Ranger O Low Titer (ROLO): Whole Blood Transfusion for Forward Deployed Units

Quality of whole blood stored in room temperature for up to 5 days

BACKGROUND

Non-refrigerated whole blood can be used for bleeding emergencies when cold-stored whole blood is unavailable. Storage time in room temperature is usually limited to 24 h although there is little evidence supporting this practice. We studied the quality of whole blood stored in room temperature for 5 days to investigate the effects of prolonged storage time.

STUDY DESIGN AND METHODS

Non-leukoreduced whole blood in CPDA-1 from 10 group O or A RhD positive male donors was stored in +22°C for 120 h. Samples were taken daily to assess blood cultures, blood count and metabolic parameters. Platelet function and blood coagulation were evaluated with multiple electrode aggregometry, viscoelastic tests (sonorheometry and rotational thromboelastometry), thrombin generation assay and measurements of individual clotting factors.

RESULTS

Blood cell counts remained stable during storage. Metabolic changes were similar to those previously reported in cold-stored blood products. Most coagulation factor levels, including FVIII, decreased during storage but remained within physiological range. Thrombin generation remained mostly intact during storage. In viscoelastic tests, clotting times prolonged, but clot strength remained stable. Platelet function in multiple electrode aggregometry impaired along with storage. No bacterial growth was detected in any sample.

CONCLUSION

Whole blood stored in room temperature for 5 days seems bacteriologically safe and retains most of its metabolic and hemostatic function. These results suggest that whole blood stored in room temperature may be usable for longer than the currently recommended 24 h.

Compact Arterial Monitoring Device Use in Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA): A Simple Validation Study in Swine

Introduction Hemorrhage is the leading cause of preventable death in trauma in both the military and civilian settings worldwide. Medical studies from Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) informed change in military prehospital medicine by influencing widespread tourniquet distribution and training on their use to stop life-threatening extremity hemorrhage. In the military setting, there has been a significant reduction in preventable death due to extremity exsanguination since the widespread implementation of tourniquets within the Department of Defense. However, noncompressible hemorrhage remains a significant cause of mortality, especially in the prehospital setting. In select patients, resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct that can be utilized to slow or stop non-compressible hemorrhage until the patient reaches definitive care. However, frontline medical providers face the challenge of reliable, accurate blood pressure measurement in REBOA patients. REBOA, used in conjunction with a small disposable pressure monitor, can bridge the gap in capabilities, creating a more balanced resuscitation and reducing blood product requirements with the added benefit of invasive blood pressure monitoring capability. The authors of this study propose the sustained use and further validation of a small, disposable pressure monitor in REBOA to monitor beat-to-beat variation in both hemodynamically stable and unstable patients and seek to offer a pathway for use in austere environments. Materials and methods Yorkshire swine (n = 4) were selected for partial REBOA (pREBOA) placement and compass transducer measurement in conjunction with a vascular experimental protocol. Appropriate vascular and arterial line access was obtained, hemorrhagic shock was initiated, and REBOA with an in-line Compass™ device (CD) pressure transducer (Centurion Medical Products, Williamston, MI) was used to occlude the aorta. Mean arterial pressures were measured via the CD, recorded, and compared to the control arterial line at hypotensive, normotensive, and hypertensive pressures. Results At hypotensive pressures, 30% of the CD readings fell within 1 mmHg of control arterial line readings, and 52.3% were within 2 mmHg. At normotensive pressures, 46% of the CD readings fell within 1 mmHg of control arterial line readings, and 64.2% were within 2 mmHg. At hypertensive pressures, 60% of the CD readings fell within 1 mmHg of control arterial line readings, and 82% were within 2 mmHg. All CD data points at all pressures were within 8 mmHg of the control arterial line readings. Conclusions In conclusion, the CD is a compact, inexpensive, portable pressure-sensing device that may potentially augment the safety and functionality of the REBOA in trauma patients both at the point of injury and in the hospital. This novel study conducted on four swine subjects demonstrated a remarkable correlation to the traditional equipment intensive arterial line setups, and issues of stasis and non-pulsatility were easily troubleshot. Future studies should investigate CD use in REBOA catheters under different physiological conditions, specifically arrhythmias, and in different environments (prehospital, air medical transport, and austere locations).

