Updated: Oct 21
Anesthesia choice and intraprocedural anticoagulation are critical for optimal patient outcomes, and IRs have some options when it comes to management during peripheral arterial disease (PAD) treatment. Dr. Sabeen Dhand and Dr. Kumar Madassery discuss their preferences for managing sedation and anticoagulation in lower extremity PAD patients.
The BackTable Brief
Moderate conscious sedation is ideal for most PAD patients, however some patients may become restless during longer procedures.
In certain patient populations, opting for general anesthesia may result in better outcomes due to reduced patient movement and subsequently less contrast use; minimizing contrast is especially important for patients with severe chronic kidney disease.
Heparin is the preferred anticoagulant for both Dr. Dhand and Dr. Madassery; following vascular access and a diagnostic run, a weight-based bolus of 100 U/kg heparin can be used with an ACT goal of 200-250 seconds throughout the procedure.
A cocktail of 2.5 mg verapamil, 200 ug nitroglycerin, and 3,000 units of heparin may prevent vasospasm and thrombosis during a pedal approach.
Disclaimer: The opinions expressed by the participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
Patient-Specific Sedation Options [Sabeen Dhand] Oh, I have a question, Kumar, and everyone else. Do you typically use moderate conscious sedation for your patients, or a lot of them under GA?
[Kumar Madassery] Majority of our antegrade procedures, if we're doing antegrade approach, are going to be moderate conscious. There's a few of them we do SAFARI with moderate conscious, if they're pretty stable. But I know that when you're dealing with a lot of the pedal ones, we're spending three, four hours, it's hard for anybody to stay still, even when they're conscious, so we'll go anesthesia, deep sedation, or sometimes general … but we don't like to do that. Mike, what about you with your [practice]?
[Michael Barraza] We did everyone at Penn with moderate conscious sedation. I'm sure that they've done a few with general anesthesia, but not in my experience.
[Sabeen Dhand] I agree. We do most of ours with moderate conscious, but a lot of this will come up in my workup now. Because I do notice I get a little bit of better outcomes when they are under GA, just because I'm not fighting their movement and what not. I'll assess the patient when I see them. If they're an old frail lady, who sometimes surprisingly is better under conscious sedation than old frail men, but I just get an assessment.
If I think there's something that's just giving me one ounce, I'm a little bit quicker to GA. So I would say right now I'm performing maybe about 15% to 20% of my outpatient procedures under GA now. Which I don't know is the right thing, increasing that, am I putting them at another risk?
[Michael Barraza] I think that sounds like a very reasonable number. Especially looking back to certain cases. I could very easily see myself starting to book the patients with really bad stage 4 CKD, because if anything, GA would save me a lot of contrast for the people wiggling around.
[Sabeen Dhand] Yeah, yeah. Exactly, exactly.
[Kumar Madassery] I think also the issue, if you try conscious sedation, which may work, it's great if it's working, then you find out the ones who can't tolerate on the table, then you got to reschedule them with anesthesia. You kind of spend extra time and another procedure, which if you think your patient population can tolerate it that’s great.
Heparin versus Angiomax for Intraprocedural Anticoagulation
[Kumar Madassery] I actually have a question for Sabeen. What is your intraprocedural anticoagulation and do you have issues with Heparin versus Angiomax? Let me know what you think.
[Sabeen Dhand] Surprisingly we don't really use Angiomax or anything. I was thinking about it, but we use Heparin. Typically once I get access, say I'm going up and over, I'll first access with a six french short sheath and I'll use an Omni Flush catheter and then get up and over. I'll do my whole diagnostic run and then once I switch over to my up and over sheath, that's when I end up anticoagulating the patient. And typically I used to start off a standard 5,000 unit of bolus. And now I've been just doing 100 units per kilogram. Which is now, on average, it's about 7,000 or 8,000 units to start the case.
And really as the case is going, if I'm doing a lot of intervention, then I'll typically, every 45 minutes of so, bolus about 2 to 3 thousand. You know I want to do ACT more, and I feel like our machines are not calibrated right, because they sometimes don't respond appropriately, or maybe they're real. But I haven't done, I don't know, I kind of just do it, and I've been luckily okay. When I have done ACTs I typically try to keep it between 200 to 250. And my typical below the knee, say a pretty long case, like a three hour case, I'll probably end up doing anywhere between 12,000 to 16,000 units of heparin, which is more than when I started. Last year I would say I would average about 5,000 to max 10,000. So I've been more aggressive lately, and I’d be interested to know what you guys do.
[Kumar Madassery] I think it's interesting. We use heparin primarily. I feel like in the community when we all talk about these things, we're seeing more and more patients that may be heparin resistant or something. When we see all these cases that they're saying they're doing a normal case, and suddenly there's thrombus that just won't kind of stop. So I don't know what's going on, but we primarily use heparin.
I agree with you we typically start at 5,000. If we're letting the fellow kind of get the access and start, and we know it's a disease vessel, we'll get 5,000 after they get access, just because you know they're going to be playing around in the artery, in the aorta. It's actually really one of the things my partners taught me, if the fellow's in there starting the angio, and you know there’s a lot of disease, just give 5,000 at the start. If we're in there from the start, then we give it after we do our sequential run, like Sabeen does. So it's very operator dependent. But we typically start with 5,000. And I do agree with you, I think the weight based may be a better way to go. And we do check ACTs. It was painful the last few years because the machine would take a minute to read, but now I think we got some newer machines where they can do it on the spot. So it's kind of sped up how fast the results come.
[Sabeen Dhand] I have the old machines then, yeah. It takes a little bit.
[Kumar Madassery] There's a point of care style one or something now that's available and that’s what we use. Where they can instantly, in every room, just check it for us quickly.
[Michael Barraza] Yeah, at Penn it would take one or two minutes, and it's just like time would stop. It's just like how it is when you're holding pressure. It's like time slows down to a halt.
[Kumar Madassery] Yeah. Yeah, the newer machines are pretty fast.
[Sabeen Dhand] Maybe it's more a fact of being inpatient or a little bit of laziness that I don't do it, and I should. Because I think it would gear and titrate my heparin better. Luckily, knock on wood, I haven't seen too many thrombi forming after intervention. I've been lucky in that. It's happened once or twice, but when you go to these meetings and they talk about Angiomax, I feel like they're saying it happened 10% or 15% of the time, which I don't see that in my patient population.
[Kumar Madassery] Yeah, we see it every now and then rarely, but I know some people who are just showing it out there on Twitter, but again, I agree with you. I don't see it that often.
Preventing Thrombosis During Pedal Access
[Sabeen Dhand] ...When I get pedal access I use a radial artery cocktail, I just treat it like a radial artery. I'll put 2.5 verapamil, 200 of nitro, and I'll even put two or three thousand units of heparin.
[Kumar Madassery] Yeah, that's interesting. That's a good approach. We've never really used the cocktail from the leg, and we haven't had any complications, but that's not a bad safety guard.
[Michael Barraza] Yeah, and quite frankly I don't see a reason not to.
[Sabeen Dhand] Yeah, really I just treat it like the radial artery. It's really just to keep that flow going across the inner dilator, the Quick-Cross, and yeah, I haven't had issues with hemostasis at the pedal site or anything like that. Yeah, I recommend that cocktail.
Dr. Sabeen Dhand is a practicing interventional radiologist at PIH Health in Whittier, CA. Dr. Kumar Madassery is a practicing interventional radiologist with Rush University in Chicago. Dr. Michael Barraza Jr is a practicing interventional radiologist at Radiology Alliance in Nashville.
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