We are talking about calcium today, you know you know it. It's in your milk and
we drink it so that we have really hard strong bones but it's also the stuff
that builds up on our dishes and in our tubs. Calcium, that stuff we want to get
rid of so how the heck does it connect to high blood pressure? Well it turns out
just as it makes our bones really hard and solid, calcium also makes our
muscles contract and makes them firm which is something we don't want when we
have high blood pressure. We're going to talk about calcium channel blockers in
this video right after this. Welcome back my name is Tammy and this is NurseMinder
and on this channel we do everything nursing so if you're new here
consider subscribing below so that you get the next video and its released.
Calcium channel blockers are another classification of medications that we
use to treat high blood pressure also known as hypertension. We know that high
blood pressure is a silent killer that means we don't have signs and symptoms
when our blood pressure is elevating above normal. In the previous video, I'll
put it here, we did talk about what is high blood
pressure what will the normal values be and when should you be concerned about
those numbers. Remember you don't have signs or symptoms and so you won't
feel like there's a problem but there are definite risks associated with high
blood pressure. In another video we talked about the stepped management that
we have in dealing with high blood pressure. the first step is always
looking at those things we can control such as our diet or environmental
factors whether that's smoking, alcohol, drug use, exercise. Those pieces that we
can chip away at slowly to make a difference but when they're ineffective
we need to add medications. So in this video we're going to talk
about what calcium does. First of all we need to understand what calcium's role
is so we understand why blocking it is so effective, then we're talking about
what a calcium channel blocker is so we're going to uncover the elements that
nurses need to know so how do I identify a calcium channel blocker? There are some
clues in our drug naming. Who would be prescribed a calcium channel blocker?
What are the considerations I need to have before I give this calcium channel
blocker? What are some of the side effects and patient teaching? And then
some of my follow-up considerations and things like that so we're going to go
over all those pieces in this video but let's start with oh and of course stick
to the end because we're going to have an NCLEX review and in these videos I
give you a question give me some time to think about it and then we go through
the rationale as to why the question has a correct answer and incorrect
answer so be sure to stay to the end for that. What is the role of calcium in the
body? As we talked right at the beginning it's about making our bones strong, we
need them for muscle contraction, that's right baby,
we also need them for our teeth and there's a lot of things that our body
needs calcium for. When it comes to where calcium works inside our
cardiovascular system and how that impacts our blood pressure we need to
look at three key things: the first is rate,
the second is force and the third is resistance. So calcium is needed to
control the rate of the heart. The SA node and the AV node these generate
their own electrical impulses I talked about this in our ECG training I can put
the description below if you're interested in more, but calcium really is
like the igniter the one that causes that muscular contraction. That muscular
contract is responsible for the force, when the heart contracts, how hard does
it need to work in order to expel the blood out of the ventricles to the
body, Now when it is contracting to move that forward out of
the ventricles to the body there is a third factor and that's resistance. You
can imagine that if we have a small tube we have to push really hard to get our
fluid through it or as if we have a really wide tube it's really little
effort. It's almost like walking through a door. If you consider this first tube
this really small narrow vessel to be like a doorway that's barely open and
you're trying to wiggle your way through it you have to exert a lot of pressure
to get through but if the door is wide open
and you can just walk through easily it doesn't require you to put forward a lot
of effort to get through the door. The same is true here the same is true here
so calcium is required for the rate, we need it for the SA node to function
inside your heart, we also need it to create a contraction inside the muscles
of the heart, and thirdly these would be the peripheral vessels so as the blood
leaves the heart how narrow - how wide those vessels are to deliver the
arteries in particular, to deliver the blood to the body is is a factor of
calcium.
Now let's look at those who would be
prescribed a calcium channel blocker. Obviously because we're talking about
high blood pressure in this video yes it is a treatment for high blood pressure.
It is also used for angina and for vasospasm so this would be like
exercise induced chest pain where those vessels are maybe slightly occluded and
not quite getting enough oxygen we have a little bit of discomfort relieved with
the medication because it causes dilation and you may also have a patient
on a calcium channel blocker who has a cardiac arrhythmia such as atrial
fibrillation because it will slow the conduction down between the SA node to
AP node and help to regulate that contraction. Now another group of
patients who may have a calcium channel blocker are those who have a diagnosis
of heart failure but there are some special precautions that we need to know
about because people in heart failure are dependent upon preload. So we look at
the different categories now of calcium channel blockers and really dive into
they have specific sites that they're more likely to have an impact on such as
rate, force, and resistance. So let's get started with looking at the categories.
