Note: post the slides for a fast review.
Today, I review, link to, and embed “How to use Vasoactive Drugs – Paediatric Emergencies 2024” from Paediatric Emergencies.
All that follows is from the above resource.
Dr Chris Flannigan talking about How to use Vasoactive Drugs. This talk is part of the Paediatric Emergencies 2024 event. To get your CME certificate for watching the video please visit https://www.paediatricemergencies.com… #PaediatricEmergencies #PaediatricEmergencies2024 #VasoactiveDrugs
Here are the slides:
0:29:
1:55:
2:17: And which of these complex methods [arterial line, CVP line, and POCUS] do we need to decide what to do; at least initially, none.
2:26: These are our goals.
4:14 – 7:30 Review text on YouTube. Epinephrine (adrenaline)
for so let’s take a look at adrenaline now if somebody to put this slide up on a talk I was looking at I would
immediately switch off it’s got lots of receptors doses halflife don’t do this um all the stuff
on this side is really really important it’s going to help you when you have one of these patient and it’s certainly
going to help you for the next lot of cases that we’re going to come on to so bear with me for a couple of minutes while we go through it so adrenaline
works on your ad generic receptors we’ve got Alpha and beta receptors the alpha receptors are the ones that squeeze the
vasculature and increase your systemic vascular resistance the beta 1 receptors are the ones that increase your heart
rate and increase your ventricular contractility whereas your beta 2 receptors they will actually cause a little bit of peripheral Vis dilation
although an all but very ludus of adrenaline not going to see this because the alpha effects are stronger and
they’ll cause the vas of constriction and don’t forget um du to as beta 2 receptor effects um adrenaline will
cause Bronco dilation so we do have a difficult to manage asmatic putting the mon adrenaline infusion for that is
actually quite helpful in terms of the dosing range it will vary depending on the regime you look at but it’s
somewhere between .01 and 1.5 mic per kilo per minute in the lower doses the
beta effects are going to predominate so you’re going to increase your heart rate your anat tropy and causing potentially
a little bit of vasor dilation or doing nothing to your afterload at those lower doses by the time you getting up to
about .1 mics per kilo per minute you’re starting to get the alpha effects predominating which are going to cause
your Vasa constriction you’re still going to have those beta effects and they will increase as the dose goes up
but this is the dose you’re going to want to start for our patient with septic shock and that’s what the guidelines recommend and the reason for
that is because this is the deuce that you’re starting to get a squeeze in the after Lo which is is what the majority of these patients are going to need
initially in terms of adrenaline it works very quickly when you start it um it has a very short halflife round about
two to three minutes so you need to have a really secure line because if you lose your line you’re going to lose the
effects really quickly and if you’re changing it from one line to the other you can simply take it off and move it
over because even that short duration where the patient isn’t getting the adrenaline can cause the blood pressure to Plum it you’re going to need to
double pump it over in terms of the special effects we’ve already mentioned as is one place where it might be particularly useful and anaphylaxis is
another situation where you’re going to find adrenaline particularly useful situations I don’t really like using
adrenaline particularly high high deces as pressor I’m not a big fan of it in older children the reason for that I
find it cause quite a marked lactic acidosis and that lactic acidosis is not due to an oxygen delivery problem so
adrenaline causes breakdown of glycogen which makes Peru it which makes lactate and older children just seem to have
this more often and the problem is in septic shock we’re using um our lactic clearance as a
marker that our patient is getting better so if actually we’re treating our patient and their lactic goes up the
first thing you think is is that is that a treatment actually working and you might falsely move away from a treatment
that’s working because your lactate is increasing so I don’t mind using it in older patients as initial drug um to get
them resuscitated but later on I won’t be happy leaving them on high deu adrenaline as op pressor because I think
it can Cloud the picture so how do we give adrenaline so we’re going to give it one method is by
infusion and this can go centrally or peripherally you’ve got the methods up on the screen that I use to make it up
it will vary a bit from region to region so essentially .3 milligrams per kilogram and 50 Ms you run it at 1 M
hour and that gives you your .1 mics per kilo per minute to make it up periphery it’s 1 milligram of adrenaline 50 Ms of
cine 0.3 times the patient’s weight so for a 3 kilo child 0.9 Ms an hour a 10
kilo Child 3 Ms an hour and that gives you your normal starting do[se of] .1 mic per kilo per minute.
