A 5-year-old boy with a past medical history of Crouzon syndrome presents in the Pediatric ED.
He is febrile and tachypnoeic, with low blood pressure and a capillary refill time of 4 seconds. His oxygen saturations are 86% in air, and he has a GCS of 8/15.
His notes suggest that he was a difficult intubation in the neonatal intensive care unit.
While you prepare the difficult airway cart, a young trainee asks about cannot intubate cannot oxygenate scenarios.
Intubation is the best way to secure the airway in a critically ill child. Yet, such intubation is rarely performed outside the intensive care unit. Although paediatric difficult airways and Cannot Intubate – Cannot Oxygenate (CICO) scenarios are rare, they are associated with high morbidity and mortality.
What is a difficult airway?
A difficult airway is one where in which there is difficulty with either face-mask ventilation or intubation. There are many aspects of a child’s anatomy and physiology that may make things more complicated. Unfortunately, children are particularly vulnerable to severe hypoxia during the management of a difficult airway. Their smaller airways and increased oxygen demand go hand-in-hand with a decreased oxygen reserve.
How to perform a pediatric airway assessment
There are lots of things to consider when evaluating the airway prior to any intubation(Table 1). Though many children are often not cooperative, things may be even more difficult during an emergency. Hence, a systematic approach is important.
Table 1: Airway assessment
Can we predict a difficult pediatric airway?
Even though there is no clear-cut answer, there are some risk factors that make a difficult airway more likely. These include:
- Setting of pediatric airway management: non-elective and rapid sequence inductions (RSI) are higher risk
- Evidence of airway bleeding, inflammation, infection, obstruction
- Positioning difficulties (e.g., patients with cerebral palsy, kyphoscoliosis)/ Prior history of difficult intubation
- Syndromes that are associated with congenital airway abnormalities and/or dysmorphic features (e.g., Crouzon syndrome, Pierre-Robin sequence, Down syndrome, Beckwith-Wiedemann syndrome)
- Injuries to the face, mandible, pharynx, or neck
- Sleeping issues such as snoring due to adenotonsillar hypertrophy
It’s essential to have a well-planned approach to managing the difficult airway. Even with the best planning, you still may not anticipate the difficult airway.
The large, multicentre Neonate-Children Study of Anaesthesia Practice in Europe (NECTARINE) study reported an overall incidence of 5.8% difficult intubations in neonates and infants. Around two-thirds of these were unanticipated. Airway complications are also more likely to occur in the emergency department (ED) than in the operating theatre. One large observational study found a 35-fold higher increase in events leading to death or brain damage in ED intubations.
Difficult airways can be extremely stressful for everyone involved and can quickly lead to cognitive overload. This can make a time-critical and challenging situation even worse.
What paediatric difficult guidelines are available?
The Difficult Airway Society (DAS) published guidelines for difficult pediatric airways in children age one to eight back in 2015. These included three algorithms based on three specific scenarios:
- Difficult mask ventilation.
- Unanticipated difficult tracheal intubation.
- Cannot Intubate, Cannot Oxygenate.
These algorithms highlight the importance of asking for help early, optimizing head position, checking the equipment and maintaining anaesthesia. However, due to the rarity of difficult airway events in paediatrics, most data comes from adult studies that are then applied to the paediatric population. The Vortex approach© is a simplified approach to managing the difficult airway.
What is the Vortex?
The Vortex approach is a visual model based on the principle that there are three non-surgical techniques to establish an airway (face mask, supraglottic device, endotracheal tube). Suppose the best efforts of each of these three techniques are not successful. In that case, it is time to declare a “can’t intubate, can’t oxygenate” (CICO) situation. Emergency front-of-neck access (eFONA) is needed to restore oxygenation.
Conceptually the Vortex is a simple visual metaphor. The three non-surgical airway lifelines are arranged in a circular fashion around a central area representing the CICO situation. If attempts at one lifeline (you can start with any of them) are unsuccessful, then there is spiral movement inward to the next lifeline. Airway management is divided into the “green zone” of relative safety and a funnel-shaped vortex (essentially a whirlpool) of progressive failure, which results in eFONA.
