Toward Resiliency in the Joint Blood Supply Chain

The Joint military community provides a wide array of medical support services to its personnel. As in the civilian medical sphere, an essential component of that care is the provision of blood and blood products to its service members at home and abroad. Blood is an important element of medical supply, given its use in a variety of medical therapies and treatments. Furthermore, its use is critical and often life-saving in the treatment of surgical patients and trauma victims.

Blood requires sophisticated logistical protocols and materiel handling procedures to ensure that its use is safe for patients. From the point of collection from a donor to testing and processing in the lab, during transportation to and storage in medical treatment facilities, and on to eventual patient use, blood is carefully logged and tracked. Moreover, throughout the supply chain, blood must be handled and maintained at appropriate temperatures to ensure its safety for patients.

There are four products most commonly handled in blood supply chain operations: fresh whole blood and its three principal components, red blood cells, platelets, and plasma.¹

• Fresh whole blood is provided by volunteer donors. However, the unit that a donor provides is generally not the product that would be transfused to a patient, except under some emergency circumstances. Once a unit of whole blood has been collected from a donor, it is tested in the laboratory to ensure its safety for subsequent transfusion. Tested whole blood units will next be separated into three constituent components, generally by being spun in a centrifuge.
• Red blood cells carry oxygen throughout the body. Patients who suffer from anemia or have lost blood due to a trauma injury could be likely candidates for a transfusion of red blood cells. For longer-term storage, red cells can be processed and subsequently frozen, where multiple steps are required to convert between the frozen and liquid states.
• Platelets act as the body's primary agent in clotting when blood vessels are damaged. Once platelets have gathered around the site where damage has occurred, they effectively plug the hole to promote clotting action, thereby limiting blood loss. Patients who could benefit from platelets include those with abnormal platelet function or who have suffered severe hemorrhage in the wake of a major trauma injury.
• Plasma accounts for over half the volume of blood, acting as the fluid in which platelets and red blood cells are transported through the body. Plasma contains a variety of elements essential to healthy blood function, such as water, glucose, and a diverse array of proteins and clotting factors. Plasma is most useful for patients who may be actively bleeding or who otherwise suffer from clotting factor deficiencies.

The U.S. military manages blood through a global network of collection points, testing labs, processing centers, warehouses for both frozen and liquid blood, transshipment centers, overseas medical treatment facilities, and storage sites for use by forces at operating locations far forward. We next highlight a few of these in more detail.

• Blood donation centers serve as the backbone for military blood collection services. They are generally associated with a nearby brick-and-mortar military medical treatment facility, which offers facile access to a wide array of laboratory assets and personnel to aid in the processing and coordination of serological testing of donated blood.
• Armed Services Whole Blood Processing Labs act as the central points for receipt of blood shipments from donation centers in the United States and for processing that blood for air shipments to medical treatment facilities located around the globe. These two facilities are also equipped to process and to ship frozen blood.
• Blood Product Depots manage the long-term storage of frozen blood in theater. These depots effectively act as storage points for large volumes of frozen buffer stock. Their design is to absorb the initial brunt of demand shocks that may occur during combat operations, providing blood until the two processing labs can surge their operations and develop pipelines from the United States.
• Expeditionary Blood Transshipment Centers act as the central receiving and shipment points for blood within a theater of operations. Each transshipment center is a portable capability that would be established at a large forward aerial port of debarkation, receiving its stock from the processing labs and ultimately acting as a local distribution hub to provide blood to medical support operations farther forward.
• Blood Support Detachments can receive blood shipments from the transshipment centers and are equipped to store and re-ice them as needed. These support detachments can operate in conjunction with Blood Product Depots to receive thawed blood as well. Furthermore, they can collect fresh whole blood to support emergency demands, such as the provision of blood for a surge in trauma patients after combat action.

