Large Vessel Arterial Pressure Monitoring

[sanityonleave]

SDN Anesthesia Hivemind--

What is your threshold for gaining large-vessel arterial access in patients with significant (or significant anticipated) vasopressor requirement?

There's obviously some (albeit not a huge volume) of data showing a significant discrepancy between radial arterial pressures and "central" arterial pressure (usually femoral). Here's a nice PulmCrit review: PulmCrit: A-lines in septic shock: the wrist versus the groin , and I've attached a 2005 paper looking at fem vs radial in liver transplantation.

I had a case from a while ago where the patient came to the OR on 18 of norepi and 0.08 of vasopressin, so I thought there was a very reasonable expectation that vasopressor requirement would get worse before it got better. I placed a brachial art line and there was a ~50 point difference in SBP, though only ~10-15 point MAP difference.

By the end of the case with the patient basically off vasopressors, the two arterial lines had equalized as seen in the second image.

Obviously large vessel arterial access carries more complications, esp in sick patients (sorry CCF, but I don't believe your data). So what's your practice for placing fem/brachial lines? Does the brachial actually count as "central", or do you prefer axillary? Do you think it makes a difference in the patient's overall morbidity? My thought in these extremely low SVR patients is that the extra vasopressor required to get 10 points to achieve the MAP goal could have a significant negative impact on tissue perfusion, but I have absolutely zero data to back that up.

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[dabears505]

Similar situation. Wondering what people would do. Patient on epi, ne, Vaso, phenl. Has an a line that is no longer functioning. Hands and feet look purple. Surgeon wants us to replace a line. Also patient a very bad vasculopath and septic. Would you place an a line in this patient?

 

[vector2]

SDN Anesthesia Hivemind--

What is your threshold for gaining large-vessel arterial access in patients with significant (or significant anticipated) vasopressor requirement?

There's obviously some (albeit not a huge volume) of data showing a significant discrepancy between radial arterial pressures and "central" arterial pressure (usually femoral). Here's a nice PulmCrit review: PulmCrit: A-lines in septic shock: the wrist versus the groin , and I've attached a 2005 paper looking at fem vs radial in liver transplantation.

I had a case from a while ago where the patient came to the OR on 18 of norepi and 0.08 of vasopressin, so I thought there was a very reasonable expectation that vasopressor requirement would get worse before it got better. I placed a brachial art line and there was a ~50 point difference in SBP, though only ~10-15 point MAP difference.

View attachment 368001

By the end of the case with the patient basically off vasopressors, the two arterial lines had equalized as seen in the second image.

Obviously large vessel arterial access carries more complications, esp in sick patients (sorry CCF, but I don't believe your data). So what's your practice for placing fem/brachial lines? Does the brachial actually count as "central", or do you prefer axillary? Do you think it makes a difference in the patient's overall morbidity? My thought in these extremely low SVR patients is that the extra vasopressor required to get 10 points to achieve the MAP goal could have a significant negative impact on tissue perfusion, but I have absolutely zero data to back that up.

My personal preference is that one should be thinking about fem or ax a-line once the requirement is ~12-15 of levo +- 0.04 vaso. And maybe less if we're talking about a little old lady or someone with small radials. I've seen too many times where pressors are being titrated to some wildly inaccurate clamped down radial pressure.

 

[anaesthetic]

My personal preference is that one should be thinking about fem or ax a-line once the requirement is ~12-15 of levo +- 0.04 vaso. And maybe less if we're talking about a little old lady or someone with small radials. I've seen too many times where pressors are being titrated to some wildly inaccurate clamped down radial pressure.

Anecdotally, we probably do a lot more brachial art lines than most practices. Some of our partners will go brachial for 100% of cardiac cases. Personally, if I anticipate significant hemodynamic issues or pressor requirements, I’ll go brachial right off the bat (high risk LVADs, heart/lung transplants, high risk CABGs, etc.). Aortic dissections will get two art lines, and I’ll usually have at least one of them be brachial. I haven’t heard of anyone in our practice having to go femoral recently (surgeons like to preserve the groin for ECMO), and we’ve had only a handful of axillary lines.

As a practice, we’ve had minimal complications (if any) with brachial art lines in the last few years. We have had, however, some complications associated with radial artery pseudoaneurysms requiring surgical repair and inaccurate radial art line measurements compared to aortic/central pressures.

Personally, I’ve had 3-4 cases where the radial art line was extremely inaccurate (>15 mmHg difference) and had to start some brachial lines under the drapes to compare, mostly detected when aortic pressures “felt” higher and otherwise the patient was doing fine. I’ve seen quite a few times in DHCA cases where the pressure differential between the two art lines will be vastly different coming off of CPB and equalize after a couple of hours, usually by the time we dropoff in ICU.

I trained at an institution where we would rather spend an hour and a half trying to get radials than go brachial/femoral. Now out in practice, I will happily place brachial lines on patients needing more reliable pressure measurements as I’ve had zero complications (so far). I’ve looked at the CCF data and so far, it’s been consistent with what we’ve seen in our practice. Trust me, our ICU docs and surgeons would be the first people to let us know if we’re doing something wrong.

 

[vector2]

Anecdotally, we probably do a lot more brachial art lines than most practices. Some of our partners will go brachial for 100% of cardiac cases. Personally, if I anticipate significant hemodynamic issues or pressor requirements, I’ll go brachial right off the bat (high risk LVADs, heart/lung transplants, high risk CABGs, etc.). Aortic dissections will get two art lines, and I’ll usually have at least one of them be brachial. I haven’t heard of anyone in our practice having to go femoral recently (surgeons like to preserve the groin for ECMO), and we’ve had only a handful of axillary lines.

