Plateletpheresis Transfusion and expected rise

[rae221]

I am wondering what general advice would be given by most Blood Bankers when asked by a physician what would be the expected rise in platelet count with the infusion of 1 unit of apheresis platelets. This may seem like an interesting question for a blood banker to ask but I am interested in what the general response would be, both theoretically and realistically.

[Malcolm Needs ☆]

I am wondering what general advice would be given by most Blood Bankers when asked by a physician what would be the expected rise in platelet count with the infusion of 1 unit of apheresis platelets. This may seem like an interesting question for a blood banker to ask but I am interested in what the general response would be, both theoretically and realistically.

You would need to know the number of platelets in your apheresis unit, which must be at least 3x10 to the 11 per litre.

Then you need to know your patient's surface area in metres squared and weight in kilograms.

So for a standard unit (3x10 to the 11), with a standard person (1.7 metres squared and 70 kilograms) the corrected increment would be;

44x10 to the 9 per litre x 1.7/0.7 = approximate rise of 108x10 to the 9.

I thought everyone knew that:sarcasm::sarcasm: !

ACTUALLY, I HAD TO COMBINE THE FIGURES FROM TWO DIFFERENT TEXT BOOKS FOR THIS, AND THEN JUGGLE THE NUMBERS, SO I WOULD TREAT THIS THEORETICAL FIGURE WITH A VERY LARGE DOSE OF SALT.

There is one thing worse than my spelling - and that is my maths!!!!!!!!!!

:eek::eek::eek::eek:

[kate murphy]

We issue guidelines to new residents that state that a DOSE of platelets should increase a non-bleeding pt's plt by 50,000. It's a very general rule of thumb, and not precise in any way. Our Dose is 5 pooled whole blood derived platelets or 1 pheresis.

Each dose has at least 3X10 to the 11th.

[AMcCord]

Our oncology patients seem to get a 20-30,000 bounce. Other patients may get a bounce up to 50,000. So, that's what we tell the docs who ask - "In our experience............" - and we leave it at that.

[labrat]

Just like AMcCord, in our Oncology patients we generally see an increase of 20-30,000. Our heart patients with a preop normal count get phersis units during surgery, however, they receive so many other products in conjunction that it is hard to tell the rise after infusion.

[jcdayaz]

We issue guidelines to new residents that state that a DOSE of platelets should increase a non-bleeding pt's plt by 50,000. It's a very general rule of thumb, and not precise in any way.

We use ONLY platelet pheresis. There is no option for pooled single donor units anymore. We generally concur with Kate....we look for @ a 50,000 increase for each pheresis given.

It doesn't normally happen. We rejoice when it does! In most patients, the order for a platelet pheresis denotes an "issue" with that patient. So, to expect them to have a normal "bump" in platelet count after transfusion is unrealistic.

[kate murphy]

We use mainly whole blood derived - much cheaper.

And you are all right - the bump depends on your patient's diagnosis.

Bleeding, drugs, fevers, antibodies - these can all eat up platelets.

So, if your patient is not bleeding, has no fever, is not refractory, and is not on any number of drugs, then you should expect at 50K bump.

[L106]

Our oncology patients seem to get a 20-30,000 bounce. Other patients may get a bounce up to 50,000. So, that's what we tell the docs who ask - "In our experience............" - and we leave it at that.

We service a large oncology clientele, and our experience is similar to what Ann has stated. (Of course, that is "in general", depending on patient's diagnosis and temperature, etc., etc., etc.)

[pstroud45]

Does anyone have any idea what the increase in platelet count would be for a newborn receiving @ 20 ml of a concentrated plateletplasmapheresis.

[Malcolm Needs ☆]

Someone probably does, but I'm blowed if I do!

[kate murphy]

Well, average newborn has about 250-300ml total blood volume. A 20ml aliquot of either a pher plt or a whole blood derived, should have about the same number of plts in it - around 2X 10 to the 10th. That amount of plt should raise a (non-bleeding, non-febrile) infant's count up about 50K. On average, in general, rule of thumb...