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 talking
about all the special considerations that i have when i'm thinking about placing IVs
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
if somebody sat me down and asked me what is the most important thing that an anesthesiologist
does, i would say getting oxygen to a patient's heart and brain when a procedure is going on.
at the end of the day i don't think there's anything that's more important than that.
in order to accomplish that goal we need to have a way to get oxygen into the patient's
body which will be a topic for another video but the other big important part of that is
being able to get medications and fluids into a patient's body. as an anesthesia resident some
of the most important medications that i use on a regular basis target hemodynamic stability,
meaning: how am i going to help the patient's heart pump blood that carries oxygen that goes
to the brain (and also other organs) and as far as fluids are concerned, anesthesiologists give
lots of different types of fluids depending on the surgery and the patient's needs during the
surgery. those fluids can range from normal saline to plasmalyte to blood products, and at the end
of the day one of the primary goals with fluid management is to make sure that the patient has
adequate blood volume in order to get oxygenated blood to the patient's brain. and the best way to
provide fluids to a patient during surgery is - you guessed it - through intravenous access.
obviously it's not going to be very practical for me to wake up a patient in the middle of surgery
and say hey you're a little bit volume down, can you go ahead and drink this gallon of water?
so for these reasons IV access is a cornerstone of anesthesiology and that means that we have to be
experts in establishing IV access in all different types of scenarios and all different types of
patients. when it comes to choosing IV equipment, the first place that i'm going to start is: what
size IV do i want to use? and that determination is going to be made based on what the clinical
circumstances are. so for example if i'm about to start providing anesthesia for a surgery where i
don't think there's going to be very much blood loss and i don't anticipate needing to give very
much fluid then i'd feel comfortable placing a smaller IV, at least to get started and if the
situation changed then i'd always have the option of adding an additional larger IV. but if i'm
going into a surgery where i expect that there's going to be a lot of blood loss, for example if
i'm involved in a liver transplant or some big orthopedic surgery i might expect from the outset
that there's going to be a lot of blood loss so i'll need to have maybe a couple big IVs in order
to be able to provide fluid resuscitation during the course of the procedure, and also afterwards.
the standard range of IV sizes goes from a large 14 gauge IV to a very small 24 gauge IV,
and those gauges only go in even increments and they get smaller IV size as you get higher in
gauge number. so let me show you both extremes of IV sizes starting off with the smallest:
this is a 24 gauge IV, not too terribly big doesn't hurt a whole lot when it's being inserted,
and then on the other end of the spectrum is this massive 14 gauge IV. and so here you can see
side by side this is night and day. now please don't become alarmed watching this if you're a
patient - it would almost never occur that a large IV like a 14 gauge would be placed without any
sort of numbing medication or while a patient isn't unconscious under general anesthesia.
it's usually the smaller IVs that are placed when a patient's awake, and a good example of that is
an IV size that i use very commonly for procedures where i don't expect too much blood loss which is
a 20 gauge IV, which is commonly colored with this pink color. and you can see by comparison the 24
gauge is smaller but not a whole lot smaller, so the 20 gauge i think is a fairly reasonably sized
IV that strikes a nice balance between patient comfort and also making sure i've got adequate
IV access. i also want to take this opportunity to show the details of an IV which actually consists
of two components. so you can see that of course there's a needle tip right here which is made out
of metal and allows me to get this device through a patient's skin. the other part of the IV is a
hollow plastic tube called an "angiocath" which you can see slides off here. and that plastic
tubing is actually what stays in the patient's veins and the metal needle comes out after it has
helped me introduce the angiocath into the vein. so you can see this slides off just like this -
and you can see that there's a safety mechanism on most types of IVs where after the metal needle is
removed from the angiocath, it has an automatic protected tip right here and here you can see
what the angiocath looks like, which is just a piece of plastic tubing. it's hollow, it's flimsy,
and it's not sharp. so i know that it can seem a little bit trivial to think about
the difference between an IV that looks like this and an IV that looks like this, because at the end
of the day it doesn't seem like it's that big of a difference. but let me remind you of a guy
who you've probably heard of if you've taken a physics class - that's right, his name's
Poiseuille. i'm not really sure how to pronounce it correctly but i put it on the screen here so
you know who i'm talking about. the clinical implication of Poiseuille's law is that if you
double the diameter of a tube then you increase by a factor of 16 how much flow you can get through
that tube. when you think about it in those terms, you actually have a pretty big difference in the
amount of flow that you can get out of say an 18 gauge IV versus 14 gauge IV. and this isn't just
theoretical - you can see on labels for IV needles how much flow you're going to get through that
specific needle size. so this 24 gauge needle for example is only going to get 22 milliliters per
minute, and that's assuming that there aren't any other things restricting the flow of that fluid,
for example longer tubing length or very viscous fluid like transfusing blood as opposed to giving
a less viscous fluid like normal saline or plasmalyte. by comparison, the IV size that
i said i use pretty commonly which is a 20 gauge is going to provide almost triple that amount with
a maximum flow rate of 60 milliliters per minute. but even a 20 gauge IV flowing at 60 milliliters
per minute is not going to be adequate if i'm anticipating a very significant amount of blood
loss which could amount to a liter in a minute, or more, so if i think that i'm going to be getting
into territory where i need to do large volume fluid resuscitation then i need to start looking
at much larger IVs for example a 14 gauge IV which as you can see here is going to provide a maximum
flow rate of 350 milliliters in a minute. i'll illustrate the difference between the flow rate of
a 14 gauge IV and 20 gauge IV soon but first let's go through some of the other equipment that's
needed in order to get IV fluid going through that angiocatheter that we just talked about.
