[gizdo]

Our facility has just started using CRRT in the past couple of weeks. We are having a huge debate amongst each other about how to calculate the patients fluid balance. Our educators insist that we just take the total fluid removed off the prismaflex and then subtract any other losses or gifts (ie pleural tubes or boluses) and that is our balance.

However, everyone else is thinking that we have to subtract our intake from our fluid removed to get a true patient fluid balance.

So far with the existing calculation we are getting a fluid removal of around 3 to 8 Liters for every 12 hour period. This seems really excessive, but we are told that it is correct. How can this be correct when we are supposed to be taking off around 600mls of fluid per shift?

Can anyone share how their facility calculates the 24 hour fluid balance?

Thanks!

[sumrluvr73]

you have to add all input.(iv fluids, parenteral feeding, blood products-whatever) Then subtract that from all out put (urine, ng, chest tubes etc). the answer is howmuch you actually took off or not

[LoraLou]

Same with regular I/O total in minus total out, iv fluids, tube feeds, etc, minus crrt minus ct, ng output, urine output if they're having any

[Dinith88]

Originally Posted by gizdo

So far with the existing calculation we are getting a fluid removal of around 3 to 8 Liters for every 12 hour period. This seems really excessive, but we are told that it is correct. How can this be correct when we are supposed to be taking off around 600mls of fluid per shift?

Thanks!

The other posters made mention of adding up every drop of output and input, including it in your calculations and all of that, and i'm sure you're doing it. To me it sounds more like you're confused because the effluent bag (and thus your 'output') is filling up so rapidly...

From your question, it seems like you're measuring 3-8 liters of EFFLUENT every 12hrs (and NOT patient fluid removal). EFFLUENT is the amount of fluid removed from the patient PLUS the DIALYSATE (and/or replacement fluid) that's running into the crrt machine. (it all ends up in the effluent bag). The dialysate (and/or replacement fluid) never goes into the patient (and thus is not an INPUT), but because it drains into the effluent bag WITH the patient removal, many people assume the entire bag is an 'output'. If you were trained properly, you'll be able to see on the machine display what the actual fluid removed is/was per hour...and be able to manipulate it depending on the hourly circumstances... (should be about/around 600 cc/8hrs for this pt, right?). The effluent needs to be recorded...but it's not an ouput. IF your institution insits on you recording the dialysate and replacement fluids as input (which technically they arent), then your i&o's should be roughly correct if you're also considering the entire volume of the effluent bags as output.

Anyway...
IF i'm wrong and your ARE pulling 3-8 liters of actual patient removal in 12 hrs you will kill the patient eventually...or at least make an already unstable patient VERY unstable...fast. Or if you ARE pulling that volume off the patient and she/he is tolerating it (MASSIVE FLUID SHIFT/LOSS) , he/she does NOT NEED crrt...and should be on standard dialysis...and you need to STOP pulling so much so fast...

[Summitk2]

Originally Posted by Dinith88

The effluent needs to be recorded...but it's not an ouput. IF your institution insits on you recording the dialysate and replacement fluids as input (which technically they arent), then your i&o's should be roughly correct if you're also considering the entire volume of the effluent bags as output.

I think Dinith is right-on with the math and explanation. These volumes aren't REALLY going into the pt or coming out of them. Make sure your net is correct.

I think most institutions should require all volumes on CRRT to be documented (dialysate, replacement, effluent). These are usually high volumes, and will show mathematical errors very easily, thank God! If you're performing CRRT yourself, you should understand the mechanism and how the fluid and solutes are shifting. You should be very involved with what the fluid goal of your shift should be, and making sure you're meeting the goal on an hourly basis. If your goal is to make your pt -1 liter on your shift, I sure hope your math doesn't show they're -6 liters!

[gizdo]

Thank you, everything you guys have said is exactly what I was thinking too. I kept telling our educators that there is NO WAY we were taking off that much fluid in a 12 hour shift. Now I just have to convince them! Sheesh...it's just simple mathematics...I can't believe we are having this much trouble with this.

Thanks!