Preparing for JRTC and Beyond

Training for Walking Blood Bank Operations and Changing Acceptable Risk Tolerance in LSCO

By CPT Spencer Cavotti

August 1, 2026 | Infantry, Summer 2026 Edition

Read Time: < 21 mins

The walking blood bank (WBB) is a familiar concept to most units when considering actions during mass casualty events. It is an intuitive practice that has been used in Army medicine since World War I. When casual-ties suffer from significant blood loss at the point of injury, they require transfused blood to ensure they survive to the next level of care. Though Soldiers are quick to mention the bene-fits of WBB programs, knowledge of the program’s mechanics and training rarely passes the theoretical stage. As brigades prepare for Joint Readiness Training Center (JRTC) rotations and large-scale combat operations (LSCO), targeted medical training and a little creativity will exponentially increase their ability to implement a successful WBB program.

This article illustrates why Army units need to change how they prepare, train, and adjudicate casualties during combat training center (CTC) rotations. Additionally, it addresses the need for leaders to reconsider operational risk as it pertains to medical running estimates and WBB operations in LSCO. During JRTC Rotation 25-10, 2nd Battalion, 14th Infantry Regiment, 2nd Brigade Combat Team, 10th Mountain Division, served as the first rotational training unit (RTU) to evaluate the effectiveness of JRTC’s updated medical adjudi-cation tables, which account for unit actions during prolonged casualty care to extend the treatment clock. 2-14 IN’s medical preparations for this rotation focused specifically on training WBB operations and adopting replication strategies for the rotation.

How 2-14 IN Approached WBB at JRTC

There is no FDA-approved methodology for deploying units to procure their own cold-stored whole blood (CSWB) without external support. The responsibility for maintaining this knowledge base rests within the brigade combat team (BCT). In the current Army deployment slate, BCTs are the smallest units that deploy organically under a unified command structure and are the standard-sized unit to partic-ipate in CTC rotations.

A successful WBB begins with a codified and dissemi-nated standard operating procedure (SOP) signed by the BCT commander. The Joint Trauma System Clinical Practice Guide (CPG) (ID:21) provides a detailed example of a WBB SOP.1The brigade’s physician assistants (PAs) and provid-ers derive their authority to conduct autologous blood trans-fusions in training scenarios from the BCT commander and their medical licensing. PAs and providers must then train their medics to conduct transfusions, delegating their author-ity to conduct autologous blood transfusions to the medics once training and certifications are complete.

Common Terms

Walking blood bank (WBB) — a system for collecting whole blood from donors in emergency situations to be given to casualties. Not FDA approved but used for decades. In practice should be LTOWB.

Low-titer O whole blood (LTOWB) — the universal donor for whole blood. Requires testing to verify low amounts of antibodies (low titer). May be either SWB or FWB. Irrespective of O POS/NEG.

Fresh whole blood (FWB) — synonymous with walking blood bank and in practice should be LTOWB.

Armed Services Blood Program (ASBP) — typical source for CSWB.

Cold-stored whole blood (CSWB) — blood collected from pre-screened individuals and kept refrigerated in for anticipated injuries. Typically procured thru ASBP.

Transfusion transmitted diseases (TTD) — CSWB undergoes TTD testing.

Stored whole blood (SWB) — refrigerated and not TTD; In practice should be LTOWB.

Autologous Blood Transfusion — blood taken from one person and given back to the same person. Only used for training.

Headquarters and Headquarters Company (HHC), 2-14 IN began training WBB practices in December 2024, nine months before JRTC Rotation 25-10. Education began with a leader professional development (LPD) series targeting the battalion’s officers, where the PA demonstrated drawing blood from a low-titer O-type donor. These donors produce low-titer O whole blood (LTOWB), which in simple terms is blood that is unlikely to trigger an adverse patient reaction when transfused (acute hemolytic transfusion reaction).2Part of the demonstration was an introduction to field blood transfusion kits and ways to replicate these kits in training scenarios. Each donor had one pint of blood drawn and then fed back into their blood stream to simulate blood transfu-sions during an active WBB.

During each subsequent training at HHC, 2-14 IN’s Role I, each medic practiced drawing units of blood and feeding them back to the donor under supervision from the PA. The limiting factor for blood transfusions was the availability of the transfusion kits. Units must begin ordering transfusion kits as early as possible through the brigade medical supply officer to have sufficient kits for training medics before JRTC.

