Gameshow or Desert Island Supraglottic Airway Devices?

There are over 20 different supraglottic airway devices on the market, each with their own pros & cons. This can lead to confusion when choosing preferred supraglottic airways to stock on emergency trolleys, with proponents favouring one device over another based on various performance characteristics or bias towards situational practice (e.g.: OT vs ED)

How to choose the ‘ideal device’?

Well, some anaesthetists have argued along the lines of a ‘gameshow’ analogy.  Imagine a gameshow where there’s a million dollar prize, for which the contestant is allowed only ONE shot i.e. claiming the prize is dependent on placing the device successfully.  Anecdotally most anaesthetists will default to choosing the classic LMA as their ‘million dollar’ airway.

 

One Chance for a Million Dollars? I’ll choose the CLASSIC thanks!

And why not?  It’s been around since 1988 and has proved a stalwart in elective anaesthesia.  However I’d argue that w’re not on a gameshow where success is judged solely by placement of a device by an anaesthetist to allow effective ventilation.

Instead we should consider a ‘desert island’ airway, a device that can be reliably placed by occasionalists such as nursing staff on the orthopaedic ward at a cardiac arrest.  Flexibility of the device to allow gastric drainage, minimise aspiration risk and ideally to act as conduit for placement of an endotracheal tube are also desirable.  If we’re going to talk about gameshow voice of airways, perhaps we need to consider ‘Survivor’ – with pluripotency across arenas most valued.

Miller described a somewhat complex classification for supraglottic devices in 2004; five years later  in 2009 the international standard ISO 11712:2009(E) was published, with five classes of device.  However the classification by Cook et al in the same year is perhaps the most useful, dividing supraglottic devices into first and second generation.

Cook’s 2009 classification of SADs into first or second generation remains most useful

Whilst it remains perfectly useful (and perhaps the vice of choice) in elective settings, the lack of gastric drainage channel and the restrictions on use as a conduit for intubation mean that the cLMA really has no place on in ED, ICU, ward MET calls or the prehospital environment. Since 2015, the UK Difficult Airway Society no longer recommendsthe use of the classic LMA as a rescue airway device. 

Emphasis is placed on assessment, preparation, positioning, preoxygenation, maintenance of oxygenation, and minimizing trauma from airway interventions. It is recommended that the number of airway interventions are limited, and blind techniques using a bougie or through supraglottic airway devices have been superseded by video- or fibre-optically guided intubation. If tracheal intubation fails, supraglottic airway devices are recommended to provide a route for oxygenation while reviewing how to proceed. Second-generation devices have advantages and are recommended [DAS 2015]

Moreover the requirement to inflate a cuff can be a particular problem in ‘occasionalist’ hands – cuffs can tear on teeth, cause difficulty with position or even fail to be inflated.  The extra steps required to inflate cuff and check seal may present additional cognitive load for the occasionalism in a high-stress situation such as unexpected cardiac arrest on the ward, in the small rural hospital or in prehospital setting.

So what are the properties of the IDEAL supraglottic device?  I’d argue they should include:

  • affordability
  • ease of use
  • presence of an integral bite block
  • ability to use as a conduit for passage of an endotracheal tube
  • presence of features to reduce risk of aspiration
  • range of sizes from neonatal, paediatric to adult
  • preferably obviate the need to inflate a cuff

But within the category of second generation supraglottic airway devices, an almost baffling diversity exists – each with own adherents.

  • The Proseal & Supreme LMA have a proven track record and as such are often seen as the ‘go to’ second generation device for anaesthetists.  
  • The FastTrach intubating LMA is still considered as a rescue device by some, to facilitate blind placement of an ETT.  But 2015 Difficult Airway Society guidelines suggest that we should NOT be attempting blind intubation through a supraglottic airway anymore!  So Ambu recommend the AuraGain acts as a conduit for a dedicated fiberoptic scope made by the same company.  
  • Meanwhile the LMA Protector is touted as best at minimising aspiration risk via dual gastric drainage ports.  And devices such as the AIrQsp obviate the need for cuff inflation.  And so on…

So many choices….

