Hemolysis while 'processing' irradiated directed donor RBC units via a cell saver in the operating room

A member of the California Blood Bank Society wrote that a hospital recently reported two separate occurrences of hemolysis while 'processing' irradiated directed donor RBC units via a cell saver in the OR. According to the inquiring blood banker, the units were collected for infants scheduled to undergo cardiac surgery, and in each case the designated (directed) donor units were drawn at a distant blood center where the products were irradiated before being sent to the hospital. By the time of the scheduled surgeries, in both cases the units were close to being outdated. Over concern for high potassium levels, both units were washed in the OR using a cell saver, prior to use. In each case the effluent from the cell saver showed complete hemolysis of the units. No other units on the same cell savers were similarly hemolyzed. The hospital wondered if any facilities have criteria for how long after irradiation they will use a unit if it requires washing by the laboratory or by a cell saver. Has anyone experienced a similar situation, and if so, what was the root cause and how was it resolved?

The following replies were submitted in response to the above question:

1. A blood banker responded that this situation raises some overlapping issues: use of a Cell Saver in surgery, irradiation of RBC units, and the attending concern of hemolysis when RBC units are washed. In the situations described the units were washed by a Cell Saver to remove products of hemolysis following irradiation of RBCs. The responding blood banker added that it is important to know who is operating the Cell Saver equipment, i.e., is it the laboratory, the donor center, the OR, or some other service? According to the responding blood banker, there was a lively discussion at the 2001 AABB annual meeting in San Antonio, that perhaps the newly published AABB Peri-Operative Standards would not apply to the laboratory, but that they would apply to Surgery, Anesthesia or to the OR staff. Thus, the responding blood banker suggested that it might be useful to inform the chair of the AABB Peri-operative Standards Committee of this discussion, so that the committee might consider such comments when developing future standards. (Editor's NOTE: The chair of the AABB Peri-operative Standards Committee has been made aware of this discussion).
   
   
2. A second blood banker responded that regarding the hemolysis observed with washed irradiated RBCs in the OR, her first thought is that the red cells might have been washed with the wrong solution (i.e., sterile water or some other hypotonic fluid instead of saline). She reports having seen this problem in therapeutic apheresis patients when the pharmacy dilutes 25% albumin with sterile water instead of saline.

ADDENDA Jan 13, 2002

3. The chair of the AABB Peri-operative Standards Committee wrote that she has been aware of some groups using cell salvage instruments to wash RBC units from the blood bank. In fact, she was asked to offer this service in her own hospital during liver transplantation in order to decrease potassium levels. She mentions that her group did some comparative studies with the 2991 cell washer and found that a 1-liter wash did significantly decrease the concentration of supernatant materials (potassium, free hemoglobin, albumin, and glucose) but not nearly to the extent of a 2-liter wash on the 2991 cell washer. Such washed products are definitely not IgA-deficient, even with a 2-liter wash on the cell salvage instrument. These results relate to the design of the cell salvage instrument - since the incoming blood has a high hematocrit to begin with, supernatant removal through hemoconcentration is decreased and washing is not very efficient. To wash each unit of blood requires one full centrifuge bowl and one partial bowl unless blood from another unit is added - either you get less efficient processing with the partial bowl or an admixture of blood from 2 units. Ultimately, she reports that they decided to not to implement OR-based washing but to maintain washing of allogeneic units in the blood bank. She reports not having encountered hemolysis of such units based on the fact that they were irradiated. Her first reaction in such a circumstance would be to check what solution was being used for washing. Selection of the wrong fluid with subsequent hemolysis has been reported.

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