Ankylosing spondylitis | Muscular-skeletal diseases | NCLEX-RN | Khan Academy

Ankylosing spondylitis | Muscular-skeletal diseases | NCLEX-RN | Khan Academy

November 8, 2019 46 By Kody Olson


– [Voiceover] We’re going
to refer to ankylosing spondylitis as AS. So you don’t have to keep
hearing me say this long thing. But if we go word by word just once, you’ll see that ankylosing means fusion. So it describes the spine
being fused together. Spondy, this first part of
the word, refers to the spine. and then -itis anywhere is inflammation. So this is an inflammation of the spine and at the sacroiliac joint, actually, and it leads to the fusion of the area. There’s some buzz words surrounding it. So one of them would be
that it is the poster child for a group of different diseases that are referred to collectively as the seronegative spondyloarthropathies. Spondylo-, so again, that’s the spine, and then arthro, which
refers to joints in general, and then pathologies or illnesses. So what this means is that they are rheumatoid factor negative. They do not have rheumatoid factor. But they also can appear
like rheumatic joint diseases because it’s systemic and it
involves the immune system. So speaking of the immune system, the other buzz word you need to know is HLA-B17. I’m sorry, I always say that. It’s B27. Again, it’s part of the immune system. It’s an antigen on the surface of the cell that can be recognized by T-cells, which can recruit things to attack it. So this is the autoimmune
component of the disease. This HLA-B27 association
actually exists for the seronegative
spondyloarthropathies in general, but here, in particular, for AS you should remember that connection. And then, just a little
background information on the group of people
that tend to get this. Remember, nothing is absolute, but if we’re looking for patterns, it’s going to be males
and relatively young ones, actually, really young ones, from 15 to 45 is going to be the mean
or the biggest group of people who get AS or that’s
when it’s diagnosed the most. So the name kind of tells us what symptoms are characteristic. We have this fusion of the spine. I drew it kind of like here, because it can be in
the middle of the back, more commonly in the middle
to lower back of the spine. So look at the curvature of this, this natural curvature of the spine. So this is a person looking
to the right at the screen. The head is over here. As you come down the back,
it kind of curves in here, and the pelvis is down here. This whole thing is
supposed to allow you to bend forward, bend backwards. If you look at the area
here, you should be able to actually bend forward more
than you can bend backwards. But the important part is that
with ankylosing spondylitis you don’t have that kind of free movement because you have fusion, and this is why one of the nicknames for the
symptom is a bamboo spine. Like a piece of bamboo, instead of a bendable stack of bones. Bamboo spine. So while bamboo spine is
what we think of immediately when we see AS, remember that it’s a systemic autoimmune disease, which means it affects, it
could potentially affect everywhere in the body. And this person might have fever, malaise, other nonjoint problems. When we’re talking about
joints, aside from the spine, it also tends to affect
the iliosacral spine. Iliosacral. I haven’t drawn the
pelvic bowl of bones here, but this is the joint that,
think of it how your leg, your thigh attaches to your body. So the pain and inflammation
can actually go down, following the spine, and
can shoot into the legs, and the iliosacral joint
itself can be affected as well. So the pain, I think of it
as this area for joint pain. If we want to talk about systemic effects, it has a pattern of
affecting two other places. One is eyes, particularly uveitis, and the other one is the aorta. So the aorta is the
big pipe, the big hoop. This is just the four
chambers of the heart, and this is the left
atrium, the left ventricle. This is not anatomic,
because technically the aorta comes kind of above the
heart, comes out this way, but just drawing our little cartoon here, just to show you the aorta is this pipe that comes off of the left ventricle, and it pumps blood to the whole body. This is where oxygenated blood, where we think of red
blood with oxygen in it, reaches the rest of the body. So if we have inflammation
in the aorta here, you’ll see at least two
cardiovascular problems. First in the eyes we have uveitis. You can have redness, inflammation. This uveitis is kind of near
the front chamber of the eyes. It can lead to redness, pain, discomfort. They can be afraid of light. They can see things floating