so we'll start with our IV pole and it sounds like a silly thing to say
but you have to consider that the higher up you have your IV pole,
the more of a benefit you're going to have from gravity helping you get that fluid into the
patient. once i've got my IV pole then i'm going to go ahead and grab my IV fluid to hang on it
the next thing i need to consider is what type of tubing i'm going to attach to my fluids.
now ordinarily the tubing that i attach is just straightforward tubing that doesn't
have anything very special about it except for an air chamber that allows me to trap air and
make sure that i don't get air bubbles going through my IV line. however there are special
circumstances where i would actually want to have IV tubing that has a filter built into it because
certain types of fluids that I use for volume resuscitation in the operating room
are going to have particles that need to be filtered, out specifically anytime i'm transfusing
blood or i'm transfusing albumin i need to make sure that i've got a filter in place. this is
what regular IV tubing looks like, where this part connects to the bag. here's an air trap and
then there's just a bunch of tubing. and here's what IV tubing with a filter looks like, which is
otherwise very similar to standard IV tubing. this tubing plugs right into my IV fluid bag
and as i'm putting together my IV equipment i have to think about whether it's going to be clinically
appropriate to run any of these fluids through a warmer before it makes it into the patient.
it's actually possible to significantly drop a patient's body temperature by giving them room
temperature IV fluids, or refrigerated blood products which can drop their temperature
even more. for that reason if i anticipate giving a relatively large volume of fluid
during a procedure then i'm going to go ahead and connect my IV tubing to this fluid warmer
which goes through this special device that plugs into the rest of the IV circuit just like this.
all i need to do here is insert the warming circuit which goes into our warmer just like this
and then the blue connection is for cold which means coming from our IV bag
and then the red connection is the hot end that comes out of the corner. now that i've got my IV
bag hooked up to tubing, and in this example going through a warmer, i can go ahead and hook up the
hot side of my warmer to, for this example, a 20 gauge angiocath and i'm gonna run this entire bag
of IV fluid, which is one liter, through this tubing and through this 20 gauge angiocath,
into a bucket and show you how long that takes to illustrate the point
of how much faster you can do it with a 14 gauge IV which i'll show you next
man this bag of fluid is still running through the 20 gauge IV. for shame
man that took a long time to get one liter of fluid through a 20 gauge IV.
