The life of a bone marrow or peripheral blood stem cell transplant patient is heavily invested in time at the hospital, seeing physicians in the clinic, and undergoing medical procedures. Even after discharge from the initial hospital stay, there is a need for frequent checkups and dependence on red blood cell (RBC) and platelet transfusions until successful engraftment occurs.¹

While these transfusions were performed at the hematology-oncology clinic at the University of California San Francisco Medical Center during weekdays, patients requiring transfusions during the weekend were required to visit the emergency room.² Not only was this arrangement inconvenient for the patients and resource-intensive for the hospital, but there was also the added risk of exposing patients with weakened immune systems to infectious agents.

With this in mind, the University of California San Francisco Medical Center launched a dedicated infusion service for patients requiring IV fluids and blood products during weekends. The Mount Zion Hospital facility was identified as the site for this new service. While only a 15-20 minute drive away from the main Parnassus campus, the fact that the Mt. Zion blood bank lacked all of the capabilities required to support the complex product requirements for the hematology-oncology patients posed a challenge. We had to devise a new approach to enable both blood banks to work together to test patient samples and set up appropriate blood products for transfusions without impacting the quality of the weekend infusion service.

Enhancing Blood Bank Communication
Hematology-oncology patients are usually seen at the Parnassus campus and their blood samples are tested at the Parnassus blood bank. While the Mt. Zion facility was already providing weekday infusion services for its patients, several issues were identified in the course of arranging for testing and selection of blood products at one site and transfusion at another site. Increased communication between the two blood banks was necessary to ensure the correct blood product got to the correct patient.

First, there was the problem of identifying those patients that had their specimens drawn at Parnassus whose transfusions were to be performed at Mount Zion. A robust system was needed to provide for pre-transfusion compatibility testing and correct unit selection.^3,4 This ultimately required redesign of the blood bank requisition to list the physical location of transfusion, as well as the date and time. This enabled the blood bank technologists to keep track of specimens by transfusion location so the workup would be completed correctly for each transfusion site.

Communication with the clinic was also critical to success of the operation. By having the clinic fax a list of patients to be transfused over the weekend, the blood bank at Mount Zion was prepared to review pre-transfusion results and order additional products, if necessary. They would then cross-check this list with one prepared by the Parnassus blood bank to make sure no patient had been inadvertently excluded. In the end, like in most medical practice, good communication between the clinic and both lab sites is what enabled the process to go smoothly and any unexpected events to be dealt with promptly.

RBC Antibodies
At UCSF, patients with a negative antibody screen and no history of RBC antibodies are eligible for electronic crossmatch. Both Parnassus and Mt. Zion blood banks are linked with the same laboratory information system, so test results are instantly available at both hospital sites--pre-transfusion testing can be performed at the Parnassus blood bank, and the appropriate RBC unit selected at Mount Zion. Without electronic crossmatch, we would have needed to physically transport patient specimens to Mt.Zion to perform compatibility testing prior to issuing RBC products.

Patients with a positive antibody screen or those with a history of RBC antibodies are not eligible for electronic crossmatch. Following antibody identification, we could choose to send the patient sample to Mt. Zion blood bank for the final setup of crossmatch compatible units or we could complete both the antibody workup and the blood product set-up at Parnassus. Because many of these patients require special blood products, such as CMV-negative or irradiated units, we chose to complete the blood product setup also at Parnassus. Crossmatch-compatible units were sent to Mount Zion where they were placed in inventory awaiting patient arrival the next day.

Transfusion Reactions
One concern with not having the pre-transfusion patient specimen at the issuing blood bank comes during workup for a possible transfusion reaction. Routine transfusion reaction workup calls for a clerical check and examination of the post-transfusion specimen for hemolysis, and performance of a DAT. If hemolysis is suspected, additional investigations such as repeating the crossmatch may be required. To tackle this problem, Parnassus blood bank was required to routinely retain a segment from the RBC units that were shipped to Mt.Zion. This gave us the ability to perform cross matches if needed, without any delays during the workup of transfusion reactions.

Another concern for these patients was the possible need for acute care in the event of a severe transfusion reaction. Because nurses staffed the infusion service, there needed to be on-site MDs available to care for acutely ill patients. After discussing this with the hospitalist MD staff at Mount Zion, they were willing and able to respond quickly to any patient emergency. Severely ill patients with transfusion-related acute lung injury or intravascular hemolysis could be cared for directly in the hospital ICU, or transferred to the emergency department.

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