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Airway FOAMed

FOAMed has been enthusiastically adopted by the Emergency Medicine and Critical Care crowds. Not surprisingly resuscitation and airway topics have been hot topics of discussion.

So what does the rural doctor need to be aware of in terms of recent developments? Most of these issues pertain to establishing an emergency airway – not just the GP-anaesthetist but also any doctor who is on call for emergency.

TOP TEN AIRWAY FOAMed FOR RURAL DOCTORS

Here is a quick run through of a selected top ten areas with which the rural doctor who manages airways should be familiar:

 (i) direct laryngoscopy vs videolaryngoscopy

A plethora of new airway devices are on the market – from disposable indirect optical devices such as the AirTraq ($80) through to expensive systems using similar blade geometry as standard Mac blades eg: C-MAC ($15,000).

Direct laryngoscopy (DL) is a core skill. Videolaryngscopy (VL) is reported to offer advantages, obviating the need for the intubator to align pharyngeal and laryngeal axes…particularly useful in a grade III/IV view or where head movement is difficult (trauma). Caution is needed because whilst VL affords a better view of the glottic opening, passage of an ET tube may not always be easy, particularly with indirect Bullard-type blades. VL may also require a different technique than VL, necessitating regular practice on elective cases before attempting on a  difficult airway.

Clearly VL has advantages for teaching intubation skills and recording/audit of cases.as well as a role in difficult airway management. Affordable devices are out there, but choose wisely – the ideal device would allow the same technique as DL, with same blade geometry as a Mac blade and both DL & VL options. Levitan summarises this well.

VL devices

 However – a word of warning – there are MANY devices out there, ranging in price, function and design. CHOOSE WISELY.

The ideal VL should allow the same technique as direct laryngoscopy, rapid switch from DL to VL, have similar blade geometry and allow recording of intubation attempts for teaching/audit, preferably with streaming to a slave monitor for other to see passage of tube. It should also be low cost and re-usable.

To date no such device exists, and one has to make a compromise between options. My advice? Try before you buy, and browse the many, many blogposts on this from rural doctors like Minh le Cong, Casey Parker and myself…

I reckon we are getting closer to affordable VL that does not require a change in technique from DL.

 (ii) difficult airway algorithms & equipment, CICO ‘needle vs knife’

The NAP4 study (2011) was a landmark study that has changed how we approach anaesthesia. It highlighted several common errors, not least around management of the difficult airway, performance of surgical airway and airway management outside of the Operating Theatre. 33 deaths and 46 cases of brain injury/death due to hypoxia were identified.

Common & recurrent errors included :

  • failure to plan for failure
  • difficult airways managed with repeated attempts at intubation rather than alternative plans
  • clear indication for awake fibreoptic intubation not performed due to lack of equipment
  • inappropriate use of supraglottic airways particularly by juniors, in the obese and where RSI indicated
  • -failure of needle vs surgical airway techniques

The UK’s Difficult Airway Society algorithms for difficult airway management are excellent and should be readily available wherever airways are managed. You can download them from the DAS website. Of course there will be differences between countries and institutions. One of my bugbears is protocols that are metrocentric or rely on specialised equipment not available to rural GP-anaesthetists.

Hence algorithms may need local adaptation to suit the rural setting – here is one from Kangaroo Island, SA.

Plans A-B-C-D Rural Hospital

Having an algorithm is one thing – you also need the equipment to manage each stage of the difficult airway plan. My 2012 survey showed clear deficiencies in access to airway equipment for rural GP-anaesthetists in Australia despite clear guidelines from ANZCA.

Not surprisingly this leads to suggestions for affordable, robust airway equipment for rural doctors. Have a look and decide for yourself on what kit YOU need in your hospital.

Some of the best advice on airway management comes from the retrieval world. Here is a Prezi from the #Retrieval2013 conference showing relevant aspects of difficult airway management. Like the isolated rural doctor, retrieval services have limited kit and personnel.

http://prezi.com/dt0805w9tco1/the-difficult-airway-in-secondary-rural-retrieval/

 (iii) use of checklists, protocols & team training

Concomitant with a difficult airway algorithm is a need for use of pre-RSI checklists and other cognitive aids to avoid error. For crisis management and problem-solving in both the ED and OT, we have a lot to learn from the aviation industry and their safety record. Feel free to download my ‘Checklists for ED/OT‘ PDF for use in your institution.

Using checklists has been discussed by Atul Gawande in ‘The Checklist Manifesto’ and Dr Kevin Fong (a chum from UK medical school) discusses this further in an excellent BBC Horizon video ‘How to avoid mistakes in surgery‘.

