Avoiding the brachial plexus when placing axillary a-lines

[combatwombat]

Recently I've been doing more axillary arterial lines in the ICU. They are much easier to place than radials, have more collateral circulation than brachials, and last way longer than either so it means torturing your patients less.

However, one thing that still bugs me about them is that I feel that there is no guaranteed way to avoid the brachial plexus. You can often see the nerve bundles around the artery with ultrasound, but not always that well. And, sometimes, the only way to get to the artery is to go very close to them.

Does anyone have any advice on how to avoid spearing the brachial plexus?

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[drmwvr]

Put in radial a lines with the 12 cm cathethers if you're having so much trouble keeping them. Routine axillary lines seem pretty overkill for the sake of ease....

 

[Noyac]

I am just curious as to the ability to keep one of these axillary lines from getting infected. The axilla is a dirty region.

If it were me, I would work on getting better at radial lines.

But I will also attempt to answer your question. Move the probe up and down the artery to find an open direct approach without nerves in the path. Typically, the nerves are located radial (posterior), ulnar (inferior) and median (superior). Disclaimer: someone should check my recall on anatomical locations since I did this from memory.

 

[Urzuz]

Do more radials, and if push comes to shove, use a femoral arterial line kit to place a brachial arterial line.

 

[AdmiralChz]

Axillary lines have got to be the most obnoxious from a patient comfort perspective, right? And definitely more infectious risk. It seems to me brachial risk is overstated as institutions like CCF with high volume go there first line for access, and they don’t have ICUs filled with 1 armed patients after one of them thromboses.

Agree with placing longer radial catheters if they are going to be in for a prolonged amount of time.

 

[DrZzZz]

Disclaimer: someone should check my recall on anatomical locations since I did this from memory.

The median is usually anterior or superior in relation to the artery, ulnar is superior to posterior, and radial is inferior to posterior.

 

[Planktonmd]

If you can't place a radial A line just try a brachial or femoral. The axillary approach is probably the most likely to get kinked or infected.

 

[MoMoGesiologist]

Do an ulnar aline.

Ulnar artery versus radial artery approach for arterial cannulation: a prospective, comparative study - PubMed

The success rate of an arterial cannulation in a patient with a strong ulnar pulse is the same as for radial artery cannulation.

www.ncbi.nlm.nih.gov

^^small study but why not

 

[Noyac]

The median is usually anterior or superior in relation to the artery, ulnar is superior to posterior, and radial is inferior to posterior.

View attachment 262475

So basically I mixed up the ulnar and radial. Not bad for an old guy.

 

[Ronin786]

Lot of hate on axillary arterial lines.

Pros:
1) They're actually quite kink resistant because you're in a large, central vessel and you use a femoral arterial catheter.
2) That large axillary vessel is going to much less likely to occlude from a catheter than a small radial artery, particularly in patients with PVD.
2) They're not bad from a patient comfort standpoint since it lies in the groove and functions independently of what position the patient's arm is.
3) I don't have any numbers as far as infectious risk, but they should be done sterilely and keep in mind that basillic PICC lines sit in close proximity without much higher infectious numbers.
4) In obese patients, the arm might be a much better target than the femoral vessels.
5) There's an emerging level of evidence that peripheral arterial blood pressures can be artificially low in patients on high dose vasopressors. Titrating to central pressures might be of some use though it's hard to tell. (PulmCrit: A-lines in septic shock: the wrist versus the groin)

Cons:
1) Potential brachial plexus injury. Usually can be avoided with ultrasound guidance, but the patient you're putting an axillary arterial line in isn't going to be complaining of paresthesias.
2) Bleeding risk associated with cannulating a large artery. Compressible area, but still a significant concern.

In my practice, I'll reach for an axillary or femoral arterial line in patients who lose their radial arterial line and are still on 3+ vasopressors. I'm not going to mess around trying to cannulate a clamped radial artery and then have to worry about kinking or it dislodging given the patients 3+ anasarca from "drowning sepsis".

 

[chessknt]

Anyone have numbers on aline infection rates? Seems like a non issue in my experience and in a supermorbid obese person with ****ty radials is a cleaner option.

There's also something to be said about a catheter projecting directly in to the aorta for accurate blood pressure readings. In a septic patient with uptrending pressors I preferentially want a central aline, not a radial.

Ive always avoided brachial but will admit it is from dogma then any proof I am aware of.