As a practice, we’ve had minimal complications (if any) with brachial art lines in the last few years. We have had, however, some complications associated with radial artery pseudoaneurysms requiring surgical repair and inaccurate radial art line measurements compared to aortic/central pressures.

Personally, I’ve had 3-4 cases where the radial art line was extremely inaccurate (>15 mmHg difference) and had to start some brachial lines under the drapes to compare, mostly detected when aortic pressures “felt” higher and otherwise the patient was doing fine. I’ve seen quite a few times in DHCA cases where the pressure differential between the two art lines will be vastly different coming off of CPB and equalize after a couple of hours, usually by the time we dropoff in ICU.

I trained at an institution where we would rather spend an hour and a half trying to get radials than go brachial/femoral. Now out in practice, I will happily place brachial lines on patients needing more reliable pressure measurements as I’ve had zero complications (so far). I’ve looked at the CCF data and so far, it’s been consistent with what we’ve seen in our practice. Trust me, our ICU docs and surgeons would be the first people to let us know if we’re doing something wrong.

I also think CCF data checks out and brachial safety is fine. The caveat is that I'm talking about experienced operators who can actually find their needle tip under ultrasound + using small, sharp needles (like in a micropuncture kit) for the initial stick as to minimize chance of significant vessel trauma.

If one is the kind of person who has to look down at their needle instead of at the screen to confirm the needle is in the vessel (or god forbid you're trying to do a brachial with blind anatomic technique) then that makes me a bit more nervous about recommending brachial.



I like the following method but with no syringe on the needle.

 

[anaesthetic]

I also think CCF data checks out and brachial safety is fine. The caveat is that I'm talking about experienced operators who can actually find their needle tip under ultrasound + using small, sharp needles (like in a micropuncture kit) for the initial stick as to minimize chance of significant vessel trauma.

If one is the kind of person who has to look down at their needle instead of at the screen to confirm the needle is in the vessel then that makes it a bit more nervous about recommending brachials.



I like the following method but with no syringe on the needle.

View attachment 368011

View attachment 368012

Agree with your caveat. I think having ultrasound readily available has been a game changer. It’s a skill that requires constant refining, and there have been very few people (other than peds cardiac folks) who I’ve seen actually use this technique effectively.

Most people just assess where the artery is in relation to the black mark on the ultrasound probe and advance the needle until they get flash, which obviously works, but this technique falls apart when it’s a smaller artery that requires finesse and risks posterior wall puncture, hematomas, etc.

I use the ultrasound on 98% of my art lines, even radials, and I use and teach this exact technique (“creep”). Some people on here will think that’s ridiculous, but it beats digging around the wrist or arm for 5-10 minutes when you’re going to go to ultrasound anyway. Some of my partners almost never use the ultrasound, but they’ve been in practice for over a decade or more, so are more adept at landmark-based approaches. We’ve not seen many complications either way.

 

[JiPo]

Why guess and stab “blindly” when you can use the US to its 100% capability. I never understood people that only use US to find the vessel and then basically do aline or iv blind.

If using US for aline or IV, should use it to follow the needle tip.

 

[GassYous]

Agree with your caveat. I think having ultrasound readily available has been a game changer. It’s a skill that requires constant refining, and there have been very few people (other than peds cardiac folks) who I’ve seen actually use this technique effectively.

Most people just assess where the artery is in relation to the black mark on the ultrasound probe and advance the needle until they get flash, which obviously works, but this technique falls apart when it’s a smaller artery that requires finesse and risks posterior wall puncture, hematomas, etc.

I use the ultrasound on 98% of my art lines, even radials, and I use and teach this exact technique (“creep”). Some people on here will think that’s ridiculous, but it beats digging around the wrist or arm for 5-10 minutes when you’re going to go to ultrasound anyway. Some of my partners almost never use the ultrasound, but they’ve been in practice for over a decade or more, so are more adept at landmark-based approaches. We’ve not seen many complications either way.

I had an attending who could place radial a lines just by looking, no palpation. It blew my mind when I saw him do it for the first time.

 

[pgg]

Our cardiac surgeons put femoral art lines in most patients. I'm not quite sure why but even a basic normal EF CABG will usually get one. It's what they do. I certainly don't mind having it.

I only mention this because I have sort of been surprised by the discrepancy between femoral and radial in the first 5-15 min coming off bypass, even in patients who aren't on any pressors. MAP usually correlates pretty well but systolic differences of 30+ are surprisingly common.

Prior to working here femoral lines weren't common in the healthier patients, so I assumed that the radial / central discrepancy was probably due to relatively high vasopressor doses. But I see it pretty often even in the ones who aren't on big doses.

 

[DocMcCoy]

Why guess and stab “blindly” when you can use the US to its 100% capability. I never understood people that only use US to find the vessel and then basically do aline or iv blind.

If using US for aline or IV, should use it to follow the needle tip.

I think ultrasound gives you a hint at how accurate/inaccurate a radial pressure would be. If I see a tiny lead pipe with no motion at the radial I go brachial/ax all the time.

 

[pgg]

I had an attending who could place radial a lines just by looking, no palpation. It blew my mind when I saw him do it for the first time.

A few years back the Navy sent me on an all expenses paid work-vacation to a developing country to work in one of their hospitals. The case volume was huge and the move-the-meat production pressure was similarly huge.

Ultrasound was available but not really conveniently available and they never used it anyway. I was amazed at their ability to slam an arterial line or 14 or 16 g IV in an arm in seconds, even without an easy (to me) target. All those reps and sets honed the skill.

