Washing pheresis platelets

[mdcbk]

Does anyone have experience washing 1/2 pheresis platelet on the COBE 2991? We have a procedure for washing a whole unit, but have not been able to find any documentation about washing smaller voumes.

[adiescast]

If the unit has to be opened anyway, why not wash the whole thing and let them take what they need from it? If you already have it split and won't waste the other half, I suspect the washing process for a full unit would work well for a half unit. You would simply need to run out more of the supernatant at each step. What are you using as the stop point for expressing the supernatant from the full unit?

[mdcbk]

We're using a super out rate of 100 and a super out volume of 500 ml. When we wash a whole pheresis, the final volume is ~60-90 mls. Since the Cobe will retain at least 50 ml volume during a super out, we made the assumption that a half pheresis would have about the same final volume as a whole unit, and would just be less concentrated. Based on that assumption, we decided to only wash whole pheresis units. We were just curious to hear if anyone did it differently. We were also wondering if anyone used something other than saline to wash and/or resuspend?

[heathervaught]

When we wash apheresis platelets for treatment of NAIT, we are often collecting a compatible unit from the mother for transfusion to a neonate. Half of the product is routinely washed and issued for transfusion upon collect, and the other half is held and used if/when the baby needs to be transfused again. The 2nd half is used for bacterial detection (unless it is needed prior to the 24-hour window). Our blood center MDs and the transfusing MDs are fine with the approx. 1.5 x 10^6 dose for a neonate. We have the same type of setup, mdcbk, our final volumes are approx 60-90 mL.