7:32: So how do we give epinephrine (adrenaline)?
8:07 – 8:49
minute the biggest thing when starting adrenaline um is to factor in your dead
space so you can see here this canul connector the total Dead Space is 0.4 Ms
if we were to start a peripheral adrenaline infusion on a 3 kilo child it would actually take 27 minutes to get
through the 9.4 Ms of Dead Space which is really alarming so if you were starting this thinking you’re treating
your patient and you haven’t facted the dead space in you’re not for almost half an hour in a small baby so you need to
know the Dead Space of the connectors that you’re using in your department you can just put a syringe of sine onto it
flush it through with a one M syringe and see how long it takes to come out the end and then you save that number
away so the next time you’re starting a critical drug in your patient you can Bish that volume through the Dead Space and the drug is going to reach the
patient without any delay
Big big point. See transcript above.
8:53: Great tips. Consider adding the transcript
9:38 – 11:10
patient without any delay another way to do adrenaline it was one of the options was push to
Adrenaline so to do this you take one M if your rest to Adrenaline 1 in 10,000
and deluded by a factor of 10 bar in 9 M of Seine to it so that’s going to make you adrenaline one in 100,000 or 10 mics
per mil in terms of dosing it’s the same volume that you would give a child in cardiac arrest so .1 Ms per kilo but
because you’ve already deleted it by a factor of 10 you’re given a tenth of the dose that you would in a cardiac arrest
another important thing to remember if I had a Nal to was uh I needed to give this to I would give them one to two Ms
at a time so for any is 20 kilos and above you tend to cap out it a Max of 2 Ms at a time and that works fairly
well so let’s go back to our patient and see what we need to do with them so in
terms of we’ve already decided adrenaline is the treatment of choice we’re going to give them some more fluid
fill the circulation up um and in terms of the regime for adrenaline we can either give them an adrenaline Fusion
starting at .1 mics per kilo per minute or we can give them some postto adrenaline and what I’m trying to decide
between the two the question I ask myself is do I have time to make up this adrenaline infusion to get it connected
up to the patient through the Dead Space and then titrate it to effect without the patient arresting if the answer is
yes then I’ll go with the adrenaline infusion because it gives you smoother control of your blood pressure with the
push to Adrenaline you get big swings where it goes up and then you have to watch very closely and it’ll fall away again and you need to give another
Bullis so adrenaline infusion would be the preferred choice if you have time if
you don’t I would go with pushu adrenaline so I would look at this patient and I would see that they have a
lactate of 11 they’re only responsive to pain and they are hypotensive which we
know as a parior sign and I would say it’s not safe to prepare an adrenaline infusion the time it takes is too long I
would give them a push a push to Adrenaline I would monitor them closely and repeat that as we need to get them
up in an adrenaline infusion and then tiate that to effect even if we did have
time to get the adrenaline infusion up on this patient and we were getting them ready for incubation I would still expect them to decompensate on
incubation I would have pushed us adrenaline proof as well because that’s highly likely to
happen
11:14 – 12:47 Case 2
happen Okay let’s go on to case number two so this time we’ve got a 12-year-old with acute lymp bastic leukemia and
neutropenic sepsis so they’re our wayse currently patent they are a little bit tack ofn 21 breasts per minute but they
are peric at over 40 so that’s not a big surprise they’re saturating at 100% in
air they’ve had a gas done which shows an elevated lactate of 4.5 and because
this is coming from a central line we’ve also got Central Venus oxygenation saturations they are low at
52% if you’re not familiar with these generally your if your blood goes at 100% saturated when you sample it from a
central line there can be all lighted up to 30% extraction of oxygen so your sat should be at least 70% saturated if it’s
more than this it would make point out that you have a problem getting oxygen to your tissues and the common reason in
septic shock is there’s just pure profusion to those tissues so it’s an early warning sign that this patient
