Transfusion support by a UK Role 1 medical team: a 2-year experience from Afghanistan

Emergency first responder management of combat injuries to the torso in the military, remote and austere settings

Traumatic injuries to the torso account for almost a quarter of all injuries seen in combat and are typically secondary to blast or gunshot wounds. Injuries due to road traffic collisions or violence are also relatively common during humanitarian and disaster relief efforts. There may also be multiple injured patients in these settings, and surgical care may be limited by a lack of facilities and resources in such a non-permissive environment. The first responder in these scenarios should be prepared to manage patients with severe injuries to the torso. We aim to describe the management of these injuries in the military and austere environment, within the scope of practice of a level 5 registered prehospital practitioner.

Temperature mapping in an air ambulance helicopter: Implications for the delivery of pre-hospital transfusion

BACKGROUND

Pre-hospital blood products, including freeze-dried plasma, are increasingly carried on air ambulance helicopters. The purpose of this study was to map the temperatures within a civilian air ambulance and consider the implications for pre-hospital transfusion.

MATERIALS AND METHODS

We conducted a single-site prospective observational study in the United Kingdom. Tinytag temperature data-loggers (Gemini, UK) were secured on to three locations throughout an air ambulance, and one was placed inside an insulated drug-pouch. Temperatures were monitored at 5-min intervals. Data were downloaded monthly and processed using R and MKT software to collate maximum, minimum, and day/night mean kinetic temperatures (MKTs). Blood was transported in Crēdo ProMed 4 containers (Peli Products, S.L.U) and monitored with QTA data-loggers (Tridentify, Sweden).

RESULTS

A total of 344,844 temperature recordings were made on 302 days during a 12-month period from January 2019. The external ambient temperatures varied seasonally from -7.1°C to 31.2°C, whereas internal temperatures ranged from -0.3°C to 60.6°C. The warmest area was alongside the left front-crew position (range 1.9-60.6°C, MKT 24.8°C). The lowest daytime MKT (16.9°C) and range (1.7°C-36.4°C) were recorded next to the patient stretcher. Temperatures ranged from 4.2°C to 40.1°C inside the insulated drugs-pouch, exceeding 25°C on 47 days (15%) and falling below 15°C on 192 days (63%) In contrast, thermally packed blood maintained a range of 2-6°C.

CONCLUSION

The temperatures within an air ambulance varied throughout the cabin and often exceeded the external ambient temperature. Appropriately selected thermal protection and monitoring is required for the successful delivery of pre-hospital transfusion, even in a temperate climate.

Practical limitations of emergency donor panels as a risk mitigation in small-scale short-term training team operations

Haemostatic resuscitation with blood products has become the expected standard of care for trauma casualties. As UK Defence increases its deployment of small-scale, short-term training teams (STTTs) in Defence Engagement and influence operations, ever greater reliance is being placed on emergency donor panels (EDP) as a source of whole blood. This paper outlines the practical limitations of using EDPs as a risk mitigation in conventional STTTs which must be considered prior to every deployment.

Pre-hospital transfusion of red blood cells. Part 1: A scoping review of current practice and transfusion triggers

OBJECTIVES

The primary aim of this scoping review is to describe the current use of pre-hospital transfusion of red blood cells (PHTRBC) and to evaluate criteria used to initiate PHTRBC. The effects on patients' outcomes will be reviewed in Part 2.

BACKGROUND

Haemorrhage is a preventable cause of death in trauma patients, and transfusion of red blood cells is increasingly used by Emergency Medical Services (EMS) for damage control resuscitation. However, there are no guidelines and little consensus on when to initiate PHTRBC.

METHODS

PubMed and Web of Science were searched through January 2019; 71 articles were included.

RESULTS

Transfusion triggers vary widely and involve vital signs, clinical signs of poor tissue perfusion, point of care measurements and pre-hospital ultrasound imaging. In particular, hypotension (most often defined as systolic blood pressure ≤ 90 mmHg), tachycardia (most often defined as heart rate ≥ 120/min), clinical signs of poor perfusion (eg, prolonged capillary refill time or changes in mental status) and injury type (ie, penetrating wounds) are common pre-hospital transfusion triggers.

CONCLUSIONS

PHTRBC is increasingly used by Emergency Medical Services, but guidelines on when to initiate transfusion are lacking. We identified the most commonly used transfusion criteria, and these findings may provide the basis for consensus-based pre-hospital transfusion protocols.

Pre-hospital transfusion of red blood cells. Part 2: A systematic review of treatment effects on outcomes

The primary aim of this systematic review is to describe the effects of prehospital transfusion of red blood cells (PHTRBC) on patient outcomes. Damage control resuscitation attempts to prevent death through haemorrhage in trauma patients. In this context, transfusion of red blood cells is increasingly used by emergency medical services (EMS). However, evidence on the effects on outcomes is scarce. PubMed and Web of Science were searched through January 2019; 55 articles were included. No randomised controlled studies were identified. While several observational studies suggest an increased survival after PHTRBC, consistent evidence for beneficial effects of PHTRBC on survival was not found. PHTRBC appears to improve haemodynamic parameters, but there is no evidence that shock on arrival to hospital is averted, nor of an association with trauma induced coagulopathy or with length of stay in hospitals or intensive care units. In conclusion, PHTRBC is increasingly used by EMS, but there is no strong evidence for effects of PHTRBC on mortality. Further research with study designs that allow causal inferences is required for more conclusive evidence. The combination of PHTRBC with plasma, as well as the use of individualised transfusion criteria, may potentially show more benefits and should be thoroughly investigated in the future. The review was registered at Prospero (CRD42018084658).