As far as I am concerned, taking a spontaneously ventilating patient and inducing anaesthesia and paralysing them is a high risk procedure. There are multiple cognitive steps to achieve, and it comes down not just to my skill but the skill and situational awareness of the team around me.

RSI KIT DUMP

An RSI kit dump with in-built checklist can help reduce
eror due to cognitive overload during an emergency

Of course having checklists and protocols is one thing – implementing them is another. Team training is vital so that everyone has the same ‘mental model’ of what is going to happen. In early 2013 a new concept ‘THE VORTEX‘ was launched in Melbourne – essentially a training tool and cognitive aid to reinforce the three pillars of BMV-LMA-ETT in maintaining an airway before plunging into the option of SURGICAL AIRWAY.

Everyone is still talking about this – whilst I don’t think it surpasses existing algorithms, as an aide memoire at the end of the resus bay bed and a cognitive tool for training, it is very powerful. Watch this video for more details or download the free eBook.

VortexCognitiveAid_1

Although infrequent in the OT, the dreaded “cannot intubate, cannot oxygenate” may be more common in the ED or prehospital environment. I must be crap at intubation because I have now done five (1 ICU, 2 ED & 2 prehospital I hasten to add)! Psychologically it is a hard step to make, requiring mental preparation. Read Greenland et al’s paper for more.

Regardless, as isolated rural doctors we need to be able to do this life-saving procedure. Andy Heard’s work from WA really helps inform the necessary steps…but needs to be backed up with CICO drill cards and team training.

In terms of team training, the best training happens in one’s own theatre or ED using own staff and equipment. This takes time and common barriers in the rural setting include the belief of ‘it won’t to me‘ or that ‘someone else will deal with a tricky case‘.

This is magical thinking. Critical illness does NOT respect geography – and staff in rural hospitals have to be able to manage whatever comes through the door until help arrives or the patient is transferred. Low cost solutions like iSimulate (basically two iPads, one as ‘controller’ the other as mock monitor display) allow even small rural hospitals to practice high-fidelity simulation using their equipment and staff. I reckon that rural doctors have a lot to benefit from this sort of technology.

iSimulate

 

(iv) cricoid pressure – friend or foe?

We have all been taught to apply cricoid pressure to prevent passive regurgitation of gastric contents during an RSI. Sellick originally described cricoid pressure with the patient in a head down, tilted to the left position.

Subsequent studies have failed to demonstrate that CP occludes the oesophagus; furthermore CP may make intubation difficult if incorrectly applied and is recommended to be abandoned if difficulty with intubation.

So…do you routinely use CP for RSI? Is this evidence-based? Or a pseudo-axiom?

Read this paper from Dan Ellis & co or Chris Nickson’s thoughts on cricoid pressure at lifeinthefastlane.com

Cricoid pressure

Perhaps a better adjunct is that of  external laryngeal manipulation. CP will NOT prevent aspiration…and indeed this is not what kills people (viz NAP4)…whereas hypoxia will. In a difficult intubation, place your right hand over your assistants and guide their hands into the position to allow best view of the glottic opening.

 (v) don’t be a “propofol assassin” – correct choice of induction agents in resus

If you haven’t already, listen to Cliff Reid’s infamous rant ‘the propofol assassins’.

Click HERE to download the MP3 (Cliff’s epic rant kicks off at about the 55s mark into this podcast).

Yes, the “Jackson Juice” (propofol) may be the only drug that anaesthetic trainees get to use in theatre…but it can be deadly in the resus bay. It’s not just about passing the tube – we need to avoid hypotension & hypoxia.

You need to be familiar with other agents, particularly ketamine. Myths of ketamine causing intracranial hypertension are not borne out from EM experience and indeed ketamine seems to be the ideal induction agent in trauma/sepsis, as well as having uses for procedural sedation, DSI and even psychiatric transfer.

Dr Minh le Cong of RFDS QLD will invariably tweet about another ‘interesting paper’ on ketamine via prehospitalmed.com – earning the nickname ‘keta-Minh

Screen Shot 2013-04-16 at 5.25.29 PM

Bottom line – ketamine is a useful adjunct to the rural doctor’s armamentorium and you need to get hands on familiarity with it – something that many anaesthetic attachments don’t give. It has a real role in the head injured or critical patient – listen to this podcast with guest Minh le Cong from ETMcourse.com.

(vi) choice of paralysis in RSI

We were all taught to use sux for an RSI because ‘it can wear off and the patient can awaken‘. Whilst this is true for elective anaesthesia, awakening is not an option in a true emergency – once the decision is made to secure the airway, it needs to be done by either orotracheal or surgical means. If things deteriorate to the point of needing a surgical airway, much easier to do on a paralysed patient than on a hypoxic, combatative one.

