South Texas whole blood consortium

Texas has developed a unique program called the Texas Emergency Medical Task Force (EMTF) with a focus on acute medical care, including transport, hospital surge staffing and mobile medical units that can be deployed during an MCI.9 It is divided into eight regional advisory committee geographic regions. After the Sutherland Springs shooting that resulted in 26 fatalities and several more wounded at a church service in November 2017, the Southwest Texas Regional Advisory Council (STRAC), South Texas Blood and Tissue Center (STBTC), University Health System, the University of Texas Health Science Center at San Antonio and the San Antonio Fire Department formed a consortium to implement the nation’s first multidisciplinary, multi-institutional, regional low-titer type O-positive whole blood (LTOWB) program. Low titer is defined as IgM anti-A and anti-B antibody (Ab) titers <256. This program established a process to provide LTOWB for prehospital transfusion for hemorrhagic shock to the area of the trauma system encompassing 22 counties and 26 000 mi², with a population of approximately 2.5 million.9 In addition, a strategy to rapidly deploy LTOWB to the site an MCI anywhere in Texas has been developed. This intervention provides the potential for life-saving prehospital resuscitation at a critical juncture, prior to patient arrival at a designated trauma center.10

MCI response in action

The first time the MCI LTOWB deployment was utilized occurred on May 24, 2022 in Uvalde, Texas, during the event of an active shooter incident at an elementary school. When the EMTF State Coordination Office received the call about the mass shooting, the MCI Whole Blood Protocol was activated and consisted of the STBTC preparing 15 units of LTOWB and 10 units of leukoreduced O-negative packed red blood cells (LPC). Concurrently, an air medical helicopter was dispatched to transport the blood from STBTC. From notification to arrival at Uvalde Memorial Hospital, a regional level IV trauma center receiving MCI casualties, it took only 67 minutes to transport the blood. Additional 20 units of blood products were available at Uvalde Memorial Hospital from medical facilities and emergency medical service (EMS) agencies in neighboring counties and regional collaborators as a part of the call to action. In total, there were an additional 45 units of blood products available within 90 minutes to augment the local hospital supply, which does not keep plasma in stock.11 This operation support plan serves as an excellent example of what is possible within our current infrastructure. After the MCI in Uvalde, all unused whole blood (WB) and blood products were circulated back throughout the system so that it was not wasted and did not overextend the main supply.

From brothers to heroes in arms

‘Brothers in Arms’ was a blood program conceived and implemented by the San Antonio Blood Consortium to generate a donor pool of LTOWB male donors throughout the city who donate blood at regular intervals. Donors in this group are part of a dedicated donor program distinct from the regular donor pool. STBTC has screened over 10 100 men for the program and the results of their anti-A and anti-B Ab testing revealed that 82% of potential male donors qualify as low titer and are allowed to enroll in the program. As of March 2023, 4411 volunteers have donated at least once in the last 12 months and 2539 have donated multiple times. With the success of the program and the rising incidence of MCIs throughout the state, the consortium shifted its focus to increase the donor pool for future MCIs. The first major step was to assess the feasibility and safety of adding women to the program as STBTC already had a large number of female donors come forward expressing interest in joining the ‘Brothers in Arms’ program. Automatically excluding women from the donor pool results in a 50% reduction of potential donors. There is some concern currently surrounding the use of LTOWB from female donors, particularly women with a previous history of pregnancy, due to the association of human leukocyte antigen (HLA) Abs and transfusion-associated acute lung injury (TRALI). In 2014, the Association for the Advancement of Blood and Biotherapies (AABB) came out with a risk reduction strategy to reduce the risk of TRALI, which is a potentially lethal side effect of transfusion. They discovered that the highest incidence of TRALI occurred from female plasma donors with a history of pregnancy and associated HLA Ab positivity.12 However, studies have shown that women who have never been pregnant carry the same risk of HLA positivity as men.13 The AABB Bulletin advocates that women who are donating plasma need to be screened by either a pregnancy questionnaire or an HLA Ab testing.12 STBTC has since begun asking all female donors about a history of live birth at every donation. Donors who answer ‘yes’ to a history of live birth are tested for HLA antibodies. Donors who test positive for HLA antibodies are deferred from donating WB, plasma and apheresis platelets. Aside from the concern for HLA positivity, the theory was that women have higher anti-A and anti-B antibody levels. However, since adopting women into the program, STBTC has screened 352 women and 69% were considered low titer. The current goal is to screen 2000 women in the coming year to qualify for LTOWB donation. The hemoglobin cut-off for women in the program is 12.5 g/dL, which occasionally results in donation deferral among women who are menstruating or have chronic anemia which will affect the number of female donors STBTC will need to identify for donation. As of January 2023, O-positive, previously pregnant, HLA negative or never pregnant women qualify for the now-aptly-named ‘Heroes in Arms’.

Potential donors are required to meet many qualifications to participate in the Heroes in Arms program. Once included in the program, Heroes in Arms donors are associated with an 89% appointment show rate, which is significantly higher when compared with platelet donors at 82% and non-LTOWB donors at 61%. The San Antonio area Heroes in Arms donors have proven to be well committed to the program and frequently answer the call when asked.

The current collection goal is 25 donations from Heroes in Arms contributors per day to always keep an inventory of 100 units available at STBTC. There are more donors being screened than enrolled in the program as evidenced by the large pool of eligible men who have never donated and that number will only increase with the addition of potential female donors. STBTC is currently limiting screening at fixed sites to a maximum of nine per day (four men and five women), which covers donors who discontinue or lapse out of the program in an effort to control for the cost associated with screening while simultaneously keeping the donor pool large enough to stock the shelves. The donor is ABO re-typed at every donation, but titer testing is only performed once per year after initial screening. STBTC screened 2151 previously pregnant women in 2022 for HLA Ab testing and 1789 (83%) tested negative while only 362 (17%) tested positive. Assuming the same low-titer screen results as non-pregnant women, 57% of previously pregnant women would be eligible for Heroes in Arms regardless of which screening test was done first.

Barriers and strategies in implementation

One of the biggest keys in the success of this program was gaining buy-in from all parties. It is truly a multidisciplinary effort from San Antonio’s Whole Blood Consortium. This is comprised of ground and helicopter EMSs, fire department, the STBTC, two level one trauma centers in the city area and all the surrounding affiliated trauma centers within the south Texas area that is overseen by STRAC.

The infrastructure within STRAC has allowed us to monitor product rotation for optimal use, with adequate storage of the LTOWB units while being transported with EMS and the ability to track and report clinical outcomes of the program. The coordinated effort and trust between all parties have been fundamental in optimizing the rotation of blood in such a way that the waste has become less than 1%. For the first 2 weeks, the units of LTWOB are being transported by EMS around the region to be available for prehospital transfusion; once the unit reaches day 15 of life, it gets transferred to our academic level one trauma center for the remining lifespan to be used for in-hospital transfusions. The willingness to take the older LTOWB after it has been rotated from the prehospital setting is critical to expanding the program while ensuring good stewardship. During the last 5 years, the use of LTOWB at University Hospital has expanded at the hospital. As University Hospital increases the amount of LTOWB units they can have on hand while carefully balancing expirations, more prehospital groups have joined the program.

Regarding challenges to implementation, determining the appropriate number of donors needed to be screened daily and from that to maintain adequate supply has been the biggest hurdle. Publicity and incentive strategies have been key to engage the population, promote blood donation and continue engagement. Another critical aspect is ensuring ongoing engagement with all program partners. Regular monthly meetings that include representatives from each party has been helpful for a continuous development of the program, as well as other aspects like our mass casualty activation program.