Clinical Case 069: Can’t Intubate, can ventilate …. for now

OK, Im reading this without looking at what happened, and I’m, learning a lot from the case scenario.

No fiberoptics, can’t see anything, but can ventilate with an LMA.

How about I give you a few ways to go here?

1. Re-sedate patient with additional propofol to maintain her tolerance of LMA, but omit the Succinylcholine.

2. Topical lidocaine through the LMA (8 ml 4% dilute in 20 ml total volume will be an awesome nerve block for the purpose of trans-LMA intubation). 30-50 mg aliquots [Ed: of Propofol] are a safe way to go.

3. Tracheal tube 6.0 cuffed preparation for blind intubation through LMA: Remove 15 mm connector, place tip of tracheal tube into the portion of tube normally occupied by connector. Wait for the plastic to get some “memory”. Place patient’s head and neck in the maximal amount of extension that her body will allow.

4. Blind LMA intubation is much like blind nasal intubation–you advance the ETT, listen, and re-position left/right twist slightly as you listen to breath sounds. Often, it is required to withdraw the LMA slightly to flatten the “angle of attack” of the tracheal tube to the glottis.

5. As the tracheal tube approaches larynx, a slight left or right turn may be necessary to clear the vocal cords. Watch the Thyroid cartilage itself to see where the tracheal tube bumps the laryngeal cartilage, and adjust appropriately.

6. Gentle cricoid pressure may help.

7. The next technique—all of the above, but put a retrograde wire through the cricothyroid membrane up through the LMA (I’ve never done it, but I will try it next time I get to Rich Levitan’s cadaver lab). Then retrograde intubate through the LMA.

——-
[Now – back to the big question. What is going on – what is the diagnosis? I think I’ll let you guess. Will update soon.] My answer—-Are you hinting at a subarachnoid hemorrhage? Why else would you go to the extent of securing her airway?

it was cavernous sinus thrombosis, n’est ce pas?

Difficult case – one of the challenges of small town country doctoring in Oz (and no doubt elsewhere) is that it is often colleagues, friends and occasionally family whom one has to manage through their critical illness.

You KNOW i’m gonna wade in on this one, as it highlights my particular passions of both :

(i) access to difficult airway equipment and

(ii) fighting to bring same level of care from city to country.

FWIW I would have done same…declared failed intubation, maintained ventilation on LMA and proceeded to secure airway via scalpel-bougie(finger)-ETT for transfer. I dont think waking up would be an option, given distances involved and potential for further drop in GCS and inability to protect airway.

But this case highlights (for me) the importance of being able to manage the unexpected difficult airway in any place where elective and emergency anaesthesia is performed.

My survey of rural docs in Oz suggests that not all of us have access to the kit required, nor the algorithms (see paper here http://rrh.org.au/publishedarticles/article_print_2127.pdf or chat to me at the forthcoming #RMA2012 conference in Fremantle)

ANZCA has a professional standard PS56 on the equipment needed to manage difficult airways. I am a fan of the UKs difficult airway society algorithms with clear plan A, B, C and D. Note that each of these steps requires specific kit to manage each of the steps.

So, what do we need?

Plan A – intubate the trachea, maximise first pass success

DL (but if anticipated difficulty consider VL as first line).

Max three attempts (2 in RSI).

Change posiiton, blade, operator.

Very few rural docs have access to VL. This will change…

You mentioned that another GP-anaesthetist was called in to have a look. I’d emphasise the dangers of repeated attempts at intubation. If you remember nothing else, remember this :

“Airways are like willies — the nore you fiddle with them, the harder they get”.

Trust yourself and colleagues. If it was a grade IV view for DrX then it is likely to be so for DrY (assuming not a novice or ocasional intubator). Start to plan for alternatives, such as…

Plan B — alternative intubation plan (omit if true RSI ? we can debate that one).

Use LMA and alternative intubation plan. Jimmy D gives excellent approaches. Important to consider early use of the newer intubating LMA devices rather than classic LMA…

Most rural docs have cLMA only. But less than 70% had proseal or supreme LMAs. Similar numbers had an intubating LMA (iLMA) to allow passage of an ETT blindly. You mentioned FastTrach…a good device but can be fiddly to remove the LMA once ETT secured.

My approach (and Minh I think you would agree) is to leave the whole thing in place for transfer. I am a fan of the newer AirQII — combines the gastric drainage of a supreme LMA with the ability to intubate like a FastTrach, but a less hyperacute angle to navigate. About A$30 each with the oesophageal obturator/drainage tube.

Whatever, I would be placing an iLMA early rather than a cLMA. But you need to have the kit!

Of course, can increase ease of intubating through the iLMA using some sort of fibreoptic device…there are affordable options out there, with both (disposable) flexible scopes (five in a pack) or sterilisiable malleable fibreoptic stylets…all for around A$2500.

Very very few rural docs have access to these…even though they are pretty much mandated at Plan B in the DAS algorithm. Of the two, a malleable stylet is easier to learn to use on mannikin, then elective lists — and allows visualisation of the cords to pass ETT through the iLMA as conduit (wont work thro FastTrach, too much of an angle).

Use a Parker tip ETT to avoid arytenoid hangup.

Plan C — maintain oxygenation, wake up

As in the Bromiley case this can be forgotten, especially in a crisis.

Following a recognised algorithm reduces risk of target fixation (“gotta intubate the trachea”).

Only 40% or less of rural GP-anaesthetists surveyed were using such an algorithm or checklist. Time and time again from Coroners reports and closed claims, such target fixation leads to catastrophe. We are humans who will err. There are recognised algorithms. Use them.

I agree though, waking up may not be an option here — she needed airway securing and faced a long aeromedical transfer with risk of further drop in GCS. So, here’s the question — if you were faced with this case again, would you consider using rocuronium at 1.2mg/kg…commits you (and the team), but means less chance of an unparalysed patient struggling through a surgical airway. Very few rural docs would have access to suggumadex, but one could argue is academic — needs a tube, either above or below the cords and one should have plans for this before start. Which leads nicely onto…

Plan D — rescue techniques for CICV

BroomeDocs has covered ‘needle vs knife’ debate about a year ago. Practical hands sessions in both dry and wet labs give us the skills to manage these infrequent but serious events.

The kit needed is not expensive — a few hundred dollars at most. Scalpel-bougie/finger-ETT works for me (n=4) and Heard’s mob in WA are to be commended for bringing rigeur to this situation (check out their youtube clips)

Bottomline — this sort of scenario can and will occur in small country hospitals. Not often, but it will happen.

The rural GP anaesthetist will have to manage it and needs appropriate equipment and cognitive aids (algorithms/checklists/ongoing training) to do so without immediate specialist backup

Affordable and robust equipment is out there for under A$5000 and there is really no excuse not to have it.

Economies of scale are to be had by purchase in bulk (pref by State health depts) and recycling kit between rural and metro areas before expiry date.

Use of similar equipment between sites and agencies (country hospital-retrieval service-Metro ED) allows for familiarity as personnel rotate as well as skills maintenance etc.

That is all

Tim