okay well welcome to another MedCram lecture we were just talking about
asthma in our first lecture about the causes the pathophysiology where exactly
this is happening this is happening in the small Airways there's many different
causes for asthma some people just have asthma because of the air they breathe
and the other genetic makeup that they have but there are things that can
actually mimic asthma and set it off and if you get rid of these things you can
make it better so like things like GERD gastroesophageal reflux disease post
nasal drip some people even have a condition associated with sampras triad
where they take an aspirin or an end set of some sort like ibuprofen or leave and
this can cause the patients to actually get set off an asthma exacerbation so
things to look out for what we're going to talk about today though is that the
diagnosis in this lecture so asthma is a clinical diagnosis type of things that
you might hear about in patients are patients who say you know when they
breathe cold air they they suddenly get a tightness in their chest and it's hard
to breathe they may wheeze maybe exercising because
they're exercising the air that's moving through their lungs is moving so quickly
that it can't be warmed and so the air inside the bronchus is is cool enough so
that it's good actually cause inflammation and constriction are the
things that can cause asthma is just an allergy to food that can cause them to
get it so these these type of symptoms of wheezing chest tightness episodic
after they they do things or if they smell different types of perfume or if
they're around someone with cigarette smoke this should make you think of
asthma but how do we make a numeric diagnosis we can do something called
pulmonary function tests and if there's any questions on that please refer to
our pulmonary function test lectures the thing about pulmonary function tests
though that may be misleading is of course that asthma is reversible so
sometimes it's bad sometimes it's good so if you schedule a patient for a
pulmonary function test and they're asthmatic you just don't know it yet and
they go in and they're having a good day well the pulmonary function test may
just come out as being normal so then what do you do well
it's also possible that it might come out to be abnormal and it may show
obstruction and from our lectures you know that obstruction is where you have
an fev1 / FEC of less than 0.7 that's also the
definition for COPD the nice thing about COPD ironically in that case is that
COPD doesn't get better so it doesn't matter when you get there
pulmonary function test that's always going to be less than 0.075 struction
it's possible that you could send the patient in they're having a good day and
they've got a normal pulmonary function test well if that's the case you do a
provocative test at that point that provocative test you're provoking the
small Airways to see whether or not they're reactive in nature and the name
of that test is called a methacholine challenge test so that's a methacholine
challenge and that's where we have patients breathe in a concentration very
small concentration of methacholine now you should know kollene it's a analog of
a muscarinic agonist in you as you recall from our first lecture if you
stimulate the smooth muscle with choline or acid steel choline or a muscarinic
agonist you're going to get constriction usually if a normal person were to
breathe in a methacholine concentration nothing should happen but if they
constrict and their Airways get smaller that is suggestive that they have
reactive Airways disease or in this case asthma and let me kind of plot for you
what this looks like so if you were to graph this and we were to plot fev1 here
on the y-axis and arbitrarily set this to a hundred percent that's what the
patient can do and then what we do here is we do different trials okay here we
do a control and of course the patient by definition is always going to breathe
at one hundred percent of their first try and then what we start to do is we
start to use a very small concentration like let's say 1 to the 16th
concentration of methacholine and we keep going 1 to the eighth one to the
fourth 1/2 one concentration and we see what happens now in a normal patient
you're going to really not much have much change at all ok so this is what
they would look like this is a patient without asthma without reactive Airways
disease however in a patient with asthma depending on if it's very reactive or
not so reactive let's let's pretend that they in this case are very reactive you
might see something like this ok and if they weren't very reactive let's say
they were mildly reactive you might see something like this
okay now the lie I didn't draw for you at the beginning was the 80% mark
because that's the key that's what determines when we stop this test so
clearly here in the very reactive patient going from 1 to 16 to 1 to 8 we
cross the line at this point and so when that were to happen we would have
reached a reduction of by about 20% in fev1 or more and the patient would then
show reactivity so it's a positive test at that point the next thing we would do
of course is instead of giving 1/4 concentration we would give them a beta
agonist like albuterol and it would go back up this V shape on a methacholine
is suggestive and very indicative of reactive Airways disease same thing for
this patient we would do the same thing now the purple versus the blue the
purple reacted earlier in the test meeting this patient is more reactive
the blue reacted later in the test meaning less reactive but still reactive
the yellow is the one who never reacted so the purple and the blue would both be
diagnosed with reactive Airways disease and again this is a methacholine
challenge test ok let's talk about the treatment of asthma ok so since asthma
is a reactive disease before we even start talking about medications we got
to start looking at what may be causing it so I want to spend a little bit of
time here because if you just skip to the medication part you could be
overlooking something that you might be able to get rid of because medicines
have side effects especially if you could be putting this patient on a
medication for a long period of time you want to make sure that you're not giving
the medication that they don't need so you need to remove causes and I alluded
to this earlier but some of the things that I would definitely look at is down
comforters down pillows so these are down feathers you're
putting up right next to your nose right next to your face you're sleeping with
it and you're staying for it for six or seven hours a night definitely want to
consider that putting a mattress cover on pets that sleep with you okay
sometimes you're allergic to the pets getting them out of the bedroom looking
for other things that might that you can control you know you can't control
everything there's there's pollen in the air you can't control that but these
things in your environment you can control so looking for those sorts of
things looking for post nasal drip treating that the treatment for that is
intranasal corticosteroids looking for gastro esophageal reflux disease this is
a big one don't underestimate how much gastroesophageal reflux disease driven
asthma there is out there the treatment for GERD is making sure the patient is
elevated when they go to sleep at night making sure they don't eat anything
three hours before they go to bed making sure they're avoiding spicy foods
avoiding alcohol caffeine cigarettes that sort of thing so I can't stress
