00:01
Now we're ready
to talk about the medications
that are used
to manage preeclampsia.
00:06
There are several categories
that might come into play.
00:09
So, let's review those now.
00:11
Calcium channel blockers,
Beta-blockers,
Nonsteroidal anti-inflammatories,
Antiadrenergic, and Diuretics.
00:20
So let's break those down,
so we can think about
how those might work
in preeclampsia.
00:25
The first one,
I'm probably the one
you're going to hear the most often
is magnesium sulfate.
00:31
So magnesium sulfate
is a calcium channel blocker,
and it's also a neurotonic.
So we get two benefits for this.
00:37
So it's recommended
for patients
who have eclampsia
or severe preeclampsia.
00:42
And patients who've had
a cesarean birth
because of the preeclampsia,
which indicates that
it's most likely a severe case.
00:49
The expected effects
that are going to happen
when we give
magnesium sulfate
are going to be a feeling of
feeling flushed,
having a metallic taste,
fetal heart rate
variability changes,
somnolence,
which means you're sort of feeling
kind of drowsy, and a little quiet,
and decrease reflexes.
01:07
So, that's all well and good.
01:09
But why do we give
the magnesium sulfate?
We give magnesium sulfate
to prevent seizures.
01:15
Say that three times,
right now.
01:18
We give magnesium sulfate
to prevent seizures,
and I'll let you do
the last two on your own.
01:24
Make sure
that you understand that
because we do not give
magnesium sulfate
to lower the blood pressure.
01:30
Now, sometimes it might
because it does relax smooth muscle,
but that is not the indication.
So don't get them confused.
01:38
It's important that
we have an antidote,
for magnesium sulfate,
in case we give too much.
01:43
And that antidote is called
calcium gluconate.
01:46
That is the antidote
for magnesium sulfate.
01:48
It's given IV,
and it's given very slowly.
01:52
Let's talk more about the effects
of magnesium sulfate.
01:55
So one of the things it does
is it sort of protects
the endothelial cells.
02:00
So it decreases the vasoconstriction
and the damage that may occur
from the preeclampsia.
02:06
It also causes vasodilation,
which can alleviate
some of the cerebral schema
that may happen as a
result of the preeclampsia.
02:14
It potentiates beta-blockers
and it increases
the potency and the duration
of muscle relaxant.
02:20
So that's good to know.
02:22
It also increases bleeding time
and decreases platelet activity.
02:27
So that might be really important,
we think about bleeding postpartum.
02:32
I want you to take a look
at this strip.
02:33
Hopefully you remember it
from our fetal monitoring lecture.
02:37
But if not,
let's take a peek here.
02:39
So this is a strip from a client
who could come in for
maybe an induction of labor,
maybe some preeclampsia severe,
and they're on a fetal monitor.
02:51
We see that we have
moderate variability
and a heart rate that's in
normal range.
02:56
We also see three contractions.
02:58
But that's not really important
for what we're going to talk about.
03:00
Pay attention to what's going on
in that green box.
03:04
Now look at this.
03:06
What do you notice?
Do you notice that the variability
has flattened out?
So if you remember that the
variability is caused by the play
between the parasympathetic
and sympathetic nervous system,
and we know that magnesium sulfate
tends to relax that interplay,
then it makes sense
of the variability
would be smoothed out.
03:26
So although this is not
what we want,
it's not a great strip,
it doesn't really show
that our fetus is particularly
neurologically active.
03:34
This is what we would expect,
because likely mom
is a little sedated,
and this passes through
the placenta,
so the baby is going to be
experiencing the very same thing.
03:45
So in order to watch
for complications
of giving the
magnesium sulfate,
and to make sure the preeclampsia
is not getting worse,
the nurse will do something called
Hourly Magnesium Sulfate Checks.
03:57
So during those checks, they'll
check for level of consciousness.
04:00
So, talking to the client is
probably good enough to elicit this.
04:04
So making sure
they know where they are.
04:06
And they're rousable.
04:08
Sometimes they'll feel sleepy,
that's normal,
but they should know
where they are, what's going on,
and have clear speech.
04:14
We'll check the respiratory rate,
because magnesium sulfate can slow
the respiratory rate down to
pretty low levels.
