Nitro/verapamil for radial a-lines

[Maverikk]

I believe @pgg and @PpfSuxTube mentioned this in another thread and I wanted to have one to discuss this topic. How many people do this? What doses do you use? I know our vascular people do 200mcg of nitro and 1mg of verapamil into their sheaths to dilate. For people who inject nitro peri-arterial with the local do you get any hypotension? Not sure how much or if any would be absorbed or go systemically. I'm thinking for the sick tiny artery people this may be of some benefit. Anyone use verapamil?

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[PpfSuxTube]

Never done verapamil. Nitro about 20 mcg per ml 2% lido. Never seen it cause systemic hypotension that's in any shape important


To be honest I've totally abandoned it in the last year and just do brachials instead. Radials are random number generators

 

[dchz]

Radials are random number generators

What do you mean by this?

 

[PpfSuxTube]

What do you mean by this?

Radial-to-femoral pressure gradient quantification in cardiac surgery

A radial-to-femoral pressure gradient (RFPG) can occur in roughly one-third of cardiac surgical patients. Such a gradient has been associated with smaller stature and potentially smaller radial artery diameter. We hypothesized that preoperative radial ...

www.ncbi.nlm.nih.gov

 

[drmwvr]

Radial-to-femoral pressure gradient quantification in cardiac surgery

A radial-to-femoral pressure gradient (RFPG) can occur in roughly one-third of cardiac surgical patients. Such a gradient has been associated with smaller stature and potentially smaller radial artery diameter. We hypothesized that preoperative radial ...

www.ncbi.nlm.nih.gov

 

[nimbus]

Radial-to-femoral pressure gradient quantification in cardiac surgery

A radial-to-femoral pressure gradient (RFPG) can occur in roughly one-third of cardiac surgical patients. Such a gradient has been associated with smaller stature and potentially smaller radial artery diameter. We hypothesized that preoperative radial ...

www.ncbi.nlm.nih.gov

I’ve done double Aline’s (radial+femoral) for most of my career. While the gradient can be significant while on pump and immediately after weaning, it usually resolves 20-30min after successful weaning. I agree it can prevent unnecessary vasopressor administration. But I wouldn’t say radial Alines are random number generators, especially in the absence of CPB. Even with CPB, radial pressures often correlate to more central pressures.

 

[sevo00]

Never done verapamil. Nitro about 20 mcg per ml 2% lido. Never seen it cause systemic hypotension that's in any shape important


To be honest I've totally abandoned it in the last year and just do brachials instead. Radials are random number generators

But you prob do brachial because you do cardiac and know you are giving huge doses of heparin. For the rest of us doing brachial is too high risk of thrombosis since we are not giving heparin

 

[2buckchuck]

But you prob do brachial because you do cardiac and know you are giving huge doses of heparin. For the rest of us doing brachial is too high risk of thrombosis since we are not giving heparin

I always internally poo-poo’d the thrombosis/ischemia risk (bc I’d never seen it). But a few months ago I put one in for a cardiac case - used a micropuncture kit with US and a tiny catheter. As soon as the catheter went in, the signal on the ipsilateral hand pulse ox went away (pre-op RN noticed it immediately). I put a dressing on the line, couldn’t feel a radial pulse. Pt then had terrible capillary refill on the same hand (was normal on opposite side), and with US the tiny radial artery didn’t pulsate at all. Line aspirated and flushed fine, didn’t improve distal perfusion. I nearly had a heart attack, debated what to do for a minute. Ultimately pulled the line after a minute or two, everything went back to normal. Pt did ok. That scared the dookie out of me.

 

[sevo00]

I always internally poo-poo’d the thrombosis/ischemia risk (bc I’d never seen it). But a few months ago I put one in for a cardiac case - used a micropuncture kit with US and a tiny catheter. As soon as the catheter went in, the signal on the ipsilateral hand pulse ox went away (pre-op RN noticed it immediately). I put a dressing on the line, couldn’t feel a radial pulse. Pt then had terrible capillary refill on the same hand (was normal on opposite side), and with US the tiny radial artery didn’t pulsate at all. Line aspirated and flushed fine, didn’t improve distal perfusion. I nearly had a heart attack, debated what to do for a minute. Ultimately pulled the line after a minute or two, everything went back to normal. Pt did ok. That scared the dookie out of me.

Exactly. Why I won’t do brachial

 

[Bertelman]

I don't exactly seek out brachials, but our minimally invasive valves do gets bilateral brachs.

