Welcome back to the Deep Dive. Today isn't just another
exploration of a topic. We are shifting gears.
We're entering some pretty high stakes territory.
I want you to imagine the lights are bright, the air conditioning
is humming a bit too loudly, your palms are sweating, and you
are standing in front of a senior professor and he's
looking at you over the top of his spectacles.
That is a very specific and I have to say, a universally
terrifying visualization for any medical resident.
It is because today we are treating this deep dive as a
dedicated exam preparation session.
Specifically, we're simulating the Gujarat University MD
Anesthesiology exam preparation, right?
So for today, I am the resident, I'm the learner, the one in the
hot seat, and you? I'm the senior faculty, the
examiner conducting this mock Viva.
I see. So the pressure is entirely on
me to perform. And my job is to drill you on
the details to make sure you're ready.
Exactly my entire medical career, at least my degree is on
the line here. And the topic you have chosen
for me today, it is the ultimate emergency, the the absolute
nightmare scenario we are talking about Cricothyrootomy.
It's the procedure that every anesthesiologist praise they
never have to do. But must know how to do
perfectly. Absolutely, if you are sitting
for your MBA exams. This is not just a technical
skill, it is a goldmine for theory questions, for short
notes, and for those breaded Viva stations.
So our mission today is really twofold.
First we need to decode that clinical nightmare of cannot
intubate, cannot oxygenate or CICO.
The big one. But secondly, and this is for
you, our listener who's prepping for that exam, we need to
provide the exact keywords, the structure and the examiner safe
answers that will get you high marks.
Examiner safe. That is the key phrase there in
an exam, and even more so in a crisis.
You want clarity. You want standard textbooks back
you up, right? You don't want to be quoting
some blog post you read. You want to be quoting the Bible
of anesthesia. Speaking of Bibles, I have
pulled a massive stack for this deep dive.
We are looking at the heavy hitters, Miller's anesthesia,
Morgan McHale, the ICU book by Marino, and for the surgical
details, BD Sharage's anatomy. All good choices, solid.
And also some practical guides like long and short cases and
anesthesiology. We're going to filter out the
noise and just stick to what the books say.
Excellent. Let's begin then.
Resident defined cricothyrotomy for me.
OK, putting on my exam face. Cricothyroidomy is an emergency
invasive airway access technique.
It's performed through the cricothyroid membrane or CTM.
OK. It's distinct from a
tracheostomy in that it's higher up in the neck, and it's
intended primarily as a rescue measure.
That is a solid start, a very solid start, but let's refine
that for the exam. Miller's anesthesia makes a very
specific distinction that examiners absolutely love to
hear. OK, It emphasizes that this is a
rescue technique, not a permanent airway.
That is a critical nuance. So I should use the word rescue?
You must. If you call it a surgical airway
without qualifying it as a rescue bridge, you might lose
marks. It shows you don't appreciate
it's temporarily. Nature now differentiated
immediately from a tracheostomy. Why aren't we just doing a
tracheostomy in the emergency room?
Right. So a tracheostomy is, it's
usually an elective procedure. It's performed lower down,
typically between the 2nd and 4th tracheal rings.
And it takes longer, maybe 15 to 30 minutes in a controlled
setting because you have to dissect through more tissue.
You'd have to move the thyroid, dismiss, manage bleeding.
Where is a Crico. A cricothyroidomy is emergent.
It's done higher up at the CTM, which is superficial.
It needs to be done in seconds to minutes, not 10s of minutes.
Correct. So here's a phrase for you to
remember. Cricothyroatomy is for
resuscitation. Tracheostomy is for maintenance.
I like that. Resuscitation versus
maintenance. That is the fundamental divide.
So where does this fit in the grand scheme of airway
management? It's the final step.
It's the end of the line. It's indicated in the cannot
intubate, cannot oxygenate scenario.
The CICO scenario it it bridges the gap between a failed airway
and a definitive surgical airway, like a tracheostomy.
Exactly now before we get into the, you know, the blood and
guts of the procedure, keep in mind how this appears in the
exam paper. You might get a short note
simply titled Needle versus surgical Cricothyrotomy or you
could get a massive 20 mark long question.
Describe the anatomy, the larynx relevant to cricothyrotomy and
the steps of the scalpel bougie technique.
And in the Viva they might just point to a mannequin and say
show me the membrane. Or draw the surface anatomy on
your own neck. Which brings us to Part B, the
anatomy. You absolutely cannot pass this
section without anatomical precision.
