Today, we talk about arterial lines. I love arterial lines: monitoring, true MAPs, easy blood draw, easy blood gases, fluid status–what's not to love.
This turned into a 2-parter. Part 1 covers radial art lines
Here is Arterial Lines – Part 2
covers everything else below
Part 1 Covers:
Radial Arterial Lines
Peripheral vs. Central Arterial Lines
Sterility
Here is a systematic review of most of the literature
[cite]24413576[/cite]
My take on it is, use sterile gloves, mask, chlorhexidine prep, and if you can grab a fenestrated drape or some OR towels.
Technique
- Kit (The one I use is Arrow RA-04020)
- Ultrasound
- Threading
- How to Save it
- Allen Test
Securing
Tegaderm alone is not enough. I suture, but I really wish we had arterial line stat-locks
I always loop around the thumb and secure with tape outside of the tegaderm–I hate replacing pulled out art lines
Central vs. Peripheral Arterial Pressures
[cite]28523028[/cite]
Part 2 Covers:
Femoral
Sterility-Full Sterile
unless you are going for speed or the Dirty Double
Technique
Use Ultrasound
Find the Common Femoral Artery
Use of a central line kit?–No!
Back of wire? Check, but yes!
Axillary
Need Ultrasound
Brachial
Dorsalis Pedis
https://www.ncbi.nlm.nih.gov/pubmed/28523028
The Arterial Line Set-Up
How to set up an art line pressure transducer
You do not need to wait for crash arterial lines
Heparin Flush
Pimping Ammunition – Where is that Catheter
sent by Intensivist, Mark Dunn
Central vs. Distal Arterial Discrepancies
- Risk Factors Involved in Central-to-Radial Arterial Pressure Gradient During Cardiac Surgery PMID: 26599795
- Pulmcrit with far more on this
Additional New Information
More on EMCrit
- PulmCrit: A-lines in septic shock: the wrist versus the groin(Opens in a new browser tab)
- Hemodynamic access for the crashing patient: The dirty double(Opens in a new browser tab)
- EMCrit 267 – They are not All Right!! An interview on Hemodynamic Assessment with Mike Patterson(Opens in a new browser tab)
Additional Resources
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- EMCrit 373 – Mike Weinstock with another Critical Care Bounceback: “Asymptomatic Hypertension” - April 18, 2024
- EMCrit Wee – Ross Prager on 10 Heuristics for the New ICU Attending - April 13, 2024
- EMCrit 372 – FoundStab Intubation SOP - April 5, 2024
I save by withdrawing the catheter until there is good, brisk arterial flow, and then placing a micropuncture wire and advancing over that. (Any wire that fits will work, but I don’t know what else would.) Reinserting needles into catheters is quite fraught, and I try not to do it as a rule; that doesn’t mean I don’t still try sometimes, but frankly it has never really worked, and unlike some situations where trying harder can equal success, in this one I feel like when you meet resistance you are traumatizing something.
when reinserting, the needle never really touches the vessel, just the wire. i guess if you hubbed it maybe the side of the needle would graze, but even then–not really a problem and no need to hub it
Yep, that’s what I aim for… but of course the needle is still contacting the sides of the catheter and could shear it. (Not too outlandish given the angle changes that often occur while placing these — i.e. the flattening-out you describe.) And inserting just enough to put a useful amount of wire beyond the catheter tip without the needle emerging is hard enough anyway. Like I said, I often give it a whirl, but rarely have any luck. I’m sure you’ve had better success with better technique. For me, I’m happier with a standalone wire, and the wire from… Read more »
never had an issue with backwalling yet, which is not to say there are not issues possible
I find if you cut the top off the arrow kit you can slide the guidewire out independent of the needle, then use that to rethread rather than having to reinsert the needle itself
This is brilliant! Thanks for this.
I think its an arrow kit we use (looks the same as the pic in another post below) and I grab the black tab that slides the wire up and down and yank the wire out the side of the clear tube.
Excellent episode. A couple of points I would add:
1) I am cognizant of how many passes I make with my needle. If I make more than 5 passes, I will withdraw the needle and flush it to remove any clots that might have formed. There’s nothing more frustrating than unknowingly puncturing an artery with a clotted needle.
2) The posterior tibialis has served me well in patients who have severe contractures secondary to neuromuscular disease.
