Arterial vs Venous Pressure

[madys911]

Hi,

I had a pt who was a hard stick and the doctor ended up trying to insert the IV. The catheter and tubing was an arterial line set up but he was searching for a vein. He finally got it. I went to give meds and noticed it was pulsating. We then set up the pressure bag and the rest of the equipment to see if it was in fact in the artery. The monitor was giving inconsistent readings and we ended up with getting a PICCm on the other side. Regardless, how would one no for sure if it is in the artery or vein? (as we still dont know) Im assuming if it was in the artery the pressure would be reading much higher? Although her pressure was already 200s/140s.

[EllaBella1, BSN]

If i was pulsating it was most likely arterial. If you're ever really not sure you could always send a blood gas off of it and see what your numbers look like.

[PixieRN1]

If it was pulsating, it's arterial. The vessel could have been in a vasospasm initially, giving you wonky readings. I second the call to getting an ABG to confirm.

The arterial reading should correlate mostly with a good cuff BP; in most circumstances I would not expect the art line to be off the cuff reading by much...you could check a cuff pressure to see if it's close to your potential arterial line BP. If it's arterial, they should come pretty close to matching (unless the artery is in vasospasm).

Either way, if you really needed the line and wanted to rule out an arterial access, a quick ABG will do the trick.

[Guest374845]

If the vein shares a wall with an artery, the IV could have been in a vein but giving you pulsations and inconsistent pressures. The only REAL way to know would be to ultrasound it.

[KatieMI, BSN, MSN, RN]

There are no big veins around radial artery, and this is not groin or AC fossa where these two things run close together. In the wrist, if it is pulsating, it is in artery.

ABGs in venous and arterial blood can "equalize" if patient is in severe distress, especially severe VQ mismatch. In this case, pulsation can be the only sing that the catheter is misplaced.

Just my $0.02 :)

[PixieRN1]

There are no big veins around radial artery, and this is not groin or AC fossa where these two things run close together. In the wrist, if it is pulsating, it is in artery.

ABGs in venous and arterial blood can "equalize" if patient is in severe distress, especially severe VQ mismatch. In this case, pulsation can be the only sing that the catheter is misplaced.

Just my $0.02 :)

In the OP's scenario, I would think that if there was that severe of a mismatch, or a scenario where the arterial blood would match the venous, that they wouldn't be taking the time to put in a PICC rather than slamming in an EJ/IJ or a standard central line.

Either way, pulsation is the cheapest and fastest way to know, absolutely agreed.

[Guest374845]

There are ABSOLUTELY IV-suitable veins paired with the radial artery. I see it daily from wrist to mid forearm when placing ultrasound IVs.