Group O low titre only emergency donor panels for small combat teams

INTRODUCTION

Military elements increasingly operate in small teams in remote areas with no immediate blood product support. Planners and operators may endorse collection of fresh whole blood from pretested donors in emergency situations. The biggest risk of transfusion is the accidental use of ABO incompatible blood which can be fatal. The risk may be mitigated by using only group O LOw (OLO) titre donors with plasma containing low levels of the naturally occurring antibody to group A and B red cells. This paper reviews the ABO blood group distribution in potential blood donors from a high readiness UK medical regiment and explores the feasibility of using only group OLO donors in small teams.

METHODS

A retrospective review of routine volunteer blood donor samples was undertaken at 6 monthly intervals during a 2-year period. Personnel were tested in groups when available during training to create multiple donor panels to simulate small teams.

RESULTS

206 donation samples were collected from 157 potential donors. All donors were acceptable based on the lifestyle questionnaire, serology and microbiology screen. Of the 206 samples reviewed, 85 (41%) were group O (D pos and D neg). 14 group O (16.5%) were shown to have high titre of anti-A or B. Therefore, 71, that is, 34% overall were suitable as OLO donors. The donor panel size varied from 15 to 44. The absolute number of OLO donors in each panel ranged from 4 to 17 and the number of O neg donors was 0-3.

CONCLUSION

A third of samples were suitable as OLO donors; however, there were insufficient 'universal' donors within smaller subgroups (<10). In this situation, we recommend the careful use of both group O and group A donors or the use of a buddy-buddy blood group matrix.

Deployed skills training for whole blood collection by a special operations expeditionary surgical team

BACKGROUND

Noncompressible hemorrhage is the leading cause of potentially preventable battlefield death. Combining casualty retrieval from the battlefield and damage control resuscitation (DCR) within the "golden hour" increases survival. However, transfusion requirements may exceed the current blood component stocks held by forward surgical teams. Warm fresh whole blood (WFWB) is an alternative. We report WFWB transfusion training developed by and delivered to a US Golden Hour Offset Surgical Treatment Team and the resulting improvement in confidence with WFWB transfusion.

METHODS

A bespoke instructional package was derived from existing operational clinical guidelines. All Golden Hour Offset Surgical Treatment Team personnel completed initial training, reinforced through ongoing casualty simulations. A record of blood types and donor eligibility was established to facilitate rapid identification of potential WFWB donors. Self-reported confidence in seven aspects of the WFWB transfusion process was assessed before and after training using a five-point Likert scale. Personnel were analyzed by groups consisting of those whose operational role includes WFWB transfusion ("transfusers"), clinical personnel without such responsibilities ("nontransfusers") and nonclinical personnel (other). Comparisons within and between groups were made using appropriate nonparametric tests.

RESULTS

Data were collected from 39 (89%) of 44 training participants: 24 (62%) transfusers, 12 (31%) nontransfusing clinicians, and 3 (8%) other personnel. Transfusers and nontransfusers reported increased comfort with all practical elements of WFWB transfusion. The confidence of other personnel also increased, but (likely due to small numbers) was not statistically significant.

CONCLUSION

WFWB transfusion is an integral part of modern deployed military remote DCR. Our in-theater training program rapidly and reproducibly enhanced the comfort in WFWB transfusion in providers from a range of backgrounds and skill-mixes. This model has the potential to improve both safety and effectiveness of WFWB remote DCR in the far-forward deployed setting.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.

NATO Blood Panel perspectives on changes to military prehospital resuscitation policies: current and future practice

The North Atlantic Treaty Organization (NATO) Blood Panel exists to promote interoperability of transfusion practice between NATO partners. However, it has served as an important forum for the development of prehospital transfusion and transfusion in the austere environment. There are synergies with the trauma hemostasis and oxygen research community especially in the areas of innovation and research. Four presentations are summarized together with a review of some scientific principles. The past decade has already seen significant changes in early transfusion support. Sometimes practice has preceded the evidence and has stretched regulatory and logistic constraints. Ethical and philosophical issues are also important and require us to question "should we" and not just "could we." The challenge for the combined communities is to continue to optimize transfusion support underpinned by evidence-based excellence.

Tactical damage control resuscitation in austere military environments

BACKGROUND

Despite the early uses of tourniquets and haemostatic dressings, blood loss still accounts for the vast majority of preventable deaths on the battlefield. Over the last few years, progress has been made in the management of such injuries, especially with the use of damage control resuscitation concepts. The early application of these procedures, on the field, may constitute the best opportunity to improve survival from combat injury during remote operations.

DATA SOURCES

Currently available literature relating to trauma-induced coagulopathy treatment and far-forward transfusion was identified by searches of electronic databases. The level of evidence and methodology of the research were reviewed for each article. The appropriateness for field utilisation of each medication was then discussed to take into account the characteristics of remote military operations.

CONCLUSIONS

In tactical situations, in association with haemostatic procedures (tourniquet, suture, etc), tranexamic acid should be the first medication used according to the current guidelines. The use of fibrinogen concentrate should also be considered for patients in haemorrhagic shock, especially if point-of-care (POC) testing of haemostasis or shock severity is available. If POC evaluation is not available, it seems reasonable to still administer this treatment after clinical assessment, particularly if the evacuation is delayed. In this situation, lyophilised plasma may also be given as a resuscitation fluid while respecting permissive hypotension. Whole blood transfusion in the field deserves special attention. In addition to the aforementioned treatments, if the field care is prolonged, whole blood transfusion must be considered if it does not delay the evacuation.