Now there are two groups of calcium channel blockers and then within one of
those we have two subgroups this is usually where students tune out
Snoozeville Just stick with me for this little
complicated piece because you're generally not gonna see this on NCLEX
but it helps to just put things into their categories right, they should be
put into the blocks that they belong. Dihydropyridine's is the first group
and then the other group is non dihydropyridines. Okay so we've got the
dihydropyridine and those are commonly the ones that end in PINE, in
fact many of them actually have DIPINE on the end di P I NE. You'll see
that a lot so amlodipine, nifedipine, felodipine, those are examples of
the dihydropyridine they are primarily focused on vascular vasodilation so
they're really looking at creating more space within the vessels for the blood
to pool, not to pool, for the blood to reside which means it's gonna take
longer to get to the heart we're gonna have a little bit less fluid entering
into the chamber so my preload, the amount of fluid coming in to the heart
is less, the amount going into the ventricles is less and then when it's
pushing out of the heart you know just like this if you were to walk through a
door for example it when the doors wide open it's really easy to walk through
the door and that's what's happening with dihydropyridines is that they are
widening the gap in which the blood is going to go through. So the pressure in
the after load, the resistance is decreased. This overall makes it easier
for the heart to do its job as you can imagine walking through a wide open door.
When the vessels are vasoconstricted or that door just has that little tiny
opening and you try to squeeze yourself through it all that extra effort you
have to put into getting through that door that's just barely opened is the
same as the heart trying to push blood through a vessel that's really small.
It's resisting. It's pushing back and so the heart has to push harder so
dihydropyridine are focusing on decreasing the pressure
that is needed to push forward that blood.
The second grouping is the non dihydropyridineS and within there there's
two different classifications. Really what this is just talking about when we are
breaking it all down into its chemical structure is that they are chemically
different but they have similarities in how they work to decrease blood pressure
and so they become classified as calcium channel blockers but they don't all look
the same chemically that's why they have
different groups. Within the non dihydropyridineS is where we're going to
find verapamil it's a phenylalkaline
which is an example of a non dihydropyridine, Don't don't tap out here!
I know it's a lot of words that we don't have a context around. They're not as
important as what happens clinically when we are on a calcium channel blocker
and in particular these three different classifications or these three
different types have some particular things we need to watch out for. The
other group of nondIhydropyridines are the benzodiazepines
and the example that is diltizem. So now that we've got just that
scientific piece taken care of let's compare the dihydropyridines
to the non dihydropyridine in terms of how they affect the vessels and the
heart rate.
All right. So now it's time to look at where these specific drugs have an
affinity towards. So they're really drawn to really work in a particular area
now amlodipine (to use P I N E S for some clues) we can look at this as the P
prevents pressure in the extremities and so we're looking at that peripheral
resistance and so is it gonna affect rate? No. Is it gonna affect how
strong my muscles contract? No, It's going to prevent pressure in the
extremities that's my clue in the pine; P is for prevent pressure in extremities
So it's going to be working on vessel size so this is the affinity of all
those drugs that end in PINES, amlodipine, nifedipine are looking to reduce
the pressure in those vessels which means we're going to vasodilate. Now
when it comes to our non dihydropyridine so that's our verapamil and diltiazem,
these are more likely to effect a change in heart rate and muscle contraction. So
heart rate and muscle contraction and one of the ways you can remember this is
that both of these have the letter M in it, M for muscle M for mighty and so we're
going to be changing the rate down are going to slow it down and we're going to
relax the muscles to decrease our blood pressure. Now remember when someone's in
heart failure they are dependent upon the fluid coming back to the heart.
They've already got a weak heart it's not functioning properly and it's
already decreasing the amount of blood it can pump out so we would not want to
see a patient on a dihydropyridine such as amlodipine because remember PINES
will prevent the pressure in the extremities
and they're going to drop even further and having even less blood coming back to
the heart and that could be disastrous.
