When I was a young lad, one of the things that would excite me was stories of pirates and murderous 'cut-throats'. At the age of ten, the idea of a 'cut throat' was somehow synonymous with a quick death. Fast wind forward a decade or so (ahem, well maybe more) and I'm reflecting on some of the more interesting cases of 2011.
One was a young man involved in a 'glassing' in the local pub. He presented to the ED via ambulance, maintaining his own airway but with an obvious zone 1 neck injury. Now, I teach in the animal lab on EMST courses and it amazes me how difficult it can be to identify the appropriate place to perform a tracheostomy. We aim for the cricothyroid membrane, but I've seen FACEMs bugger it up completely and transect the trachea (even once the oesophagus and damn near severe the vertebral column!)
Anyhow, this chap's assailant had obviously either been on an EMST course or had performed percutaneous tracheostomies in the ICU - because with just a broken beer glass, he'd managed to make a perfect incision in the victim's trachea, between 2nd and third tracheal rings. OK, not the cricothyroid membrane, but otherwise a damn near perfect tracheostomy!
So we took him upstairs and performed an awake fibreoptic intubation with a surgeon scrubbed and ready to perform a tracheostomy. And the patient did OK (had an injury to posterior tracheal wall with oesophageal perforation confirmed on oesophagoscopy, but no mediastinitis and injury healed over time in ICU).
So I've been thinking about these sort of injuries and how best to manage them with my (limited) kit back in the bush. Although reasonably rare, both blunt and penetrating laryngotracheal injuries present difficulties for the rural GP-anaesthetist...as the airway needs to be secured ASAP.
And this is not a hypothetical - such injuries are not uncommon in the bush - the classic is 'clothes-line' injury where a quad or trail-bike rider impacts a fencing wire at speed, sustaining tracheal injury. Add to that 'robust' sports, the usual gamut of farming and motor vehicle injuries..so the rural docs needs to have some form of game plan on how to manage these. And the 'exam answer' for ANZCA may not be applicable for the rural doctor, with limited equipment/backup.
The danger of course is that attempts at direct laryngoscopy may cause complete tracheal disruption, with subsequent passing of the ETT tube down a false passage, development of subcutaneous emphysema, failed ventilation and a spiral down into demise.
Every now and then, one hears of paramedics just popping a suitably sized ETT tube through the hole made in a traumatic tracheostomy - a fine strategy for the penetrating injury, but not available for blunt injury or small penetrating wounds.
How then to approach this? There isn't a great deal in the literature and my FANZCA colleagues fall back on the 'awake fibreoptic intubation' answer...which is fine in the tertiary centre, but impractical in a small rural hospital.
So, what to do when faced with a patient with tracheal injury and needing emergent intubation (let's assume they are becoming obtunded or failing to keep SpO2 up). My thoughts?
- direct laryngoscopy. May seem controversial, but this is what I am best at and the equipment is readily to hand (ETT/bougie). However DL risks disruption of the larynx/trachea and a false passage, making further attempts at intubation impossible.
- do a formal tracheostomy under local. Sounds fine, especially if can delegate to a surgeon. If I am in luck there may be an ENT surgeon visiting for a fishing trip, otherwise it's going to be a messy scrabble with a patient who may refuse to lay flat/be combative. Nasty, but potentially do-able with equipment to hand (betadine-gloves-drape-local anaesthetic-scalpel-lots of gauze-retractors-ETT-lots of light-assistant)
- indirect laryngosocopy using videolaryngoscope. I like this idea, as intuitively seems to involve less mechanical distraction of the larynx...and the KingVision allows easy passage of a bougie, then railroad ETT over the top. Parker-tipped ETT to try and avoid any 'hang up' at the arytenoids...
- use an iLMA to maintain oxygenation - then intubate with ETT through this using either AmbuAscope or a malleable intubating stylet such as Bonfils or Levitan. To my mind the Ascope seems to offer an advantage here as could use iLMA as a conduit then follow down to carina...ensuring no false passage - then railroad ETT over the top. The shaped intubating-stylets allow one to visualise the laryngeal inlet..but not to insert down to carina, so potentially will intubate through the cords, but suffer false passage further down.
- topicalise the airway and perform an awake fibreoptic intubation. Preferred technique of my FANZCA colleagues, but it's hard to do enough AFOIs to keep 'current'. Now is not the best time for a relative novice to be trying!
What do other's think?
- any thoughts on above?
- gas induction or classic RSI?
- what kit do you have available to assist you, either now..or planned.
Bring it on...
I'm merely an EMT from the states, but if you were electing to do a non-crashing cric/trach, a little ketamine would seem like a nice complement to the local in a patient who is anxious or combative and doesn't want to lay flat (which I imagine would be almost anyone with a severe tracheal injury). Not having to perform such a task myself, I'm curious what you or other docs think of such an approach.
ReplyDeleteThanks for the quality blog, I always enjoy your posts.
- Vince D
Disassociated awake with ketamine 0.5-1mg/kg. Patient will keep breathing, but will let you do what you need to do. Slip a cannula with o2 at 15 lpm down the defect and then stop gather resources and figure out what to do next.
ReplyDeleteHi Tim
ReplyDeletegreat discussion topic! In my mind, when you are in a limited resource setting, say your small rural hospital, with this type of injury, yuo should approach it in terms of a double setup. There should be a provider each and preferably and airway assistant for each provider! Depending upon the injury you may choose to make one attempt orally with the second team set to access the neck if need be. Even if you decide to go through the neck, you need a team at the mouth to try to provide some support using BMV for example. Awakw techniques in low resource settings by novice providers are risky. If you are good at rSI and oral intubation, a double setup approach is probably your best shot. The awake surgical airway under local is also a reasonable plan but has its own risks.
One colleague had to deal with a traumatic tracheal transection due to a nasty farming machinery injury where the guy was spun around at high speed by his shirt collar. The doc luckily chose to fly in with an anaesthetist friend and they both decided to proceed with a doubel setup RSI. The patient had a very swollen neck with subcut emphysema already. The RSI oral intubation failed as they could not pass the ETT past the level of injury. The only thing that worked was BVM oxygenation incredibly! A needle cric failed, and as they were doing the open surgical cric, the patient started to crash his SaO2!! It took the HERO INCISION, floor of mouth to sternal notch cut to find the transected trachea proximally within the upper mediastinum and pass a bougie down it. Somehow they managed to pass a small ETT over the bougie and voila could ventilate the lungs! The patient made a full recovery after formal surgical repair and ICU stay!