If you were holding a scalpel over a patient's neck, you
better know what is under the skin.
Definitely. So walk me through the surface
anatomy. How do you find the spot?
Let's say you're in that emergency.
OK, visualizing the neck. I'm walking my finger down the
midline. The first hard structure I'd hit
is the high weight bone, but coming down further I feel the
Adam's apple, which is that's a laryngeal prominence of the
thyroid cartilage. Good.
Stop there now, keep moving down.
OK. So below the thyroid cartilage,
there's a soft depression. That's the dip, and immediately
below that dip is a hard ring. A very firm ring.
That's the cricoid cartilage. Right, and anatomy for
anesthetists places the cricoid cartilage at what vertebral
level? It's a classic MCQ fact.
C6 level of the C6 vertebrae. Correct.
So your target is that dip, that soft spot between the thyroid
and cricoid cartilages, that is the cricothyroid membrane.
It feels, it feels really small when you actually palpate it on
yourself. It's not a big window at.
All it is small and you should be palpating it on yourself
right now as you listen. Oh, it's intensive care manual
gives us the dimensions. It's approximately 9mm high
vertically and about 30mm wide. 9mm that is not a lot of room
for error when you're stressed and the SAT's are dropping.
Not at all, and according to BD Char Asia, the membrane itself
is described as yellow, elastic and relatively avascular.
That relatively avascular part sounds promising.
It is promising, but the word relatively is doing a lot of
heavy lifting in that sentence. What are the relations?
What are the structures you were terrified of hitting when you
make that cut? Well, the vessels, definitely
the vessels, the cricothyroid arteries, which run horizontally
across the upper part of the membrane.
Which means clinically, what does that mean for your
technique? It means I have to stay low,
make my incision or puncture in the lower half of the membrane
to avoid those arteries. Precisely.
Let's dig a little deeper into those vessels, because this is
the kind of detail that separates a pass from a
distinction. The cricothyroid arteries are
usually branches of the superior thyroid artery.
In asthmos, they join together right across the upper part of
the membrane. So if you cut high right under
the thyroid cartilage, you are slicing directly through that
arterial arch. And that's arterial bleeding,
which in an airway emergency is just a complete disaster.
It would obscure your view instantly.
Correct blood sprays into the field or even worse down into
the trachea. That is why the recommendation
is always the lower third of the membrane.
You are using anatomy to buy yourself safety.
So it's not just stay low, it's stay in the lower 3rd.
That's the exam safe answer. That's the answer that gets you
the marks. What about veins?
We know the jugulars are lateral, but are there any veins
directly over the membrane? The anterior jugular veins run
vertically, but they're usually lateral to the midline, aren't
they? They are, but there can be
communicating veins, anatomical variants, but the bigger venous
risk is actually hitting the inferior thyroid veins if you go
too low and you're below the cricoid on the trachea or the
isthmus. Right, which is why staying
strictly within the CTM boundaries is absolutely vital.
And strictly midline. Strictly midline.
If you deviate laterally, what do you hit?
The cricothyroid muscles and what's?
The problem with that? Well, it's going to be bloody
for one, but that's also the tensor muscle for the vocal
cords. If you damage that, you could
alter the patient's voice pitch permanently.
Exactly, BD Troasia also mentions the external laryngeal
nerve is nearby. Oh right, the external branch of
the superior laryngeal nerve supplies that muscle.
It runs deep to it. But you know, inflammation or a
very wide dissection could theoretically endanger it.
I see, but let's be honest, in a cannot oxygenate situation,
bleeding is a secondary concern to death and voice changes are a
very distant third. Life over voice like that as a
mantra. OK, what else?
What lies behind the trachea? The esophagus.
It lies immediately posterior,
so if you stab too deep you could get a through and through
puncture. You've just created a
tracheoesophageal fistula with. A scalpel, which is.
Not ideal. Definitely not so for the
examiner. What are the two key anatomical
landmarks you must mention by name?
The thyroid notch and the cricoid ring.
Good and the technique of identifying them.
The laryngeal handshake, stabilizing the larynx with one
hand while identifying these landmarks with the other.
Excellent. The physical manifestation of
that anatomical knowledge. Now let's move on Part C
indications. Why are we even doing this?
So the primary indication is CICO, cannot intubate, cannot
oxygenate. Define that for me.