Okay so now we're ready to give this medication. These medications for the
most part our oral tablets or capsules. Now here's a critical thing if you have
a long-acting or an extended-release I should say an extended-release tablet do
not cut it in half without talking with your pharmacy first. When we have a
sustained-release pill as soon as we cut it in half we've
actually broken the integrity of the pill and now we'll get a quicker release
and we can have toxic buildup of medication. So be careful which pills you
are separating into two. Of course before we give them we need to do an assessment
we're going to assess our patient's cardiovascular system which includes
vital signs we want to do an ECG to find out what their baseline is you'll want
to listen to the lungs because if these medications are slowing the heart rate
and increasing the amount of blood that the vessels can hold there is a risk for
some edema in the lungs so we definitely want to be listening to the lungs as
well and of course your lab work should include liver and kidney profiles
because the drug is metabolized by the liver and excreted in the kidneys. If
your patient has a history of liver or kidney disease that would be a
consideration in dosing as well. One of the biggest things you need to remember
before you give this medication is that you need to check for heart rate and
blood pressure. This is usually tested in your NCLEX as well there's another NCLEX
tip for you it's on your patients findings so you definitely want to be
watching for a systolic blood pressure of greater than 90 and a heart rate of
greater than 60 before you consider giving this medication. If it's lower than
either of those values you'll want to hold it and reassess with the doctor.
Part of the patient teaching is that because this is given calcium channel
blockers are given to decrease blood pressure is
that they may need to change position slowly if they start to notice they're a
little bit faint or woozy when they get up really quickly. Here's a really
important consideration that your patients need to know. If they're taking
a calcium channel blocker they should not be taking grapefruit juice at the
same time. In fact they should be spacing it out by like four hours so it may just
be even better just to avoid it all together - and the reason grapefruit
juice is a no-no is because when grapefruit juice is present in the
system the concentration of calcium channel blockers increases.
So now that we know how the drugs work, predicting what side effects we could
expect or anticipate becomes easier. Now that I know that my dihydropyridine are
focused primarily on peripheral vascular resistance opening up those vessels I
might think that we've got swelling and edema happening now I have less blood
flow coming to the heart I might have some problems with the patient feeling a
little bit uncomfortable dizzy, faint because they're not having as much
perfusion and that impacts the amount of output from the left side of your heart.
With anything we take into our mouth we always have nausea to consider. We can
end up with a reflexive tachycardia meaning that the heart has not been
giving as much fluid as it normally likes we've decreased that and then the
heart's that whole renin-angiotensin-aldosterone
pathway the baroreceptors are all triggering for the heart to work harder
and so you may end up having a tachycardia so you'll want to watch for
that as well. Now in addition for those patients who are on the non
dihydropyridine we know that they have an affinity towards the SA node and the
muscle contraction itself. So in particular they often are used to treat
arrhythmias however they can also cause arrhythmia so we definitely want to be
following up on our patients EKGs to make sure we're not getting into a heart
block of some sort as a result of that calcium being prevented from entering
into those cells. So now it's time for an NCLEX review :)
The nurse is discharging a patient home on a new sustained-release calcium
channel blocker what is a priority teaching point about this medication? a)
be sure to take your blood pressure two hours after you have taken your
medication B) swallow the pill whole and do not crush cut or chew it C) take the
drug with grapefruit juice to prevent stomach upset D) headaches can be a side
effect of this medication. Go ahead and make your selection. All right now let's
take a look at these answers. If you selected a take your blood pressure two
hours after your medication that be incorrect and the reason is we need to
assess blood pressure and heart rates before giving these medications. If you
said B swallow the pill hole do not cut crush or chew it that would be the
correct answer because we know this is a sustained release drug and when we cut
it we have changed the integrity of the pill and they are at risk of drug
toxicity. If you selected C take the drug with grapefruit juice to help prevent
stomach upset well we actually want to avoid
grapefruit juice because grapefruit juice will increase the concentration of
calcium channel blockers not what we want. And if you selected D headaches are
or headaches can be a side effect of this medication you would be correct. Yes
it is a side effect of these medications but is that the priority? The priority
is airway, breathing, circulation, pain. ABC's pain and so in this case if we
crush the pill cut it in half we have toxicity and then we're at risk of an
airway, breathing, circulation, problem. Thanks for watching I hope you learned a
ton because it was an awful lot of fun bringing this video to you. Make sure you
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great day :) Hey I know you're probably not ready to
get off your phone or go back to work just yet or maybe even turn the lights
off to go to sleep so why don't you spend a little bit more time here
watching another video THANKS!