Antti V

Hi everyone, We’re seeing Terumo apheresis platelet collection sets (82420) that have flowback from the platelet bag to the tubing, after the apheresis is over and the tubing is closed with the clip from the set. This used to be practically nonexistent. We can work around it, but is it just us, or do others see a similar thing as well?

The local university hospital has a massive transfusion protocol for adults in the OR which starts with 8 RBC units, 8 units of OctaplasLG, and 12 units of platelets (3 bags of 4 units each). A bag of platelets here contains pooled buffy coat platelets from 4 whole blood donors, or apheresis platelets with pretty much the equivalent platelet count, depending on what's available. So that's more like a 1:1:1,5 ratio in one sense, but in terms of "how many bags do I send up" it's 8:8:3. It used to be 1:1:1 (or 8:8:2). The general idea of the 1:1:1 ratio as I understand it is to be roughly in the same ratio as whole blood: and ideally, to be simple to remember and apply. Once you move from single units (of single donor platelets from whole blood) to pooled platelets or apheresis platelets, I don't think it's going to be perfectly clear for everyone all the time what is meant by 1:1:1. You might need to look at the platelet count of your apheresis platelets if you want to estimate what would be a 1:1:1 ratio for them.

Terve KatarinaN, I'm more of an infrequent lurker than a poster, but I welcome you as a fellow Finn.

It was only my second BBTS meeting and it was very good. My memory of the scientific part will, I'm afraid, blur in years to come, but I bet I'll always remember the time I got to say hi to Malcolm in the flesh.

Thank you, Malcolm. Neither was the OB/gyn specialist now working at our serology lab aware of any K immunisations by platelets only. Also, she knew of no recommendations or policies which would limit fertile women to K negative platelets. We've been handing out K negative reds for girls and fertile women for quite a while now, but haven't limited platelets. Like you said, not knowing doesn't mean it hasn't happened, but at least we're in good company in not knowing.

Related to the topic and revealing my ignorance: regarding serving fertile women with K negative blood, do you mean the Kell status of RBCs only, or platelets as well? There are bound to be a few K antigens in there no matter how the platelets were collected, if they're from a K positive donor, I think. Are platelets from a K positive donor sufficient to cause antibody formation? Is there a safe dose? Or a least known immunising dose?

Thanks, everyone, for the warm welcome. Well it's a small world. Or I suppose a small country is more like it. I was born in Tampere.

Hi everyone, I'm an MD working in blood donation for two years now, so still a newcomer to the whole field. I'm somewhat awed by this use of a web forum for good (as in the opposite of evil) instead of the idle chatter I'm more accustomed to. I've had half a dozen questions answered already by the combined powers of your willingness to help and the search function. Don't know if I can ever return the favor, but I will try if the opportunity appears. Antti V

Hi everyone, As I have another weight-related question I'll piggyback on this fine thread. My blood service has a body-mass index (BMI) upper limit of 36 for apheresis donors for reasons that were poorly documented (well, not documented) at the time, years back. The word of mouth from people who knew people who used to work here back then is that sometime somewhere in the world there had been a morbidly obese plasma donor (in the US possibly), donating as much and as often as allowed (in the US that's plenty compared to EU where we operate), and he or she had a serious adverse effect (possibly death). I can't find such a case reported. The general idea was that the donor's total blood volume was poorly estimated because of obesity and thus too much plasma was collected, followed by some major cardiovascular trouble. I'm trying to evaluate whether we need such a limit - from what I've gathered so far there are plenty of places that do not have such limits. Does anyone know of a) any reports of cases similar to the above? any other institution that has an upper limit on apheresis donors' weight or body mass index (apart from couch issues)?