It is not uncommon to find a bewildering array of supraglottic devices within a single institution. The ambulance service may use iGels; the ED may use classic LMAs, the ICU may use Supremes and the Theatre suite may have everything from cLMAs, sLMAs, iLMAs etc depending on personality & preference, available funding, likely case mix and a myriad other factors.

Take a wander through your Hospital visiting ED, ICU, Wards and Theatre – how many different supraglottic devices are there?  Are classic LMAs still being used as rescue devices on crash carts?

I believe that this is where the ‘gameshow’ analogy falls down.  It’s not important what the anaesthetist would want in the ‘million dollar’ gameshow challenge.  Instead we need to consider use of supraglottic devices that will function across a system and which allow maximum flexibility and ease of use. A device that can be used from prehospital, into ED, across wards and into ICU as a rescue airway. Use of a single device allows practice and familiarisation for individuals, regardless of location.

A true systems approach suggests the need for a ‘desert island device. 

 

Enter the iGel

Many prehospital services (New South Wales, Victoria and shortly South Australia) are using the iGel device.  Available in a range of sizes, it is a second generation device with orogastric drainage, ease of insertion and no cuff – instead the thermoplastic allows moulding to the hypopharyngeal anatomy to make a seal.

Removing the need for a cuff obviates the above mentioned problems in ‘occasionalist’ hands, applicable to the ward as well as the prehospital service. Having gastric drainage is important for use as a rescue device in the non-fasted patient. But perhaps best is the potential to use the iGel as a conduit for passage of an ETT.  Hence the need for familiarity across a system.  In short, if the ambulance are using it, we need to understand it!

Choking the chicken – placement of ETT via IGel as a staged airway

Imagine the following not uncommon scenarios – a sudden cardiac arrest in the prehospital environment…or on the orthopaedic ward.  Or a failed intubation in the ED or ICU. The immediate responders, whether trained paramedics, emergency clinicians or ward staff, place an iGel and are able to ventilate, thus entering the ‘green zone’ of the Vortex.  What next?

It makes no sense to remove the iGel and replace it with another form of supraglottic as the patient transitions through ED or ICU.  Nor does it make sense to remove the iGel to intubate.

Instead, the combination of the iGel with the Scope (an affordable flexible fiberoptic device) means that an ETT can be passed under direct vision with no interruption.  

Use of the LMA as a conduit democratises fiberoptic skills

This ‘staged airway’ is a simple technique and relies upon use of the iGel as a conduit – essentially democratising the skill of fibreoptic intubation for the masses, rather than a requiring the Ninja-like airway skill of a senior anaesthetist.

The key steps are

  • place an iGel and establish effective ventilation (green zone of Vortex)
  • Confirm appropriate position of the supraglottic using fibrescope
  • Load ETT
  • Ensure adequate anaesthesia & paralysis
  • Pass fibrescope through glottic opening
  • Railroad a preloaded ETT into the trachea using ‘chicken choke’
  • Leave the ETT/SGA complex in place
  • Inflate ETT cuff & confirm ventilation with waveform capnography

But what about ‘choking the chicken’?

Well it’s not uncommon for the leading top if an endotracheal tube to ‘hang up’ on the right arytenoid cartilage when being railroaded (whethr over a bougie or a fiberoptic scope). 

Flip-Flop manoeuvre from ScanCrit http://www.scancrit.com/2012/03/11/arythenoid-hang-ups/

Rather than wait for this to happen, withdraw it then perform a counter-clockwise ‘flip flop’ manoeuvre, my mate Jim DuCanto suggests a deliberate rotation of the ETT before rail-roading over fiberoptic scope and through the glottic opening.