Great podcast. My two cent contribution…Grab your art line kit and make a mental note of the distance from the tip of the needle to the tip of the catheter. Once I have blood return, the guidewire passes easily and is fully inserted, I then advance the whole set-up a distance slightly greater than the mental image. I believe this alleviates the problem of not being able to advance the catheter despite good blood return and easy guidewire passage. Also, the extended guidewire prevents vascular injury from the needle and keeps you on the right path. Or, I just use… Read more »
Ari & GM–great comments. I’ve never had an issue advancing the catheter if the wire is in the right place. Ari, sounds like you are talking about real seldinger technique–non-integrated wire separate wire needle catheter
very informative, and helpful scott . thank you.
Great Podcast! Why not always use ultrasound for radial puncture? If you use ultrasound you can place the arterial line anywhere on the forearm. I normally place it midway to the cubital fossa. If the patient is awake and moves his hand/wrist it helps alot by not kinking. I also like to use BD Floswitch Arterial Cannula for perioperative monitoring.. And if you take off the indicator at the end and replace it with a 2cc syringe without the plunger you can advance the Cannula a couple times. It also helps to put the Cannula in the fridge to harden… Read more »
Agree it is nice to place a more proximal radial line when possible; the crease of the wrist (where the pulse is strongest) is dirty/hard to dress, often has other activity (restraints, IVs), and kinks easily. The caveat is that more proximal sites are deeper, so I have seen them pulled out when using the short Arrow kits. There are somewhat longer catheters meant for brachials/axillaries and such which may be a better choice; not available in my shop. (Femoral lines are probably too long.)
only reason to place without ultrasound is speed. i have everything i need already in the resus rooms. I can have an aline in <30 sec if the pt has good pulse, so it is worth a shot in selected candidates. Usually if i have the time to get local, i have the time to get the ultrasound. obtunded moribund patients, i just pop it in.
We (ICU, Norrköping, Sweden) use the mediq floswitch, I don´t know if this works with you´r set, but I save by attaching a syringe 2.5ml half filled with saline and then withdrawing until reflux of blood. It´s then usually no problem advancing the catheter while flushing with the syringe. In that way I don´t get blood all over the place. My other save, when I think the problem is spasm in the artery, is injecting a minimal amount of mepivacaine (before the procedure I inject LA around the artery and for the skin so it´s already in a syringe). The… Read more »
love these tips
Why use mepivacaine?
I like to use lidocaine. Due to its vasodilation properties it would be better compared to mepivacaine..
Having worked at a few institutions in the course of training, I’m amazed by the number of arterial line products out there. That said, I totally agree, the Arrow sets seem to have dominated in popularity, at least where I have been. One interesting feature I don’t think was mentioned was that Arrow sets that are the all-in-one devices (like the Arrow RA-04020 mentioned), the wire can be removed if you need to rewire a catheter. The trick is to pop off the top cap, and then take the plastic wings (usually black or orange) that is attached to the… Read more »
yep. and on some others, you can cut off the back cap to get the wire
My rule of thumb is this—if I am planning on leaving something in the patient, then full gloves, gown, hat, mask, drape. That is for art lines, central lines, chest tubes. If nothing is to be left, then gloves, hat, mask are good enough. That’s thoracentesis, paracentesis, etc. I know of no literature looking at this and it may in fact not be amenable to study given the low rate of art line infections we see. I use the femoral Arrow kit for all lines as it has a small 18g catheter for radial and the longer one for the… Read more »
Love ultrasound- as you say it is actually faster for most pts…. once you miss the first attempt… this has been shown Also I really don’t like it when folk use no local in awake pts. This is a painful procedure, we should numb them first. The beauty of US is that it allows us to use liberal local, not worry about losing the ability to palp the pulse. Doing it without local is cruel outside of the crashing / tubed patients We have the art line snap lock fixation dressings- they are nice. I reckon this is easy, robust… Read more »
The dressing fixation we have is called : Statlock by Bard
Great post Scott. I have two questions: 1. I had to insert an a-line in the ulnar artery, after several attempts failed un radial. Inexplicably, the radial artery had less than 1 mm diameter under ultrasound, whereas the ulnar was three times larger. I was wondering what is your experience with the ulnar artery and would you recommend looking with ultrasound if patient is not crashing? 2. You mentioned the issue of clots in your hollow bore needle, and I in the past have used the wire loaded onto the needle to occlude the needle (a-la stylet of LP needle,… Read more »
Be aware that preadvancing the wire will prevent blood from flashing into the column, which (as discussed) does not entirely preclude the procedure (if you have ultrasound and can visualize placement) but can be a bit vexing.
I have done ulnars and see no reason why they are not reasonable alternatives to radials. I agree that if the visualized lumen of any vessel is truly tiny, that should not be an invitation to cram a catheter into it, as this probably invites ischemia. Instead scan proximally for a larger caliber, or pick another vessel.
