MS 3 Neuro Project: Myasthenia Gravis

MS 3 Neuro Project: Myasthenia Gravis


Hi everybody this is Dani, student nurse,
no .com, and today I’m gonna be going over myasthenia gravis and this review is a part
of the project that I have to put together in order to pass MedSurg three and thus, nursing
school. So let’s get started! Myasthenia gravis, what is it exactly? It is a chronic and progressive autoimmune
disorder that causes weakness of the striated skeletal muscles. Why does this happen? Well, in individuals with myasthenia gravis there
is a significant reduction of acetylcholine. Acetylcholine is a very important neurotransmitter,
we’re going to get to that, but first let’s talk about this guy the thymus gland. The thymus gland is present at birth, right
here below the breastbone and it is active until about puberty, at which time it stops
producing antibodies and begins to atrophy. It is thought that in people with myasthenia
gravis the thymus does not stop producing antibodies well past puberty. And why this becomes a problem is that,
we have here in this lovely illustration, is an axon and whenever you want to have a muscle
contraction it’s gonna send a signal down the synapse where the signal is going to release
acetylcholine. And in normal individuals acetylcholine will
then bind to its receptor sites and you will get a muscle contraction. However, in people with myasthenia gravis
the receptor sites are already taken up by the antibodies that were produced by the thymus
gland. And to make matters worse we have cholinesterase,
which is an enzyme that is going to break down acetylcholine. So essentially, you have a lack of acetylcholine and what acetylcholine is present, cannot bind to the
receptor sites because antibodies are already taking over. Thus, the difficulty in having a muscle contraction. Because this is an autoimmune disorder there’s
no real way to prevent it, but there are some risk factors that we can be on the lookout
for that might pre-disposed a person to developing this disorder. That is women ages 15 to 35, men ages 40+,
the ratio between men and women is 3 to 2. This disorder is marked by periods of exacerbations
and remissions. Things that are going to predispose an individual
to developing an exacerbation are: infection, stress, fatigue, cathartics, which are your
laxatives and heat. So you want to teach these patients no sunbathing,
no saunas, no hot tubs. Now that we kind of have an idea of what this
disorder is, let’s look at the clinical manifestations. So what you’re going to see is progressive
weakness and fatigue of the skeletal muscles. An inability to maintain position without
support. Ptosis, diplopia, and they can’t maintain an
upward gaze. Dysphagia and respiratory compromise. This is because the muscles that we take for
granted, the intercostal muscles and the diaphragm, that help us to breathe, in individuals with
myasthenia gravis because they have such weakened ability and impairment with their muscles
they’re having difficulty inhaling and exhaling. This is something that is very important that
we’re going to go into further a little bit later. In order to help you remember the clinical
manifestations you want to remember weakness. W- weakness in the face, arms, and legs. E- eyelid drooping ptosis. A- ability to emote is impaired. They’re going to have a very sleepy like
appearance because even these muscles in the face just becomes very difficult for them
to move them. K- keep choking and gagging so we’re going to be
worried about aspiration risk. N- no energy, lots of fatigue. E- extraocular muscles involvement, the strabismus,
which is gonna be your cross-eyedness. S- shortness of breath. S- slurred speech. Remember weakness, in case you get one of
those select all that apply questions. So now these are the symptoms you’re seeing
in your patient. Do they have myasthenia gravis? We don’t know we’re going to have to test
for it. So then you’re going to perform the Tensilon
test. This is the gold standard for identifying
myasthenia gravis. What happens is, is you start an IV on your
patient and then they are ejected with Edrophonium. And you want to teach your patient that when
they receive the injection, their stomach might become a little upset and their heart
rate my increase. With this test you’re going to have the individual
perform something such as repetitive arm moving, standing up sitting down, standing up sitting
down, walking trying, to say as many words as possible. When they begin to fatigue they will get another
injection, and if over the course of the test you notice that every time they are injected
their muscle endurance increases, that’s a positive test, which means they do have
myasthenia gravis. Other test that can be performed are electromyography,
MYO muscle, EMG. CT scans of the thymus and thyroid studies. So now let’s talk about the nursing care,