04:22
So we want to make sure
we're not overdosing them
with magnesium sulfate.
04:26
So a respiratory rate
less than 12
would be a sign
of potential toxicity.
04:31
We're also going to check
deep tendon reflexes.
04:35
I'm taking it back
to the beginning of the lecture.
04:37
And remember, that hyperreflexivity
may be a result of the preeclampsia.
04:42
So, if we give magnesium sulfate,
what should happen to the reflexes?
Right, they should go down.
04:49
They may go from 3+,
which is considered hyperreflexic
to maybe 2+ or 1+.
04:56
But if we get to zero,
then that may indicate
that we're giving too much
magnesium sulfate.
05:02
So we don't really want zero,
we just want it back down
to a normal level.
05:06
Do you remember
how to do your clonus exam?
There are very few times
unless you work on neuro
that you will actually
do this test.
05:12
So, I want to show it to you
one more time.
05:15
So, to check for clonus,
you dorsiflex the foot,
which means you pull the toes
back towards the knee,
and you let go,
and you watch for taps of the foot.
05:24
And you count those taps.
05:26
Normally,
there shouldn't be any taps.
05:28
You dorsiflex the foot,
it relaxes, no problem.
05:31
If you have clonus,
instead of flopping back over,
it'll tap, like this.
05:37
And that lets you know
what's going on
with neurologic irritability.
05:41
The more clonus you have,
and it can even be like this
a tetanic clonus response
lets you know that you're
more likely to have a seizure.
05:50
So, that can tell you, hopefully,
that your magnesium is working.
05:53
Someone who may present
with clonus,
You may find over time
that the clonus disappears,
or someone maybe
has one bit of clonus,
and it goes to two
or it goes to the titanic,
and that may mean
you need to turn up
your magnesium sulfate.
06:08
We're also going to watch
the blood pressure.
06:11
Now, the blood pressure may decrease
because of the magnesium sulfate.
06:15
But again,
that's not why we give it.
06:19
We are checking
the blood pressure
because the preeclampsia
may be getting worse.
06:23
And that may be
how we notice that.
06:25
We're also going to check
urine output.
06:28
Not the magnesium is going to do
anything to the urine,
it doesn't really affect
that system,
but the preeclampsia does.
06:35
And this is how the magnesium
is actually going to be excreted.
06:40
So if the urine output is limited
because of the preeclampsia,
then it sets us up for toxicity
to the magnesium sulfate
because there's no way
for it to get out.
06:49
And we're also going to check
the heart rate
because the magnesium
can slow the heart rate.
06:54
And a heart rate
of less than 60
might be an indication
of magnesium toxicity.
06:59
Let's talk about
a few other medications.
07:01
The first one is hydralazine.
07:03
So, maybe you've
given this medication
when you're on a cardiac unit
for someone else with hypertension.
07:08
This will work
in this case too.
07:10
It causes direct
peripheral vasodilation.
07:13
So that's going to help
bring the blood pressure down.
07:16
It also increases
cardiac output and heart rate.
07:19
So the dosages typically are about
5 mg IV up to 10 mg IM.
07:24
And it can be given about
every 20 to 30 minutes.
07:27
The max dose for this IV
is going to be 20 mg,
and IM is going to be 30 mg.
07:34
So thinking about what could happen
when you give hydralazine.
07:37
Sometimes we have some effects
we have to be aware of
and that is definitely
the case here.
07:41
So we give it
to lower the blood pressure.
07:44
We might lower it too much.
And we may have hypotension
and the client may begin to
experience symptoms related to that.
07:50
Or we can develop
tachycardia
where the heart rate
begins to go up.
07:53
So sometimes clients may feel
a little strange
when they take
hydralazine.
07:57
And we want to make sure
that they are aware.
08:00
The next medication
is labetalol.
08:02
So labetalol is
a nonselective beta-blocker.
08:05
And it helps to again,
lower the blood pressure.
08:08
So remember, magnesium sulfate
is not what we give
to decrease blood pressure.
08:13
We're going to give
these medications.
08:15
So it's given IV for blood pressure
is greater than 160/110.
08:19
Hopefully,
that's ringing a bell
and letting you know
that that goes along
with someone
who's experiencing,
what?
