Leveling Art Line

Specialties MICU

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I'm sure this has been discussed many times on this site, but here goes......

I have been in the MS ICU for about 6 months, and don't have a lot of experience with hemo monitoring with A-lines, Swanz, etc. We just don't get many patients that critical who need them, and when we do, they go to the more experienced nurses.

I have had maybe 3 patients who have had A-lines. I have asked the more experienced nurses for help in setting up, leveling, and zeroing the A-line, and have repeatedly been told to level the transducer to the insertion site rather than the phlebo axis.

I really trust and respect these nurses, but tried to do some research to support what they were telling me. However, all I could find was to level all lines (Art, CVP, Swanz) to the phlebo axis.

Last night, I had a post-brain biopsy pt who had an A-line that I leveled to the radial artery. She also happened to be laying on her side on that same arm with the BP cuff on the opposite arm. Anyway, her A-line and cuff pressures in no way correlated. Her cuff pressure was like 120-130 and her A-line pressure was 170-190. I'm assuming the A-line pressure was artificially high since she was laying on that arm, and her cuff pressure was artificially low since it was on the upper arm.

And, as a theoretical question, if leveling to the A-line insertion site, I am assuming the pressure reading would be an accurate measurement of blood pressure AT THE INSERTION SITE. But, if leveled to the phlebo axis, the BP reading would be an artificial APPROXIMATION of central pressure due to the effects of atmospheric pressure on the transducer. Does that make sense? And, if so, why would we want an APPROXIMATION when we can have an ACTUAL?

Thanks all!

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And, as a theoretical question, if leveling to the A-line insertion site, I am assuming the pressure reading would be an accurate measurement of blood pressure AT THE INSERTION SITE. But, if leveled to the phlebo axis, the BP reading would be an artificial APPROXIMATION of central pressure due to the effects of atmospheric pressure on the transducer. Does that make sense? And, if so, why would we want an APPROXIMATION when we can have an ACTUAL?

Thanks all!

For swan/cvp/a-line you should level at the 4th ICS Mid-axillary line. You need to check your hospital policy on invasive monitoring. AACN Procedure Manual is also a good place to check.

Why would there be effects of atmospheric pressure if leveled at the 4ICS-MAL? That's why you zero the transducer. Atmospheric pressure isn't going to change from the 4ICS-MAL to the radial artery. I'm not sure I'm following you here.

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Specializes in SICU.

Next time you have a pt with an a-line I want you to do a little experiment. Put the transducer next to the insertion site and move the arm really high in the air above the pt. Then look to see the pressure reading. Next hang the arm over the side of the bed so it is a low as it can go and look at the pressure reading.

When you see the readings I want you to think. Does my Central blood pressure really change that much just because I have raised or lowered one arm? Remember you are trying to find out about central blood pressure in order to check for organ perfusion.

Next level that a-line transducer to the phelbostatic axis (4ICS, MAL) like EVERY hemodynamic book, policy manual tells you to.

The very next thing you need to do is talk to the unit educator. Those experienced nurses that you have talked to, do not understand a-lines and some unit re-education is needed.

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Specializes in Critical Care.

In support of the other nurses who have already posted, you need to look to the agency which is responsible for setting the gold standard of ICU care. That is the AACN. They set the standards we should practice by and their findings are evidenced based. I loved the AACN Practice book so much, I bought one for myself (not cheap) and have used it repeatedly over the years. This isn't a situation where you want to model improper practice, you want to use EBP.

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Specializes in Not too many areas I haven't dipped into.

4ICS-MAL!!!! Always always always. I feel you though, when I was new to the ICU, I looked up to the more experienced nurses and found a lot of inconsistency in practice. I look to policy and gold standard each and every time.

Good for you for questioning it!!!!

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Specializes in CVICU.
http://www.pacep.org Go here
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Specializes in SICU, MICU.

http://www.pacep.org go here

thanks acrnahopeful for posting this link... its a great refresher on cardiac for new sicu nurses like myself :)

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