so just imagine that you're an anesthesiologist taking care of a critically ill patient and you
need to do large volume fluid resuscitation in a short period of time, there's no way that a 20
gauge IV is going to cut it. so that's where you have to start looking at your 16 gauges,
14 gauges, or in other videos i'll get into other options we have like
rapid infusion catheters and central lines that can provide even faster flow. now let
me show you what it looks like to run one liter of fluid through a 14 gauge IV
which is double the diameter of a 20 gauge IV. a 20 gauge IV is a 1.1 millimeter diameter
whereas a 14 gauge is 2.2 millimeters. so let me show you what that looks like
placing a large bore IV like a 16 or 14 gauge not only has the benefit of being
clinically helpful for your patients, but also can buy you some bragging rights when you're
talking shop with your other friends early on in residency
when it seems like a pretty big deal when somebody can put in some large bore IVs
hey brohiem what's up
hey bro what's up
oh well i just threw in a couple of 14s in this lap appy
niiiiiiiiiiiiiiiiiiiice
well peace
peace
trying to figure out the most appropriate vein to place an IV in for surgery is actually a lot more
nuanced than i originally thought when i started residency, and some of the considerations that
come into that have to do with patient positioning so depending on what type of surgery is going on
the patient might be in a position that will make it very difficult for an IV to run if it's
in a specific place, and one example of this would be, say neurosurgery or orthopedic surgery that's
happening on the spine that would require that the patient be prone or face down like this with their
arms up and in that situation if i've placed an IV in the antecubital fossa and the patient's arm
is bent, there's really not a good conduit for my IV to run very well into the patient's vein,
and so it's a pretty useless IV to have for that specific type of procedure. as i've gone along my
CA-1 year i've noticed that i've developed this sort of subconscious habit of always evaluating
good places to put IVs in people. and the thing is this subconscious thought process
definitely extends outside the hospital. like i'll be walking down the street and i'll pass
somebody and i'll see that they've got a big vein in their arm and be like man i'd get a 16 there,
i'd get a 14 there. and it's one of these things that it's just impossible to turn off. it kind of
feels like what i imagine Neo felt when he finally came to understand what the Matrix really is.
[Morpheus] You walk down the street, what do you see? businessmen, teachers lawyers...
[Max] 14 gauge! RIC line! RIC line!
[Morpheus] are you listening to me Neo? or were you looking at the woman in the red dress?
okay maybe not quite like that but, you know, you get the point
another positioning-related consideration that i have is whether or not the IV that i place is
accessible during a surgery in the event that i need to troubleshoot while the surgery is going
on. i often have to think about this for example in a room where i'm doing ENT surgery where the
patient is rotated 180 degrees away from me so their feet are facing me and i don't have access,
or i don't have very easy access to their hands and so if i've placed an IV in their hand,
then i either need to crawl underneath the drapes in order to get to the IV. alternatively i can
place an IV in a patient's foot which isn't ideal for the patient when they're awake but if their
foot is what's closest to me and there's an issue that comes up that involves IV access, then at
least having an IV right there is something that is ultimately going to be safer for the patient
another factor that i think about is whether or not patients have any contraindications to
having IVs placed in certain areas, and the two examples that come up fairly commonly
are if a patient has an AV fistula commonly used for dialysis, or if a patient has had what's
called a lymph node dissection for breast cancer which can happen on either the left or right side,
or on both sides. in patients who have had lymph node dissections there's a risk of what's
called lymphedema, which means that lymphatic tissue doesn't drain adequately and so if i
am placing an IV on the affected side then in theory this could contribute to lymphedema so
for these patients it's better to avoid placing IVs in the affected side. another really important
consideration that i have is patient comfort. so there are certain areas where IVs hurt quite a
bit more than other areas and a prime example of that is the hand. so having any IV placed
here generally hurts quite a bit more than having one placed for example in the antecubital fossa
so if i have the choice i prefer to go for the AC fossa so that i don't have to cause quite as
much discomfort as going in the hand. then one of the corollaries that goes right along with that
is if i'm planning to administer a medication called propofol, it can actually sting a little
bit when it goes through the IV, and it stings a little bit less if that goes into a bigger vein
which happens to be the AC fossa compared to the hand for the most part. the last consideration i
have for thinking about where to place an IV is whether or not me blowing that IV, meaning going
through the blood vessel not being able to get my IV inside of it, and then subsequently causing the
blood vessel to swell up and not be usable - if i do that, am i going to compromise my ability to
place IVs in other potentially suitable areas? let me give you an example of what i mean by that:
let's say i decide that i want to try to place an IV in a patient's AC fossa, so i go ahead and try
but i blow the IV and it's not usable, and patient gets a little bit of a hematoma here.
and so if i blow an IV in the AC fossa and then subsequently get an IV in the hand, it's possible
that any of the fluid that i'm giving in the hand is going to travel up to the hematoma
that's formed here and not actually make it much further into the patient's systemic circulation,
meaning that any medications or fluids that i administer aren't going to be effective.
well that wraps up this video. if you have any feedback i'd love to read it
in the comments. below thanks very much for watching and i'll see you next time
you