They did landmark based PNBs too - no ultrasound, no nerve stim, 10 seconds to draw up the drug, 3 seconds to wipe the skin with alcohol, less than 10 seconds to eyeball the landmarks, get stabby, quickly aspirate, and then drop 20 mL in. And while the failure rate wasn't trivial (10%? 20%?) and wouldn't be acceptable in a US practice, I was similarly amazed that they got effective surgical blocks most of the time and at least an analgesic effect almost all the time.

I'm not holding that up as an example of best practice but it is interesting how good you can get at these monkey skills with forced austere practice.

 

[Iso4ane]

A few points of thought.

I have a reasonably low threshold to go brachial (large sick cardiac cases) and I always do brachial art line ultrasound. (With radials I'm probably 80/20 (without/with) for preinduction art lines, and nearly 100% without if post-induction) CCF does brachial lines all the time, and they did it consistently before US guided lines were a thing. The reason for a slightly higher usage for pre-induction is partially due to availability of the US and partially due to better deep local deposition around the artery, which reduces pain and leads to vasodilation of the vessel as well.

I've asked our vascular surgeon about this, and there is an optimal window where to do the brachial art lines, and its essentially the soft triangle at the antecubital fossa. Combination of easiest place to apply pressure, surgical access if you get a pseudoaneurysm, and is compliant enough to minimize risk of nerve injury if you get a hematoma.

I agree with the POCUS 101 images posted. But, POCUS 201 would be you can tilt your probe to get to perpendicular without decreasing the angle of your needle (or at least get yourself closer to 90 degrees), the face of probe should be perpendicular with the vessel and not the arm (more important at the brachial than the radial).

POCUS 301: If you want to get pedantic.... to really get the tip of the needle visualized, the probe and the shaft and the needle should be more than 90 degrees given the bevel at the end of the needle.

 

[vector2]

Our cardiac surgeons put femoral art lines in most patients. I'm not quite sure why but even a basic normal EF CABG will usually get one. It's what they do. I certainly don't mind having it.

I only mention this because I have sort of been surprised by the discrepancy between femoral and radial in the first 5-15 min coming off bypass, even in patients who aren't on any pressors. MAP usually correlates pretty well but systolic differences of 30+ are surprisingly common.

Prior to working here femoral lines weren't common in the healthier patients, so I assumed that the radial / central discrepancy was probably due to relatively high vasopressor doses. But I see it pretty often even in the ones who aren't on big doses.

It's a post-bypass phenomenon that's been known and described for a long-time

​

The pathophysiology of RFPG remains a subject of debate. Since its first description by Stern and colleagues in 1985,23 numerous studies have suggested various explanations. Changes in distal arterial elasticity,29 aging with a reduction in leg postjunctional alpha-adrenoceptor responsiveness to endogenous noradrenaline,30 lower hematocrit level,7 lower minimal body temperature,8 CPB and clamping times,1,2 vasoactive medication,1,2,9,10,31,32 plasma catecholamine levels,9,10 vascular thrombosis,33 vascular decoupling in vasoplegia,34 and demographic data1,2 have all been described as potential risk factors. There is also a discrepancy in regard to vasoactive medication, since vasopressors and vasodilators have both been associated with the RFPG in different studies.9,28,31,32,35 Although none of these risk factors can explain the phenomenon by itself, most of them are related to vasoconstriction and thus to radial artery diameter. Our observations support the concept that a smaller preoperative radial artery diameter can affect pulse pressure and thereby generate an abnormally low reduction in radial arterial pressure compared with central or femoral arterial pressures.​

​

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

​

Unfortunately still no solid idea about the mechanism, but people have identified the main risk factors, namely high pressors (duh), long pump run, older women, small stature (i.e. small radials). Some authors believe 1/3rd of all pump cases have a post-cpb radial bp which is too unreliable to use, which is pretty staggering.

 

[DrN2O]

Our cardiac surgeons put femoral art lines in most patients. I'm not quite sure why but even a basic normal EF CABG will usually get one. It's what they do. I certainly don't mind having it.

Anyone still works with CT who does fem a-lines by palpation? I had one that did this after full heparin, must have passed 20x and I had to call the vascular guy at the end of VAD to fix the mess. Luckily most fellows these days use US.

 

[vector2]

A few points of thought.

I have a reasonably low threshold to go brachial (large sick cardiac cases) and I always do brachial art line ultrasound. (With radials I'm probably 80/20 (without/with) for preinduction art lines, and nearly 100% without if post-induction) CCF does brachial lines all the time, and they did it consistently before US guided lines were a thing. The reason for a slightly higher usage for pre-induction is partially due to availability of the US and partially due to better deep local deposition around the artery, which reduces pain and leads to vasodilation of the vessel as well.

I've asked our vascular surgeon about this, and there is an optimal window where to do the brachial art lines, and its essentially the soft triangle at the antecubital fossa. Combination of easiest place to apply pressure, surgical access if you get a pseudoaneurysm, and is compliant enough to minimize risk of nerve injury if you get a hematoma.

I agree with the POCUS 101 images posted. But, POCUS 201 would be you can tilt your probe to get to perpendicular without decreasing the angle of your needle (or at least get yourself closer to 90 degrees), the face of probe should be perpendicular with the vessel and not the arm (more important at the brachial than the radial).

POCUS 301: If you want to get pedantic.... to really get the tip of the needle visualized, the probe and the shaft and the needle should be more than 90 degrees given the bevel at the end of the needle.