What does it mean? It means that mask ventilation
has failed, a superglottic airway like an LMA has failed,
and tracheal intubation has failed.
All non invasive options are off the table.
And the textbooks. Milla and long and short cases
are very clear. This is the definitive rescue.
Is it only for failed intubation?
No, no, it's also for a primary upper airway obstruction, a
situation where you can't even try to go in from the top.
For example, massive facial trauma, A smashed face injury
where the oral and nasal routes are just blocked by blood and
bone, or severe angioedema like Ludwig's angina where the
tissues of the tongue and glottis are so swollen you can't
see anything. Correct.
Or a foreign body that's impacted at the glottis, a piece
of food for example. Now imagine you are in the Beva.
The examiner leans forward and asks candidate, give me a one
sentence definition of the indication.
What do you say? I would say Sir, the indication
is the immediate need for an airway when all non invasive
methods have failed. Good.
Concise to the point. Now the trap question.
What are the contraindications? Is there anytime you would never
do a surgical cricothyrotomy? Yes, the age limit in young
children, specifically under say 6 to 12 years depending on the
text. Let's use a safe number
prepubertal. OK prepubertal children.
Surgical cricothyrootomy is contraindicated.
Why? This is the why question that
gets you the distinction. Tell me the path of Physiology.
It's because in young children the cricoid cartilage is the
narrowest part of the airway, not the glottis like in adults.
And the membrane itself is tiny, way smaller than that 9mm we
talked about. It's too small to accept a tube
without completely destroying the cartilage ring.
Miller is very specific about this.
It says for them you have to do a needle crocothyrotomy.
Correct, it is a bit of a Gray zone because children grow at
different rates. Miller suggests 6 years is a
hard cut off. Morgan sometimes references 10
or 12. So what do I say in the exam if
they give me an age like 8? Acknowledge the controversy.
That shows advanced understanding.
You say Sir, in an 8 year old the anatomy is transitioning.
I would need to assess the size of the neck.
However, the needle technique remains the safer initial choice
to avoid the devastating complication of cryptoid damage.
That sounds very nuanced. Examiners must love that.
They do. It shows you aren't a robot
repeating facts. You're a clinician weighing
risks. What's the other absolute
contraindication? Laryngeal fracture A smashed
larynx. Because if the larynx is already
fractured, digging around in the CTM could cause complete
laryngotrycheal separation. You could.
You could effectively evolve the entire airway.
You pull the 2 ends apart, it's an unsurvivable injury in that
setting. In that case, you might need a
formal tracheotomy or to go in below the site of injury.
That makes perfect sense. So let's talk about where this
fits in the algorithms, The difficult Airway society, the
DAS Guidelines. They're the Bible for this.
Right, they are in the DAS guidelines, where is.
This it's Plan D, the last resort.
Walk me through the plans. OK, so plan A is intubation.
That's your primary goal. If that fails.
After a reasonable number of attempts.
Right, Not endless attempts. Then you move to Plan B, which
is a super glottic airway device like an LMA to try and rescue
oxygenation. If that fails, plan C wake the
patient up, go back to face mask ventilation if you can abort the
procedure. What if you can't?
What if you can't mask ventilate them and you can't wake them up
fast enough? But then you're at plan DCICO
rescue cricothyronomy. Right.
And Miller discusses the vortex approach, which is a really
great visual. You have these three life lines,
ace mask, tube, LMA. If one fails you siral inwards.
If they all fail, you hit the center of the vortex.
Which is CICO rescue. Exactly.
The key for the exam and for your clinical practice is that
transition. When do you move from Plan C to
Plan D? When do you decide to cut?
When the patient is becoming hypoxic and you cannot wake them
up, you have to declare it. I think that's the examiner safe
point stressing the importance of declaring CICO out loud.
Yes, you don't just keep trying to intubate a hypoxic patient.
You have to announce to the team, I cannot intubate, I
cannot oxygenate. We are proceeding to a surgical
airway. That's it.
Decisiveness is a markable quality in the Viva.
It shows leadership and a clear thought process under pressure.
Now Part D the meat of the matter.
Types and techniques. OK, so we have what, 3 main
flavors here, Needle crooked thyrotomy, surgical crooked
thyrotomy, and then the percutaneous or Seldinger
techniques. Let's break them down.
Differentiate needle from surgical for me.