Two months before JRTC 25-10, 2-14 IN’s medics began the process of certifying company senior medics in autolo-gous blood transfusions for the rotation. Each medic in the battalion began by watching U.S. Army Institute of Surgical Research’s “Warm Fresh Whole Blood Transfusion Training” before observing the PA demonstrate the technique live at the Medical Simulation Training Center (MSTC).3Each Army base has an MSTC, which is often the most underused training resource on the post. These facilities, however, offer crucial resources for training units. The PA also led classes on the physiology of transfusions, indications for blood trans-fusions, and managing adverse reactions. After viewing the PA’s demonstration and completing classroom instruction, each senior medic paired with a junior medic to draw one unit of whole blood and feed it back to the donor. Our battalion considered medics certified to conduct solo autologous blood transfusions once they demonstrated competency.

By the time 2-14 IN arrived at JRTC 25-10, the battalion had six medics certified to draw and administer whole blood on the battlefield. Furthermore, each of the 19 medics at the Role I could complete the procedure under PA supervision. The training the unit completed beforehand would enable medics to perform an actual WBB during the rotation, but the intent was to execute notional WBBs and prolonged casualty care with replicated kits at JRTC. During reception, staging, onward movement, and integration (RSOI), the battalion medical team delivered the BCT WBB SOP to the JRTC Operations Group and briefed the pre-rotation certifications that the medics completed.

One additional data point that we completed was our LTOWB donor list. In preparation for 2/10 MTN’s 2023-2024 Operation Inherent Resolve (OIR) deployment, the brigade allocated funds to conduct titer-testing during Soldier Readiness Processing (SRP). From titer-testing, the brigade deployed to Iraq and Syria with roughly 23 percent of the brigade identified as LTOWB donors. Titer testing is certainly not a requirement for units that want to train WBB at JRTC because only autologous transfusions or simulated transfu-sions should be performed in training scenarios. Units simply need to use common sense when notionally identifying a roster of LTOWB donors and ensuring that those Soldiers understand that they are identified as WBB donors.

For JRTC 25-10, 2-14 IN took 23 percent of our Soldiers with O-type blood and notionally identified them as LTOWB donors for WBBs. Each donor carried a replicated transfusion kit, consisting of plastic bags for collection bags, paracord for tubing, and food coloring for blood, and each subordinate unit had the donor list on their person for the exercise. For further discussion of replicated kits and Ops Group adjudica-tion, reference The Crucible: The JRTC Experience Podcast episodes filmed during the rotation.4

The Results

During JRTC 25-10, 2-14 IN had the brigade’s best died of wounds (DOW) rate at 31 percent; however, with small adjustments, that number could have been far lower. The battalion experienced zero DOW casualties at its Role I, and the only casualties that died at higher levels of care than the unit in contact were those present during an attack at the Role II. Despite our best efforts to place blood as far forward on the battlefield as possible to conduct WBB transfusions, we sustained the greatest number of DOW casualties from the point of injury (POI) to the company casualty collection point (CCP).

The overwhelming number of casualties sustained during each engagement proved to be the largest factor that limited participation in the newly introduced prolonged casualty care adjudication tables. Though our LTOWB donors carried field-expedient, replicated transfusion kits, they were not used during treatment because the scale of casualties sustained in the platoons diverted all medical attention to triage and transport. Units need to replicate the scale of JRTC casu-alties long before their rotation. The number of casualties sustained at JRTC can cripple a unit in contact. Conducting a complete mass casualty (MASCAL) rehearsal at JRTC-scale during company and battalion-level situational training exercises (STX) is crucial. Units must experience losing 40-60 percent of their combat power to traumatic injury and train how to triage, treat, transport, and prolong the life and care of their casualties to be successful at JRTC.