Yeah another thing I forgot to mention is that I tilt the face of the probe toward me to start and "creep" forward by tilting away. I don't "slide" the probe up and down the arm for a radial or brachial. For an axillary or femoral in a fat person some tilt + slide may be required though.

 

[DrN2O]

I also think CCF data checks out and brachial safety is fine. The caveat is that I'm talking about experienced operators who can actually find their needle tip under ultrasound + using small, sharp needles (like in a micropuncture kit) for the initial stick as to minimize chance of significant vessel trauma.

If one is the kind of person who has to look down at their needle instead of at the screen to confirm the needle is in the vessel (or god forbid you're trying to do a brachial with blind anatomic technique) then that makes me a bit more nervous about recommending brachial.



I like the following method but with no syringe on the needle.

View attachment 368011

View attachment 368012

Residents have become 100% dependent on US for a-lines. The POCUS 101 picture can be misleading. I've seen more than once with the target sign and no flash. The US image is not the end all be all. So I have to respectfully disagree with not looking at the needle for flash. I also disagree with the "creep" method of "walking" the needle in the artery under US if you are going to use the Seldinger technique with the wire. Walking should be done after wire is threaded and the angle flattened, which is near-impossible when you hold the kit like a pencil.

 

[vector2]

Residents have become 100% dependent on US for a-lines. The POCUS 101 picture can be misleading. I've seen more than once with the target sign and no flash. The US image is not the end all be all. So I have to respectfully disagree with not looking at the needle for flash. I also disagree with the "creep" method of "walking" the needle in the artery under US if you are going to use the Seldinger technique with the wire. Walking should be done after wire is threaded and the angle flattened, which is near-impossible when you hold the kit like a pencil.

I can really only speak for myself without actually seeing what's going on, but most of the time when one definitely sees "tip" in the vessel but there's no flash, it's likely because one is either 1. looking at the shaft of the needle, or 2. looking at reverberation artifact that's getting mistaken for the tip.

WRT to flattening and walking with radial a-lines, I do it frequently with the arrow kit. I press the heel of my hand into the patient and kinda push my articulating fingers down and that flexes the needle a bit into a gentle arc. Allows flattening with simultaneous advancing.

 

[abolt18]

Residents have become 100% dependent on US for a-lines. The POCUS 101 picture can be misleading. I've seen more than once with the target sign and no flash. The US image is not the end all be all. So I have to respectfully disagree with not looking at the needle for flash. I also disagree with the "creep" method of "walking" the needle in the artery under US if you are going to use the Seldinger technique with the wire. Walking should be done after wire is threaded and the angle flattened, which is near-impossible when you hold the kit like a pencil.

Disagree with you here. Fully in the camp of creeping and bullseye.

 

[nimbus]

Our cardiac surgeons put femoral art lines in most patients. I'm not quite sure why but even a basic normal EF CABG will usually get one. It's what they do. I certainly don't mind having it.

I only mention this because I have sort of been surprised by the discrepancy between femoral and radial in the first 5-15 min coming off bypass, even in patients who aren't on any pressors. MAP usually correlates pretty well but systolic differences of 30+ are surprisingly common.

Prior to working here femoral lines weren't common in the healthier patients, so I assumed that the radial / central discrepancy was probably due to relatively high vasopressor doses. But I see it pretty often even in the ones who aren't on big doses.

In residency and at our current hospital, we always do radial+femoral or brachial Alines for pump cases. Having 2 Alines is eye opening. Like you, we see big discrepancies in SBP during the first 20min after coming off pump. I’ve seen 50mmHg differences more than a few times. We’d been coming off on a lot more pressors if we only used radial Alines.

 

[Beeftenderloin]

Residents have become 100% dependent on US for a-lines. The POCUS 101 picture can be misleading. I've seen more than once with the target sign and no flash. The US image is not the end all be all. So I have to respectfully disagree with not looking at the needle for flash. I also disagree with the "creep" method of "walking" the needle in the artery under US if you are going to use the Seldinger technique with the wire. Walking should be done after wire is threaded and the angle flattened, which is near-impossible when you hold the kit like a pencil.

I’ve had more than a few radial art lines placed under ultrasound where I can see the tip in the vessel (target sign or whatever), but my arrow’s chamber is totally dry, proceed to just walk the needle further into vessel, wire and catheter go smooth and it’s a totally functional a-line. Sometimes weird stuff happens (maybe a small tissue plug in needle tip?), but the ultrasound doesn’t lie (assuming you know what you’re looking at).

 

[nimbus]

I’ve had more than a few radial art lines placed under ultrasound where I can see the tip in the vessel (target sign or whatever), but my arrow’s chamber is totally dry, proceed to just walk the needle further into vessel, wire and catheter go smooth and it’s a totally functional a-line. Sometimes weird stuff happens (maybe a small tissue plug in needle tip?), but the ultrasound doesn’t lie (assuming you know what you’re looking at).

Also happens when the BP is very low.

 

[DrN2O]

I’ve had more than a few radial art lines placed under ultrasound where I can see the tip in the vessel (target sign or whatever), but my arrow’s chamber is totally dry, proceed to just walk the needle further into vessel, wire and catheter go smooth and it’s a totally functional a-line. Sometimes weird stuff happens (maybe a small tissue plug in needle tip?), but the ultrasound doesn’t lie (assuming you know what you’re looking at).

But you just proved my point, US shows the needle tip is in the artery, bullseye (at least you think) and you have no flash. So US does "lied." Then how much more do you walk in before threading the wire? Is it a fixed distance? Does the US image change? Or do you wait for a flash? It's not tissue plug either--where did it go when you got the flash?

