Double Filtering?

[Michaele]

Hi all, I just found out that my open heart physician is having his post op patient transfusions double filtered. We issue a standard 170 micron filter when the nursing staff takes the unit, but they have also been instructed to filter the blood through a 40 micron filter AS WELL. So the nursing staff has been ordering those filters through our Central Supply department. Our units are already leuko reduced by ARC. Does anyone understand why the physician would want this? Are there any indications for such a practice?

We do have an auto salvage program here, and the 40 micron filters are used during surgery, which makes sense to me, but filtering with an already leuko reduced unit through a 170 and a 40 micron filter does not.

Any input is appreciated.......

[adiescast]

He may be concerned about some of the reports that older blood is bad for cardiac patients. He may also be concerned about risk for lung injury from microparticles that would get through a 170 micron filter. I don't know why he would need both, except that prefiltering the larger stuff out first would reduce clogging of the smaller bore filter. You could always ask him in a non-trhreatening manner to explain the reasoning to you. I know that our institution purchases 40 micron filters that we do not issue from blood bank, so someone is using them without consulting with us. There may be something in the cardiac literature that promotes it.