Prehospital Blood Product Transfusion Research Articles

Factors affecting physicians' decision to start prehospital blood product transfusion in blunt trauma patients: A cohort study of Helsinki Trauma Registry.

Prehospital blood transfusions are increasing as a treatment for bleeding trauma patients at risk for exsanguination. Triggers for starting transfusion in the field are less studied. We analyzed the factors affecting the decision of physicians to start prehospital blood product transfusion (PHBT) in blunt adult trauma patients. Data of all adult blunt trauma patients from the Helsinki Trauma Registry between March 2016 and July 2021 were retrospectively analyzed. Univariate analysis for the identification of predictive factors and multivariate regression analysis for their importance as predictive factors for the initiation of PHBT were applied. There were 1652 patients registered in the database. A total of 556 of them were treated by a physician-level prehospital emergency care unit, of which by transfusion-capable unit in 394 patients. PHBT (red blood cells and/or plasma) was started in 19.8% of the patients. We identified three statistically highly important clinical triggers for starting PHBT: high crystalloid volume need, shock index ≥0.9, and need for prehospital pleural decompression. PHBT in blunt adult trauma patients is initiated in ~20% of the patients in Southern Finland. High crystalloid volume need, shock index ≥0.9 and prehospital pleural decompression are associated with the initiation of PHBT, probably reflecting patients at high risk for bleeding.

Operationalizing the Deployment of Low-Titer O-Positive Whole Blood Within a Regional Trauma System.

The implementation of a low-titer O+ whole blood (LTOWB) resuscitation algorithm, particularly in the prehospital environment, has several inherent challenges, including cost, limited and inconsistent supply, and the logistics of cold-chain management. The Southwest Texas Regional Advisory Council has implemented the nation's first multidisciplinary, multi-institutional regional LTOWB program. This research effort was to illustrate the successful deployment of LTOWB within a regional trauma system. A deliberate systems approach to the deployment of LTOWB was used. Tenets of this program included the active management of blood donor sources and blood supply levels to minimize wastage as a result of expiration, maximize product utilization, the use of prehospital transfusion triggers, and efforts to decrease program costs prehospital agencies. A novel LTOWB rotation system was established using the concept of a "rotation site" and "rotation center." Standardized transfusion criteria, a regional approved equipment list, a regional Prehospital Blood Product Transfusion Record, and a robust multilevel communication plan serves as the framework for the program. The San Antonio Whole Blood Consortium was developed to create a consensus driven forum to manage and guide the program. From January 2018 to October 2019, LTOWB has been placed at 18 helicopter emergency medical services (HEMS) bases, 12 ground emergency medical service (EMS) agencies, 1 level I trauma center, and 1 level IV trauma center. A total of 450 patients have received a prehospital LTOWB transfusion. Program wide, the wastage rate of LTOWB due to expiration is between 1% and 2%. No complications related to prehospital LTOWB administration have been identified. This work demonstrates a novel model for the development of a trauma system LTOWB program. The program's implementation augments remote damage control resuscitation strategies and requires the integration and collaboration of a multidisciplinary stakeholder team to optimize efficiency, performance, and safety of the program.

UK Helicopter Emergency Medical Services’ use of circulatory access devices, blood product transfusion and fluid warmers – a cross-sectional survey

Introduction The pre-hospital environment provides significant challenges to clinicians who wish to rapidly administer warmed blood products and fluids to patients with haemorrhagic shock. Large-bore circulatory access is required with the use of devices that will successfully warm cold blood with minimal impact on flow rates. Until now, no information has been available that defines UK Helicopter Emergency Medical Services’ (HEMS) use of circulatory access and fluid warming devices, nor the recent adoption of pre-hospital blood product transfusion. Methods A survey was sent to all 22 UK HEMS asking which circulatory access devices crews have available, whether blood products are being transfused and if fluid warming devices are used as part of their resuscitations. Results All services responded. All UK HEMS use peripheral intravenous cannulae and intraosseous access. In addition, seven use central venous catheters and three use large-bore peripheral access (the Arrow Rapid Infusion Catheter®). Three services use landmark technique alone to gain central venous access, whereas four use a combination of landmark and ultrasound-guided techniques. Different sites for central venous access are used: subclavian (seven services), internal jugular (four) and femoral (four). Fourteen services carry pre-hospital blood products of which six transfuse packed red blood cells; four transfuse packed red blood cells and fresh frozen plasma; four transfuse packed red blood cells and lyophilised plasma. Eight services carry no pre-hospital blood products. Seventeen HEMS use fluid warmers; 13 use the Belmont® buddy lite™ and four use the QinFlow Warrior. Conclusion The use of a variety of policies and range of equipment has evolved across UK HEMS, demonstrating a lack of consensus on best practice. This is the first study to record a complete picture of current UK HEMS practice with regard to the use of circulatory access devices, fluid warmers and blood product administration.