Daniel – a note of caution – if you have failed radial side (particularly if you’ve gotten a flash but not cannulated), ipsilateral ulnar attempts are contraindicated as you can potentially cause critical hand ischemia. Would switch to other wrist before ulnar, then move to brachial/axillary/femoral. Also, with the wire loaded into the needle to prevent catheter clots, you may lose the visual feedback of the flash of hitting artery. If using ultrasound and you’re sure you’re intraluminal, it’s probably NBD but then that begs question of why you’re occluding the flash chamber and catheter to begin with. I prefer… Read more »
I hate the Arrow kit, way too floppy (the femoral one is even worse). I use a Cook these days, and hardly ever fail. Go a bit further in than you feel you have to, flatten the needle’s angle, then insert the wire. Really easy.
both companies make like 20 versions of both the radial and femoral, so you need to make sure you have tried the same arrow and hated it and specify which Cook you love.
Thanks Scott! What are your thoughts on just using a needle open to air + guidewire (micropuncture kits) for art lines? I’ve been doing this more often and find my success rate is a lot higher this way for the more challenging lines.
for radial or femoral. in the latter, this is the way most interventionalists do it and it works great.
Can the micropuncture kit catheter be left in place for several days or do you place another dedicated catheter from the arterial line kit.
Probably can but I would not. Very stiff (not unlike an arterial sheath for angio/cath procedures). Definitely too big for radials. Just get your microwire placed then railroad the arterial catheter directly over that, no need to use the dilator/sheath.
Good discussions. For radials I tend to just use a 20 gauge angiocath and always use ultrasound. If I follow the needle tip into the vessel and then center it in the lumen and continue to advance another centimeter, there is never any difficulty advancing the catheter. Often it appears to be in the vessel and there will even be a flash, but when you advance it more you see and feel that it was tenting the intima. This is the same as a peripheral IV. People are too afraid of brachial and axillary lines. Complication rates for any of… Read more »
I don’t think the phenomena described is a function of vasospasm because I notice it often with PIVs as well. When I place anl IV under US guidance I will frequently get no flash, but thread the catheter anyway as I see it is in the vessel, subsequently getting an IV that draws and flushes. I am of the opinion that you should try all radial a-lines without US if you have a palpable pulse because I don’t want to lose the skill. If I do use US, it’s always an in-line view – although I found the technique to… Read more »
What are your feelings on emerging Non-Invasive arterial pressure monitoring systems such as the “Clearsight Device”? We looked at this technology for rural retrieval’s from ED’s where Art line placement just isn’t going to happen. Repetitively picking up significantly hemodynamically comprised patients and attempting to manage pressers vs. fluids is extremely difficult in an ambulance and especially in the aircraft. It seems promising yet still cost prohibitive with single patient use “finger cuff’s” exceeding $300. Is there an indication or future for this technology in the small / rural ER or transport environment?
Great podcast, as always. I am curious about your concern re the catheter to artery ratio in the brachial location (i.e. catheter takes up most of the artery luminal diameter), when surely this is much more of a concern with a 20g catheter in the radial artery (our go to location for art lines)?
Hey Scott, i had a few thoughts/questions… 1) One of the things that i find makes aiming for the radial a. easier, particularly for interns/those not as facile wit hUS guided needles, is to actually use lidocaine to my advantage by essentially plumping up the soft tissue space between skin and artery. I end up having more room to adjust my needle tip’s trajectory. Also, though this may be overkill, when i find my tip in the lumen, i drop my angle significantly, and mm by mm advance my needle with US so that the needle tip is continuing to… Read more »
Dr. Weingart, Regarding the use of the traditional seldinger technique where you backwall the artery, do you withdraw just the catheter (having already removed the needle) or are you withdrawing both the needle and catheter together as you try to get back into the vessel, then removing the needle, and threading the wire. I’ve been taught both ways.
Hi Scott, I love your podcasts, have been listening since one year. Quick question based on situation I faced in code in ICU: “how reliable is a-line reading / curve in detecting pulse”. Can we rely on the pulse wave in cpr?. In our case, pulse was not palpable, doppler could not catch one. I told my buddies not to start cpr / code, since there is a pulse wave on a-line (new and fully functional a-line). Though the pulse wave was very small (1/2 a cm bump on a-line wave on monitor) and rate was 28 and map was… Read more »
What it comes down to is if the MAP is <40 on the aline they need CPR unless you are able to bring it up in the next 5 secs or so. So regardless of the bumps, CPR is the right choice.
and i have found the same thing re: hand placement, another nice reason to have the aline