Arterial Line Versus Cuff Pressure

[MQ Edna]

Hi there,

I would like to know what nurses do when you come on to a patient on various inotropic sgents and the nurse you are following has decided to follow the cuff pressure for the blood pressure monitoring because the arterial line pressure was much lower. You see that the waveform of the arterial line looks satisfactory. What other methods do you use to decipher whether or not to use the arterial line or the cuff pressure?

[Aritchie-loynes]

Steps of troubleshooting: a) ensure properly inflated pressure bag b) level transducer at phlebostatic axis c) re-zero d) ensure a-line is not "positional" (catheter is not stuck against vessel wall, kinked, etc.) e) if necessary, aspirate near insertion site to r/o air within catheter and/or ensure good blood return f) ensure good waveform with dicrotic notch; if need be, adjust scale on your monitor based on current blood pressure (If your scale is set to 150 and your BP is only 90, your waveform can appear dampened)

In our unit, we will use a cuff pressure just as a reference point. I have never seen anyone zero the transducer at the insertion site. We only use the phlebostatic axis because this is used as a reference point for the level of the heart. Bottom line, if you are visualizing a good waveform, your a-line will be the most accurate.

[ErraticThinker]

I work in a surgical ICU, and when I first come on, I make sure the a line is leveled and zero'd, trouble shoot for little things like positioning, and making sure the pressure bag is inflated enough.

ultimately what i'm worried about though is that the mean arterial pressures match up because that determines how i'll titrate my drips. so a little variation between them isn't the end of the world for us as long as the MAPs match up closely.

[NeosynephRN]

We never take the initiative to choose which one we want to titrate to. If there is an a-line, that is what we must use. If there is a discrepancy, the MD will have to right for us to titrate to NBP if that is what he/she desires, but we would then typically d/c a-line if it's not accurate.

I am so glad that I have the right to choose...man if you have to run off an iffy A-line until you get a doc to tell you otherwise...Do they have to give you an order to D/C an inaccurate line or can you do that based on nursing judgement?

[registeredin06]

We would never titrate drugs to an a line we knew was inaccurate, that would be silly. I guess I didn't make myself clear.

We do what is necessary and then relay the change to the MD and he/she will change orders as necessary. You can't have each nurse come on shift titrate to something different, gtts should be titrated to an a-line and if the one in isn't accurate, you need to get a new one. The issue should be resolved with orders in place before the next nurse comes on shift, hopefully. Sorry if I was previously confusing.

[NeosynephRN]

We would never titrate drugs to an a line we knew was inaccurate, that would be silly. I guess I didn't make myself clear.

We do what is necessary and then relay the change to the MD and he/she will change orders as necessary. You can't have each nurse come on shift titrate to something different, gtts should be titrated to an a-line and if the one in isn't accurate, you need to get a new one. The issue should be resolved with orders in place before the next nurse comes on shift, hopefully. Sorry if I was previously confusing.

Thanks for the clarification...obviously I was confused...

[IDoNotGiveOut]

This thread is more than 10 years old, and the issue still seems to remain unresolved. It seems like common practice is to go with whichever one is "better", which is, obviously, illogical. People where I work also seem to trust automatic NIBP more than the a-line, and tend to distrust the a-line pressure when the two don't "correlate". This is especially dumb when going by systolic pressure, because those almost never correlate. The MAP, however, does usually correlate, which is what we should be titrating to anyway, IMO. But we titrate to systolic according to the a-line pressure, unless we don't like that pressure then we check the NIBP, and if we like that number better we say the a-line is inaccurate. The whole issue is a big pet peeve of mine where I work. Even worse, we don't have a manual cuff in the entire unit. I had to send someone down to a regular floor once to get a manual cuff. Seriously.

[BelgianRN]

Even worse, we don't have a manual cuff in the entire unit.

I hear you. I've had discussions with people still trusting NIBP when they had beautiful curvatures on their A-line. Also had the opposite people trusting an A-line with obvious overshooting or dampening. And no manual cuff anywhere to be found (I think even the wards have automatic NIBPs now).

Here we titrate to MAP but some people forget it when the systolic's good enough and stop titrating pressors just because they have a systolic of 100 mmHg even with a MAP that is still in the 50's with barely any urine output.

The best one a cardiac surgeon that insisted his fiberoptic IAPP aortic pressure was the only correct one (and thus the patient was fine) as all other BP's screamed hypotension with lactate rising (well above 10 mmol/l) and blood pouring out of the chest while supported on about all vasopressors known to man.

Close second the new nurse whose A-line was partly disconnecting and his pressure dribbled to low nearly non pulsatile 30's. We saw him leap into action stressing while fetching the intensivist for help. We tried to help out and make pulsatile gestures with our fingers because obviously there was a pulse on the plethysmogram and there was still end tidal CO2. But seeing him get all panicky was fun for 20 seconds.

Bottom line is there is no improvement in that department. I find it scary sometimes how blindly data gets trusted because "modern computers hardly ever fail" or how some data just doesn't get explored to the fullest or interpreted with the right mind set.

[silentRN]

This thread was started in 1999, I can't believe that it is still going! That's kinda neat. :)