(P-IV-3) Bled Dry: The Civilian Trauma System Must Be Ready for Large Scale Combat Operations

Background/Case Studies: With the increasing risk of large scale combat operations (LSCO), the United States (U.S.) and our allies must prepare for the overwhelming numbers of casualties not seen since World War II. Understanding the resources needed to acutely manage these casualties (predicted 30,000/month) is critical and will require civilian hospitals support. Blood supply is a key factor, influenced by casualty volume, injury patterns, transport times, and injury severity. This study aimed to describe blood utilization and acute hospital length of stay (LOS) for combat casualties over the recent 20 years of conflict, to support civilian resource planning.

Study

Design/Methods: Eligible patients were US service members. Data were extracted from the Department of Defense Trauma Registry, for each Role of care: point of injury (R1), damage control surgery (R2), combat support hospital (R3), outside continental U.S. definitive care (R4), and CONUS R4. To determine ISS for fatalities who died early, we used autopsy data from the Armed Forces Medical Examiner System. Blood use in the combat zone (CZ) was compared to transfusion outside the combat zone (OCZ) stratified by ISS. Casualties may have received transfusions at multiple locations. Median hospital LOS was calculated for all casualties and transfused patients in both settings. Blood product planning factors were based on 30,000 projected patients/month, percent evacuated OCZ, percent transfused OCZ, and median units transfused. Bed day planning factors used the same population, percent evacuated OCZ, median LOS, and percent transfused OCZ (for transfused patients only).

Results/Findings: Of 32,013 casualties, 4,870 (15.2%) received transfusions (CZ + OCZ). 82.4% (4,013) were transfused in the CZ and 56.0% (2,727) OCZ. Median (interquartile range (IQR)) blood use per transfused patient was 11 (4, 29) units in CZ and 4 (2, 9) units OCZ. A planning factor based on these data are that a median of 8,180 units of blood products/month. For OCZ, the median (IQR) number of units of blood transfused stratified by ISS is in Figure 1. Of all casualties, 53.4% (17,085) were evacuated OCZ, with 12.8% (2,181) receiving transfusions there. Median (IQR) LOS was 1 (1, 2) day in the CZ and 5 (2,13) days OCZ. For transfused OCZ patients, LOS was 2 (1, 2) days in CZ and 29 (8, 49) days OCZ. Patient bed day requirements/month OCZ will be 80,100 for all casualties and 59,306 for those transfused.

Conclusions: With a potential 30,000 casualties/month, civilian medical leaders must prepare for high blood product use and prolonged LOS for these resource intensive patients. These findings highlight the increased blood demands and inpatient bed days required to provide high quality care for combat casualties in the US civilian health care system. In caring for casualties from LSCO, the military health system will be rapidly overwhelmed, and utilization of civilian trauma systems will be crucial.