employed at the right time.
This systematic approach is the most effective way to improve patient safety and outcomes in the challenging environment of critical care.