As to the other comment about mistaking the shaft for the tip, then the needle should be further into the artery, shouldn't the flash already happened?

Flexing or bending you needle when working on a delicate vessel, I can't stand this bad technique.

 

[NumTacos]

But you just proved my point, US shows the needle tip is in the artery, bullseye (at least you think) and you have no flash. So US does "lied." Then how much more do you walk in before threading the wire? Is it a fixed distance? Does the US image change? Or do you wait for a flash? It's not tissue plug either--where did it go when you got the flash?

As to the other comment about mistaking the shaft for the tip, then the needle should be further into the artery, shouldn't the flash already happened?

Flexing or bending you needle when working on a delicate vessel, I can't stand this bad technique.

The ultrasound did not lie, 99% you take the needle out, you are clearly in the vessel: those arrow kits are weird like that, I’ve even done in plane, obviously in the vessel, zero flash. I trust what the image tells me, thread the catheter and be done with it. Getting hung up on seeing a flash of blood is really pointless if you are experienced with ultrasound.

 

[PpfSuxTube]

Radial art lines are for simple cases like cabg or single valve. Theyre basically useless for any form of complex wean from cpb like transplant, double valve, redo, inf endocard case.

I put brachials for every big case I do. Radials to check the box only

 

[PpfSuxTube]

Throw a drop of nitro in your lidocaine for every art line. You'll never need ultrasound ever again

 

[Mehd School]

The ultrasound did not lie, 99% you take the needle out, you are clearly in the vessel: those arrow kits are weird like that, I’ve even done in plane, obviously in the vessel, zero flash. I trust what the image tells me, thread the catheter and be done with it. Getting hung up on seeing a flash of blood is really pointless if you are experienced with ultrasound.

Another issue with those arrow kits (which I use personally and do like) is that if the "flag" is advanced AT ALL during cannulation it can prevent flash. Multiple times I have done it with zero flash although I see I'm in the vessel or get good feedback by landmarks, and I withdraw that flag a hair and blood climbs right up the column.

 

[pgg]

Residents have become 100% dependent on US for a-lines. The POCUS 101 picture can be misleading. I've seen more than once with the target sign and no flash. The US image is not the end all be all. So I have to respectfully disagree with not looking at the needle for flash. I also disagree with the "creep" method of "walking" the needle in the artery under US if you are going to use the Seldinger technique with the wire. Walking should be done after wire is threaded and the angle flattened, which is near-impossible when you hold the kit like a pencil.

They're also 100% dependent on ultrasound for IJ central lines and that's OK because it's the standard of care now.

I think ultrasound ought to be SOC for art lines too. The number of times I put the probe on some crusty old vasculopath, see an obviously un-cannulatable artery, and go look elsewhere 3 seconds later is not trivial. In ye olden days without ultrasound that wrist would've been poked a few times.

I learned to do lines and blocks without ultrasound, but for years now I never (never) do them without. I don't like to casually throw the phrase standard of care around, but I do think it ought to be for arterial lines.

I have nice healthy arteries and a bounding radial pulse and if someone tried to put an a-line in me without ultrasound I'd think they were a dinosaur. There's just no reason to ever not use it

 

[sanityonleave]

My personal preference is that one should be thinking about fem or ax a-line once the requirement is ~12-15 of levo +- 0.04 vaso. And maybe less if we're talking about a little old lady or someone with small radials. I've seen too many times where pressors are being titrated to some wildly inaccurate clamped down radial pressure.

Seems to be the consensus overall. I have always felt like we have too high a threshold at my institution to put in a brachial/fem -- people flogging in lines in 2mm radials in sepsis bomb patients on 50+ mcg/min of norepi. One of my smarter CTICU colleagues is fond of saying, "If you can bill for an angioplasty when the arterial line goes in, it's not going to last very long."

I also think CCF data checks out and brachial safety is fine. The caveat is that I'm talking about experienced operators who can actually find their needle tip under ultrasound + using small, sharp needles (like in a micropuncture kit) for the initial stick as to minimize chance of significant vessel trauma.

If one is the kind of person who has to look down at their needle instead of at the screen to confirm the needle is in the vessel (or god forbid you're trying to do a brachial with blind anatomic technique) then that makes me a bit more nervous about recommending brachial.



I like the following method but with no syringe on the needle.

My only concern about the POCUS 101 approach is I think that if you aren't careful it's very easy to wayyy overshoot your desired landing zone, especially with deeper femorals. People take a very shallow angle and don't appreciate just how much they end up "chasing" the probe and they hit the artery 5+ cm more proximal -- while I haven't seen any data the theory (and our vasc surgeons certainly feel) this increases risk for RP bleed. I always try and cannulate the fem 2-3 cm above the bifurcation.

You can certainly control for this by sliding down more distally with the probe before you enter the skin, but it's hard (in my experience) to control exactly how far you need to slide back and then make sure you actually hit the vessel precisely where you intend to. I actually favor a little more "triangulation" for these access cases -- find the area you want to cannulate the vessel, back your needle up a couple centimeters and then insert and advance underneath the probe. I purposely aim too shallow with the initial pass and then see where my needle passes into the beam. Withdraw a bit, steepen angle, readvance --> repeat 1-2x until I'm right on top of the vessel where I want to be, then follow myself as I pop in.

It's not as clean as the POCUS 101 technique (which I use for all my radials and PIVs, fwiw), but if it really matters where you cannulate the vessel I think it makes it easier to control. As with everything operator experience with ultrasound is a big part of the picture.

