Radial A line difficulty

[deleted875186]

As an academic anesthesiologist who gets called all the time by colleagues after 30 minutes of poking to do US-guided radials, please learn the US-guided approach. It's fine if you want to do palpation-guided to start, but please learn it at least as the back-up option. An US-guided technique should take no longer than 30sec with >98% first pass success. Much more elegant and faster. If you don't have ready access to an US, you should question your facility and what they provide to you.

Agreed, I would say an ultrasound at a bigger vessel like a brachial has a 99% pass. Definitely worth not repeatedly poking the same artery with blind attempts.

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[Twiggidy]

I think we’re all saying a bit of the same thing, that is, it is of benefit to know how to use the ultrasound for the sake of speed and safety, but I’ll just reiterate that to know how to do so without is just an added bonus to your skills. I’m not saying it’s the same but it reminds me of people who ONLY use a glide scope to intubate. Probably faster and probably safer, but you better also know how to DL if the glide isn’t available or broken.

 

[cuiw99]

As far as threading the catheter, IMO the trick is to advance the entire apparatus (needle, catheter and wire) once you've threaded the wire. Given that the wire is already in the vessel, everything will follow. Super helpful with really superficial arteries where the needle is in the artery and above the skin simultaneously. Only applies to the arrows though, which I personally prefer. Much less of a mess.

The problem of easy wire but unable to thread the catheter is due to the inability of the relatively blunt catheter to penetrate the arterial wall. The above suggestion of advancing the entire apparatus (after the wire is in , and dropping the angle) 2-3mm helps bring the catheter into the artery by leveraging the additional rigidity of the needle inside the catheter. Think of it like an IV except with the added help of a wire.

When the catheter is bouncing or crinkling as you try to tread it off, it is actually meeting the resistance of the calcified wall, not the subcut tissue. Dilating the skin/soft tissue with 18g is pointless. Ever see on US the needle tip inside the vessel on short axis and no flash? That's how resilient the arterial wall can be. That's a sharp metal tip. Now imaging a softer, blunt, plastic catheter. The wire gets kinked by most people because the catheter deforms the artery from above (outside).

Dropping the angle as close to zero as possible before advancing the whole thing helps to avoid the back wall. I literally go from holding the kit like a pencil, to dropping the kit (laying it down), to holding it like a paint brush before advancing it. Never back walled.

US is nice, but most residents are not using it right. A flash with palpation, you are the boss. With US, you need to see the tip hit the fat part of the vessel (SAX) or even better in LAX. That will increase the success of the wire. Transfixing the artery should be the last result when you can't thread the wire but still has good flow. Sometime it's the only option, see calcified artery, or pedi. Residents, remember it's transfixing the radial artery (<5mm), not the radius.

 

[anbuitachi]

The problem of easy wire but unable to thread the catheter is due to the inability of the relatively blunt catheter to penetrate the arterial wall. The above suggestion of advancing the entire apparatus (after the wire is in , and dropping the angle) 2-3mm helps bring the catheter into the artery by leveraging the additional rigidity of the needle inside the catheter. Think of it like an IV except with the added help of a wire.

When the catheter is bouncing or crinkling as you try to tread it off, it is actually meeting the resistance of the calcified wall, not the subcut tissue. Dilating the skin/soft tissue with 18g is pointless. Ever see on US the needle tip inside the vessel on short axis and no flash? That's how resilient the arterial wall can be. That's a sharp metal tip. Now imaging a softer, blunt, plastic catheter. The wire gets kinked by most people because the catheter deforms the artery from above (outside).

Dropping the angle as close to zero as possible before advancing the whole thing helps to avoid the back wall. I literally go from holding the kit like a pencil, to dropping the kit (laying it down), to holding it like a paint brush before advancing it. Never back walled.

US is nice, but most residents are not using it right. A flash with palpation, you are the boss. With US, you need to see the tip hit the fat part of the vessel (SAX) or even better in LAX. That will increase the success of the wire. Transfixing the artery should be the last result when you can't thread the wire but still has good flow. Sometime it's the only option, see calcified artery, or pedi. Residents, remember it's transfixing the radial artery (<5mm), not the radius.

what is transfixing

 

[deleted162650]

If you’re doing long axis w/ U/S there is no point in using a wire. Just take a shallow angle and advance until the cath is a few mm into the vessel and thread it off.