Awake fibre optic intubation (AFOI)

I’ve had an interesting few weeks around this subject – enough thoughts that a twitter thread seemed a bit painful…

It’s long been known that anaesthetists avoid doing AFOI‘s – the national audit project in the UK demonstrated that, despite solid indications for AFOI multiple occurrences led to bad outcomes because it was avoided.

The thoughts on why this are well covered elsewhere but boil down to fear, or lack of talent, or lack of ability to practice or never really been taught the art properly. That has now been compounded by the videolaryngoscope. (VL) Essentially if there’s enough mouth opening then I think a good percentage of anaesthetists are going to do some sort of spontaneously breathing, sedated/deeply sedated VL or a combined technique with a fibrescope.

Which is where I’m at. I’ve had the fear for several years. I work in a tertiary centre and a legitimate AFOI opportunity is probably twice a year and getting a patient to consent for an optional AFOI seems a bit dicey…

I’ve tried every which way but loose with topicalisation and sedation and never really had the same result twice. Certainly the demeanour of the patient has a significant bearing on toleration of the procedure.

I have most definitely hedged and my favourite is the STRIVE Hi anaesthetic as demonstrated in the BJA a couple of years ago: https://academic.oup.com/bja/article/118/3/444/2999638

They talk about obstructed airways but the principle works fine in unobstructed airways. I.e. HFNO2, step wise TCI propofol, maintenance of sats and spontaneous respiration allows a “quick look” with a VL. If a view of the tracheal outlet is good then roc and intubation or an asleep FOI.

I’ve used this several times now with only one patient showing obstructive breathing but with none of the patients actually becoming apnoeic.

It has the reassurances of your patient not remembering what you did and the reassurance of not having to topicalise properly. But therein lies the rub, it could well be a false reassurance…

So I did an AFOI course in Cambridge in 2019 to try and pimp my skills. (I recommend it it was very good) 10 very highly motivated doctors got assaulted, sorry practiced on, with good topicalisation and not a jot of sedative. Two of them definitely reached their limit of LA and would have needed some pharmacy to complete though.

So the majority of our patients could probably manage if you take your time and give them 1mg midazolam…

But the AFOI when it’s really needed is really needed and that’s the case that terrifies me (and I suspect many others) you know, 150kg with a dental abscess at 0200…

And I know watching somebody who does AFOI regularly can make that look easy but I’m not sure that would be me.

But I’m not shy about asking for help if I need it even at 0200 – but you can see how that could lead to a spiral of woe…

Then I came across a presentation recently by Dr John C Sackles of Arizona at the Difficult Airway Society meeting. He introduced me to the concept of the “physiologically” difficult airway. To my surprise I’d never really considered this before even though I knew exactly what he was talking about. Our 150kg patient above has a normal airway but has septic shock and needs a laparotomy…

What the good Dr Sackles pointed out is that we’ve all seen near or actual CVS collapse on induction of a shocked patient. But if you do an AFOI that is highly unlikely.

Which leads me to the next case where I got shouted down in no uncertain terms after I considered the above scenario.

So imagine BMI 50, needs a Caesarean section, has critical care cardiomyopathy (EF <50%) from a previous dose of HELLP syndrome which is why they need a section again…

Has been previously intubated but no record of grade. Is fully anti coagulated on enoxaparin. Haematology say that anticoagulation should be started as soon as possible after surgery.

So with a bit of management then yes do a CSE. But if it’s more urgent and the time window isn’t long enough…

Then GA and sure we could all do a rapid sequence induction with a VL and ramping and HFNO2 and all the stuff.

But I suggested an AFOI, because this is a physiologically difficult airway. Risk of CVS collapse with a bad heart ✔️, risk of CVS collapse if rendered hypoxic ✔️, badness for the baby if hypoxic ✔️, a spiralling airway if hypoxic and a bad heart ✔️ to me if time allowed then actually an AFOI on HFNO2, orally whilst running a smidge of pressor if needed and a very gentle induction once the tube is in seemed eminently reasonable. Certainly reasonable if you happened to be skilled at AFOI.

Not so apparently – from several corners of the floor. (Although one person stood up for me – thanks!)

And ever since I’ve been cogitating on it. Are we so inexperienced or afraid of AFOI (I got accused of wanting to torture the patient 😳) that a modality in the hands of an AFOI expert would probably not be thought about twice??

I also considered the idea of awake VL and so with an arteriopathic patient of 150kg but a known grade 1, I STRIVED them on TCI propofol and TCI remi after topicalising the tongue and oropharynx passed a HA-VL round the corner for a spont breathing grade 1 view, sprayed the cords, intubated and maintained sats of 100% throughout and a BP that didn’t budge from their normal on a bit of pressor.

So I definitely think that the AFOI or even the sedated AFOI especially with the advent of HFNO2 is really something we shouldn’t forget despite the hedge of videolaryngoscopy

In fact I’m going to be STRIVE Hi tastic with my morbidly obese patients from now on be it with a VL or a fibrescope. The 0200 case might not be quite so confronting in future I hope…