 

[2buckchuck]

I don't exactly seek out brachials, but our minimally invasive valves do gets bilateral brachs.

Curious as to the reasoning?

 

[anaesthetic]

Curious as to the reasoning?

He hates distal perfusion.

 

[Bertelman]

Au contraire, I am pro-perfusion.

You arrest the heart with an Endo Balloon. If it migrates distally, it can occlude flow to the Innominate. Bilateral brachials are the most reliable monitoring to detect this.

Previous surgeon allowed a radial on the left. This one insists on brachials. It’s his surgery, he orders them, I don’t argue.

 

[DrN2O]

I always internally poo-poo’d the thrombosis/ischemia risk (bc I’d never seen it). But a few months ago I put one in for a cardiac case - used a micropuncture kit with US and a tiny catheter. As soon as the catheter went in, the signal on the ipsilateral hand pulse ox went away (pre-op RN noticed it immediately).

Was it the 5fr MP sheath, a 20g catheter, or the inner cannula of the MP kit? That's why I always put a pulse ox on the ipsilateral limb if possible. What were you deciding other than remove the line, calling vascular with the line in place?

 

[vector2]

Was it the 5fr MP sheath, a 20g catheter, or the inner cannula of the MP kit? That's why I always put a pulse ox on the ipsilateral limb if possible. What were you deciding other than remove the line, calling vascular with the line in place?

There is def no reason to put anything bigger than a 4fr MP in a brachial or femoral if it's only being used for pressure monitoring

 

[drmwvr]

There is def no reason to put anything bigger than a 4fr MP in a brachial or femoral if it's only being used for pressure monitoring

View attachment 385743

why put something that big in?

 

[Ronin786]

There is def no reason to put anything bigger than a 4fr MP in a brachial or femoral if it's only being used for pressure monitoring

While you don't need anything larger than a 4Fr, there is nothing to suggest a 5Fr in the brachial is going to impede arterial flow.

This is based off the IR guidelines for access, for a 3mm vessel a 5Fr is going to occupy ~30% of the vessel.

Reducing catheter-related thrombosis using a risk reduction tool centered on catheter to vessel ratio - Journal of Thrombosis and Thrombolysis

In vascular access practices, the internal vessel size is considered important, and a catheter to vessel ratio (CVR) is recommended to assist clinicians in selecting the most appropriate-sized device for the vessel. In 2016, new practice recommendations stated that the CVR can increase from 33...

link.springer.com

I do wonder if these arterial occlusion/thrombotic events are more prevalent in patients where this rule is violated and whether we should be routinely measuring vessel size.

 

[2buckchuck]

Was it the 5fr MP sheath, a 20g catheter, or the inner cannula of the MP kit? That's why I always put a pulse ox on the ipsilateral limb if possible. What were you deciding other than remove the line, calling vascular with the line in place?

it was a 20g 12cm catheter that Arrow makes. There was a bare bones micropuncture kit with a good needle, good wire and a sheath that I’ve never used. I also opened an arrow prepack kit for the lidocaine, 20g catheter etc.

In my head, if removing the line didn’t fix it my plan was: call the cardiac surgeon and tell him what was going on (I did this anyways). Discuss postponing case, discuss stat doppler vs CTA of affected extremity. From there it would have been vascular - I was lucky at this job to be really friendly with the heart surgeon (we play video games online together) and the vascular surgeon (he was one of my references for my new job).

I asked my vascular friend about it later that day, he just kinda shrugged. I’m guessing the fix would have been small cutdown + fogarty embolectomy if thrombus, small cutdown + stent if a dissection in the vessel. We had a pulse ox on that hand the whole case and when we got to the ICU I asked them to do q1h pulse checks on that arm.

I ended up being able to get a radial on the other arm without much of an issue - both radials looked not great with US and I didn’t want my line to poop out. Did the case, I think a CABG, and she did fine. The heart surgeon messed with me the next day, said “oh yeah she had her arm amputated overnight”.

 

[Bertelman]

Sounds like the surgeon I used to work with.

 

[sanityonleave]

While you don't need anything larger than a 4Fr, there is nothing to suggest a 5Fr in the brachial is going to impede arterial flow.

This is based off the IR guidelines for access, for a 3mm vessel a 5Fr is going to occupy ~30% of the vessel.