In silico model of the dilutional effects of conventional component therapy versus whole blood in the management of massively bleeding adult trauma patients.

There are multiple approaches to the blood product and fluid resuscitation of a bleeding trauma patient. An in silico model of different trauma resuscitation strategies was constructed to predict their effects on the volumes of the different body fluid compartments and on several important hemostatic factors. This multicompartment dynamic deterministic model comprised four interconnected modules (hemostatic, resuscitation, body fluid compartment, and dilutional coagulopathy). The model was divided into five resuscitation phases with simulations using six different resuscitation strategies: whole blood (WB) only, conventional component therapy (CCT) only or 10 units of WB followed by CCT, with either 1 L of crystalloid or 1.5 units of WB or red blood cells in the prehospital phase. At the end of the simulations using 1 L of crystalloid fluids in the prehospital resuscitation phase, the use of WB led to a 1.4 g/dL higher hemoglobin concentration, 32 mg/dL higher fibrinogen concentration, and 0.9 L lower total extracellular fluid volume compared to CCT. Prehospital blood product transfusion in place of crystalloid resulted in higher hemoglobin and fibrinogen concentrations and a lower international normalized ratio throughout the resuscitation regardless of the resuscitation strategy used. Throughout both the prehospital crystalloid and prehospital blood product transfusion simulations, the hemoglobin and fibrinogen concentrations and platelet counts were higher, and the international normalized ratio was lower, when WB was used compared to CCT. This model predicted improved hemostatic factor levels and a smaller total extracellular fluid volume volume when WB was transfused instead of CCT to bleeding trauma patients.

Isolated traumatic brain injury results in significant pre-hospital derangement of cardiovascular physiology

IntroductionMajor trauma can result in both life-threatening haemorrhage and traumatic brain injury (TBI). The pre-hospital management of these conditions, particularly in relation to the cardiovascular system, is very different. TBI can result in cardiovascular instability but the exact incidence remains poorly described. This study explores the incidence of cardiovascular instability in patients undergoing pre-hospital anaesthesia for suspected TBI. MethodsRetrospective case series of all pre-hospital trauma patients attended by Kent, Surrey & Sussex Air Ambulance Trust (United Kingdom) trauma team during the period 1 January 2015–31 December 2016. Patients were included if they showed clinical signs of TBI, underwent pre-hospital anaesthesia and hospital computed tomography scanning subsequently confirmed an isolated TBI. ResultsOut of 121 patients with confirmed isolated TBI, 68 were cardiovascularly stable throughout the pre-anaesthesia phase, whilst 53 (44%) showed signs of instability (HR > 100bpm and/or SBP < 100 mmHg pre-anaesthesia). Hypotension (SBP < 100) with or without tachycardia was present in 14 (12%) patients. 10 (8%) patients with isolated TBI received pre-hospital blood product transfusion. ConclusionIncreased awareness that traumatic brain injury can cause significant derangement to heart rate and blood pressure, even in the absence of major haemorrhage, would allow the pre-hospital clinician to treat cardiovascular instability with the most appropriate means, such as crystalloid and vasopressors, to limit secondary brain injury.

Utilizing Propensity Score Analyses in Prehospital Blood Product Transfusion Studies: Lessons Learned and Moving Toward Best Practice.

Recently, observational studies analyzing prehospital blood product transfusions (PHT) for trauma have become more widespread in both military and civilian communities. Due to these studies’ non-random treatment assignment, propensity score (PS) methodologies are often used to determine an intervention’s effectiveness. However, there are no guidelines on how to appropriately conduct PS analyses in prehospital studies. Such analyses are complicated when treatments are given in emergent settings as the ability to administer treatment early, often before hospital admission, can interfere with assumptions of PS modeling. This study conducts a systematic review of literature from military and civilian populations to assess current practice of PS methodology in PHT analyses. The decision-making process from the multicenter Prehospital Resuscitation on Helicopter Study (PROHS) is discussed and used as a motivating example. Results show that researchers often omit or incorrectly assess variable balance between treatment groups and include inappropriate variables in the propensity model. When used correctly, PS methodology is an effective statistical technique to show that aggressive en route resuscitation strategies, including PHT, can reduce mortality in individuals with severe trauma. This review provides guidelines for best practices in study design and analyses that will advance trauma care.

