Weight of donor units

[evilwarning]

I was curious as to how other facilities documented the weight of their stock donor units. At my former hospital, whenever we received a shipment of units, we would scan the information in the computer and then weigh them on a scale. We would then subtract 50 grams from the weigh observed on the scale. I assume this is to account for the weight of the bag and the segments. Is this what everyone else does?

[Sophie1210]

We don't weigh our units at all. We only record volume and our computer system defaults to 350mL for RBC's and then we put in the volume found on the bag for plasma and platelets.

 

Why do you weigh the units?

[John C. Staley]

I'm with Sophie, why are you weighing every unit?  Seems like an awful waste of time to me. 

[LJGunderson]

As long as the units are being weighed during the collection process and as long as the scales being used to do so are calibrated and maintained per manufacturer's specs, you should not need to weigh the units again.

[evilwarning]

We don't weigh our units at all. We only record volume and our computer system defaults to 350mL for RBC's and then we put in the volume found on the bag for plasma and platelets.

 

Why do you weigh the units?

 

According to my supervisor, it is to determine the volume of blood in the bag. That number we type into the system prints out on a transfusion tag. Then when a nurse transfuses the unit, he/she can right down how many cc's are being transfused.

 

 

 

As long as the units are being weighed during the collection process and as long as the scales being used to do so are calibrated and maintained per manufacturer's specs, you should not need to weigh the units again.

 

Oh. Hmmm. Sorry I don't want to sound dumb. However, I don't think the donor units say how much blood is in each bag or even what the weight is. Is that something you have to call the blood donor center for?

 

 

 

I'm with Sophie, why are you weighing every unit?  Seems like an awful waste of time to me. 

 

Well a lot of the stuff done at this hospital seems like an awful waste of time or doesn't make sense at all. The blood bank still uses red tops for crying out loud!!

[Cliff]

It sounds like some of your policies are simply "we've always done it this way" issues.

 

There isn't an easy way to determine how much blood is in the bag.   It started as 450ml or 500ml of whole blood (unless it was apheresis red cells) +/- 10%.  Then as you know it's spun done and most of the plasma is removed and an preservative is added.  All of these steps, along with the donors hematocrit make for a wildly varied red cell product volume.

 

That said, the human body doesn't react to red cells as it would a different medication.  A unit is a unit and the recipient should receive an approximate increase in hematocrit regardless of the variable size product.  There isn't a direct correlation between the increase in hematocrit and the mls of red cells received that all recipients will exhibit.

 

If you are a small facility the physicians may be used to and want to continue to receive this information.  It's up to your medical director to convince them it's archaic and of little value.  It is a waste of your resources which translates into money.

 

As for sounding dumb, I firmly believe the only dumb thing to do is remain silent and not ask questions.  The people on this site are an amazing wealth of information.  I'm almost afraid to post now.  

[carolyn swickard]

We have weighed the RBCs for a long time now.  The plasma products all have an approx volume on them, but not all of the RBCs do - and they do vary.  The normal range is from 270 - 400 (rare 430) gms.  We weigh them on a little postal scale and subtract 50 gms for the approx weight of the bags - which we determined after weighing several returned empties.  We weigh them because the RNs needed more help on volumes "in and out" on their pts and their original "guess" of 250 mls was woefully inadequate.  Doesn't take long - we just write it on the crossmatch tags.  We don't record it in the computer because Meditech doesn't print it out anyway.

[AMcCord]

If the blood is run via an IV pump, the volume dispensed (the volume in the unit) is displayed on the pump when the infusion is complete. If the volume is important, it can be documented from that. There are a few patients where volume overload is a very touchy issue - for those, they may need the unit volume to add up for total intake. Most patients - thankfully - are not that sensitive.

 

We tell nurses to set the pump rate for 300 mL for a unit a red cells, with the understanding that this is simply a ball park number,  and to document the pump volume for the actual volume infused. That's the only volume we give. Seems to work just fine.

[Cliff]

As a few people have said in support of writing the volume on the unit, they are right.  It doesn't take much time to write the volume and record it in the computer.  Multiply that by more than 30,000 red cells transfused a year and it adds up quickly.  I don't see the value in doing it.  I can see the cost.

[tricore]

We receive a lot of apheresis collected RBCs and the volume is on the bag.

[Abraham]

_{We document volume on the bag at issue. Niursing wanted the information for I/O documentation and to enter volume for the pump they use to administer products.}

[David Saikin]

I have never worked anyplace that weighed the bags. Before ISBT 128 labeling, the bag would say that it was approx 350mL. I don't believe that is on the current labeling.

[Dr. Pepper]

We also use a default of 350 mL for red cells. Never had any issues, nor any questions like "Huh. How come they're always 350?" FFP and pooled or apheresis platelets we record the volume from the bag, simply because it's there.

By the way, I am normally a little suspicious of round or arbitrarily derived numbers (think exact 1 year outdates for FFP, 4 hour max duration for transfusions, give RhIG within 72 hours, manual BPs that are always in multiples of 5...) that may be based more on "sounds reasonable" than hard data. But we actually did weigh a bunch af units, factored in specific gravity and came up with an average pretty darn close to 350. OK, we did round that but just a little bit!

[tbostock]

We use a default for the red cells.  I don't see a need to weigh each one, but we have had nursing complaints over the years.  "Just buy one of those cheap kitchen type scales" they said....yeah, as if it would be that easy. 

[mewilde1]

Places I've worked have always used default volumes for random donor platelets, pooled platelets, pre-pooled platelets (by blood provider), cryoprecipitate and red cells.  When we get a call from nursing, we always let them know the default value.  When relabelling we would also use the default volumes.

 

The major difference is for neonates.  These are aliquotted according to the doctor's orders with extra (usually 5 - 10cc, according to your policy) for the transfusion tubing.  The final dispensed volume is available from the pump, as stated previously.

 

I've only weighed blood products when I actually worked in a donor center or drawing autologous units.