[Marlene]

Transfused platelet don't last very long to begin with. And yes, you can burn through those platelets very quickly. I'm not sure about the timing of the CBCs and transfusions from your post. Let's say he was transfused on Monday and checked again on Wednesday and was OK, then by Thursday he could be low again.

If they are doing a post-transfusion platelet count, it will usually be high. But if the body doesn't like those platelets, he could be back to 2 or 4 again by the next day or sooner. After a while, the body may become refractory to some or all platelet products.

You may want to have his clotting time checked if he's bleeding at 15 -20 K. Just to make sure he has enough clotting factors. You do need more than platelets for blood to clot. But platelets of 2 -4 K are pretty risky. John never had serious bleeds at 4K.

We found platelet counts to be pretty accurate. There were alway differences between the hospital and our doctor's office but they were never far off. If there are too few for the machine to count, they will count them manually. We also found that John's own 8K platelets worked much better than the 20-30K transfused platelets.