Association of Prehospital Blood Product Transfusion During Medical Evacuation of Combat Casualties in Afghanistan With Acute and 30-Day Survival

Prehospital blood product transfusion in trauma care remains controversial due to poor-quality evidence and cost. Sequential expansion of blood transfusion capability after 2012 to deployed military medical evacuation (MEDEVAC) units enabled a concurrent cohort study to focus on the timing as well as the location of the initial transfusion. To examine the association of prehospital transfusion and time to initial transfusion with injury survival. Retrospective cohort study of US military combat casualties in Afghanistan between April 1, 2012, and August 7, 2015. Eligible patients were rescued alive by MEDEVAC from point of injury with either (1) a traumatic limb amputation at or above the knee or elbow or (2) shock defined as a systolic blood pressure of less than 90 mm Hg or a heart rate greater than 120 beats per minute. Initiation of prehospital transfusion and time from MEDEVAC rescue to first transfusion, regardless of location (ie, prior to or during hospitalization). Transfusion recipients were compared with nonrecipients (unexposed) for whom transfusion was delayed or not given. Mortality at 24 hours and 30 days after MEDEVAC rescue were coprimary outcomes. To balance injury severity, nonrecipients of prehospital transfusion were frequency matched to recipients by mechanism of injury, prehospital shock, severity of limb amputation, head injury, and torso hemorrhage. Cox regression was stratified by matched groups and also adjusted for age, injury year, transport team, tourniquet use, and time to MEDEVAC rescue. Of 502 patients (median age, 25 years [interquartile range, 22 to 29 years]; 98% male), 3 of 55 prehospital transfusion recipients (5%) and 85 of 447 nonrecipients (19%) died within 24 hours of MEDEVAC rescue (between-group difference, -14% [95% CI, -21% to -6%]; P = .01). By day 30, 6 recipients (11%) and 102 nonrecipients (23%) died (between-group difference, -12% [95% CI, -21% to -2%]; P = .04). For the 386 patients without missing covariate data among the 400 patients within the matched groups, the adjusted hazard ratio for mortality associated with prehospital transfusion was 0.26 (95% CI, 0.08 to 0.84, P = .02) over 24 hours (3 deaths among 54 recipients vs 67 deaths among 332 matched nonrecipients) and 0.39 (95% CI, 0.16 to 0.92, P = .03) over 30 days (6 vs 76 deaths, respectively). Time to initial transfusion, regardless of location (prehospital or during hospitalization), was associated with reduced 24-hour mortality only up to 15 minutes after MEDEVAC rescue (median, 36 minutes after injury; adjusted hazard ratio, 0.17 [95% CI, 0.04 to 0.73], P = .02; there were 2 deaths among 62 recipients vs 68 deaths among 324 delayed transfusion recipients or nonrecipients). Among medically evacuated US military combat causalities in Afghanistan, blood product transfusion prehospital or within minutes of injury was associated with greater 24-hour and 30-day survival than delayed transfusion or no transfusion. The findings support prehospital transfusion in this setting.

Multicenter observational prehospital resuscitation on helicopter study.

Earlier use of in-hospital plasma, platelets, and red blood cells (RBCs) has improved survival in trauma patients with severe hemorrhage. Retrospective studies have associated improved early survival with prehospital blood product transfusion (PHT). We hypothesized that PHT of plasma and/or RBCs would result in improved survival after injury in patients transported by helicopter. Adult trauma patients transported by helicopter from the scene to nine Level 1 trauma centers were prospectively observed from January to November 2015. Five helicopter systems had plasma and/or RBCs, whereas the other four helicopter systems used only crystalloid resuscitation. All patients meeting predetermined high-risk criteria were analyzed. Patients receiving PHT were compared with patients not receiving PHT. Our primary analysis compared mortality at 3 hours, 24 hours, and 30 days, using logistic regression to adjust for confounders and site heterogeneity to model patients who were matched on propensity scores. Twenty-five thousand one hundred eighteen trauma patients were admitted, 2,341 (9%) were transported by helicopter, of which 1,058 (45%) met the highest-risk criteria. Five hundred eighty-five of 1,058 patients were flown on helicopters carrying blood products. In the systems with blood available, prehospital median systolic blood pressure (125 vs 128) and Glasgow Coma Scale (7 vs 14) was significantly lower, whereas median Injury Severity Score was significantly higher (21 vs 14). Unadjusted mortality was significantly higher in the systems with blood products available, at 3 hours (8.4% vs 3.6%), 24 hours (12.6% vs 8.9%), and 30 days (19.3% vs 13.3%). Twenty-four percent of eligible patients received a PHT. A median of 1 unit of RBCs and plasma were transfused prehospital. Of patients receiving PHT, 24% received only plasma, 7% received only RBCs, and 69% received both. In the propensity score matching analysis (n = 109), PHT was not significantly associated with mortality at any time point, although only 10% of the high-risk sample were able to be matched. Because of the unexpected imbalance in systolic blood pressure, Glasgow Coma Scale, and Injury Severity Score between systems with and without blood products on helicopters, matching was limited, and the results of this study are inconclusive. With few units transfused to each patient and small outcome differences between groups, it is likely large, multicenter, randomized studies will be required to detect survival differences in this important population. Level II.