One scenario that is viewed as especially stressing to the military's blood supply chain is the possibility of a large-scale conflict against an adversary capable of generating a contested, degraded, or operationally limited combat environment. Over the past few decades, the defense community has taken increasing note of potential adversaries across the globe who have focused significant research into the development of long-range, high-precision conventional missile capabilities. In the employment of these missile systems across a theater of operations, an adversary could significantly degrade the freedom of movement for U.S. forces by targeting critical military infrastructure, including command and control centers, runways, and fuel depots.

The widespread occurrence of blast events would also likely generate significant numbers of casualties, many incurring severe trauma injuries. Over the course of a protracted series of missile strikes, the resulting trauma casualties would yield a long-term, large-scale demand signal for blood. Furthermore, these same strikes would limit the timely movement of blood into the theater from donation centers and warehouses in the continental United States. As the conflict wears on, blood in local storage at medical treatment facilities across the theater could be depleted, leading to challenges in providing blood in sufficient quantity to combat casualties.

In light of the challenges that might eventuate in the military's future combat environments, the defense community has begun to explore alternative capabilities, technologies, and concepts of operation that might afford additional flexibility in military operations. To that end, the Defense Advanced Research Projects Agency stood up a program known as the Complex Adaptive System Composition and Design Environment (CASCADE). In this program, researchers are developing novel mathematical frameworks to explore approaches for augmenting operational resiliency.

For the analysis here, we examined potential challenges to the Joint blood supply chain through the lens of this program. While we do not address the specifics of any specific mathematical constructs in this study, we do focus on the integration of three resiliency principles central to the CASCADE effort—fractionation, composition, and functional substitution:

• Fractionation enables the scaling of elements within the supply chain to deploy capabilities relative to the level of their need farther downrange. It may be important to expedite the deployment of a small expeditionary capability to pave the way for follow-on augmentation capabilities. For example, a small blood collection center could be rapidly deployed and employed until a larger capability could be established with follow-on forces and supplies.
• Composition supports the tailoring of capabilities to best meet downrange needs. For example, a small Army medical brigade does not typically deploy with equipment to handle the thawing and processing of frozen blood. The Air Force, however, does have a small deployable capability that offers these services. Under some circumstances, it may prove useful to deploy the Air Force's team in concert with the Army brigade.
• Functional substitution looks for opportunities to amend currently used stocks and capabilities with substitutes better tailored to operational needs. For example, medical research and development could be targeted to provide approaches and technologies to replace current short-lived blood products with longer-lasting alternatives.

To enhance access to blood supplies and their delivery to medical treatment facilities at forward operating locations, a variety of approaches might be leveraged. Some practices may need to be revisited, such as Cold War–era airdrop of palletized blood. Other mechanisms are emerging technologies, such as stem cell–based production of red blood cells in laboratory bioreactors. While promising in their capacity for risk mitigation and distributed access to blood supplies, nascent technologies will require further research and development to improve their cost-effectiveness. Other methods may incur some risk in their implementation, such as the activation of walking blood banks to collect blood at remote operating locations, or the utilization of a partner nation's blood supplies. There may also be value in employing alternate delivery platforms, such as unmanned aerial vehicles. Existing technology here is sufficiently advanced that these assets can be designed or tailored for blood delivery requirements relative to operational parameters, such as payload, distance, and speed.

A portfolio of additional mitigation options offers promise for improving blood supply chain operations, starting from deployed medical facilities and spanning downrange during contingency operations to the point of injury. Some approaches employ lessons learned from decades prior, such as freeze-drying plasma and refrigerating platelets to extend their shelf lives. Other mitigations, such as using tranexamic acid to limit blood loss and employing tactical buddy transfusion to provide access to supply at the point of injury, offer recognized benefits but have not yet entered mainstream use, potentially requiring training to promote awareness and employment protocols. Still other techniques in the research and development pipeline may become available in the near- to mid-term, including technologies to accelerate frozen red cell thawing and processing and mechanisms to limit blood loss due to severe trauma injuries to the torso. Other evolving technologies may require significant time to reach broader application, such as synthetic oxygen carriers to substitute for traditional red blood cells and bioelectrical stimulation techniques to limit blood loss.

