Leveling art line to tragus for cpp???

[jimmy_hat]

Hello all. I am taking a class that stated in a sitting/semi-fowlers patient that we have concerns with CPP, we should level the art line at the tragus (or where every you would level your ICP monitor). I have never done that in any of my neuro units. Art was at phleb axis and ICP at tragus and we used those numbers to calculate the CPP. That big of a difference would give you about a 20-30 mmhg difference (lower) pressures. These are huge differences. Anyone doing this? Does it modify your reference numbers for goal cpp?

Jimmy

The only articles I am able to find are ones from journals that state that the transducer should not be leveled to insertion site. I am shocked because I thought that was old news but the research based ones are from 2001 in CHEST. I was practicing back then but it was never taught to me as anything other that the phleb axis.

[penthes]

I'm currently working in a SICU that does a lot of head trauma. The TBI protocol states that we level the A-line transducer at the external auditory meatus. I follow the protocol and we treat with hypothermia, 3% saline, Mannitol, and pressors. Sometimes we drain CSF and sometimes we only monitor with the Camino.

I previously worked in a NICU that required we level it at the phlebostatic axis. I had understood this to be the proper place to measure MAP. I'm not sure if you can find any research or textbook that will tell you to measure MAP anywhere else. I would think that an accurate MAP would be important since CPP=MAP-ICP.

I follow the policy of the facility where I now work, but do not agree with it.

Penthes

[rachelgeorgina]

I've just done a placement in one of the biggest and most specialized, well regarding neuro ICUs in the country. They leveled their art transducer at the tragus. With regard to the EVD/ICP these were most often open to the drain (& therefore the icp on the monitor would be grossly inaccurate) and clamped hourly to transduce an accurate ICP. obviously drainage orders were per neurosurg however.

[Starmnm]

We level our art lines to the phlebostatic axis. We level our EVDs to the tragus. I haven't heard of leveling art lines to the tragus before.

[CCRNDiva, BSN, RN]

I'm in a level II trauma center and we level ABP at the tragus when they have an ICP to calculate CPP. I've been there 7 yrs and thats how I was trained to do it.

[I see you RN]

We're phleb axis people on our NICU. I'll be interested to see what research comes out to support zeroing at the tragus. We also use 3% saline and mannitol; I've never seen a higher concentration of saline ordered. We don't have a standard practice regarding ventrics; we require orders be written for every one. Typically what I see is a pop off around 12 mmH2O and then clamp after a certain amount of drainage for an hour, then open depending on the ICP/CPP. My unit is small and specialized; trauma has their very own floor so our practice might be different because of that.

ETA that I clamp every hour to get the reading.

[experienceawareness]

My unit does not transduce art lines at the tragus for cerebral perfusion nor at the kidneys, colon or anything other than the phlebostatic axis. I'm curious to see the evidence based practice or something on this.

[link51411]

if pt has an evd we level our A line with the EVD for CPP

[majahindmarsh]

Hi!

I am probably a few years late for this thread but I thought I would put my two cents in! i am currently working at a Private Hospital Intensive Care unit which specialises in all specialties in sydney. I have also previously worked in one of the leading neursurgical ICUs in Sydney. At both of my areas of employment we ALWAYS level our arterial lines at the tragus for all our neuro patients. I know that this is also common practice at most other neuro ICUs in Sydney. However, I have not been able to find any evidence or documentation to back this up. It is just what we do and i think the initial orders for this have come from our neuro surgeons. If anyone could tell me where I could find information to back up this practice i would be greatful! I have just because the CNE in my unit and the cluey new staff are wanting to know why we do what we do! Thanks!!

[miss arron]

I'm a year or two late on this thread, but I found it so interesting....

I've worked in two ICU's that have had neuro patients and both places have leveled the art at the phlebostatic axis and just wondering if there's be any additional research on this topic that anyone has heard of

[aCRNAhopeful]

I dont have any evidence to support the practice of leveling to the tragus but it makes sense. The perfusion pressure of any organ is going to be equal to the MAP minus the highest force opposing the map. In the brain it could be ICP or CVP if that is higher. Most organs perfusion pressure is going to be MAP minus the venous pressure. The point is the closer you can approximate the arterial pressure directly entering the organ of interest the closer you are going to be to the actual perfusion pressure of that organ. The physics just make more sense that way than leveling the art line to the heart and calling it good enough.