Reducing catheter-related thrombosis using a risk reduction tool centered on catheter to vessel ratio - Journal of Thrombosis and Thrombolysis

In vascular access practices, the internal vessel size is considered important, and a catheter to vessel ratio (CVR) is recommended to assist clinicians in selecting the most appropriate-sized device for the vessel. In 2016, new practice recommendations stated that the CVR can increase from 33...

link.springer.com

View attachment 385749

I do wonder if these arterial occlusion/thrombotic events are more prevalent in patients where this rule is violated and whether we should be routinely measuring vessel size.

Just to add to the confusion:

Micropuncture sheaths (like the Cook set https://www.cookmedical.com/products/e4790704-1c72-48bc-95f7-6c5bd6ea3b53/), which I think a lot of us use for brachial lines, are measured by their outer diameter (4Fr) - so that's the largest dimension in the artery.

However, if you're using something like a Pinnacle sheath (PINNACLE® Introducer Sheaths), which I like for femoral access due to the sidearm -- the French size is referring to the inner diameter -- and the outer diameter varies by manufacturer. This variability can even be clinically significant in small arteries (Variation in the outer diameter of vascular sheaths commonly used in infant cardiac catheterization - PubMed).

Obviously overall brachial is more risk for clotting, femoral more risk for bleeding, so I tend to use a slightly larger sheath with a sidearm (4Fr ID) for fem and a smaller 4Fr micropuncture for brachial -- though the MP sheaths are kind of a pain to sew in because they're not really designed with that in mind. The fem sheaths are also nice in that they have a diaphragm to introduce a wire through if you need to upgrade to ECMO/IABP/etc.

 

[PpfSuxTube]

Guys the risk of a 20g brachial a line is staggeringly low compared to the operation they're having. Give over. Move on

 

[anbuitachi]

I always internally poo-poo’d the thrombosis/ischemia risk (bc I’d never seen it). But a few months ago I put one in for a cardiac case - used a micropuncture kit with US and a tiny catheter. As soon as the catheter went in, the signal on the ipsilateral hand pulse ox went away (pre-op RN noticed it immediately). I put a dressing on the line, couldn’t feel a radial pulse. Pt then had terrible capillary refill on the same hand (was normal on opposite side), and with US the tiny radial artery didn’t pulsate at all. Line aspirated and flushed fine, didn’t improve distal perfusion. I nearly had a heart attack, debated what to do for a minute. Ultimately pulled the line after a minute or two, everything went back to normal. Pt did ok. That scared the dookie out of me.

how do you know its not vasospasm? did you scan the entire artery with ultrasound and doppler? its hard to believe a 20g art line occluded a brachial artery unless its a very tiny artery.

 

[anbuitachi]

I believe @pgg and @PpfSuxTube mentioned this in another thread and I wanted to have one to discuss this topic. How many people do this? What doses do you use? I know our vascular people do 200mcg of nitro and 1mg of verapamil into their sheaths to dilate. For people who inject nitro peri-arterial with the local do you get any hypotension? Not sure how much or if any would be absorbed or go systemically. I'm thinking for the sick tiny artery people this may be of some benefit. Anyone use verapamil?

our neuroIR guys do 200mcg nitro, 2.5mg verapamil. we do see some hypotension from it

 

[vector2]

While you don't need anything larger than a 4Fr, there is nothing to suggest a 5Fr in the brachial is going to impede arterial flow.

This is based off the IR guidelines for access, for a 3mm vessel a 5Fr is going to occupy ~30% of the vessel.

Reducing catheter-related thrombosis using a risk reduction tool centered on catheter to vessel ratio - Journal of Thrombosis and Thrombolysis

In vascular access practices, the internal vessel size is considered important, and a catheter to vessel ratio (CVR) is recommended to assist clinicians in selecting the most appropriate-sized device for the vessel. In 2016, new practice recommendations stated that the CVR can increase from 33...

link.springer.com

View attachment 385749

I do wonder if these arterial occlusion/thrombotic events are more prevalent in patients where this rule is violated and whether we should be routinely measuring vessel size.

After seeing that I'd feel much better if people were actually measuring the size of the vessel, either semi-quantitatively or quantitatively before slamming something in. And the IR guys probably need the larger catheters cause they're using them as working port access, whereas we should be trying to minimize catheter size whenever possible or reasonable for any access site.

 

[PpfSuxTube]

After seeing that I'd feel much better if people were actually measuring the size of the vessel, either semi-quantitatively or quantitatively before slamming something in. And the IR guys probably need the larger catheters cause they're using them as working port access, whereas we should be trying to minimize catheter size whenever possible or reasonable for any access site.

Have you ever done a tf tavi?