Furthermore, other classes of mitigation might also add resiliency to the Joint blood supply chain. For example, access to energy is key in keeping blood at the right temperatures, and the availability of communications plays an important role in ensuring timely resupply of blood. However, during contingencies such as natural disasters or large-scale combat, access to these resources may be degraded. This suggests the potential value in leveraging alternatives, such as redundancy in diesel generators and training to use low-bandwidth communication modes. Risks in activation of mitigation approaches might need to be managed, including using technologies such as pathogen inactivation to limit the risk of transfusion-related infection from partner nation blood supplies and the potential to recruit donors whose blood has especially low antigen levels as a mitigation against adverse transfusion reactions.

Overall, the intent of this research is to stimulate discussion in the Joint medical community to help in the exploration of where resiliency measures may be needed in the overall blood supply chain. By examining mechanisms for resiliency across the blood supply chain, this community can be better equipped to tailor a robust portfolio of resiliency investments. Such a portfolio would better ensure the availability and safety of blood under a wide array of system stressors and threat conditions.

Over the course of the analysis, several key themes emerged.

Systemwide modeling frameworks are essential to understanding supply chain operations. To frame a common basis for examining supply chain operations, it is critical to have a flexible, systemwide view. With a model that can account for and integrate a range of different supply chain operations, it is possible to assess resiliency measures that can support an individual medical treatment facility as well as those supporting a theaterwide network of medical treatment facilities.

Understand stressors that may challenge the supply chain. Whether undertaking an assessment of historical experiences of mass casualty events or participating in a table-top exercise to explore possible future combat operations, a community of practitioners can posit scenarios both reasonable and extreme. When those stressors are applied in concert with a supply chain modeling framework, their outcomes can then be examined to determine effects on the supply chain. The outcome of these stress tests will highlight supply chain processes in need of attention.

Identify gaps or brittleness in current capabilities. Understanding simply that an element is brittle is insufficient—knowing how it became a gap and identifying the circumstances under which it will fail are essential. For example, a supply stockout at a treatment facility forward might drive consideration for augmented storage there. However, if that stockout was more a failure of transportation to provide sufficient throughput of blood, an extra refrigerator will ultimately prove inadequate. With nuanced information in hand, it then becomes possible to think through the mitigation approaches appropriate to bridge the capability gap.

Explore how current capabilities, evolving technologies, and alternative concepts of operation can mitigate those gaps. Here, understanding the "why" from the previous point is most useful. For example, is there a functional substitute for the blood that stocked out in the stress test? Is it possible to cost-effectively procure more testing or collection equipment that proved to be shortfalls? Could the limited capabilities of a forward operating unit be augmented by a small, agile capability from another service? A multidisciplinary and multiservice approach can help to better expose capabilities outside the scope of individual communities, especially in exploring the tripartite resiliency dimensions of functional substitution, alternative composition, and fractionation of capability.

Ensure that mitigations function on the scales needed. Some resiliency options, such as accelerating the capability to thaw and process frozen blood, can offer significant throughput capability for a short time to a local catchment area. However, if a broader network of treatment facilities requires longer-term support, leveraging options such as partner nation blood support may be warranted.

Combined mitigations can offer strengths that individual solutions may not. Here, it is essential to think through the broader dimensions of resiliency to determine where options may need to be linked. For example, partner nation blood support can be coupled with pathogen inactivation capabilities to ensure access to safer supplies. Similarly, combining the prophylactic use of tranexamic acid for forces on high-risk combat missions with reliable resupply of blood and medical supplies by unmanned aerial vehicle offers opportunities for longer-term support than either mitigation alone.

Ultimately, going through this process of supply chain stress assessment will yield a better roadmap toward enhanced resiliency in blood operations. With adherence to that roadmap, the military's medical support network will be better prepared to provide quality care to its patients under a wider array of system stressors, contingency considerations, and threat conditions.