Case+2

Case #2__

Your vascular doctor’s nurse has just added on a patient for you to do an indirect arterial study. She has already obtained ABI’s on this patient who has claudication at rest in her left calf. Her ratios are as follows:

Right ABI: 1.1 Left ABI: 1.7

These are not numbers that I would expect with resting claudication. The normal values that you would expect for resting claudication would be <0.5, which would indicated severe claudication
 * Are these the numbers you expect with resting claudication?**

Madeline: I think they make sense (maybe not so much the right as the left). A normal ABI reading is .9-1.0, so the fact that this is 1.7 could mean that some of the vessels are calcified and will represent a bounding pulse. If the vessel walls are calcified it would demonstrate a chronic stenosis

Ashley: These numbers are not consistent with rest claudication, because rest claudication indicates a severe arterial disease. That would be associated with an ABI of less than 0.5, when both of these readings are above 1. The fact that the left ABI is significantly high above 1.0 could indicate pathology.

Jen: I would expect to see much lower resting ABI's on a patient with claudication at rest. These ABI's are considered normal on a healthy individual/what you would expect in a patient with no disease. On a patient with upper arterial symptoms, indicating a disease superior of the heart, or the upper extremities, these ABI's might indicate NO lower arterial disease, but instead a stenosis off the aortic arch, decreasing the pressures in the brachials, and increasing the resting ABI's.


 * Are they normal?**

McKenna: The right ABI is normal since it is 1.1 which is around the >1.0 range. The left ABI however is not normal. The ABI is 1.7 which is abnormally high and indications calcified arteries.

Madeline: This right seems pretty normal, but the left is not normal.

Ashley:These numbers are both normal and abnormal. The left ABI is only 1.1, which is still where the normal values lie for this test at 1.0. When we look at the right ABI, that reading is significantly greater than 1.0, so that means we should be suspecting something further going on in the artery. This is abnormal because it is even over the acceptable ABI of 1.3 still being a normal reading.

Jen: They COULD be considered normal in a healthy patient, especially in the side of 1.1 ABI. But since this patient has rest claudication, I am expecting calcific and incompressable arteries, producing falsely elevated pressures in the legs. According to the VA vascular lab, an ABI from 1.0-1.4 is normal, and >1.4 indicates calcified arteries.

McKenna: I would expect that the patient has calcific arteries which is causing the abnormally high ABI ratio. You may take Doppler waveforms so that you are able to assess the severity of the arterial disease based on the waveforms as well.
 * What might you expect is going on? How may you alter your exam based on these numbers?**

Madeline: I suspect there are calcified vessels. This means that the walls can't be compressed therefore the segmental pressures aren't accurate because you can never get the pulse to diminish in order to find when the pressure returns. This is going to cause the ratio to be high.

Ashley: I might expect that there are calcified arteries that are being tested in this case. When someone has non-compressible arteries, that indicates calcification and will also mean you have obtained higher pressures throughout the exam. For further testing, you should next get the Doppler pulses and/or PVR waveforms to evaluate flow in the artery.

Jen: I agree with McKenna, Madie, and Ashley -- this patient has falsey elevated segmental pressures/ABI's because the cuffs can't compress the calcific arteries in order to diminish the blood flow. I think that Doppler and even duplex imaging might be useful to take a closer look at 2D, color, and waveforms. In a normal patient, we would be expecting a triphasic waveform, but based on the possible severity of disease in this patient, the waveform may be biphasic or monophasic.