2-14 IN’s 31-percent DOW rate for all casualties, which generally occurred before patients reached higher levels of care, is nothing new. In a 2012 study of combat fatalities from Operation Inherent Freedom (OIF) and Operation Enduring Freedom (OEF) between October 2001 and June 2011, researchers determined that 87.3 percent of all injury mortalities occurred in casualties in the pre-medical treatment facility (pre-MTF) environ-ment.5More than 90 percent of these casualties died of exsanguination or massive hemorrhage with only 25 percent of the pre-MTF deaths deemed potentially survivable (PS) through medical intervention.6The number one factor determining the outcome of combat casualties with PS trauma injuries is the “reduction of the time interval between the battlefield point of injury and surgical intervention.”7Autologous blood transfusions and the activation of a WBB is the only way that BCTs can effectively extend the life of PS combat casualties by providing fresh whole blood. New evidence from the Joint Trauma Service suggests that the new “golden hour” for casualty care is 36 minutes between point of injury and the first blood transfusion, a measure that improves survivability of potential lethal injuries fourfold.8During JRTC, we averaged 20-30 minutes between time of injury and arrival of medics to an ambulance exchange point. If our evacuation and treatment medics at the Role I were the only medics to provide transfusions for trauma casualties, we would only have minutes to begin transfusion after casualties arrive.

Though our rifle companies did not employ replicated or actual WBB procedures before casualties arrived at the Role I, 2-14 IN tested the medical adjudication tables through true blood transfusions at the Role I. During the rotation, patient evacuation to the Role II was not always possible within the allotted two hours outlined by Operations Group. The standard JRTC medical adjudication table provides units one hour for casualties to reach the Role I from point of injury and another hour for units to evacuate casualties to the Role II. In past rotations, casualties that missed these key gates would be considered DOW. We were able to extend these thresh-olds by as many as four hours by simulating WBB activation through autologous blood transfusions. To our knowledge, our use of actual transfusion kits to draw and return blood was the first time that an RTU conducted WBB replicating transfusions during JRTC force-on-force fighting.

Evaluating how we arrayed leaders and senior medics and changing our emphasis on experience would have increased our survivability at the POI. We would have seen greater returns on DOW if we had placed our senior medics and most experienced medical personnel at the POI. Traditionally, the company senior medic remains with the first sergeant at the company CCP while the more junior medics serve in the rifle platoons, closer to the POI. We found that our junior medics became overwhelmed by the sheer number of casualties at the POI, leading to incomplete tactical combat casualty care (TCCC), triage, and treatment before the unit had time to evacuate casualties. There was too much work and too many casualties that needed urgent care for a junior medic to process in a timely manner, leading to a higher DOW rate at the POI. Doing the exercise again, placing the most experienced medic at the point of greatest risk to force would unburden the forward elements and lead to more complete TCCC at the POI.

Our medics are proficient at TCCC, but treatment at the POI needs to be completed by all. Self-aid and buddy-aid are the primary and alternate means of treatment for one reason: Early intervention in trauma cases saves lives. We need to do a better job of training self-aid and buddy-aid at scale during our pre-rotational training. Platoon sergeants and squad leaders need to be involved in triage actions when medics are overwhelmed by massive casualty numbers.

2-14 IN maximized the number of medics on the battlefield by training Infantrymen unable to fully participate as ground combatants to operate the Field Litter Ambulance (FLA). By replacing FLA drivers with Soldiers, military occupational specialty immaterial, we added seven 68Ws to the fight to support medical treatment. This practice should be standard for units preparing for JRTC for two reasons: It improves your unit deployment numbers by filling needed roles within the formation with Soldiers who would otherwise occupy admin-istrative positions, and it also places more medical personnel on the battlefield.

We fielded seven FLAs during JRTC, with eight FLAs operating out of our Role I. To prepare for additional casualty transportation requirements, we drew two additional Light Medium Tactical Vehicles from the JRTC prepositioned vehi-cle stock to support transportation in MASCAL events. This was a critical capability for the battalion, as we were able to receive, treat, transport, and return more than 120 casualties in a single night, preserving combat power for the next battle period.