The ultrasound did not lie, 99% you take the needle out, you are clearly in the vessel: those arrow kits are weird like that, I’ve even done in plane, obviously in the vessel, zero flash. I trust what the image tells me, thread the catheter and be done with it. Getting hung up on seeing a flash of blood is really pointless if you are experienced with ultrasound.

Agreed, though I will usually continue to walk in the vessel several centimeters with the "chase the probe" technique -- sometimes you have a little tissue plug you're pulling along with you and it'll eventually "pop" back and you'll get flash. But I have definitely had lines that didn't bleed back - either because of a tissue plug or clot or whatever - and once I placed the wire and cannula were fine.

Thanks for the thoughts, everyone. Great to see some discussion of different opinions.

 

[patriot6]

Residents have become 100% dependent on US for a-lines. The POCUS 101 picture can be misleading. I've seen more than once with the target sign and no flash. The US image is not the end all be all. So I have to respectfully disagree with not looking at the needle for flash. I also disagree with the "creep" method of "walking" the needle in the artery under US if you are going to use the Seldinger technique with the wire. Walking should be done after wire is threaded and the angle flattened, which is near-impossible when you hold the kit like a pencil.

The “creep” method has made my success rate pretty dang close to 100%. I don’t use the arrow / wire. Long 20G angiocath. I never look to see if there’s blood return. Why would I? I park the entire catheter in the lumen under ultrasound guidance and just withdraw the needle. There’s a right way and a wrong way to use U/S.

 

[Beeftenderloin]

But you just proved my point, US shows the needle tip is in the artery, bullseye (at least you think) and you have no flash. So US does "lied." Then how much more do you walk in before threading the wire? Is it a fixed distance? Does the US image change? Or do you wait for a flash? It's not tissue plug either--where did it go when you got the flash?

As to the other comment about mistaking the shaft for the tip, then the needle should be further into the artery, shouldn't the flash already happened?

Flexing or bending you needle when working on a delicate vessel, I can't stand this bad technique.

You’re going to have to help me understand how seeing the needle inside the vessel on ultrasound then finding out it was in fact inside the vessel when I hook up and transduce proves that the ultrasound lied?

I walk the needle into the vessel. Get no flash. Walk needle further into vessel. Still
No flash, but I can SEE that a large portion of my needle/catheter is now intralumenal. I trust myself and what I am seeing on US because I’ve done this many many time. So I thread it off and it works. The ultrasound didn’t “lie” to me. If anything, the arrow was the liar. Then I used the ultrasound to prove that the arrow was lying to me and got it to work anyway.

It sounds like you’re bad at, or don’t fully understand the technique of walking the needle/catheter into the vessel and you’re looking for a reason to blow it off. There are, AMPLE opportunities for user error when you don’t know what you’re doing/looking at, vis a vis artifacts, sub optimal image quality, etc, but lying is not a property of ultrasound (at least not one I recall learning about when I took the NBE exam). As long as it’s a halfway decent image, your problem is user error.

 

[PpfSuxTube]

I learned to do lines and blocks without ultrasound, but for years now I never (never) do them without. I don't like to casually throw the phrase standard of care around,

I hope uss for alines doesn't become soc, although it probably should for learners or those not expert at placing. Glidescope probably should too and I hope waveform capno for every intubation, and audible tone variable pulse ox.

But we almost never have learners or residents and even our AAs are close on mastery level of line placement thru sheer volume... so I hope exception is made for high level, high volume practioners

But you just proved my point, US shows the needle tip is in the artery, bullseye (at least you think) and you have no flash. So US does "lied." Then how much more do you walk in before threading the wire? Is it a fixed distance? Does the US image change? Or do you wait for a flash? It's not tissue plug either--where did it go when you got the flash?

As to the other comment about mistaking the shaft for the tip, then the needle should be further into the artery, shouldn't the flash already happened?

Flexing or bending you needle when working on a delicate vessel, I can't stand this bad technique.

Uss doesn't lie. Monitors don't lie. Tissue plug in the catheter preventing flash is not rare, but also not very common, prob about 0.5%.

Many needles flex or bend on their path to a target, depends how deep it is, whats in the way etc. At times the fem art is directly posterior to the fem vein. Its advanced level technique to deliberately flex and bend a needle around an object to hit a target.

 

[pgg]

But we almost never have learners or residents and even our AAs are close on mastery level of line placement thru sheer volume... so I hope exception is made for high level, high volume practioners

We can agree to disagree but again ... I like to think of myself as a relatively high level high volume practitioner, and I learned and practiced without ultrasound for years, and today, in my own practice, I can think of NO REASON to ever not use ultrasound for an arterial line. Except hubris, maybe, and that's not a good reason.

 

[Beeftenderloin]

We can agree to disagree but again ... I like to think of myself as a relatively high level high volume practitioner, and I learned and practiced without ultrasound for years, and today, in my own practice, I can think of NO REASON to ever not use ultrasound for an arterial line. Except hubris, maybe, and that's not a good reason.

I work with a lot of uhh, seasoned anesthesiologists that don’t use ultrasound for a-lines (and a lot that do). The ones that don’t are objectively terrible with it. Takes way longer and way more likely to result in a complication because they become all thumbs. No one ever taught them good technique. Safer to just leave these folks be. We can start calling it standard of care when the current older generation retires.

 

[Iso4ane]

We can agree to disagree but again ... I like to think of myself as a relatively high level high volume practitioner, and I learned and practiced without ultrasound for years, and today, in my own practice, I can think of NO REASON to ever not use ultrasound for an arterial line. Except hubris, maybe, and that's not a good reason.