What's the core difference? Needle crooked thyrotomy uses a
wide bore cannula, something like a 14 gauge or 16 gauge IV
cannula. It requires a high pressure gas
source, which we call jet ventilation, but.
There's a big but. But, and this is the huge
distinction, is a temporizing measure.
It only buys you time, maybe 30 to 45 minutes, because you can't
effectively blow off CO2 through that tiny needle.
Correct. It oxygenates, but it doesn't
ventilate well. Carbon dioxide accumulates,
leading to a severe respiratory acidosis.
What about? Surgical Surgical cricket
thyrotomy uses a scalpel and a small cuff tube, usually a six
point O millimeter internal diameter tube.
This is considered a definitive airway.
Like definitive. Because you can ventilate
properly, you can scrub CO2 and the cuff protects the airway
against aspiration. Good and the percutaneous or
Seldinger technique. That's using a guide wire and a
dilator like a milker. Kit Miller notes that while we
anesthetists are comfortable with this because it feels like
putting in a central line, which.
We do all the time. Right, but it can actually be
slow, lower than the scalpel technique.
In a true crisis, fiddling with wires and dilators when a
patient is turning blue is stressful and prone to error.
It is. That's why the DAS guidelines
have shifted. They now heavily recommend the
scalpel bougie technique. This is an exam favorite.
If they ask you for the steps of a surgical critco, this is the
technique they want to hear. Walk me through it step by step.
Step one position, you extend the neck to bring the airway
forward. Unless, of course, there's a
suspected C spine injury. Good Step 2.
Identify. Palpate the CTM, use the
laryngeal handshake we talked about, stabilize the larynx.
Step 3. The scary part?
Incision. Make a horizontal stab incision
through the skin and the membrane.
At the same time. Yes, simultaneously 1 decisive
movement. Just go for.
It Step 4. This is a crucial, often
forgotten step. The twist This is critical.
You rotate the scalpel 90° and the edge should be facing
caudally towards the feet. This holds the hole open.
Let's pause there. I want to really visualize that
twist. I've heard people ask why not
just put the bougie in through the slit?
Why do we need to rotate the blade?
Well, you have to think about the tissue.
The CTM is elastic like a rubber sheet.
You make a horizontal slit. The moment you remove the
pressure, that slit just wants to close up.
If you try to push a soft flexlogum elastic bougie against
that closed slit, it might just bunch up, or worse, create a
false passage in the subcutaneous tissue.
Exactly. The twist turns that linear slit
into a triangular or square opening.
It physically levers the cartilages apart slightly and
creates a patent hole. You can often hear a gasp or a
hiss of air immediately. So it confirms you're in too
and. It creates a clear open path for
the bougie to slide down alongside the flat of the blade.
Right, because if you take the scalpel out to put the bougie
in, you've lost the hole. You'll never find it again
through the blood and the panic. Precisely, the blade acts as a
guide and pointing the sharp edge caudally.
Why is that detail so important? It's for safety.
If the patient bucks or your hand slips and the sharp edge is
pointing up cephalid, you could cut the vocal cords.
A disaster. But if it points down coddle,
you just cut into the tough crickoid ring.
It's cartilage, it'll stop the blade.
That is a critical examiner. Safe detail, sharp edge down.
You've twisted Step 5. Bougie.
Slide a gum elastic bougie down the side of the blade into the
trachea. You should feel for the
tracheal. Click.
We'll come back to that Step 6. Railroading you slide a
lubricated 6 pointer millimeter cuff tube over the boozy and
into the airway. And the final, most important
step. Step 7.
Confirm, inflate the cuff, check for chest rise and most
importantly get a waveform on your end title CO2 monitor.
The AB twist, bougie tube. Memorize that sequence in the
exam. Use active verbs.
I will stab, I will twist. It shows confidence.
Got it. Now can we loop back to the
needle technique you mentioned jet ventilation?
That seems like a high yield Viva topic.
It is. How do you do it?
You insert a 14 gauge cannula at a 45° angle pointing caudally
towards the lungs. You confirm you're in by
aspirating air bubbles in a saline filled syringe.
Then you connect it to a high pressure source.
Oh wait, Morgan adds a very specific detail here about
confirmation. Do you just aspirate once?