Severe preeclampsia.
You got it.
08:28
So someone with mild preeclampsia
is not going to get labetalol.
08:31
So, we give 200 to 1200 mg/dL
in 2 to 3 divided doses.
08:37
And patients who've had
a history of asthma,
or a history of bradycardia,
they will not be candidates
for this medication.
08:46
Nifedipine.
08:47
So this is a
calcium channel blocker.
08:49
And we give this in doses of
30 to 120 ml/dL.
08:54
This is given intravenously
for patients
who have a blood pressure
that's greater than 160/110.
09:00
Severe preeclampsia.
09:02
Expected effects with nifedipine
are going to be
flushing,
peripheral edema,
again, that reflex tachycardia,
and potentially a headache
from that rapid vasodilation.
09:13
Methyldopa is another
antihypertensive.
09:15
And it reduces
blood pressure
by reducing the SVR or
systemic vascular resistance.
09:21
The dosage for this
is 250 to 800 ml,
and it's given PO q 8 hours.
09:26
So this is not something
we typically give
at the bedside in the hospital.
09:30
This is going to be given to someone
unexpected management
that's at home.
09:35
Expected effects are going to be
headache, flushing, tachycardia.
09:39
So think about it.
09:40
Anytime we give a medication
to lower the blood pressure,
the potential is going to be
that we're going to have
these reflexive responses.
09:49
Just to review and let you know,
and most often,
most of the time your instructors
are not going to require
that you memorize all the dosage
for each of these medications,
but it's a good idea to have a range
when you go clinical
so you can
maybe tell your preceptor,
or your clinical instructor
about them.
10:04
So, magnesium sulfate.
10:05
We typically give a
4-6 gram loading dose,
And then there's a maintenance dose.
10:10
We want to onboard
and get it into the system,
and then continue to give
the magnesium sulfate
until it's discontinued.
10:17
The reason we give it
is to decrease seizure activity
and not for
blood pressure.
10:22
And the antidote is...
10:25
Calcium gluconate.
Awesome.
10:27
Hydralazine.
10:28
We're going to give 5 mg maybe IV,
or we may give 10 mg IM,
and that's going to be repeated
every 20 to 30 minutes.
10:37
And this is going to decrease
the blood pressure
by causing vasodilation.
10:40
Labetalol.
10:41
Again, is going to be given around
200-1200 ml/dL in divided doses.
10:47
This is also going to decrease
the blood pressure.
10:50
Nifedipine is going to be
30 to 120 mg
decreases the blood pressure
through vasodilation.
10:56
And methyldopa is going to be
something that's given
during the antepartum period
250 to 800 mg.
11:02
This is a PO dose.
And it also reduces SVR.
11:07
I'm often asked by students,
is there anything we can do
to prevent preeclampsia?
Now we, there's lots of research
that's going on
and I want to share with you
what's up to date.
11:17
But know that this
information changes.
11:18
And so when you watch
this video,
especially if it's a
few years from now,
you may want to go back,
and double check,
and see what's new,
and hopefully they have
some new options for treatment.
11:28
So acetylsalicylic acid,
150 milligrams per day.
11:31
There are some studies that show
that it results in a 62% reduction
in preterm deliveries,
and preterm preeclampsia.
11:39
So, that might be
something to suggest
if you're working
in a high risk population.
11:43
Calcium giving elemental calcium
has shown some benefits.
11:47
Vitamin C and vitamin E.
11:49
unfortunately, have not shown
to be particularly effective
Zinc and vitamin D
might be effective,
but that evidence is not conclusive
at this point.
11:59
We have studies
that are examining right now
the effect
of oxidative stress.
12:04
And that's link between that
and preeclampsia.
12:07
And early studies right now
are looking at the use of statins.
12:10
And they're showing
some promise with that
as a possibility of preventing
preeclampsia.
12:15
The only thing
that's really tried and true
that works most of all,
is reducing the risk
for chronic hypertension,
engaging in exercise,
and diet, and stress reduction
prior to pregnancy.
12:26
That is the most important thing.
12:28
So, when we think about wellness
and how we can prevent
complications,
we want to think about that
well before conception occurs.