So the new mantra has changed from ‘sux rocks and roc sucks’ to SUX SUCKS, ROC ROCKS!

Roc at 1.2mg/kg gives the same onset of intubating conditions as sux…without fasiculations which may burn up more precious O2. True, you cannot reverse it (unless you’ve got suggumadex handy)…but in an emergency setting, waking up is not an option. You need to be moving through your alternative airway plans…

Not convinced? Read this from Seth Trueger at MDaware.org

 (vii) Increasing your margin of safety during RSI

Apnoeic diffusion oxygenation (NODESAT) was the big game-changer in 2011…make sure you read Weingart and Levitan’s paper on preoxygenation and prevention of desaturation during emergency airway management.

This is an idea that has been around for a long time  – there was a classic experiment from the 1950s where healthy volunteers paralysed with sux and then NOT ventilated whilst receiving FiO2 1.0 via ETT passively – SpO2 maintained up to 50 mins, albeit with impressive rises in CO2 and acidaemia.

Here is a summary of nasal cannula oxygenation during RSI

I now try and perform all my RSIs with supplemental nasal oxygen to allow apnoeic diffusion oxygenation during intubation. But it is still a concept new to some clinicians and the airway team around them. Try it – it may give you an extra margin of safety during RSI of a critically-unwell patient, in addition to standard preoxygenation.

As an adjunct to ADO, remember to adequately position your patient – checklists are useful. Ramping is useful for the obese – allowing both ear-to-sternum positioning to facilitate intubation as well as aiding ventilation. In an immobilised trauma patient, you can always drop the bed into reverse Trendelenburg…

Obese Desat

(viii) The New Alphabet of Airway Management

NODESAT – DASH-1A – Delayed Sequence Intubation DSI – Rapid Sequence Intubation (RSA)

NODESAT (nasal oxygenation during efforts securing an ET tube) is just a reminder to use supplemental nasal oxygenation and apnoeic diffusion oxygenation during a trauma or sick RSI

How about DASH-1A?  This is a concept championed from Dr Bill Hinckley in the States to remind us ‘definitive airway sans hypoxia on first attempt’. Watch this video for more details on DASH-1a.

Then there is DSI as opposed to RSI – delayed sequence vs rapid sequence intubation. Picture the scenario – it is 3am and the ambos have dropped off a 130kg patient with COPD who also has bilateral pneumonia. He is combatative and pulling off his face mask. He is intolerant of NIPPV or indeed a non-rebreather mask at 15 l/min. He needs to be intubated for transfer. RSI may be calamitous – you cannot adequately preoxygenate him due to intolerance of the face mask, and yet you are certain that he will desaturate rapidly once you attempt to intubate – due to both his obesity and his lung pathology. Delayed sequence intubation (DSI) may help get you out of trouble.

DSI suggests giving an aliquot of ketamine to allow adequate “procedural sedation” – the procedure being pre-oxygenation. A concept alien to us who are used to a standard RSI, DSI may have a role in the sick/combatative emergency patient who cannot be adequately pre-oxygenated due to confusion.

The technique is not without criticism, but one can see it may have a role in the emergency or retrieval setting. Preoxygenation can then continue with either CPAP circuit or addition of a PEEP valve to BMV.

DSI flow chart

OK, is that enough acronyms? How about Rapid Sequence Airway or RSA?

Leading on from the concept of DSI is that of the rapid sequence airway (RSA), attributed to Darren Braude in the States and enthusiastically championed by Minh le Cong of prehospitalmed.com. Basically this is reserved for those (very, very few) patients in whom even with adequate pre-oxygenation, marked desaturation occurs before time to place an ET tube ie: they drop from 100% to 85% in the few seconds to induce anaesthesia, paralyse and place an ETT. Again Seth Trueger gives us his thoughts on the RSA concept

 (ix) new Supraglottic Airway Devices (LMAs & iLMAs)

We are all familiar with Archie Brain’s invention, the ‘classic’ LMA…and many GP-Anaesthetists will be used to using second generation ProSeal or Supreme LMAs with a gastric drainage port and integral bite block. This is a useful review of supraglottic devices pros and cons.

Intubating LMAs such as the FastTrach can be used both to rescue ventilate but also allow blind passage of an ET tube. They are useful kit – but one can get into problems. The FastTrach does not have a gastric drainage port, so if you need to decompress the stomach, the iLMA has to be removed OVER the ETT tube, risking dislodgement of the ET tube and loss of the airway. The hyperacute (90 degree) angle of the FastTrach also makes use of an intubating stylet to visualise the cords difficult.