Band-Aid Fix — Applying WBB Beyond JRTC

Activating the WBB cannot be a unit’s sole avenue to providing whole blood to casualties on a battlefield; it is a time-sensitive bandage that will prolong life during urgent casualty care, but it has its limitations. A standard whole blood unit is one pint or approximately 450 milliliters. The American Red Cross recommends that donors wait 56 days between donations before providing another donation.9For reference, my company had 23 Soldiers identified as LTOWB donors during JRTC. If the WBB was our only source of whole blood, we would be limited to 23 units of blood for the monthlong exercise, with each donor needing an additional four weeks post-exercise to replenish blood for another donation. Preliminary studies show that Soldiers may provide two units of blood within a short timeframe and retain battlefield facul-ties; however, this practice is reserved for extreme situations, and the studies are few.10On average it takes between eight to 10 minutes to draw one unit of blood from a donor and from four to eight minutes to provide fresh whole blood to a patient.11

Most casualties sustained in the simulated LSCO of JRTC are gunshot wounds (GSW) and shrapnel wounds from indi-rect fires (IDF). These are particularly traumatic injuries where casualties may experience non-compressible hemorrhaging. Soldiers are trained to slow bleeding by applying the Combat Application Tourniquet (CAT), but no blood-loss prevention techniques are perfect.

Johns Hopkins University published a study in 2018 cover-ing the number of whole blood units given to their patients between 2005 and 2017. The study concluded that patients presenting with GSWs were five times more likely to require blood transfusions than other trauma patients. Additionally, those patients required 1,000 percent more blood in transfu-sions than any other urgent patient without GSWs.12Johns Hopkins treated 2,672 GSW patients between 2005 and 2017. Each patient in the study required an average of 3.1 units of whole blood during damage control resuscitation/ damage control surgery.13

During our battalion’s final movement-to-contact at JRTC, our forward rifle companies seized ground at such a rapid rate that they quickly outpaced supply lines and invited a swift opposition force counterattack. The leading company suffered 95-percent casualties during the counterattack, the equivalent of 100 Soldiers. Many died of wounds immedi-ately, but even if 25 percent of the casualties could have been treated through immediate blood transfusions and prolonged casualty care, the demand for whole blood would surpass the supply of the WBB. This means that a unit could consume all available donor units of whole blood through a WBB in one two-hour battle period.

The traditional understanding of MASCAL events involves sustaining more casualties than an organic unit can effec-tively treat, transport, and secure. During past operations, a MASCAL for a platoon could be four casualties. This is no longer an accurate understanding of the term. JRTC is designed to force units to react to enemy actions and pres-sures that mimic the reality of LSCO. A 95-percent MASCAL is the reality, and just like we adjusted how many water cans we filled and stocked at the combat trains command post to account for increased consumption during an August rota-tion, we must also adjust to a higher demand for whole blood on the battlefield. Combat units must have the capacity to transport and store CSWB on the battlefield to be successful in a MASCAL transfusion.

Blood Supply Paradox

WBBs are currently the emergency solution for providing fresh whole blood to Soldiers on the frontline. In current acceptable practices, WBBs only provide fresh whole blood that units can store for 24 hours at ambient temperatures. The Armed Services Blood Program (ASBP) provides higher-level medical treatment centers with cold-stored whole blood that is titered and tested for transfusion transmissible diseases (TTD). Though the risk associated with using LTOWB during WBB transfusions is low for acute patient reactions, blood that is not screened for TTDs poses potential long-term risks to recipient health. ASBP CSWB is the preferred blood for transfusions because of this risk.

Figure 3 shows the blood transfusion priority list from a U.S. Navy Expeditionary Medical Unit (NEMU) that operated a Role II in CENTCOM in 2021.14The NEMU’s priority list identifies the risk of TTDs as the main differentiator between CSWB provided by the ABSP and LTOWB provided by a pre-tested WBB. The issue with ABSP CSWB is its availabil-ity. Even in a Role II supporting an entire theater, there is typi-cally only limited units of CSWB on hand, and the NEMU had to fight to cut the Role III out of that supply chain to mitigate time and transportation constraints.15All studies referenced in this article suggest that three to 10 units of on-hand blood will not be enough to treat the MASCALs that we expect to face in LSCO. The NEMU’s planning factor for their WBB Program was that 50 donors could massively transfuse two to four patients with WBB donations.16This assumption was built for a Role II with the assumption that casualties would begin receiving additional blood transfusions at the point of injury from their parent units.

