Page 66 - JSOM Fall 2023

TABLE 1 Various Cellular and Acellular Blood Components and to armed forces blood-processing laboratories for support of
Their Functions 4 military or contingency operations, and to civilian hospitals
Component and local governments under specific circumstances or when
of Blood Function excess products are available. 5
Erythrocytes Deliver oxygen to tissues via hemoglobin
(RBCs) Although prompt transfusion is often a key intervention, not
Leukocytes (WBCs) Defense against pathogens: bacteria, viruses, all echelons of care have the same blood-product resources
parasites available (Table 2). Additionally, some models have predicted
T-Lymphocytes Kill infected cells and coordinate immune a shortage of blood units in the millions, both nationally and
responses internationally, which does not account for how a conflict
6,7
B-Lymphocytes Produce antibodies and serve as immune with a near-peer threat would further exacerbate a strained
system’s memory supply line. Blood substitutes offer the potential to supplement
Natural killer cells Members of the innate immune system that the use of blood units in military medical treatment facilities,
kill cells infected by pathogens civilian emergency rooms, and ambulances. Furthermore,
Neutrophils First-line defense, especially against bacteria blood substitutes would provide an advantage during pro-
Eosinophils Fight parasites and aid in allergic reactions longed casualty care situations and at low-level care facilities
Basophils Serve in allergic reactions before more robust care could be administered at higher-level
Platelets Cell fragments that form blood clots in trauma centers. Overall, using blood substitutes could ease
response to vessel injury the logistical burdens of maintaining whole human blood and
Electrolytes Maintain blood osmolarity and regulate nerve somewhat alleviate the need for difficult triage decisions of
(Na , Cl , K , function, muscle contractions, and cellular who should receive scarce units of donated blood based on
+
+
-
HCO , Ca ) metabolism
2+
-
3 likelihood of survival, especially in a high-casualty scenario.
Proteins Regulate fluid balance, act as hormones,
protect from infection, aid in clotting Even though the military supplies many of the approximately
Albumin Maintain blood osmolarity and carry water- 13 million units of blood that are collected annually within the
insoluble molecules
Antibodies Circulate in the blood and bind to non– United States, it inevitably encounters blood shortages, both
self-molecules (such as allergens and domestically and in deployed areas. During the SARS-CoV-2
pathogens) pandemic, the American Red Cross and the Armed Services
Clotting proteins Fibrinogen, prothrombin, von Willebrand Blood Program reported decreased donations because of blood
factor (vWF), coagulation factors drive cancellations and persons who were unable or unwilling
RBCs = red blood cells; WBCs = white blood cells to travel to donation sites. 8–10 Blood donation faces other chal-
lenges, including blood transportation issues, the limited shelf
lives of all blood products, and the relatively large quantities
5
and military-leased facilities, as well as aboard ships. Techni- of blood required for typical military trauma patients, which
cians divide whole blood into components: RBCs, fresh-frozen tax already limited supplies. Human blood has a shelf-life of
plasma (i.e., plasma frozen within 24 hours), cryoprecipitate, up to 6 weeks, at which point the blood is deemed “expired”
and platelets. Logisticians then distribute these products world- and no longer usable. However, several recent studies have
wide to military medical treatment facilities for transfusions, shown that blood can expire as soon as 3 weeks. 11

TABLE 2 Blood Product Availability at Military Roles of Care
Role of Care Provider Examples Blood Products and Hemorrhage Interventions
Role 1: First responders • Self-aid • Low-titer type O whole blood
• Buddy aid • Tourniquet
• Combat life saver • Hemostatic agents
• Combat medic • Ranger type O low-titer (ROLO) program (*unit
dependent) Tranexamic acid (TXA)—reduce bleeding
Role 2: Forward • Forward surgical teams • Low-titer type O whole blood
resuscitative care • Landing helicopter dock vessels • Fresh-frozen plasma
• Cryoprecipitate
• Platelet products (*limited due to short shelf life)
• Walking blood banks
• Recombinant Factor VIIa (clotting)
Role 3: Theater hospitals • Combat support hospitals • Blood type matching
• USNS Mercy/Comfort • Fresh-frozen plasma
• Cryoprecipitate
• Packed red blood cells
• Apheresis platelets
• Role 2 resources
Role 4: Definitive care Landstuhl Regional Medical Center (Germany) Role 3 resources with definitive medical and surgical care
Brian D. Allgood Army Community Hospital in medical centers outside the combat zone (OCONUS or
(Republic of Korea) CONUS)
Walter Reed National Military Medical Center
Brooke Army Medical Center
CONUS: the continental United States; OCONUS: outside the contiguous United States
*Should be considered in operative planning purposes for forward deployed providers and unit medical officers due to disproportionate resources
available between different units.

64 | JSOM Volume 22, Edition 3 / Fall 2023