No good point. You aspirate air when the needle
tip enters the trachea. Then you slide the plastic
catheter forward off the needle. But you must aspirate again
after the catheter is in place. And why is that double check so
critical? Because it's a very common
failure point. You might hit the trachea with
needle tip, great, you get air. But as you slide the plastic
catheter forward, maybe the needle was barely in the
catheter catches on the cartilage or pushes the membrane
away. Where?
Does it end up? In the subcutaneous tissue, the
needle is out. You, I think you're in.
You hook up the jet ventilator and you inflate the patient's
neck instead of their lungs. Catastrophic subcutaneous
emphysema. So the sequence is puncture,
aspirate, slide, catheter, aspirate again.
Only then do you connect the jet.
That double check is a Viva Gold Star right there.
OK, that's burned into my brain now.
What about the pressure? What pressure do you need for
jet ventilation? It's high 50 PSI pounds per
square inch. You need that driving pressure
because the cannula is so narrow and.
Where do you get that from? You can use a dedicated device
like a Sanders injector, or you can use the oxygen flush valve
on the anesthesia machine, often with some self-made tubing.
Let's expand on the physics of jet ventilation.
The classic teaching was about the Venturi effect, wasn't it?
That the high velocity jet entrains room air?
Is that what's happening in CICO?
Actually, Miller clarifies this. While that's true in an open
system like rigid bronchoscopy, in a CICO situation with a
narrow 14 gauge needle and a potentially obstructed upper
airway, the entrainment is minimal.
So what's the main mechanism? It's just high pressure mass
flow. You're just blasting oxygen into
the lungs to keep the sats up. It oxygenates, but it doesn't
ventilate. Good and the IE ratio
inspiration to expiration time. Inspiration has to be short one
second on, but expiration needs to be long, 3 to 4 seconds off.
Why this is the most critical Viva point about TTJV?
Why the long expiratory time? Because expiration is passive,
you're pushing air in under high pressure through a tiny hole,
but the air has to get out through the patient's natural
upper airway, through the glottis.
It can't come back out the needle efficiently.
Precisely which leads us to the absolute contraindication for
transtrycheal jet ventilation. Complete upper airway
obstruction. If the glottis is totally
blocked, the air goes in but it can't get out.
You just start stacking breaths, the pressure builds and builds
in the lungs until massive Barra trauma and bilateral
pneumothorsis. Excellent.
If the plumbing is blocked at the top, do not pump from the
bottom. Remember that?
Got it. OK, moving on to part E
anaesthetic considerations, What are we the anaesthetists doing
while all this cutting and jetting is happening?
Well, oxygenation is priority number one. 100% oxygen
immediately. What about drugs?
If the patient is arresting or unconscious, which is very
likely in a CICO scenario, you don't need any drugs, you just
need the airway now. And if they're not, If they're
awake or struggling? Then the ICU book mentions
ketamine as a good choice. It preserves respiratory drive.
Or if you're converting to a surgical airway in a semi
controlled way, you might use a rapid sequence induction agent.
Why ketamine specifically? Why not give a slug of propofol?
Oh, because propofol causes apnea and a total loss of airway
tone. If you have a patient who is
maintaining their own airway, gasping but moving some air, and
you give them propofol, their airway completely collapses.
Now you have a total obstruction where you had a partial 1.
Ketamine is a dissociative anesthetic.
It provides analgesia and amnesia, but the pharyngeal and
laryngeal reflexes often remain intact.
And crucially, spontaneous respiration continues.
It allows you to operate on the neck while the patient keeps
trying to breathe. What about muscle relaxants?
Rachronium. This is controversial and it
depends on the guidelines you follow.
In a true CICO, where laryngospasm might be the cause,
a dose of muscle relaxant might break the spasm and allow you to
ventilate. So the DAS guidelines.
The DAS guidelines generally suggest ensuring the patient is
fully paralyzed before you declare a failed intubation,
just to rule out inadequate relaxation as the cause.
So so the sequences ensure paralysis, try to intubate,
fail, try LMA, fail, mask, fail, then you declare CICO and you
cut. That is the sequence.
But if you are doing a primary cricyrotomy, say on an awake
patient with that smashed face we talked about, you would avoid
paralysis. You want them breathing until
that tube is in and secure. That's a key distinction.
Rescue CSO versus primary emergency airway.
What about local anaesthesia? If time permits, which it rarely
does in a true CICO crisis, you can you can infiltrate lidocaine
with adrenaline to reduce bleeding, but honestly as we
said, in a cannot oxygenate situation you just cut.