I have become a fan of the AirQ-II (Cook Gas) iLMA which has not only the ability to allow blind passage of an ET tube, but a less acute angle so can combine with a malleable fibreoptic stylet to allow visualisation of the cords to facilitate ET placement. An in-built gastric drainage port and bite block mean that the AirQ-II combines the advantages of both Supreme LMA and FastTrach iLMA in one.

Watch this video for more details on the AirQ iLMA and this one for the use of a malleable stylet to aid intubation through the iLMA.

This is an incredibly robust and yet affordable technique for a small rural hospital – if you have difficulty intubating, drop in an AirQ-II iLM< rescue ventilate, then use a malleable fibreoptic device to pass an ETT under direct vision using the iLMA as a conduit. Nice!

AirQ-II iLMA and Levitan Stylet

The AirQ-II (left) and a malleable stylet (right, held by Jm DuCanto)
affordable & robust kit for the rural doctor as an alternative intubation plan

 (x)  use of ETCO2, bougie for all emergency intubations!

 Of course we all KNOW to use end-tidal CO2 monitoring – but failure of it’s use was marked in the NAP4 study, particularly in ICU and ED. I now use ETCO2 not just for intubated patients, but also for sedation lists & procedural sedation in the ED.

Similarly we all know about bougies – but the lessons suggest that if we are ‘occasional intubators’ performing an emergency intubation, then we should use a bougie as a default and not worry about penis size. With that comes finesse such as using a pistol trigger or Kiwi-grip, or performing a ‘flip-flop’ manoeuvre if there is arytenoid hangup – demonstrated in this video. We also need to be familiar with oxygenating bougies and their pitfalls…as the infamous Ewing case demonstrated.

Screen Shot 2013-04-16 at 5.45.37 PM

flip flop manoeuvre to overcome arytenoid hang up

This is as good a place as any to slip in a comment on BIS (bispectral index monitoring). Heralded as the solution to avoiding awareness under anaesthesia, it really is just another tool for the anaesthetist to use. Indeed there is some evidence that BIS does NOT prevent awareness compared to standard monitoring (including measuring end tidal anaes gas). Comment here from BroomeDocs and KIDocs on BIS…or this from OpenAnaesthesia wiki. I reckon it may be more useful for avoiding transfer in the paralysed, intubated patient on propofol/M&M infusion, where disconnect and awareness a possibility.

 SUMMARY

Putting it all together? You couldn’t do much better than this demonstration from the mob at GSA-HEMS in Sydney showcasing many of the above FOAMed concepts..on the side of a cliff.

Although this was a video for the SMACC2013 SimWars competition, in a few short minutes it demonstrates nicely the concepts that all of us – even rural doctors – should be able to manage in our resus room or theatre. Specifically the GSA-HEMS team demonstrate the use of

  • team training before a crisis
  • team briefing and checklists
  • proper patient positioning & 360 degree access
  • ketamine for trauma RSI
  • apnoeic diffusion oxygenation
  • external laryngeal manipulation
  • bougie and ETCO2
  • first pass, no desat, no hypotension intubation
  • post intubation plan

You can download their RSI manual HERE – a useful refresher for rural doctors. Listen also to emergency airway management podcast from ETMcourse.com – interview with Minh le Cong Pt 1

A key point to emphasise is that we are ALL ‘occasional intubators’ and need to use adjuncts and team training to make us perform better. It is NOT just about passing the plastic – we need to do so without causing even transient hypotension or hypoxia, maximising first pass success. Using FOAMed resources helps.

Now it’s time to train the team around you in your rural hospital – because you need the nursing staff to be as familiar with this material as you are, in order to “make things happen”.

Finally consider joining the Australia & NZ Airway registry – I reckon that rural doctors could and should demonstrate that our airway management is as good as that in the city. Audit can throw up some unpleasant truths as the initial audit data from an Australian ED showed. If we are serious about our trade as rural GP-Anaesthetists, then we need to consider joining this audit project.


1 Comment

  1. […] such as rotating stylet right to enter trachea without impingement on the tracheal rings and my all-time favourite ‘the flip-flop’ manoeuvre as illustrated below (from GSA-HEMS, natch) for advancing ETT on […]

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About

Http://about.me/timleeuwenburg

Http://about.me/timleeuwenburg

I am a Rural Doctor on Kangaroo Island, South Australia with interests in EM, Anaes & Trauma. Currently working with MedSTAR Retrieval, SA. Avid user & creator of #FOAMed; EMST & ATLS Director, Instruct on ETMcourse.com. My sites include KIdocs.org & RuralDoctors.Net, affiliated with smaccUs in Chicago 2015 Opinions expressed on these sites must not be used to make decisions about individual health related matters or clinical care as medical details vary from one case to another. Reader is responsible for checking information inc drug doses etc.

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