Alright. Let's talk about dyspnea now.
Dyspnea is something you see fairly commonly.
Patients maybe don't always complain of it.
Sometimes you find it with a low pulse
oximetry or a high rate of breathing.
But let's take a look at a case to start.
I’ve got a smoker with increasing dyspnea.
He’s definitely smoking.
You’re seeing a 60-year-old man.
He complains of increasing dyspnea
for the past three weeks.
And we’ll use this case – as we go through,
think about what your differential diagnosis is and then we’ll move
into the major causes of dyspnea or shortness of breath.
So, he's got – if you look at the right there,
dyspnea over the past three weeks, it
began after an upper respiratory infection.
He's got a persistent cough, but no fever.
And his past history, he says, yeah, maybe there was some asthma or
some chronic obstructive pulmonary disease, but he’s not really sure.
And now, we’re going to the left side.
He’s used now albuterol metered dose inhaler and
as well he uses an inhaled steroid intermittently.
Past medical history also includes hypertension.
He was treated with a beta blocker,
a calcium channel blocker
and an ACE inhibitor.
He has a 30-pack year of smoking history and
he now smokes a half pack of cigarettes daily.
So, what do you think – just think about what
you may think is going on with this patient.
We’re going to come back to him at the end.
Oh, I forgot to mention his vitals,
of course, that’s very important.
Before you even go in the room,
you want to check those out.
You can see he’s breathing a little bit
(inaudible) 20 breaths per minute.
His oxygen saturation is down,
not severely, but 94%, not normal.
His pulse is getting near tachycardic and
there's no doubt his blood pressure is high.
Lots to consider here.
So, let’s take a look at the major differential
diagnosis for shortness of breath or dyspnea.
Let’s start with asthma, one of the more common conditions,
chronic obstructive pulmonary disease,
heart failure and ischemic heart disease.
Those are a great four to start with,
but it's not a comprehensive list.
Interstitial lung disease can also promote
dyspnea as, of course, can pneumonia.
There’s psychogenic dyspnea as well,
people with panic disorder or severe anxiety disorders.
And iatrogenic, sometimes giving patients,
like this patient, with a history of asthma,
possibly a beta blocker,
particularly a non-selective beta-1, beta-2 beta blocker
can be dangerous for them,
And it’s not just that he might have one of these diagnoses,
and this is a big hint for you
who are thinking about this case,
dyspnea may be due to multiple
causes in about a third of cases.
And in addition, there’s some less common
things to think about that don't usually
come up that much in clinical practice,
but certainly can consider GERD which is common,
but rarely causes dyspnea.
May cause cough.
I think that cancer is always on a differential
diagnosis for just about any symptom.
Aortic stenosis and severe pulmonary
valve insufficiency are fairly rare thankfully.
Pulmonary embolism usually presents more acutely,
and so acute dyspnea is not really
what we’re talking about, as in our case.
It's usually something more subacute or chronic,
but patients can get chronically dyspneic
who have had a history of pulmonary embolism.
And then atrial fibrillation is also –
promotes dyspnea as well.
So, I think some of the key elements to history,
as I just mentioned, duration.
So, a sudden attack of shortness of
breath is a lot more concerning.
That patient needs to be evaluated
urgently for conditions such as
myocardial infarction and pulmonary embolism.
But for these subacute cases,
could it just be a simple recovery – this prolonged,
after an upper respiratory infection.
Could it be an exacerbation of COPD?
And then, how long was he
having symptoms before that?
In our case,
it sounds like he was using albuterol
metered dose inhaler along with a corticosteroid.
So, I assume he does have one of
those pre-existing diagnoses.
He’s probably had asthma and/or COPD for a long time.
How does it relate to exercise?
That's helpful for conditions particularly such as COPD,
asthma and heart failure,
but it doesn't help you differentiate
between those three very much.
therefore, it's important to call out specific symptoms
to heart failure because they will be different than those in COPD.
So, patients with orthopnea who need multiple pillows at night,
those with paroxysmal nocturnal dyspnea,
those with lower extremity edema
suggesting a more heart failure diagnosis.
And then, think about medications as well.
Have they tried – how does he do
when he uses albuterol inhaler?
Does it improve his symptoms dramatically?
That’s going to be more consistent with asthma.
Does it have a mild effect?
Maybe it’s more COPD.
Does it have no effect whatsoever?
Maybe it’s heart failure.
And beta blockers.
When he takes his beta blocker,
does that make his symptoms worse?
That would indicate some kind of airway hyperresponsiveness.
And then other risk factors to worry about,
pulmonary embolism, looking at his risk factors for thrombosis.
If he's having a lot of palpitations,
maybe he is having arrhythmia such as atrial fibrillation,
promoting that shortness of breath.
So, just to understand, patients with dyspnea,
vital signs may well be normal.
You’re going to be listening for wheeze and/or crackles,
so some kind of pulmonary findings.
And then again,
look for signs of heart failure.
We already covered the symptoms,
but look for jugular venous distention,
the presence of edema,
the presence of an S3 on cardiac exam.