I do not disagree with the notion that US and even VL should be used more often, but that's after you reached some level of competency without them. In my short career of working with resident, I find that their skills grow at a much slower rate when using US or VL.

I'll be honest, my practical knowledge of landmark based CVC skills are on the lower end, but my knowledge of them is probably higher than your average resident, and their are considerations taught during landmark based techniques, that are not always taught during US guided techniques, but can still be useful during US guided placement of lines. The base skill is landmark based and DL, US/VL are an additional skills on top of the base skill.

 

[pgg]

I work with a lot of uhh, seasoned anesthesiologists that don’t use ultrasound for a-lines (and a lot that do). The ones that don’t are objectively terrible with it. Takes way longer and way more likely to result in a complication because they become all thumbs. No one ever taught them good technique. Safer to just leave these folks be. We can start calling it standard of care when the current older generation retires.

General agreement here. But we didn't wait for them to retire before calling US for IJ central lines standard of care ...

They can certainly become proficient with ultrasound. They just don't want to, because they think there's no benefit. The SOC label would be a useful nudge in the right direction.

 

[NumTacos]

Throw a drop of nitro in your lidocaine for every art line. You'll never need ultrasound ever again

Interesting. Are we talking like 0.1 cc? There are times that even with ultrasound this might be helpful.

 

[deleted875186]

I use US most of the time for art lines. Let’s you see a crappy target and pick another site before poking the patient. Increases first pass success rate, let’s you place any line with local and no sedation because it’s a single pass and I can deposit local all around the artery. I think it should be used more frequently. Agree with creep method, although if using a wire I usually wire the vessel once needle tip is in center of the lumen. Small minority of times the needle is in the lumen without flow, not sure the mechanism, more often happens with arrow kits probably because they are crappy, but catheter still works.

 

[Beeftenderloin]

General agreement here. But we didn't wait for them to retire before calling US for IJ central lines standard of care ...

They can certainly become proficient with ultrasound. They just don't want to, because they think there's no benefit. The SOC label would be a useful nudge in the right direction.

Stakes are much higher with an IJ (PTX, dilating a carotid, dissection, stroke). Can’t kill someone mucking around in their wrist.

 

[pgg]

Interesting. Are we talking like 0.1 cc? There are times that even with ultrasound this might be helpful.

100-200 mcg in the usual 3 mL syringe full of local does a good job.

Presently I have anesthesia techs who draw up lidocaine for me and set it out with the rest of the a-line supplies, so I just go with that. When I was with residents, or solo and had to get everything myself, I'd just take 1/2 mL of nitro from the 400 mcg/mL bottle and add it to the syringe with local. I think it helped a bit, especially if the resident took a couple of sticks to get the a-line and there was some spasm to deal with.

 

[NumTacos]

I do not disagree with the notion that US and even VL should be used more often, but that's after you reached some level of competency without them. In my short career of working with resident, I find that their skills grow at a much slower rate when using US or VL.

I'll be honest, my practical knowledge of landmark based CVC skills are on the lower end, but my knowledge of them is probably higher than your average resident, and their are considerations taught during landmark based techniques, that are not always taught during US guided techniques, but can still be useful during US guided placement of lines. The base skill is landmark based and DL, US/VL are an additional skills on top of the base skill.

In most hospitals, “land mark based skills” for a central line are not even allowed by policy. I’d much rather trainees learn ultrasound, heck maybe ONLY ultrasound, for IJs. If I were a patient (maybe an exception for some older pro that is really slick with landmark based techniques) but I would really prefer to have that line inserted under real time guidance by someone highly experienced with ultrasound.

 

[pgg]

I think the days are over when one could reasonably speculate that ultrasound might not be available everywhere, so it was necessary for trainees to become proficient at landmark-based techniques for lines and blocks. Useful? Maybe. It probably forces them to build a better mental model of where things are and how to get a needle into the right place. Necessary ... I don't think so.

In the residency I did and later was faculty at (a military hospital) we often talked about the need to be prepared to function in austere environments while deployed. We did some cases with artificially limited supplies but mostly it was thought-experiment kind of discussions. Anyway, the reality turned out to be that every place I ever deployed to, even forward surgical teams that literally functioned out of four tents pitched together that got pelted with rocks when the helicopters arrived, had ultrasound. It's compact, durable, inexpensive, and useful for many things. It's everywhere. It's been everywhere for 10+ years.

Anyone working anyplace in the USA who doesn't have an ultrasound machine handy at all times needs to kick or punch whichever beancounter is holding up the show. No excuse.

That doesn't mean residents shouldn't know anatomy, of course. They need to know what they're looking for and where to find it, and how to deduce where structures are based on other nearby structures if the image quality is poor, the patient is obese, mysterious fabled "anatomic variants", etc. You can also force your residents to go through the motions of identifying where they think the target it is and where they'd put their needle before putting the ultrasound probe on, if you think it's a useful exercise.

But I don't think there's much if any downside to residents only learning ultrasound-based techniques. Times change, technology advances. Internists don't diagnose diabetes with the taste test any more, and it'd be silly to expect IM trainees to learn that first or in addition to new-fangled glucometer technology.

 

[Beeftenderloin]

In most hospitals, “land mark based skills” for a central line are not even allowed by policy. I’d much rather trainees learn ultrasound, heck maybe ONLY ultrasound, for IJs. If I were a patient (maybe an exception for some older pro that is really slick with landmark based techniques) but I would really prefer to have that line inserted under real time guidance by someone highly experienced with ultrasound.

