Lifeline for the front lines: blood products to support the warfighter.

BACKGROUND: Hemorrhage is the leading cause of death on the battlefield. Damage control resuscitation guidelines in the US military recommend whole blood as the preferred resuscitation product. The Armed Services Blood Program (ASBP) has initiated low-titer group O whole blood (LTOWB) production and predeployment donor screening to make whole blood more available to military forces. STUDY DESIGN AND METHODS: ASBP donor centers updated procedures and labeling for LTOWB production. Donors are screened according to US Food and Drug Administration regulations and standard operating procedures. Group O donors are tested for anti-A and anti-B titer levels. Additionally, military personnel notified for pending deployment coordinate with their local ASBP donor center to complete whole blood donor prescreening. The process consists of completing a donor history questionnaire, processing of blood samples for blood group and infectious disease testing, and titer determination for group O personnel. RESULTS: Since March 2016, 7940 LTOWB units have been manufactured at ASBP donor centers and shipped in support of combat operations. Additionally, ASBP donor centers have screened several thousand service members before deployment. From these screenings, the donor low titer rate was 68% and infectious disease reactive test rate was extremely low (≤0.004). CONCLUSION: Whole blood is now the preferred blood product for resuscitation of combat trauma patients. The ASBP partnered with combat forces to screen personnel before deployment. Additionally, LTOWB is manufactured and shipped in support of combat operations. These efforts are expanding the availability of LTOWB for the warfighter.

Incompatible type A plasma transfusion in patients requiring massive transfusion protocol: Outcomes of an Eastern Association for the Surgery of Trauma multicenter study.

With a relative shortage of type AB plasma, many centers have converted to type A plasma for resuscitation of patients whose blood type is unknown. The goal of this study is to determine outcomes for trauma patients who received incompatible plasma transfusions as part of a massive transfusion protocol (MTP). METHODS: As part of an Eastern Association for the Surgery of Trauma multi-institutional trial, registry and blood bank data were collected from eight trauma centers for trauma patients (age, ≥ 15 years) receiving emergency release plasma transfusions as part of MTPs from January 2012 to August 2016. Incompatible type A plasma was defined as transfusion to patient blood type B or type AB. RESULTS: Of the 1,536 patients identified, 92% received compatible plasma transfusions and 8% received incompatible type A plasma. Patient characteristics were similar except for greater penetrating injuries (48% vs 36%; p = 0.01) in the incompatible group. In the incompatible group, patients were transfused more plasma units at 4 hours (median, 9 vs. 5; p < 0.001) and overall for stay (11 vs. 9; p = 0.03). No hemolytic transfusion reactions were reported. Two transfusion-related acute lung injury events were reported in the compatible group. Between incompatible and compatible groups, there was no difference in the rates of acute respiratory distress syndrome (6% vs. 8%; p = 0.589), thromboembolic events (9% vs. 7%; p = 0.464), sepsis (6% vs. 8%; p = 0.589), or acute renal failure (8% vs. 8%, p = 0.860). Mortality at 6 (17% vs. 15%, p = 0.775) and 24 hours (25% vs. 23%, p = 0.544) and at 28 days or discharge (38% vs. 35%, p = 0.486) were similar between groups. Multivariate regression demonstrated that Injury Severity Score, older age and more red blood cell transfusion at 4 hours were independently associated with death at 28 days or discharge; Injury Severity Score and more red blood cell transfusion at 4 hours were predictors for morbidity. Incompatible transfusion was not an independent determinant of mortality or morbidity. CONCLUSION: Transfusion of type A plasma to patients with blood groups B and AB as part of a MTP does not appear to be associated with significant increases in morbidity or mortality. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Army Air Ambulance Blood Product Program in the Combat Zone and Challenges to Best Practices.