the collaborative care, and some complications you might see with myasthenia gravis. Some nursing diagnosises related to this disorder
are: Impaired Gas Exchange related to ineffective breathing pattern. Fatigue related to increased energy needs
from neuromuscular involvement and Risk for Aspiration. When you think of myasthenia gravis really
focusing in on the fact that these patients are experiencing severe muscle weakness. So what are we gonna be worried about? Well, with those intercostal muscles and that
diaphragm beign impaired, impaired gas exchange and fatigue. When we think of their ability to swallow,
that takes a muscle, risk for aspiration. Collaborative care, the nurse is going to
work with the physician as well as PT and OT to really help these patients optimize
the most out of the most out of their activities of daily living. They’re also going to be prescribed cholinesterase
inhibitors pyridostigmine, Mestinon is the first line medications prescribed. Some other therapeutic procedures they might
be getting is plasmaparesis, irradiation, respiratory and nutritional support and possibly
a thymectomy, which would be the removal of the thymus. Nursing management, you’re gonna focus on
assessing and maintaining airway and assessing their ability to swallow. These are two huge important things you need
to be on the lookout for, especially when you’re working with a patient who has muscle
weakness and fatigue. We don’t want to cause an exacerbation. You’re going to cluster or activities in the
morning and allow for frequent rest periods. You’re going to teach this to your patience
as well. If you have something important you need done,
you want to do it in the morning when your muscles are really at their highest peak of
the day. You’re also going to teach the patients taking
Mestinon to take it with food to prevent G.I. upset. When you give this medication, you’re going
to give it, and then within 45 minutes of giving it, you’re going to give them their
food. This is because you’re going to take it advantage
of that medication’s affects and they’re going to have the strength to really chew
and swallow their food which will reduce the risk of aspiration. You’re also going to teach thees patients
the importance of maintaining therapeutic levels with this medication. This is key to reducing their risks of having
an aspiration, going back to our nursing diagnosises. They have to be able to breathe, they have
to be able to swallow, and of course as part of daily life, they want to be able get around
be involved with people, family, friends. Monitor their albumin levels. Provide small frequent high calorie meals
because the fatigue easily and because were trying not to exacerbate the condition, we
want to give them small meals that they will be able to chew up and swallow without the
risk of aspiration. Some medications you’re going to be administering
are the corticosteroid prednisone. The immunosuppressant Azathioprine. You can also give IV Ig (Immunoglobulin) and
again Mestinon. Some complications of myasthenia gravis are,
Fluminating Severe Myasthenia Gravis, which is a rapid onset, characterized by severe
weakness. You will see early respiratory involvement. They’re going to have difficulty just struggling
to even breathe in and out. It caused by myasthenia or cholinergic crisis. And the response to treatment is often poor
with very high mortality rate because of the respiratory failure and aspiration that occurs
with this. The other complication is a myasthenic or
cholinergic crisis. I’ll break it down for you right here. If they are having a myasthenic crisis, there
are not enough meds on board they are not in therapeutic range. You’re going to see signs of weakness, incontinence
fatigue, and hypertension. It’s treated with a cholinergic. one of the medications given is pyridostigmine,
Mestinon again. If it is a cholinergic crisis, there is too
much medication on board. Your signs and symptoms are nausea, abdominal
cramps, diarrhea, HYPO-tension, and increased respiratory secretions. You’re going to treat it with an anti-cholinergic
atropine. That’s gonna go ahead and help dry up all
those secretions for you. So that does it for me and this presentation
on myasthenia gravis. I hope you enjoyed it. If you did enjoy it, that’s great, I’m probably
never doing another video like this again, but if you did enjoy how I broke down the
content, go ahead on over to Registerednursern.com, where you will find Sarah. She does videos on absolutely everything that’s
covered in your classes. She breaks it down in a way that is easy for
you to retain and utilize on your exams. She also has a nifty little quiz at the end,
full of NCLEX style questions and select all that apply, because we all know we need more
help with, which orange is the most orange? But again that does it for me, I hope you
enjoyed it, and maybe you’ll see me again.

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