Right speed Is everything OK? Confirmation.
How do you know the tube is in the right place?
Clinical science first. Chest rise misting in the tube.
But the gold standard, the one you must mention is capnography.
You want to see that square wave ETCO 2 trace on the monitor.
Why not just auscultation? I will listen to the chest.
Examiner safe answer in a noisy trauma room or a chaotic
resuscitation, auscultation is completely unreliable.
You can hear sounds everywhere. You have to rely on capnography
and direct visualization of chest rise.
Good now part F complications. You save the life, but what mess
have you potentially made? Well, there are immediate and
late complications. Immediate would be hemorrhage
from the thyroid vessels or even the jugular veins if you deviate
too far laterally. And what about air?
Subcutaneous emphysema. If the tube is placed in the
pretracheal tissue, a false passage, you're just pumping air
into the skin. It causes that Rice Krispies
crackling feeling on palpation. Let's.
Talk about that false passage. How do you know in the moment
that you've made one? The tactile feel might be
different, but clinically you place the tube, you inflate the
cuff and you try to ventilate and one the chest does not rise
2 the end title CO2 trace is flat, it's 03 the next starts to
swell up like a balloon. That is a terrifying triad of
signs. What do you do?
You have to pull the tube out immediately.
You are not in the airway, you are in the pre tracheal space.
You need to repelpate, re stab or more likely extend your
incision so you can visualize the trachea directly.
This is why the bougie is so important.
It gives you that tactile confirmation.
You mentioned it earlier. Feeling the tracheal clicks.
Yes, as the bougie goes down, you can often feel the tip
bumping over the cartilage in his tracheal rings.
It's a very distinct sensation. If you don't feel clicks, or if
the bougie stops after just a couple of centimeters, it's in
the. Wrong place.
It's in the wrong place or it's hit the Karina the hold up sign.
If it goes down a bronchus it will also stop, but if it's in
soft tissue it might just feel mushy or keep going
indefinitely. And if you go too deep with the
initial stab. Esophageal perforation and the
big one with jet ventilation that we already covered.
Barotrauma and pneumothorax. Now, late complications.
This is what the ENT surgeons will be worried about later.
Subglottic stenosis, the ICU book states this is the most
feared long term complication and the risk is very high if the
cricothyrotomy tube is left in for too long.
Why is it so bad there? Because the cricoid cartilage is
a complete ring, it's the only one in the airway, so
inflammation and scarring there can lead to a fixed narrowing of
the airway that is permanent and very difficult to treat.
And voice changes. Yes, damage to the cricothyroid
muscle or the recurrent laryngeal nerve can affect the
quality and pitch of the voice. So how do we manage these
complications? Immediate recognition is key.
If you see that subcutaneous emphysema spreading, stop
ventilating immediately. If there's significant bleeding,
you pack it. But the real management is
prevention and conversion. Which leads us perfectly to Part
G post procedure care. You've done the Crico, the
patient is alive, the Sats are up.
What do you do now? First you have to secure it
properly, suture it in place, use ties, don't let it fall out.
But then you immediately need to plan the exit strategy.
You need to convert to a definitive airway.
What is the time frame for that conversion?
Both Miller and Morgan suggest converting to a formal
tracheostomy within 24 to 72 hours.
You want to get that tube out of the CTM as soon as the patient
is stable enough for the procedure.
And the reason is. To minimize the risk of
subglottic stenosis and partly erosion.
Correct. Remember our phrase?
It's a temporary bridge. You cross it, then you build
something more permanent. Also remember the ICU care.
You've bypassed the nose and mouth.
What do they do? They are the body's natural
humidifiers and filters. Exactly.
Now you are blasting dry cold gas directly into the trachea.
What happens? Crusting thick, tenacious
secretions. Massive crusting.
The secretions can dry out and form concrete like plugs.
You can obstruct your life saving airway within hours.
So what is mandatory immediately post procedure?
Heated humidification and regular diligent sectioning.
Absolutely. And what about sedation?
You generally want to keep them heavily sedated.
Having a tube through your cricothyroid membrane must be
incredibly irritating. It would trigger the cough
reflex constantly. And you don't want the patient
coughing the tube out or causing more trauma to the site.
Makes sense? OK, Part H This is about
comparison and exam integration, bringing it all together.
Let's do a rapid fire comparison.
Creeco versus Trac site. Creeco is the CTM.
