what's up everybody my name is max feinstein and i'm an anesthesia resident at the mount
sinai hospital in new york city in this video i'm going to be showing you how to use this
miller straight blade to intubate a patient if you find this video interesting or helpful i'd
really appreciate it if you liked it and subscribed to the channel. let's dive in!
before i break down the steps for an intubation i want to just show you what it all looks like.
so i'm starting by pre-oxygenating a patient who's already under general anesthesia,
i'm tilting their head back, inserting the miller straight blade in the right corner of the mouth
angled towards the midline, finding my view of the vocal cords, inserting the endotracheal tube,
watching it pass through the vocal cords, sliding out my stylet, inflating
the cuff on the endotracheal tube, connecting my endotracheal tube to my circuit- being careful to
not pull out the tube before it's been secured- and then confirming proper placement of the tube
there are many different types of devices available to intubate patients,
one of the most common being this macintosh curved blade that's commonly used in adult anesthesia.
the miller straight blade which is the focus of today's video is used very frequently in
pediatric anesthesia and sometimes in adult anesthesia but honestly for adult cases i think
sometimes people just use a miller straight blade because they think it makes them
look cooler. i'm not even making this up, there are literally memes about this. but anyways it's
a very helpful device to be familiar with and so i wanted to go over technique for using it today
several quick disclaimers: number one, this is not medical advice. this is a YouTube video. if
you need medical advice go see a doctor. and disclaimer number two is that because this
is anesthesiology, pretty much everybody is going to have a different opinion about the correct way
of doing something. while one attending who's peering over your shoulder and watching this
video may nod along and agree that everything that i'm explaining is correct, the attending
who's leaning over your other shoulder may think that everything i'm doing here is wrong. just keep
in mind that there are a lot of different ways to accomplish one thing in anesthesiology. when we're
talking about intubation in anesthesiology, we're typically referring to endotracheal intubation
meaning using an endotracheal tube such as this and passing it through the vocal cords represented
by my fingers. the reason that we would even want to do endotracheal intubation is so that we can
control a patient's breathing using our ventilator as shown behind me. because vocal cords can close
shut, particularly an unconscious patient, we want to have our endotracheal tube pass the vocal
cords so that we don't have them as an airway obstruction. as you study airway anatomy, one of
the most important structures to become familiar with from the anesthesiologist's perspective is
the epiglottis which is a cartilaginous piece of tissue that sits just above the vocal cords and
keeps them protected. when performing endotracheal intubation the epiglottis can obstruct your view
of the vocal cords and so intubation devices are designed to get us around the epiglottis
in certain ways. this curved macintosh blade is designed to sit in the space just at the base of
the epiglottis that's called the vallecula and then act as a fulcrum to lift up the epiglottis
indirectly and then reveal the vocal cords underneath that. by contrast, the miller
straight blade is designed to directly pick up the epiglottis and move it out of the way thereby
revealing the vocal cords. you can see that this miller straight blade has a little bit of a flange
on the end of it which is designed to easily scoop up the epiglottis and move it out of the way
there's a lot of preparation that precedes being able to intubate a patient and that
includes checking all of your equipment including the intubation blade that you're using, the tube,
making sure that you've inflated the cuff on the tube and checked that, that you've checked your
ventilator, checked for a circuit leak. you can check out my MSMAIDS mnemonic video for
a more complete run-through of setting up for anesthesiology. the other major component of
preparing for intubation is making sure that you have thoroughly evaluated your patient including
taking a history that involves prior anesthetics, asking about any factors that may contribute to a
difficult airway, making sure that you've done a physical examination and looked at the patient's
airway, asking about any loose teeth or any factors that might complicate this intubation, and
also considering whether it's important for you to have backup intubation equipment available in the
room. an extremely important principle to keep in mind if you are a trainee learning how to intubate
is to narrate everything to whoever is supervising you. your supervising anesthesiologist most likely
won't be able to directly see what you're seeing so it's really important that you just describe
everything as you move along. patient positioning is also very important when intubating somebody
and we classically say that patients should be in the sniffing position which looks like
this image on the screen. for intubating with a straight blade in particular i find that it's very
helpful to extend the patient's head back just a little bit more as i'm getting ready to intubate.
this is where it's really important to be aware of any sort of cervical spine pathology
like atlanto-axial instability or rheumatoid arthritis that could potentially lead to damage
if you were to extend a patient's head while they were under anesthesia. it's also very
important once you induce general anesthesia to immediately protect your patient's eyes
which you can do by placing tape over them. once patients are under general anesthesia they lose
their lid reflex and their ability to protect their eyes which can lead to corneal abrasion
for approaching intubation with a straight blade i recommend coming in the right corner of the
mouth and aiming the blade towards the midline of the patient. you're actually aiming at the
epiglottis because as we talked about before you want to physically pick up the epiglottis with
the tip of your blade. as you advance the blade into the patient's mouth you must be
extremely careful not to press the blade against their teeth at all. if the back of the blade ends
up pressing against someone's tooth it can break which is not only cosmetically a problem but then
the tooth itself can become an airway obstruction before you have an endotracheal tube in place.
as you're advancing your blade you can start lifting your handle towards the back wall of the
room, as we commonly say. it's really important to avoid cranking your blade back like this
which can make it much easier to bump the back of the blade into the patient's teeth. as you insert
your blade you're looking for the epiglottis and with the miller blade you want to get directly
underneath the epiglottis. it's not uncommon to insert a blade and just see epiglottis in
which case you may need to make some adjustment like advancing your blade a little bit and then
you can pick up the epiglottis and hopefully reveal vocal cords immediately behind that.
as your intubation skills become more advanced you can start intubating without
necessarily seeing all of the vocal cords or without seeing the vocal cords at all
but as you're just getting started you should really only be passing the endotracheal tube
through vocal cords that you can see directly. once you've got the cuff of your endotracheal
tube past the vocal cords you can go ahead and remove your stylet, remove your blade,
and inflate the endotracheal tube and connect it to your circuit. once you've done that it's
important to confirm proper endotracheal intubation by looking for chest rise,
looking for condensation in the endotracheal tube, looking for in tidal CO2 on your ventilator,
and listening for bilateral breath sounds. there are a host of other things that need to be done
immediately after intubation and you can check out my video that i made on post-induction to-dos
well that wraps up this video, i hope you found it helpful and i just want to give
a big thank you to the mount sinai department of anesthesiology for allowing me to use this
state-of-the-art simulation equipment and also airway modeling equipment,
and also for just accepting me into the residency program and teaching me how to
become an anesthesiologist. thanks very much for watching i'll see you next time