in front of their vision that’s not really there
or not physically there. So that’s uveitis, and it has an HLA-B27 association as well. And then in the aorta, like I said, this is where all the
blood goes to the body. So if we have inflammation, inflammation in the
walls of the aorta here, we can get what’s called an aneurysm. An aneurysm is kind of like
if you have a pipe here and you have some slack in the walls or some weakening in the
walls, kind of bulges out here and becomes a weak point in the pipe. This can happen in our blood
vessels all over the body, but if it happens here,
this where the heart and the aorta are connected
is the aortic valve. Very important valve
that prevents the blood from flowing this way, the
backflow into the heart. So if you have uveitis,
you might have a stretching or an aneurysm near the
opening here, near the valve. This part is just slack, and
the valve can’t close properly. And then what you get is some backflow into the chamber of the heart. And we use green to show backflow. So red, forward flow. Green is back. So not only is the body
not getting enough blood, but the heart has to pump extra volume because each time what’s
pumped out comes back in. So this can lead to a
serious problem in the heart, and we call it aortic regurgitation, meaning from the aortic
valve there’s backflow. Regurgitation. This is a side effect of the aortitis, but it’s also it’s own disease. Oh, I forgot to write
out aortitis, aortitis. If you realize the pattern here, -itis. Itis in spondylitis, everything
-itis means inflammation. Unfortunately, AS is very
difficult to diagnose. DX for diagnosis. Because the symptoms,
even though it looks like I’ve demonstrated a pattern here, it really can occur anywhere. It can just look like plain
old osteoarthritis for years. So it’s a tricky thing to diagnose, and there’s different ways to
go about it, different levels. So we can start with an x-ray. The bamboo spine, if it’s
already fused, we can see it. There might be blood tests,
because the blood will show us, there’s no AS blood
test, but it will show us how much inflammation is there. For example, the erythrocyte
or red blood cell sedimentation rate. This is a marker for inflammation. So is the C-reactive protein. So these are also nonspecific to AS, it could be any autoimmune disease, but at least it will help
us know we’re dealing with an autoimmune disease and
not just wear and tear. There’s also genetic, because
this disease seems to have a pretty genetic pattern. Also, the coding for HLA-B27,
the coding for the antigen, we can trace that as well. And then there’s something
I guess we don’t really use to diagnose AS, but we do use it to track how it’s progressing,
how fast and how bad, and it’s called the Bath, which is the place in England
where it’s discovered, Ankylosing Spondylitis Disease Activity Index. What a mouthful. Everything is an acronym. But this index allows us to again track how this patient is doing over time, how they’re doing with their treatment. And speaking of treatment, managing AS can seem, can
look actually a lot like managing rheumatoid arthritis
or the autoimmune diseases because the principle is the same. You need to reduce inflammation. There’s a class of different drugs that with different mechanisms but they’re grouped together
as disease-modifying anti-rheumatic drugs, because it used to be developed for rheumatoid arthritis. So what’s special about
them is even though they go about it in different directions, it actually slows the
progression of the disease, not just treat the symptoms. And we’re going to use
this for AS as well. There’s tumor necrosis factor, which is something that causes
inflammation in the body. It’s basically something
that can program a cell to kill itself, which can
be helpful in preventing cancer within our body, but here it’s just acts to the inflammation. So TNF inhibitors can be used, again to reduce the inflammation
going around in the body. We can use NSAIDs. These are the over-counter, you think of probably as pain meds, for example, your ibuprofen. And they not only treat the pain, because the fused spine and everything can be really painful, they
can also reduce inflammation. And then stronger pain meds as well, depending on the level of discomfort. So, as you see, the theme here
is to decrease inflammation. That’s the most basic ankylosing
spondylitis in a nutshell. Remember that it can be similar
to rheumatoid arthritis, in terms of affecting the whole body and a lot of inflammation. But the fact that it fuses
and affects the spine, the eyes, the heart, and the
fact that it does not have rheumatoid factor makes it different.