 

[deleted59964]

Recently I've been doing more axillary arterial lines in the ICU. They are much easier to place than radials, have more collateral circulation than brachials, and last way longer than either so it means torturing your patients less.

not saying they'll cause ischemia ... but what is the collateral artery for the axillary???

 

[vector2]

Did dozens of ax a-lines (sterile technique) in the cticu as a fellow. Never had any infectious complications.

Here are the collaterals

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images.app.goo.gl

 

[deleted59964]

Did dozens of ax a-lines (sterile technique) in the cticu as a fellow. Never had any infectious complications.

Here are the collaterals

Redirect Notice

images.app.goo.gl

So how proximal in the axillary artery do you place these lines?
Must be a regional variation but I’ve never seen one

 

[vector2]

If I can manage, I try to do it a bit distal from the intertriginous area around the same spot where a basilic PICC is done. If artery doesnt look good there then I'll move proximal to where we typically do an axillary block. If median nerve is at 12 o clock then I come in at an oblique trajectory to miss it. Also I use a 10cm micro puncture kit so I dont risk spearing nerves with the 18g from the fem art kit.

 

[combatwombat]

So how proximal in the axillary artery do you place these lines?

As long as you actually place the catheter in the axillary artery - and not in the brachial - there should be plenty of collateral circulation. You can usually see the collaterals well on ultrasound - just make sure you're upstream of where they join the axillary artery.

Anyone have numbers on aline infection rates? Seems like a non issue in my experience

According to this paper, infection rates for axillary venous lines are similar to IJ central lines. According to this article, the rates of septic complications are equivalent to femoral a-lines, while the rates of local skin infection are higher. I have to wonder whether this is confounded by the amount of time the catheters are left in, though. UpToDate doesn't have much to offer on differences in complication rates between different a-line sites, other than mentioning that brachial plexopathy and cerebral embolism are possibilities with the axillary approach.

Put in radial a lines with the 12 cm cathethers if you're having so much trouble keeping them. Routine axillary lines seem pretty overkill for the sake of ease....

Radial is always my first go-to. However even with the 12 cm catheters they sometimes crap out after a day or two.

Agree that axillary shouldn't be the first option

Axillary lines have got to be the most obnoxious from a patient comfort perspective, right?

I hear more complaints about radials. Patients can move both arms freely with an axillary a-line. Unlike femoral a-lines, they can also mobilize with PT. And once you have a working axillary catheter, it means you get a break from daily wrist sticks by the interns/residents. Placing axillary lines is definitely less comfortable though... I rarely do them awake

 

[jthedestroyr]

f I can manage, I try to do it a bit distal from the intertriginous area around the same spot where a basilic PICC is done. If artery doesnt look good there then I'll move proximal to where we typically do an axillary block. If median nerve is at 12 o clock then I come in at an oblique trajectory to miss it. Also I use a 10cm micro puncture kit so I dont risk spearing nerves with the 18g from the fem art kit.

I did an elective rotation that stressed using micropuncture for access. It's absolutely amazing once you know how to use it.

 

[DM27]

The micropuncture is an excellent access device, it is my routine go to when I have any issues with standard a-line kits in larger vessels. The 4Fr kit can also accommodate most IABP wires if you are placing it femorally.

 

[drmwvr]

The micropuncture is an excellent access device, it is my routine go to when I have any issues with standard a-line kits in larger vessels. The 4Fr kit can also accommodate most IABP wires if you are placing it femorally.

For routine invasive arterial BP monitoring? What catheter are you using for that?

 

[DM27]

Routine monitoring I typically just use a 4.45cm 20g arrow kit or a 20g long PIV depending on the hospital. For femoral access I typically will use the longer 20g a-line kit (~16cm). If it is a cardiac case where there is anticipation of a balloon pump I will typically use an 18g 16cm a-line kit.

One facility I rotated through when I was a resident ONLY had micropuncture kits for whatever reason, so I was routinely using 4Fr for radial a-lines (for context, cath labs typically use a 5Fr).

When I have difficulty, especially with femoral, my next move is routinely to use the 4Fr Micropuncture. I have RARELY moved to the 4Fr micropuncture for radial, but not in over a year, generally switching to ultrasound and selecting my puncture site better has ameliorated this. The advantages that I have found with the micropuncture is that the wire is extremely thin, which makes it more forgiving when it has to navigate a calcified vessel. Also, the obturator within the micropuncture makes it very resistance to compression or bending when working through a lot of soft tissue for larger femoral access patients.

