RAP/CVP measurement with a temp dialysis cath.

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Specializes in SICU, NICU, CCU, CIC, ICU, MICU.

Just wondering if anyone has any thoughts on the accuracy of measuring RAP/CVP with a temporary dialysis cath. versus a swan or TLC. I thought I remembered reading somewhere that using a temporary dialysis cath is not as accurate. By the way I am only asking about temporary dialysis cath placed in the SVC/RA.

Any links anyone can share would be appreciated.

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Specializes in CVICU.

I have done it a couple of times before, but it's at night, so I have never had the chance to ask the doc about the accuracy.

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While it might not be the best access or most accurate way to monitor CVP...if you are in the middle of doing fluid resus you can certainly use it to help monitor the trends (not necessarily the number).

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Specializes in Critical Care, Organ Transplant, Educ.

Definitely...not accurate. I think it would be a waste of time, effort, and increases the risk for infection. But like the previous poster mentioned...ok for trending purposes.

If you think about it....if you use a temp dialysis cath such as a quinton....it is not a very long catheter. In order to measure RAP/CVP..the tip of the catheter or central line must lie where the vena cava basically meets the right atrium....hence right atrial pressure.

On another note....I have never in my practice used a quinton to monitor CVP. We have used a PICC line before...that was simply out of desperation just for trending purposes...but also less accurate. Remember...the longer your line and IV tubing you have...the less accurate your reading will be since the pressure has to be transduced via a longer distance.

Hope this helps.

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Specializes in CVICU.
Remember...the longer your line and IV tubing you have...the less accurate your reading will be since the pressure has to be transduced via a longer distance.

Hope this helps.

That's pretty much what I was thinking as well. I couldn't believe the renal docs even wanted me to access it for a trivial number... It must have been for the trends.

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It is acceptable short term but there are downsides.

Infection, as mentioned above, is the first.

Thrombosis of the line is second. HD lines are generally heparin flushed for this reason. The flushing/irrigation of CVP lines could pose a problem for this.

Re: catheter and tubing length.....dual lumen venous lines for dialysis (quinton, mahurkar) come in various lengths. Most caths range 13-19 cm. The average distance for an IJ to the SVC-RA junction is about 16 cm, and maybe 19-20 cm for a subclavian approach. Unless you have a short catheter in the left subclavian, you should be OK.

And unless your tubing length (cath tip-transducer) is >100cm, there should be minimal effect on pressure transduction.

If it for short term trend to guide fluid resuscitation/vol status, it's alright.

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Actually, CVP measured from even a PICC line correlates extremely well with CVP measured from a central line. Peripherally inserted central catheters are equivalent to centrally inserted catheters in intensive care unit patients for central venous pressure ... - PubMed - NCBI

Femoral lines can accurately measure CVP as well, though it is probably more important for the patient to be lying flat.

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