Trac is the 2nd to 4th tracheal rings seed.
Creeco is 1 to 2 minutes, Trac is 15 to 30 minutes.
Well, you can risk. Creeco is low, it's midline and
they're relatively A vascular membrane.
TRAC is higher. The thyroidismus and a plexus of
veins are right in the way. Long term use.
Crico is contraindicated. Long term track is suitable for
maintenance and long term airway access.
Excellent. Now let's talk about Viva traps.
These are the questions designed to trip you up where you
mentioned the age trap. Right.
Would you perform a surgical cricothyrotomy on a three-year
old? The answer is an emphatic no.
Needle Creek atherotomy only. What about the delay trap?
When should you cut? The answer is not after 10
minutes or when the Sats hit 50. The answer is as soon as CICO is
declared. The delay is what leads to
hypoxic brain injury. Precisely.
And the landmark trap What if the patient has a short fat neck
or massive edema and you cannot feel the membrane?
This is. This is the nightmare scenario.
The book answer is you have to use a vertical midline incision
to dissect down. You cut through the fat and
fascia until you can physically feel the cartilage with your
finger. And ultrasound.
Miller does mention ultrasound, but in a true CICO crash, you
probably don't have time to go get the machine, turn it on,
find the probe. You just have to cut to feel.
Cut to feel that is a brave but necessary answer for the exam.
But what about using Ultrapound before the crisis?
Oh, in an anticipated difficult airway.
Exactly. Tell me about that.
So if you have a patient with say a huge goiter or distorted
anatomy from previous surgery or radiation, but you are planning
a standard intubation. You're worried, but hopeful.
Right, you can use ultrasound to identify the CTM and mark it on
the skin with a pen before you even put the patient to sleep.
That's brilliant. So if everything goes South and
you end up in a CICO situation. You have an X that marks the
spot. It shows incredible foresight.
If you mentioned that in an exam answer about management of the
anticipated difficult airway, you will score very, very
highly. It mitigates the landmark trap.
You don't have to find it through the panic.
You found it while you were calm.
Pre procedure ultrasound marking of the CTM.
Adding that to my notes. Finally, for the exam
presentation itself, if you're asked to draw this.
Always start with a definition, then anatomy, boundaries,
contents, relations and you must draw the diagram, a simple
square showing the thyroid cartilage, the cricoid in the
membrane in between, draw the cricothyroid arteries running
across the top half and then label safe zone in the bottom
half. Diagrams actually get marks.
Diagrams save you time and they get you marks.
A bad drawing is often better than a good paragraph because it
shows you understand the spatial relationships.
Then list your indications and contraindications, then the
step, stab, twist, bougie tube, then complications, then your
conclusion. The conclusion we drafted was
cricothyrotomy is a life saving, albeit temporary, procedure that
demands precise anatomical knowledge and decisive action.
Mastery of the CICO algorithm and the Scalpelbuji technique is
mandatory for every anesthesiologist.
That is a consultant level conclusion.
Memorize it. Use it.
OK, so let's summarize for everyone.
Give me the bullet points for the listener who might be
driving to their exam right now. The absolute must knows.
All right, one cricothyronomy is an emergency rescue procedure,
not a permanent airway. The anatomy is the CTM, the soft
spot between the thyroid and cricoid cartilages.
The technique of choice in the UK, and increasingly everywhere,
is the scalpel booty tube technique.
The main long term complication to fear is subglottic stenosis.
You must convert to a formal tracheostomy, usually within 24
to 72 hours. Perfect.
So, expert, before we sign off, what is your single final piece
of advice for the exam day when the examiner stares at you and
asks about airway away emergencies?
In the Viva, when you're asked about an airway emergency, the
most important thing you could do is take a breath, Don't panic
and ramble. Structure your answer.
Say first I will call for help, then I will optimize
oxygenation. If that fails I will declare
CICL and I will cut early. Confidence saves lives and
confidence passes exams. Declare CICO and cut early.
I will remember that and for our listeners, I would say visualize
that anatomy on your own neck right now, find the dip, feel
the ring. That tactile memory might just
save a life or your exam results one day and.
Remember, everything we discussed today is based
strictly on standard medical texts like Miller, Morgan and
Cherasia. Stick to the books and you will
be safe. Thanks for joining us on this
very high stakes deep dive. Good luck with the exams.
We'll see you next time.