 

[drmwvr]

My only concern with a 4 fr sheath would be the necessity for a more robust period of direct pressure when the line was taken out. Perhaps a TR band or the like? The ICU RN's would probably riot if something like that were necessary. Agree that the needle and wire in the micro puncture kit are a great bail out for terrible arteries, but I've just used the long 20 ga from another kit, not the 4 fr. sheath.

 

[Hork Bajir]

I’ve used the micro puncture kit a fair amount, but always find it to be a little bit awkward without a second set of hands (especially when using it for small/deep targets). For those who have used it more extensively: once you access the artery, are you comfortable letting go of the needle? I’ve had people tell me that you can let go of the needle, and that the muscular media of the artery will prevent it from coming out... But I’m always worried that letting go of the hub will create torque and cause the needle tip to move. Maybe letting go of the needle makes more sense for deeper targets (femoral, brachial)... what have other people found?

 

[abolt18]

I’ve used the micro puncture kit a fair amount, but always find it to be a little bit awkward without a second set of hands (especially when using it for small/deep targets). For those who have used it more extensively: once you access the artery, are you comfortable letting go of the needle? I’ve had people tell me that you can let go of the needle, and that the muscular media of the artery will prevent it from coming out... But I’m always worried that letting go of the hub will create torque and cause the needle tip to move. Maybe letting go of the needle makes more sense for deeper targets (femoral, brachial)... what have other people found?

Every one of my CT attendings has had me let go of the needle as soon as I have access. It has worked flawlessly every time. I will continues to do it. This is even true for pretty superficial radial lines.

 

[vector2]

I’ve used the micro puncture kit a fair amount, but always find it to be a little bit awkward without a second set of hands (especially when using it for small/deep targets). For those who have used it more extensively: once you access the artery, are you comfortable letting go of the needle? I’ve had people tell me that you can let go of the needle, and that the muscular media of the artery will prevent it from coming out... But I’m always worried that letting go of the hub will create torque and cause the needle tip to move. Maybe letting go of the needle makes more sense for deeper targets (femoral, brachial)... what have other people found?

I think you can let go of the needle for arteries, but I use the kit for venous access as well. For these, I transfer control of the needle from right hand to left after getting flash and then use a pincer grip to feed the soft tip wire with thumb and forefinger.

 

[chessknt]

My only concern with a 4 fr sheath would be the necessity for a more robust period of direct pressure when the line was taken out. Perhaps a TR band or the like? The ICU RN's would probably riot if something like that were necessary. Agree that the needle and wire in the micro puncture kit are a great bail out for terrible arteries, but I've just used the long 20 ga from another kit, not the 4 fr. sheath.

Isn't the 20g catheter bigger than the micropuncture hole? I have put a fair number of the 4fr catheters in and not seen serious issues removing it but will admit my n is not high enough to know. Anyone else have a bad experience with the 4fr in a radial?

 

[DM27]

Using the long 20g and making use of the micropuncture wire makes sense as well, it is rare that you will have an issue in the radial artery that requires a stiffer obturated catheter, usually it's just a matter of the wire finding its path. In these scenarios though, I did not use the needle included in the micropuncture kit. I usually obtained access with a normal shorter 20g a-line kit, found that the wire wouldn't thread properly, took the wire out and had robust blood flow. In these scenarios I took the micropuncture wire and put it through my 20g that still had good blood flow, then took the 20g out, leaving the wire behind, and used a longer 20g over it. Sometimes I also just thread the current 20g over the micropuncture wire, also with good results.

I never heard any complaints about major differences about time holding pressure with the 4Fr either, but also my N for them in the radial site also is not enormous.

 

[OneFellSwoop]

community practice where I don't place a ton of a lines anymore, but when I do, I'm often placing a central line as well so US is in the room. I've started going straight to an ultrasound guided brachial a line, identify median nerve and avoid, as easy as and quick as US RIJ central line. complications unlikely to be much higher, probably approximates central aortic pressure better than radial a line and will likely last longer in the ICU. It is also a well tolerated location.

Brachial Arterial Pressure Monitoring during Cardiac Surgery Rarely Causes Complications

Brachial artery cannulation for hemodynamic monitoring during cardiac surgery rarely causes complications

anesthesiology.pubs.asahq.org