enough looking for the underlying cause because this is a reactive disease and
we really need to make sure that we're eliminating that once you've done that
let's talk about pharmacotherapy okay so everybody is going to get certain types
of medications and the one that everyone's gonna get is a Samba s a B a
that's a short-acting beta agonist specifically its albuterol comes in many
different forms there is also this is an enantiomer there's a D and an L or R an
S form the other one that you will see is leave albuterol okay there's many
different brand names for albuterol there's pro air there is ventolin there
is xopen X which is the brand name for leave albuterol everybody needs to carry
one of these around with them wherever they go and they need to be educated on
that because you never know when an asthma exacerbation is going to hit and
they need to make sure they've got a rescue inhaler with them now there's
always the debate metered dose inhalers versus nebulizers there's really no
difference between these two the MDI is which are
amita dose inhalers are actually easier to carry around the nebulizers you've
got to have power for some people can't activate the md eyes and so in those
cases i don't have a problem giving nebulizers these are the things that
people use on a as-needed basis so if they have an exacerbation they can use
it it's usually prescribed up to every four to six hours two puffs that type of
thing so everybody gets one of these things no matter how severe their asthma
is if it's very mild this may be enough so if they're only having an
exacerbation once or twice a week or a flare-up this may be all that they need
now if they're having difficulties with exercise and they know exactly what it
is that flares it up then they can take this before they're about to do that
exercise and that would eliminate the need for it later it's always better to
treat before the problem comes then after there is a distinction made
between intermittent and persistent asthma intermittent is if it's two or
less times per week okay if that's the case then this is all you need if it's
persistent however if you're having to use this albuterol inhaler more than two
times per week then it's persistent at that point we need to go to something
higher and we'll talk about that okay so let's talk about these steps that are
reported in terms of treatment from one being the least severe all the way up to
six being the most severe and as we talked about step one is the
intermittent asthma and so the Saba or the short-acting beta agonist is all
that's needed once you have more than two exacerbations per week because of
the fact that you're having inflammation that's the cornerstone there you're
going to start the patient everybody gets a Sabba of course but you're going
to add an inhaled corticosteroid and you could start this out of the low dose and
go from there so I'll say a low dose
when you get to step three if that's working and if your if the patient is
still using this - 2 + times per week then move on to the next step which
would be of course keep using that Sabba if you'd have to and use that low-dose
inhaled corticosteroid so you can use low dose or medium dose okay and these
inhaled corticosteroids by the way are medications like fluticasone mometasone
budesonide these are all inhaled corticosteroids that come as packaged
into many different marketing tools you'll see advair you'll see symbicort
you'll see dual era these are all inhaled corticosteroids as combinations
so you use the Saba which is the albuterol that's going to take care of
your exacerbations and then you want to add this inhaled corticosteroid to
reduce the inflammation and so you can either increase the dose to a medium
dose or at step three what you can do is you can add a lab la VA and that's a
long-acting beta agonist not a short-acting but a long-acting now I
want to make a point here that's important they're long-acting beta
agonists are medications like salmeterol and for Adel okay for moderate and some
either all these are the two long-acting beta agonists I want you to notice an
important point they may ask you about this and test you on a test regarding
this is that the lava is always added to the inhaled corticosteroid never in
asthma will we ever start a patient on a mono therapy with Alaba
a long-acting beta agonist first before starting the inhaled corticosteroid they
have noticed and there there's some literature out there that there are
increased cardiac deaths when a patient is placed on just a lawn acting beta
agonist without an inhaled corticosteroid so you can see as we step
up the lab is always added to the inhaled corticosteroid I think I made
that point okay step four of course we're gonna go back and continue the
Saba and we're gonna probably be using an inhaled corticosteroid slash lab ah
okay the other thing you can add here as an alternative is this Luco
I mean receptor antagonist that would be medications like montelukast or zephyr
Lu caste these are medications like singulair
accolade those are the brand names for them and remember what we talked about
before this medicine is actually very helpful if you know you're dealing with
something like santer's triad where you've got nasal polyps and aspirin or
NSAIDs sensitivity these are medications that that you could add at this point
and these are basically inhibiting the leukotrienes when we give it to step 5
then we're going up to Sabbath of course we always have the Sabha and the inhaled
corticosteroid / lab but these are high-dose inhaled corticosteroids so
we're using very high dose in combination with your lab so you've got
a low dose a medium dose and a high dose now when you get up here to step five
there's another medication that I've alluded to that you could use remember
we talked about IgE in the first lecture when these immunoglobulins are high they
could be driving the reaction there's a medication called o mal is you mAb which
is actually an antibody itself which attacks the IgE antibody now this is a
very expensive medication we don't use it very frequently and we usually use it
if nothing else is going to work but that's another potential thing that we
can use and then finally when you get up to stage six you're using everything
that we use before but now you're putting the patients on oral prednisone
which we don't like to do now let's talk about side effects briefly Sabah these
are the short-acting beta agonists tachycardia you have to watch out for a
fast heart rate inhaled corticosteroids these are inhaled corticosteroids even
though they're being inhaled there are some side effects that you have to be
aware of osteoporosis pneumonia and make sure your parents are aware of this also
you need to rinse mouth out after use because they can cause fungal
infections on your tongue the OMA Lizzie mAb this has got a side effect of cancer
of lymphoma so you definitely want to be having a conversation with your patients
in terms of risks and benefits the risk of cancer is pretty small and you're
gonna use Oh Melissa mab if you've got a higher risk of death from asthma than
you would from cancer okay so just be aware that you've got to always weigh
the risks and benefits of course oral prednisone increases your risk of
osteoporosis pneumonia and fungal infections but this is higher than
inhaled corticosteroids because this is being given orally and it's getting into
your system systemically okay so that was a overview of asthma the
pathophysiology causes diagnosis and treatment thanks for joining us
you