might not be profusing their organs particularly well we can see the reason for this when we come on to the cardiovascular system we are hypotensive
with a map of only 48 but when we look at the blood pressure the thing that I’m noticing is the diastolic is quite low
compared to the systolic normally it [should] be about half the systolic so we’ve got a widened pulse pressure and
we’ve got other signs of Warm shock here with flash cap refill time binding pulses and warm peripheries so we’ve
already given 40 Mills per kilo of fluid resusitation um and then we need to decide what we’re
going to do next so I’ll put the options up on the screen so if you want to go slido and vote and the options are
exactly the same as what I gave you the last time okay so I think most you are going for nor adrenaline
12:43
12:52 Most course participants went for Noraderenaline infusion
12:58 – 14:31 Dr. Flannigan agrees with the audience that noradrenaline 0.1 mcg/kg/min is the right choice and explains the details in this text.
going to do next so I’ll put the options up on the screen so if you want to go slido and vote and the options are
exactly the same as what I gave you the last time okay so I think most you are going for nor adrenaline
here so when we look at this patient we have to decide what we want to do with their circulation
so as I’ve mentioned the most alarming thing here is that our circulation is too dilated and we want to squeeze that
down in terms of filling the other thing our circulation is a bit empty but the reason for that is it’s because it’s too
dilated we could of course fill that dilated space with more fluid and that would temporize things doesn’t solve the
underlying problem and that fluid is going to leak out into the tissues and cause more problems later on so the
ideal way is actually to squeeze things down rather than putting more fluid in in terms of cardiac function we may or
may not need to augment this child’s function but we have time here this is not a crashing child and as I’ve
mentioned older children I’m not a big fan of using adrenaline unless I have to crashing child no problem this kid isn’t
crashing so we do have other options they’re not going to appreciate you making their heart beat much faster than what it’s doing and giving them
palpitations put their blood glucose up and actually potentially causeing that lactate to rise further so my Preferred
Choice For This child would be I would agree with you I would go with a nor adrenaline infusion and particularly as we’ve got the central line there it
would be fairly simple to put up I would then put the echo Probe on and see what’s happening with the heart function
if it wasn’t pared we could add in some nudus adrenaline um but even if I didn’t have the ability to put the echo Probe
on we could look for lactic clearance Improvement and blood pressure as signs that things are improving on the
noradrenaline and if they weren’t and we didn’t have the ability to do an echo then we could start some Lotus adrenaline to cover s potential m
dysfunction so let’s take a look at noradrenaline, so again it works on the ad generic receptors Alpha and beta
receptors but it has more of a predominance for the alpha receptors so it is going to give you more Vaso
constriction per dose than what adrenaline will do and less beta effects so it doesn’t have beta 2 receptor
effects but it does a beta one which will increase your heart rate and ventricular contractility I’m not a big believer
that it has an awful lot of beta one effect generally when I started I find that the heart rate actually slows
rather than increases um as a reflex due to the phase of constriction that you get and I wouldn’t be relying on it to
improve ventricular function and a child that I know the function significantly impaired and there is other mechanisms
by raising the blood pressure where the function will improve it’s going to improve preload by squeezing the Venous
circulation and also by improving blood pressure it improves your coronary perfusion pressure which should improve
your ventricular contractility as well doings very similar to Adrenaline .02 to
one mics per K per minute the game we’re starting about No.1 mics per K per minute similar onset and a half lifee
round about two and a half minutes so again you have to be careful when you’re moving it from one line to the other and
you need a secure line okay moving on to case number three
14:32 -15:44 Dr. Flannigan discusses why he chose noradrenaline. See text above.
