Acute Limb Ischemia: Rutherford Classification, Imaging Techniques & Essential Labs

[Dr. Alexander Ushinsky]
I think that when we are assessing the history of the patient, some important things to consider are whether they do have underlying peripheral vascular disease and trying to assess the etiology of why this patient may have developed acute limb ischemia. Making sure they don't have atheroembolic disease or something else that would require cardiology consultation, maybe considering whether they may have some coagulopathic process going on or are prone to clotting that may need to then follow up with a hematology referral.

The first thing is to take the patient's history and assess those risk factors. The other thing is the temporality of the limb ischemia. There are not infrequent cases where we are called for acute limb ischemia. When you actually speak to the patient yourself or the fellow speaks to the patient, you can ascertain that this is more on the worsening chronic limb ischemia, which you would treat sometimes less urgent fashion but it's certainly different.

Getting the medical history of the patient, like we discussed, getting the temporality of the symptoms. Always want to assess the progression of symptoms to see if the acute limb ischemia is getting worse. I tend to have my fellows try to grade the patient's face on the Rutherford classification acute limb ischemia grading, meaning assess their degree of sensory loss and their degree of motor weakness.

Then the other thing on the physical exam is obviously a pulse exam and an exam of the limb. The patient have immobile, paralyzed woody limb, or does the patient just have some subjective sensory loss but otherwise can wiggle their toes? That is a massive inflection point in how I determine to manage the patient.

[Dr. Chris Beck]
Going back to the physical exam, I don't know if you considered an extension of the physical exam, but do you guys Doppler the leg?

[Dr. Alexander Ushinsky]
Yes, we'll certainly get bedside Doppler.

[Dr. Chris Beck]
Oh, I didn't know. Sometimes you can just carry them around. Some places you just grab one off the IR wall and pop over. Cool.

[Dr. Alexander Ushinsky]
We usually do it, and they'll usually be at the bedside if the patient's in the emergency department. We have little carry totes with the Doppler and a little bit of gel for the fellows, definitely. The expectation is the fellow or myself if I'm going out there to the community hospital, we'll Doppler the leg. I will say that for the chronic limb ischemia patients, it can be difficult at baseline. It depends on what the patient's baseline vessels like. For those that have very calcified vessels, it can be very difficult to find those signals.

[Dr. Chris Beck]
Before we get into imaging, any lab work that's important to know ahead of time?

[Dr. Alexander Ushinsky]
Certainly all of the coagulation parameters, a normal CVC, and a chemistry panel to look at their kidney function. If you're really concerned about a pretty severely affected limb, you could start looking at lactate or other markers of tissue loss really, but if it's getting to that degree, there may not be much intervention that you can offer but certainly need to assess that.

[Dr. Chris Beck]
Moving from labs to imaging, I wanted to get your idea of how does ultrasound fall into the role of, like, how important is that for your practice and for your pre-procedure workup?

[Dr. Alexander Ushinsky]
Separate from the question of being able to Doppler, just pedal pulses or popliteal pulse. I would say that historically, I've relied a lot on CTA. I will say that, and we actually had a recent case of this where the patient just had so much severe calcific, small vessel disease and tibial disease that it was very hard to make out much of anything on the CTA below the knee.

In those patients, I think there's a really important role for a good duplex ultrasound from a vascular lab that can do a good exam to see the vessels and evaluate the weight forms if they're present.

[Dr. Chris Beck]
You touched on it, CTA versus MRA, prefer CTA.

[Dr. Alexander Ushinsky]
I think CTA is more readily available, especially in the on-call setting. I think getting a high complexity like a twist MRA is pretty difficult to do in an ER at 3:00 in the morning to get a good exam. The images that can be generated on a Monday at 8:00 AM are really nice, but it's very difficult in an emergency setting. The time commitment for that type of exam if someone who may have an emergent condition, a limb-threatening condition can be sometimes limiting.

[Dr. Chris Beck]
Absolutely. All right. Anything else I missed as far as workup goes? We did HMP, we did labs, imaging, anything else?

[Dr. Alexander Ushinsky]
The only thing I'll say is a lot of the patients are already on medication reconciliation, both for inpatient ordered meds and for outpatient medications, whether the patient's already on anticoagulation if they have not been put on anticoagulation and there's a high index of suspicion. Those are all important things to assess because actually, mobilizing your forces, and if the patient needs an intervention, bringing them for intervention may take some time and making sure that the patient's appropriately, medically treated, if nothing else is paramount.

[Dr. Chris Beck]
Will you guys go ahead and fill that gap as far as the medical treatment? You guys will haptenize them more?

[Dr. Alexander Ushinsky]
Definitely, especially in the community hospitals with the consultant being asked the question or order the exam, order the CTA, order the heparin drip or the Lovenox if the patient's not a good candidate for a heparin drip for whatever reason. In the university hospital where there are resident teams, we'll make the recommendation for whichever anticoagulation is appropriate for the patient if they haven't already received it from the referring provider.

[Dr. Chris Beck]
That's good. You guys are getting your fellows well-trained, right?

[Dr. Alexander Ushinsky]
In our practice here, we've had a very clinically-oriented practice for many years. We were the primary site for the attract trial for venous lysis and we've had an emitting service for a long time as well. Our fellows are generally very comfortable in terms of all aspects of inpatient management and interacting with the inpatient side of the hospital and the referring providers from hospital medicine or cardiology or whomever.

[Dr. Chris Beck]
That's just a way of things from here on out. I graduated eight years ago, and the IRS that are coming up now, they're just a new breed of super docs. Thank you for training these guys up and getting everyone, but you're kind of the ilk-like. Four years ago you were in fellowship, right?

[Dr. Alexander Ushinsky]
Yes, exactly right.

[Dr. Chris Beck]
That's awesome.

[Dr. Alexander Ushinsky]
It's definitely been the culture here for a long time. In retrospect, I hope that the fellows appreciate it. It's definitely burdensome to have to drive in at 3:00 in the morning to see a patient on call. It sounds luxurious to our colleagues who spend the night in the hospital three nights a week, but it becomes important, especially if you want to treat patients of any complexity or be involved in the medical decision-making for a patient.

[Dr. Chris Beck]
That's right. Patient prep, you've seen the patient, you've gone through the workup and you think this is a patient who needs to move on to intervention. The category is patient prep and we can start off in a couple areas, but one of the easy things to knock out is antibiotics, sedation level. Where do you stand on these things with these patients?

[Dr. Alexander Ushinsky]
If you'll allow me before we get into patient prep, one thought.

[Dr. Chris Beck]
Of course, Sasha. You're the guest. Of course, you can do whatever you want.