 

[sanityonleave]

Guys the risk of a 20g brachial a line is staggeringly low compared to the operation they're having. Give over. Move on

I support your underlying point: if you need the line to take care of the patient safely, put it in. Anesthesia has become so safe that some providers are so scared of doing any procedure that has risk attached to it that we're becoming ineffective (or simply turfing what should be our domain to the surgeons).

That said, brachial art line complications are uncommon but not benign. Even in the CCF data (which led them to claim the lines are "equally safe", at least for CV surg patients), the patients who did have brachial artery complications had significantly increased mortality. Now it's retrospective so it could be that those patients were just sicker at baseline, but their modeling did not immediately suggest that explanation.

 

[2buckchuck]

how do you know its not vasospasm? did you scan the entire artery with ultrasound and doppler? its hard to believe a 20g art line occluded a brachial artery unless its a very tiny artery.

It definitely could have been vasospasm. I have injected nitro into art lines (usually when we try to start weaning from bypass, the aortic valve is clearly opening on echo but the art line has little/no pulsatility and it’s been power flushed - this works sometimes). But I saw an ischemic limb and a patient who ideally would be going back for surgery soon with arms tucked for 3+ hours - I needed to get it sorted asap.

 

[pgg]

I believe @pgg and @PpfSuxTube mentioned this in another thread and I wanted to have one to discuss this topic. How many people do this? What doses do you use? I know our vascular people do 200mcg of nitro and 1mg of verapamil into their sheaths to dilate. For people who inject nitro peri-arterial with the local do you get any hypotension? Not sure how much or if any would be absorbed or go systemically. I'm thinking for the sick tiny artery people this may be of some benefit. Anyone use verapamil?

our neuroIR guys do 200mcg nitro, 2.5mg verapamil. we do see some hypotension from it

To state the obvious, it's very different to add some nitro to the local used to infiltrate around the artery, and to inject it intravascularly.

Of course 200 mcg of intra-arterial nitroglycerin causes hypotension. But there isn't any hypotension with peri-arterial infiltration.


I don't use nitro in my local any more, mainly because our art-line setups are kindly prepared by anesthesia techs, and because I just don't encounter significant vasospasm that often. If you do a lot of arterial lines, and use ultrasound for all of them, the number of times you encounter vasospasm due to needing multiple sticks and/or going after a marginal artery in the first place, just plummets to a number close to zero.

I support your underlying point: if you need the line to take care of the patient safely, put it in. Anesthesia has become so safe that some providers are so scared of doing any procedure that has risk attached to it that we're becoming ineffective (or simply turfing what should be our domain to the surgeons).

That said, brachial art line complications are uncommon but not benign. Even in the CCF data (which led them to claim the lines are "equally safe", at least for CV surg patients), the patients who did have brachial artery complications had significantly increased mortality. Now it's retrospective so it could be that those patients were just sicker at baseline, but their modeling did not immediately suggest that explanation.

Retrospective data is garbage.

The statistical methods the publish-or-perish guys use to "match" risk are are a bunch of handwaving.

I don't believe for a second that there are mortality differences in patient outcomes because of the brachial art-lines, and neither should you. The only way to match risk between experimental groups is in a randomized prospective manner, full stop. "Studies" like this are busy work to abuse residents and pad academic resumes.

 

[sanityonleave]

Retrospective data is garbage.

The statistical methods the publish-or-perish guys use to "match" risk are are a bunch of handwaving.

I don't believe for a second that there are mortality differences in patient outcomes because of the brachial art-lines, and neither should you. The only way to match risk between experimental groups is in a randomized prospective manner, full stop. "Studies" like this are busy work to abuse residents and pad academic resumes.

I agree they're capturing underlying illness, but I don't think a brachial embolectomy is a benign procedure -- especially if you're, I don't know, POD3 from your total arch. Even if you don't have a procedure, let's say we decide to heparinize due to the thrombus from the art line and now you rebleed into your chest and need a washout?

Again I agree with your sentiment that most of what we are capturing is the underlying illness, but I'm not sure I'm willing to grant you that all of it is. At the very least increased morbidity and LOS are likely to exist in those patients that do develop complications.

You're 100% right that retrospective data, no matter how fancy the propensity score matching, is largely garbage. I am thrilled to see the results of your RCT for radial vs brachial art lines. Until then, it's what we have, except for your (and others') anecdotes -- which are just unmatched, recall-biased, low-n retrospective data.

Again, I'm very much in favor of placing these lines when needed. I'm just in favor of a) considering the risk/benefit before it's done and b) also making sure we're using excellent technique (i.e., ultrasound) to minimize the risks.