Preparing Future Military Medical Officers to Conduct Emergency Fresh Whole Blood Transfusions in Austere Environments: A Novel Training Curriculum

INTRODUCTION

Providing resilient Damage Control Resuscitation capabilities as close to the point of injury as possible is paramount to reducing mortality and improving patient outcomes for our nation's warfighters. Emergency Fresh Whole Blood Transfusions (EFWBT) play a critical role in supporting this capability, especially in future large-scale combat operations against peer adversaries with expected large patient volumes, restrictive operating environments, and unreliable logistical supply lines. Although there are service-specific training programs for whole blood transfusion, there is currently no dedicated EFWBT training for future military medical officers. To address this gap, we developed, implemented, and evaluated a training program to enhance EFWBT proficiency in third-year military medical students at the F. Edward Hebert School of Medicine at the USU.

MATERIALS AND METHODS

After reviewing both the 75th Ranger Regiment Ranger O-Low Titer program and the Marine Corps' Valkyrie program, along with the relevant Joint Trauma System Clinical Practice Guidelines, we created a streamlined and abbreviated training curriculum. The training consisted of both online preparatory materials as well as a 2-hour in-person training that included didactic and experiential learning components. Participants were 165 active duty third-year medical students at USU. Participants were assessed using a pre- and post-assessment self-reported questionnaire on their confidence in the practical application and administrative oversight requirements of an EFWBT program. Participants' performance was also assessed using a pre/post knowledge assessment consisting of 10 multiple choice questions identified as critical to understanding of the academic principles of EFWBT along with the baseline questionnaire.

RESULTS

Differences in the mean scores of the pre- and post-assessment self-reported questionnaire (increased from 2.32 to 3.95) were statistically significant (P < .001). Similarly, there was a statistically significant improvement in student test scores, with the mean score increasing by approximately 3 points or 30%. There was no significant difference in student confidence assessment or test scores based on branch of service. Students who had previously deployed did not show a statistically significant difference in scores compared to students who had not previously deployed.

CONCLUSIONS

Our results suggest that the implementation of streamlined EFWBT training into the undergraduate medical education of future military medical officers offers an efficient way to improve their baseline proficiency in EFWBTs. Future research is needed to assess the impact of this training on real-world applications in forward-deployed environments.

Blood consumption in the Role 2 setting: A Department of Defense Trauma Registry analysis

BACKGROUND

The Role 2 setting represents the most far-forward military treatment facility with limited surgical and holding capabilities. There are limited data to guide recommendations on blood product utilization at the Role 2. We describe the consumption of blood products in this setting.

STUDY DESIGN AND METHODS

We analyzed data from 2007 to 2023 from the Department of Defense Trauma Registry (DODTR) that received care at a Role 2. We used descriptive and inferential statistics to characterize the volumes of blood products consumed in this setting. We also performed a secondary analysis of US military, Coalition, and US contractor personnel.

RESULTS

Within our initial cohort analysis of 15,581 encounters, 17% (2636) received at least one unit of PRBCs or whole blood, of which 11% received a submassive transfusion, 4% received a massive transfusion, and 1% received a supermassive transfusion. There were 6402 encounters that met inclusion for our secondary analysis. With this group, 5% received a submassive transfusion, 2% received a massive transfusion, and 1% received a supermassive transfusion.

CONCLUSIONS

We described volumes of blood products consumed at the Role 2 during recent conflicts. The maximum number of units consumed among survivors exceeds currently recommended available blood supply. Our findings suggest that rapid resupply and cold-stored chain demands may be higher than anticipated in future conflicts.

Whole blood administration within USCENTCOM

Introduction

Blood product use by the U.S. military has evolved during the conflicts in the U.S. Central Command's area of responsibility to become the preferred resuscitative fluid for damage control procedures. This study evaluates the transition to a whole blood-based trauma system over the past 5 years.

Methods

Patients who received blood product transfusion within USCENTCOM between January 1, 2017, and December 31, 2021, were identified from the Medical Situational Awareness in Theater (MSAT) blood reports. Transfusion recipients were categorized as recipients of whole blood only, component therapy only, or mixed therapy. The type of transfusions, number of recipients, number of available blood products were compared over the 5-year period.

Results

A total of 1762 unique patients were included. Of this population, 220 (12.5%) received whole blood only, 1196 (68.9%) received component therapy, and 346 (19.6%) received mixed therapy. The monthly proportion of individuals receiving whole blood (only or mixed) significantly increased over the 5-year period ( p < .0001). The number of individuals requiring transfusions over this same period decreased significantly ( p < .0001). Individuals receiving component therapy (only or mixed) were transfused component platelets 15.7% of the time. The mean and median number of units required per patient receiving whole blood was 2.39 and 1 unit of blood respectively (IQR 1.0–2.5).

Conclusion

Whole blood use increased significantly within USCENTCOM's AOR secondary to increased supply and low clinical requirement. Without a long-lasting platelet component, component therapy cannot be expected to provide a balanced therapy to casualties in remote locations.