Although I agree US for IJ is SOC, I do have a serious internal struggle with this notion of not even learning landmark based approaches. I’ve had 2 situations come up in the last 9 months where I needed large bore central access yesterday and the US was not immediately available for that purpose. Both times I did landmark IJs (I can do subclavians, but didn’t have adequate access to that geography).

Although I finished training relatively recently, I was fortunate to learn from someone who swore up and down that knowing how to do landmarks would save my @$$ one day, and they were right.

They actually did a decent job of teaching how to do it without US, by using ultrasound. Mark where you think IJ is gonna be (truly blind), then find it with US and actually mark out its path with a marker. Then prep/drape do the procedure from there with the finder needle and no US using your skin marks. Do enough of them like that and you got to “graduate” from marking it out with a marker.

 

[DesiredMemberName?]

We do enough VAD/ECMO/Shock patients that I’ll often go straight to US and get plenty of reps with that approach.

However, if I can palpate a decent pulse, I’ll just place it blindly so I don’t have to wait for someone to hand me the probe. If I don’t get it immediately, I’ll ask for the US. Often I’ll still get it in before they can even hand me the probe. I never spend more than one minute trying blindly.

Once the probe is in my hand, I use the technique described by others above, and it takes less than a minute to place the line (similar to blind placement).

I think this is a reasonable middle way. It saves a small amount of time and effort for most cases, but I don’t have any problem going to US. I also don’t have any problem with people who want to use US every time.

 

[T-burglar]

There is no reason at all to do blind arterial sticks in 2023..

Being a Luddite in cardiac surgery makes you look and sound like a *****. Use the ultrasound and stop getting blood everywhere and stabbing nerves.

 

[DesiredMemberName?]

There is no reason at all to do blind arterial sticks in 2023..

Being a Luddite in cardiac surgery makes you look and sound like a *****. Use the ultrasound and stop getting blood everywhere and stabbing nerves.

I think your blind technique may be different than mine.

 

[PpfSuxTube]

There is no reason at all to do blind arterial sticks in 2023..

Being a Luddite in cardiac surgery makes you look and sound like a *****. Use the ultrasound and stop getting blood everywhere and stabbing nerves.

Wow thats a strong response. Did you have an issue with someone?

And definitely not my experience 9 out of 10 times, the thing is in faster than a piv without a drop of blood...

 

[Ronin786]

I can't honestly agree with the US being SOC for arterial lines. Had an overly obese patient today whose BP cuff just wouldn't work after induction. Kept reading too high a diastolic for somebody with this patient's comorbidities. Called for an ultrasound but it was taking them too long. Took me two sticks with a micropuncture to get the arterial line and she honestly didn't have a palpable pulse.

Could I have caused damage with the extra stick? Possible but very, very unlikely. If US was SOC I don't see how I could have justified not waiting for US to get there.

The risk-reward profile just isn't the same as blind CVCs. Central line is SOC with US because it drops complications like inadvertent arterial dilation and PTX to almost zero. Those serious complications don't exist with arterial lines even if it's more slick or better first pass success with US. I'd make the same argument with VL. With the availability of VL when absolutely necessary, faster first pass success just isn't enough of a benefit to justify mandating no DL or changing the SOC.

 

[NumTacos]

I can't honestly agree with the US being SOC for arterial lines. Had an overly obese patient today whose BP cuff just wouldn't work after induction. Kept reading too high a diastolic for somebody with this patient's comorbidities. Called for an ultrasound but it was taking them too long. Took me two sticks with a micropuncture to get the arterial line and she honestly didn't have a palpable pulse.

Could I have caused damage with the extra stick? Possible but very, very unlikely. If US was SOC I don't see how I could have justified not waiting for US to get there.

The risk-reward profile just isn't the same as blind CVCs. Central line is SOC with US because it drops complications like inadvertent arterial dilation and PTX to almost zero. Those serious complications don't exist with arterial lines even if it's more slick or better first pass success with US. I'd make the same argument with VL. With the availability of VL when absolutely necessary, faster first pass success just isn't enough of a benefit to justify mandating no DL or changing the SOC.

Yeah, I don't know about "officially" standard of care. However, if I were a patient, I don't care how good you are with landmark/palpation techniques for a-lines; I would WANT you to use the ultrasound. However, I remember during my training that some of my attendings had an almost magical ability to put a line in anywhere on any patient without the benefit of ultrasound. Not everyone can be a magician, though.

 

[T-burglar]

The solution to US “not being readily available” in time sensitive situations is to not take care of traumas or emergencies in rooms where there isn’t a dedicated US.

similarly with VL not being readily available. Change your system so it’s always available.

 

[DocVapor]

The solution to US “not being readily available” in time sensitive situations is to not take care of traumas or emergencies in rooms where there isn’t a dedicated US.

similarly with VL not being readily available. Change your system so it’s always available.

Sometimes **** happens in your regular old scheduled laparoscopy room, like the OBGyn bagging a uterine artery inadvertantly.

Sometimes the trauma or emergency surgery rooms are already being used for the lap choles added on from the night before.

Sometimes the vascular surgeon decides he wants the dedicated ultrasound from his usual room instead of the ICU's machine, so he comes and grabs it and doesn't tell someone.

I fully agree that U/S should be standard of care, but no hospital is ever going to have enough of them. I recognize that **** can happen and if there isn't one available then the anesthesiologist, at least for radial arterial lines and PIV access, should be able and willing to attempt whatever technique they feel like until an U/S is ready.

i carry a butterfly on my hip now, in the place where the stethoscope used to go. Because even when things aren't an emergency, tracking down an u/s machine is a waste of time.