 

Key steps in this technique are:

  • grab the preloaded ETT – ‘like the neck of a chicken’
  • Deliberately rotate the ETT 90 degrees counter-clockwise – ‘choke the chicken’
  • Railroad ETT down into the trachea
  • Rotate ETT back to neutral alignment inflate cuff and secure

Summary

In my opinion, use of the iGel across a system (from prehospital-ED-ICU-wards) makes sense.  This rescue device can be reliably placed by non-anaesthetists, can allow gastric drainage and most of all allows a staged airway for placement of an ETT using an affordable fibereoptic scope.  moreover use of a single device across a system allows training and familiarity for occasionalists; leaving the theatre suite to host a suitable array of devices from cLMA through to select second generation devices according to particular needs.

References

Frerk et al (2015) Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults (Difficult Airway Society intubation guidelines working group) Br J Anaesth. 2015 Dec; 115(6): 827–848. Published online 2015 Nov 10. doi:  10.1093/bja/aev371

Miller (2004) A Proposed Classification and Scoring System for Supraglottic Sealing Airways: A Brief Review Anesthesia & Analgesia: 99(5): 1553-1559 doi: 10.1213/01.ANE.0000134798.00069.2B

White et al. (2009), A critique of elective pediatric supraglottic airway devices. Pediatric Anesthesia, 19: 55–65. doi:10.1111/j.1460-9592.2009.02997.x

See also

OPEN AIRWAY resources on supraglottics – http://openairway.org/airway-devices/supraglottics/

 

 

 

 

Airway Popups

on the big stage with friends at #dasSMACC – with Susan Biswas, Michelle Johnston, Marcelo Amato, Di Egerton-Warburton, myself, MJ Slabbert

Just heading home from a whirlwind European trip, ostensibly for the purposes of attending #dasSMACC in Berlin.  I’m proud to have been involved with smacc as speaker, workshop presenter and occasional twitter moderator since inception in Sydney 2013.  It’s cemented itself as the premier conference for critical care and emergency medicine on a global stage – so after Sydney, Gold Coast, Chicago, Dublin & Berlin and pleased to hear it’ll be coming back ‘down under’ for the sixth smacc in Feb 2019 (having a year off)

Catching up w Mark Wilson & Kevin Fong – interns together in London, now diverse careers as neurosurgeon/HEMS doc, anaesthetist/HEMS doc and NASA guru, and rural generalist

smacc is best considered an opportunity to meet and connect in person with like-minded clinicians, many of whom already collaborate in the Social Media space under the banner of FOAMed.

My particular interest is in airway management in the rural setting, contextualising existing ‘best practice’ to the needs of those clinicians who must provide high-quality services without immediate back up (whether prehospital or rural-hospital based)

The ‘light side’ of airway management has traditionally been emphasised in the smacc workshops and FOAmed world, leading on as it does from the 2012 work by Weingart & Levitan on oxygenation and prevention of desaturation in the ED.  Back then, apnoea diffusion oxygenation was considered a ‘game changer’ for ED RSI.  Since then FOAMed has emphasised and made routine the use of ramping, of airway planning, of checklists, of nuance in post-intubation ventilation strategies and so on.

However the ‘dark side’ of airway management, namely dealing with the massively contaminated airway has been relatively neglected.

Ewen McPhee tackles dark side of airway management

Standard anaesthesia practice has been to either fast patients, or pass a nasogastric pre-ETT…or if unexpected soiling, to place head down, left lateral and suction using a rigid-suction catheter such as the Yankaeur.

In 2015 at smaccCHICAGO, James DuCanto and I modelled the SALAD (suction assisted laryngoscope airway decontamination) technique as part of the airway workshop – we repeated this again in smaccDUB (Dublin, 2016) and many others have developed their own airway trainers to mimic airway contamination and train others in this technique.

So at dasSMACC James & I concentrated on supraglottic airways (particularly the second generation devices such as AirQsp, AuraGain and iGel)…and taught the specific skill of using these SGAs as a conduit to pass an ETT under fiberoptic guidance.