The narrowing funnel represents time running out, whilst the deepening blue is a visual reminder of the worsening hypoxia.
Why is the Vortex effective?
Clinicians should prepare for difficult airways by training, practising, and undertaking a thorough assessment. However, even with the best assessment, you may not anticipate the difficulty, and even the most experienced clinician may struggle. Difficulties are often not related to a lack of skill or knowledge; instead, errors are more likely due to human factors and clinicians becoming cognitively overloaded. The consequences of this are impaired decision-making, task fixation, task omission, and failure to act. These can make it challenging to move forward in an algorithmic approach.
The Vortex is simple, flexible, and easy to recall under stress. It can also able to be applied in multiple scenarios, not just the operating theatre, and it more accurately depicts real-world practice. Moreover, the visual prompts are useful to all team members and can help maintain team situational awareness.
Why is it important?
The “cannot intubate, cannot oxygenate” situation, although rare, is one of the highest stakes and time-critical emergencies that clinicians can encounter.
Children pose additional challenges for emergency front-of-neck access. They have smaller anatomy; it can be hard to identify the cricothyroid membrane, and very few of us have ever performed one. These technical challenges may act as a barrier to moving towards eFONA. A number of psychological factors can also act as barriers towards performing eFONA. These include fear, denial, pride, fixation errors, lack of situational awareness, and loss of time perception.
The Bromiley case is a tragic example of what may happen when clinicians lose perspective. The psychological factors described above resonate strongly in this case. It highlights the dangers of fixating on one lifeline (intubation) instead of optimising other techniques and managing the situation. Sadly, Mrs Bromiley experienced a significant period of severe hypoxia before an intubating LMA was successfully placed.
Using the Vortex helps avoid the CICO situation through the use and optimisation of available airway lifelines and helps recognise when front-of-neck access is needed. Rather than an abrupt pivot in management, it represents a more efficient and gradual transition to eFONA. This mitigates many of the psychological barriers and facilitates better teamwork.
What is the next step in a CICO event?
– Call for ENT help if it has not already arrived.
– Ensure best efforts as per Vortex approach
– Declare a CICO event – BE CLEAR – everyone in the team should hear it
– Prepare for Front-of-Neck Access (FONA)
Children, aged one to eight years old should have a formal tracheostomy if an ENT surgeon is present
If ENT is unavailable, prepare for FONA, while continuing attempts to oxygenate
– Open FONA kit and prepare the equipment
– Identify anatomy – don’t forget kids are not small adults!
– Optimize the position of the patient
– Obtain front-of-neck access
There are lots of different FONA techniques (Table 2) for infants and children. The DAS guidelines favour scalpel cricothyroidotomy. However, there are no good quality studies available on the best approach for infants and children older than eight. Remember that FONA is only a temporary airway to assist oxygenation while someone is trying to secure a definitive airway.
Table 2. Approaches to FONA in children
Does the simplified approach work?
A randomised controlled trial compared the Vortex approach to the more conventional algorithmic approach (ASA difficult airway algorithm).
They included 67 third- and fourth-year medical students doing their anaesthetics rotation. Participants were randomised to receive education on either the Vortex (n=34) or the algorithm (n=33) before going on to manage a simulated airway crisis. Decision-making, completeness of management, anxiety, and task load were all measured using objective scoring systems. The study showed that those in the Vortex group performed better overall, with less anxiety, and had a lower task load, suggesting the Vortex is easier to learn, recall, and apply.
The study is somewhat limited by its small sample size and use of unblinded scorers. However, they did use an objective scoring checklist, which may have minimised the impact of lack of blinding. Although the use of novices may mean the results are less generalisable to experienced anaesthetists; in the ED setting, this is a strength. These events are rare, there is little opportunity to rehearse, and when they are encountered, they are stressful.
This randomised controlled study strongly supports the use of the Vortex approach due to its simplicity and learnability.
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