Now what shall we do for imaging?
If you're very worried about this condition
or the patient has a known history of AAA
and they come in and they’re very unstable.
One of the first things you wanna do is you wanna get a surgical consultation.
So you wanna get your surgeon who’s on call on the phone
and let them know your concerns.
You wanna involve them early.
You wanna make sure that they're aware of your concerns
and you wanna make sure that they you know that you potentially
want them to come in and evaluate the patient
and possibly even take the patient to the operating room.
The next thing you can do is you can get a plain abdominal film.
And to be perfectly honest with you
this isn’t something that we do super regularly in the ED
when we’re looking for AAA, but you can potentially see a calcified aorta.
And obviously calcification in the aorta
will make you concern about further atherosclerosis or disease of the aorta.
The other testing you can do is CT imaging.
CT imaging is ideally done with IV contrast.
And when you do with IV contrast you're able to get the most information.
Now that’s not to say that if you can't administer IV contrast for your patient
that you shouldn't do the test at all
because a non-contrast study can actually still give you some information.
The CT with IV contrast though it’s gonna be the thing
that’s gonna give you the best look at your anatomy.
It’s gonna be the thing that’s gonna show you most accurately
whether there's a false lumen, whether the aorta is ruptured.
It’s gonna give you the most accurate information.
Ultrasound is the last test or the other test that you should be thinking about.
Ultrasound is great for patients who have hemodynamic compromise
because again, the ultrasound machine can be brought to the bedside of the patient
the patient doesn’t have to go anywhere or leave the Emergency Department.
So if your patient is unstable in any way, this is your test of choice, really.
It has a greater than 90% sensitivity and it’s technically adequate study.
Ultrasound, if you remember, is based on whose hands it’s in.
So it’s based on operator dependence.
An operator experience.
So someone who’s very good in performing ultrasounds
will likely have a more sensitive test.
It also depends a little bit on the patient’s body habitus.
So patients who are obese or overweight
or they have a lot of overlying bowel gas from their aorta
it may be more challenging to see what you're looking for.
Just a reminder, the normal size of the aorta in the abdomen is about 3 cm.
And when we’re looking at the aorta with ultrasound
we measure from the outside wall of the aorta to the outside wall.
You wanna measure on both longitudinal and transverse views.
So you wanna get a couple of different picture in order to make sure
that you know what you're looking at.
Obesity, tenderness in the belly can definitely limit your ability to perform this
because your pushing on the abdomen from the outside.
And bowel gas may limit the ability to get a good look at the aorta.
Because of the location of the aorta, all the intestines overlay it.
So it can sometimes be hard to get that posterior view.
Again, best for the unstable patient
as it can be performed at the bedside.
And the other thing that’s good about ultrasound
is that it’s performed more frequently or very readily
by emergency medicine physicians and it’s a big part of our training.
Sometimes you don’t even have to wait for the ultrasound tech from radiology to come
and help you out with that study.
CT scan again ideally done with IV contrast.
On the CT scan picture you could see that there is the original aorta
which is the bright white area in the center
and then the large area surrounding that is the area of aneurysm,
that grayish area that surrounds.
A CT scan without IV contrast still can get you a look
but might not necessarily tell you if there’s active bleeding
or get you as a good of an anatomy picture as the others.
CT is a good test for stable patients.
Because CT while it gives us lots of information and is a great test,
the patient still needs to go ahead and leave the Emergency Department.
One of the worst things in Emergency Medicine physician can ever hear
is a code blue or a cardiac arrest patient in the CT scanner.
That’s something that you never wanna hear.
You know, it does it happen?
It does from time to time,
but ideally you wanna make sure that you're selecting those patients
who are going to the CT scanner,
and that you're sending the appropriate patient to the CT scan
because you don’t want your patient who’s unstable to go there
and then become more critically ill
and have an arrest or a bad outcome in the scanner.