Now five years ago, if you’d said to me that fiberoptic skills were useful in the ED, I would have laughed – use of a fibrescope has traditionally been associated with the nuanced and Ninja-like skill of airway fibreoptic intubation.

However, placement of a second generation SGA and use of an affordable device such as the Ambu Ascope means that an ETT can be rapidly delivered to the glottic opening, bypassing secretions, salvia and so on va the supraglottic.

Brilliant technique.  I can see no reason why such affordable scopes aren’t the routine in the ED, especially when prehospital services are using second generation devices already – allows a ‘staged airway’ – placement of SGA in the field, then passage of fiberoptic scope and ETT in the ED with minimal interruptions or change of device.

James and I spent 8 hours training 160 people in this skill….then went on to run ‘pop up’ events in SALAD at #GelFEST (point-of-care ultrasound and airway training in a Berlin nightclub) and during the breaks in the main #dasSMACC programme.

I reckon we’ve trained another 200 people via popups; all unofficial, all FOAMed and of course unpaid.


Prior to #dasSMACC I also spent time teaching SALAD to prehospital providers in Dublin and Cork – including a fascinated member of the public who was anxious to learn how to intubate as ‘had seen on TV’ – I reckon we had him up and running in under 90s!

Proves point you CAN teach airway on the run….

I hope others will be tempted to do the same.  Do contact the SALAD team if you want to make your own SALAD simulator or share tips and tricks….

NB : I will be demonstrating the SALAD technique again on Chris Nickson’s ‘Critically Ill Airway’ course in Melbourne September 25/26th and again at the NSW Peripheral Hospital Emergency Conference September 27/28th as part of an airway workshop with Rich Levitan and myself

Critical Ill Airway Course Nickson-Leeuwenburg, Sept 25/26th 2017

Peripheral Hospital Emergency Conference Levitan-Leeuwenburg airway workshop, Sept 27/28th 2017

 

References

Nemesis of emesis – training for massive airway contamination ANZCA Bulletin

EM-Crit Having a violent SALAD with DuCanto

Facebook SALAD SIM

Portable Vomit Simulator KIDOCS

Community CPR, AEDs & Out-of-Hospital-Cardiac Arrests

The value of Bystander CPR and Public Access AED use is shown nicely in this NEJM article

http://www.nejm.org/doi/full/10.1056/NEJMoa1601891

What does this mean?

I think it means that a sensible approach to out-of-hospital cardia arrest is NOT about hospitals and helicopters (although post ROSC transport and critical care is vital!)

Rather, we need to ensure robust systems such as

– training the public in ‘hands only’ CPR

– making Public Access Defibrillators available as the norm, not the exception

– using smartphone technology to alert and crowdsource trained BLS-providers in the vicinity (such as GoodSAMapp)

– integrate such technology into existing systems

All of which is eminently do-able – and I am pleased to see that some Ambulance Services overseas and interstate have managed to do this

Hoping the remaining Ambulance Services in Australia will be able to follow suit!  Word is that New Zealand and Victorian ambulance services will be going live with GoodSAMapp.org in 2018…

 

Making Communities HeartSafe

Meanwhile at a local level I’ve been busy, along with other concerned clinicians, to ensure our local community becomes ‘Heart Safe’

The Heart Safe community concept is from the USA and again something that would seem relatively easy to apply to Australia.

We’ve pushed ahead in our small Island community to get public access AEDs into the townships, followed by tourist hotspots…..at the same time training community members in hands-only CPR.

Read more about the project at Facebook.com/heartsafeKI & twitter @HeartSafeKI – give us a follow!

Integration with smartphone apps such as GoodSAMapp is also an easy target to achieve.

And if you want to see proof that such a system works, look no further than this local success story from Kangaroo Island.

Read more about Heart Safe Communities here