The next differentiator between ABSP units and WBB units listed on the NEMU chart is cold-stored vs. warm blood. Cold-stored blood is preserved through the anti-coagulating agents present in the blood collection bags. In the 1950s, medical professionals adopted a citrate-phosphate-dextrose (CPD) solution in blood collection bags that yielded a 21-day shelf life for blood stored between 2-4 degrees Celsius.17Though shelf life of CSWB was extended to 35 days through the 1978 introduction of citrate-phosphate-dextrose-adenine (CPDA-1) coagulants, CPD anti-coagulants are the most common in blood and blood products.18Blood must be stored at stable temperatures, posing a challenge for ground combat units. BCT Role I’s have blood storage refrigerators as part of unit equipment. Maintaining a stock of CSWB at the battalion Role I buys back time for treatment because it removes the time and potential for confusion present during a WBB under fire. Medics need to bring CSWB to temperature before transfusion but have the necessary blood fluid warmers on hand to account for this.

It would be particularly helpful for units transitioning into periods of heavy fighting to have a surplus of CSWB on hand before initiating their operations. Though it takes weeks to replenish blood, it is a renewable resource. We produce our own blood internally. To those that would worry about poten-tially wasting CSWB by placing a surplus so far forward in a combat operation, removing the risks and costs associated with transporting CSWB is only one of the mitigating factors. Studies indicate that 86 percent of all donated CSWB expires before it is transfused.19I would argue that if most blood donations expire anyway, it is best to store that blood as close to the POI as possible if 36 minutes after time of injury is truly our transfusion goal.

Figure 3 Example Blood Transfusion Priority List23

Buying Down Risk Levels

The only factor preventing units from taking fresh warm whole blood from a WBB and storing it as CSWB is the potential for the transmission of TTDs. Units are unable to conduct TTD screening at the POI, so any units of blood used in emergency blood transfusions would bear this same risk. Storing WBB as CSWB truly reduces the risk to force during autologous blood transfusions because it narrows risk factors to solely the communication of TTDs, taking the inherent risks of battlefield blood donation and the time it takes to procure blood out of the equation. The intent of WBBs is to provide and transfuse blood from a unit donor pool during combat operations. We cannot accept that risk on the one hand and completely disregard a more convenient method for that same transfusion on the other.

Units can reduce risk of TTDs in their WBB donor pool by conducting TTD testing during pre-deployment SRP operations. If units decide to prioritize WBBs in theater, a combination of TTD screening and full titer testing of their O-type blood would cost around $50,000 of unit funds.20This is a small price to pay for risk reduction. Additionally, adopting a blood transfusion priority list like the one used in the NEMU’s WBB program would ensure that CSWB from a unit WBB would be only used when no ABSP CSWB was on hand. One of the unit blood refrigerators could be reserved for ASBP blood while the other stores unit donations. Each type of blood has the same shelf life, so in theory, blood donated from a unit WBB would last longer at a unit Role I because it is procured on site and has no transit time. While CSWB has a shelf life between 21 and 35 days depending on the anti-coagulant, studies show that CSWB undergoes platelet depreciation at around 28 days.21Maintaining an ample supply of CSWB at a Role I for one month would be a massive improvement in the availability and accessibility of transfusion operations for combat units. Right now, the only thing that prevents combat units from pursuing solutions like this is our own risk tolerance rather than science.

Conclusion

The need for readily available and packaged whole blood on the battlefield is clear. LSCO introduces more combat casu-alty patients that require faster transfusions than ever before. As units transition their training focus and risk tolerance in maneuver operations from counterinsurgency to LSCO, the appetite for advanced and experimental medical strategies to combat increased casualty numbers must also transition and grow. Right now, the Army’s appetite for maneuver risk is much higher than its appetite for medical risk, leading to an imbalance. Until walking blood bank operations are second nature, units must prepare for LSCO casualties by establish-ing WBB SOPs and building proficiency at combat training centers like JRTC.

Units preparing for JRTC will set themselves up for success by beginning to train on prolonged casualty care and WBB operations early in the training cycle. It works. Leaders and medics will experience the real-time feedback from their observer-coach/trainers who provide additional care hours for casualties when medics demonstrate the capacity for autologous blood transfusions and WBBs.

The walking blood bank itself is an acceptance of risk, and the potential for acute hemolytic transfusion reactions and TBB does not fully disappear with tested and titered blood. We accept and train for this risk in emergency situ-ations to save lives already. The expansion of risk does not surpass the expansion of our medical capabilities in LSCO by attempting to store blood provided by WBBs as CSWB. We cannot let risk prevent us from preparing for the realities of our next fight.

Editor’s Note: As with all Infantry articles, the views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Department of the Army, Department of War, or U.S. Government.

Notes