arterial lines and NIBP

[uabrn06]

Could anyone in CV tell me which BP is more accurate...arterial line or NIBP. I work in a neuro ICU and many of our really sick pts have arterial lines, but we generally go by the NIBP. I've asked some of the veteran nurses and they say that the art lines can be unreliable because they can be very positional. But if the RTF is accurate wouldn't the line be the better choice? Thanks!!

[mikinklr]

if I"m zeroed and leveled w/ a good wave i usually trust the A line more

.I at least use it for a baseline and look for changes (when its not obviously dampened). I prefer not to repeatedly do NIBPs' if I can help it when the pt has an Aline.

[Burnt2]

I just had this issue with a patient, and talked with a cardiologist about it.

If the waveform is good, a-line beats NIBP/manual BP.

My gut instinct was to trust that my manually auscultated BP was more accurate (because there was a big discrepancy). the a-line was positional - but the doc informed me in not so kind words that a-line with good waveform trumps all.

Edit: As Mikin stated - the caveat is, of course, that its zeroed and positioned at the phlebostatic axis.

[meandragonbrett]

automatic NIBPs uses an averaging mechanism to come up with it's blood pressure. art lines is real-time continuous BP monitor. As long as your wave form is appropriate (dichrotic notch, and your complex correlate with each QRS) and you have your transducer at the phlebostatic axis....your art line will be the most accurate.

[cardiac.cure03]

The complex on the a-line waveform is supposed to match up with each QRS on the monitor? Never heard of that before, good to know! (I'm also not with a bunch of experience, so hope I don't sound like a dumb newbie!) lol

[Burnt2]

The complex on the a-line waveform is supposed to match up with each QRS on the monitor? Never heard of that before, good to know! (I'm also not with a bunch of experience, so hope I don't sound like a dumb newbie!) lol

well, the QRS = electrical ventricular systole, right? And the waveform you see is because of the pressure generated by the mechanical effort of the left ventricle during systole (ergo your systolic pressure at the peak of the waveform and the diastolic at the trough of the waveform).

So yes, they will match up (although technically the waveform on the a-line will come slightly after the QRS of the ECG due to the delay between electrical relay and mechanical response)

[BBFRN, BSN, PhD]

This gives s/w of an idea of what you're looking for.

[longroadahead]

I also like to compare the NIBP with the a-line at the start of shift. The majority of the time the MAPs correlate within 5mmHg but often the SBP and DBP will be off. But if the A-line has a good wave I always trend the a-line and if for some reason I lose my A-line I have a general feel for what it would be compared to the NIBP reading.