BACKGROUND: Identify challenges and best practices in the development of an austere air ambulance transfusion program. METHODS: A search of PubMed using combinations of the key terms 'prehospital,' 'blood product,' 'red blood cells,' 'damage control resuscitation,' 'transfusion,' 'air ambulance,' 'medical evacuation,' and 'medevac' yielded 196 articles for further analysis, with 14 articles suitable for addressing the background of prehospital transfusion within a helicopter. Retrospective analysis of unclassified briefs, after action reports, and procedures was also undertaken along with interview of subject matter experts. The initial series of 15 transfusions were discussed telephonically among flight crew, trauma surgeons, and lab specialists. Review of Joint Theater System data was readily available for 84 U.S. Army air ambulance transfusions between May-December 2012, with December marking the redeployment of the 25(th) Combat Aviation Brigade. RESULTS: Standardized implementation enabled safe blood product administration for 84 causalities from May-December 2012 without blood product shortage, expiration, or transfusion reaction. Challenges included developing transfusion competency, achieving high quality blood support, countering the potential for anti-U.S. sentiment, and diversity in coalition transfusion practices. DISCUSSION: Blood product administration aboard the air ambulance is logistically complex, requiring blood bank integration. Repetitive training enabled emergency medical technicians (EMTs) with basic medical training to safely perform transfusion in accordance with clinical operating guidelines. In the austere environment, logistic factors are significant challenges and political sensitivities are important considerations. Best practices may facilitate new en route transfusion programs. Powell-Dunford N, Quesada JF, Gross KR, Shackelford SA. Army air ambulance blood product program in the combat zone and challenges to best practices. Aerosp Med Hum Perform. 2016; 87(8):728-734.

Risk management analysis of air ambulance blood product administration in combat operations.

BACKGROUND: Between June-October 2012, 61 flight-medic-directed transfusions took place aboard U.S. Army Medical Evacuation (medevac) helicopters in Afghanistan. This represents the initial experience for pre-hospital blood product transfusion by U.S. Army flight medics. METHODS: We performed a retrospective review of clinical records, operating guidelines, after-action reviews, decision and information briefs, bimonthly medical conferences, and medevac-related medical records. RESULTS: A successful program was administered at 10 locations across Afghanistan. Adherence to protocol transfusion indications was 97%. There were 61 casualties who were transfused without any known instance of adverse reaction or local blood product wastage. Shock index (heart rate/systolic blood pressure) improved significantly en route, with a median shock index of 1.6 (IQR 1.2-2.0) pre-transfusion and 1.1 (IQR 1.0-1.5) post-transfusion (P < 0.0001). Blood resupply, training, and clinical procedures were standardized across each of the 10 areas of medevac operations. DISCUSSION: Potential risks of medical complications, reverse propaganda, adherence to protocol, and diversion and/or wastage of limited resources were important considerations in the development of the pilot program. Aviation-specific risk mitigation strategies were important to ensure mission success in terms of wastage prevention, standardized operations at multiple locations, and prevention of adverse clinical outcomes. Consideration of aviation risk mitigation strategies may help enable other helicopter emergency medical systems to develop remote pre-hospital transfusion capability. This pilot program provides preliminary evidence that blood product administration by medevac is safe.

Contextual diversity, not word frequency, determines word-naming and lexical decision times.

Word frequency is an important predictor of word-naming and lexical decision times. It is, however, confounded with contextual diversity, the number of contexts in which a word has been seen. In a study using a normative, corpus-based measure of contextual diversity, word-frequency effects were eliminated when effects of contextual diversity were taken into account (but not vice versa) across three naming and three lexical decision data sets; the same pattern of results was obtained regardless of which of three corpora was used to derive the frequency and contextual-diversity values. The results are incompatible with existing models of visual word recognition, which attribute frequency effects directly to frequency, and are particularly problematic for accounts in which frequency effects reflect learning. We argue that the results reflect the importance of likely need in memory processes, and that the continuity between reading and memory suggests using principles from memory research to inform theories of reading.

Cognitive flexibility and adaptability to environmental changes in dynamic complex problem-solving tasks.

People who show good performance in dynamic complex problem-solving tasks can also make errors. Theories of human error fail to fully explain when and why good performers err. Some theories would predict that these errors are to some extent the consequence of the difficulties that people have in adapting to new and unexpected environmental conditions. However, such theories cannot explain why some new conditions lead to error, while others do not. There are also some theories that defend the notion that good performers are more cognitively flexible and better able to adapt to new environmental conditions. However, the fact is that they sometimes make errors when they face those new conditions. This paper describes one experiment and a research methodology designed to test the hypothesis that when people use a problem-solving strategy, their performance is only affected by those conditions which are relevant to that particular strategy. This hypothesis is derived from theories that explain human performance based on the interaction between cognitive mechanisms and environment.