Prehospital Blood Transfusions in Non-Trauma Patients.

Despite advances in trauma care, hemorrhage continues to be the leading cause of preventable mortality in trauma. The evidence to support its use in non-trauma patients is limited. We aim to report our experience with prehospital blood product transfusion. We hypothesize that it is safe, appropriately utilized, and that our protocol, which was designed for trauma patients, is adaptable to fit the needs of non-trauma patients. Patients transfused with blood products, packed red blood cells (pRBCs) or plasma, in the prehospital environment between 2002 and 2014 were included. Trauma patients were compared to non-trauma patients using descriptive statistics. A total of 857 patients (n=549 trauma and n=308 non-trauma) were transfused with pRBCs (76%, n=654, mean 1.6±1.1 units en route), plasma (53%, n=455, mean 1.7±0.7 unit), or both (29%, n=252) during ground (12%) or air (84%) critical care transport. Mean age was 60.8±21.6years with 60.1% (n=515) males. Subsequently, in-hospital blood transfusions were performed in 80% of patients, operations in 44%, and endoscopy in 31%. Five percent (n=41) of patients did not require any of these interventions. Thirty-day mortality rate was 18%, and one patient (<0.01%) had a transfusion reaction. The majority of patients were non-trauma (n=549, 64%). Of the non-trauma patients, 219 (40%) were surgical, 193 (35%) gastrointestinal bleeds, and 137 (25%) medical. Both non-trauma and trauma patients require blood products for life threatening hemorrhage and the majority required further interventions. Further research on the benefits of transfusion among non-trauma patients is warranted.

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

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. 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. 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. 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.

Abstract 315: Characterization of Out of Hospital Resuscitation Utilizing Blood Transfusion

Introduction: While blood transfusion in the hospital setting has been extensively studied, little data exists on out of hospital administration of blood products. We aimed to characterize patients receiving out of hospital blood product transfusion in a critical care transport network that carries blood products. Methods: We performed a retrospective review of patients transported by a regional critical care transport service from 1/1/2003 to 6/30/2012 who received blood products during transport. This service carries two units of un-crossmatched Packed Red Blood Cells (pRBCs) on every transport. We describe prehospital factors (vital signs, mechanism of injury, volume and type of blood product transfused) associated with blood transfusion. We further categorized out of hospital transfusions of blood products into three groups based on the volume transfused (lt350 ml, 350-700ml, gt700ml). We compared in-hospital outcomes (mortality, volume and type of subsequent blood transfusion, and need for emergent surgery [lt24 hours]) among these three groups to ascertain the impact of prehospital blood product transfusion. Results: We reviewed 1441 transports in which blood products were transfused. Most transfusions were inter-facility transfers (92%, CI 91-93%) and for non-traumatic illness (75%, CI 73-77%). The most common reason for transport was upper gastrointestinal bleeding (20%, 18-22%). A vast majority, 80% (CI 78-82%), of patients required subsequent in-hospital blood transfusion. In hospital 30-day mortality was high, 22% (CI 20-25%), as was need for emergent surgery 27% (CI 25-29%). Mean length of stay was 10.6 days and mean ICU length of stay was 7.2 days. Among those receiving blood products, those transfused with &amp;gt700ml had higher heart rates (94 vs. 103, p=0.01), whole blood lactate levels (3.5 vs. 6.2, p&amp;lt0.01), and lower systolic blood pressure (108 vs.122, p&amp;lt0.01) Conclusions: In this sample, the majority of patients receiving blood during critical care transport are during inter-facility transports and for non-traumatic conditions. Gastrointestinal hemorrhage is the most common indication for transfusion and 30-day mortality in this cohort is high.

Prehospital Blood Product Transfusion by U.S. Army MEDEVAC During Combat Operations in Afghanistan: A Process Improvement Initiative

U.S. Army flight medics performed a process improvement initiative of 15 blood product transfusions on select Category A (Urgent) helicopter evacuation casualties meeting approved clinical indications for transfusion. These transfusions were initiated from point of injury locations aboard MEDEVAC aircraft originating from one of two locations in southern Afghanistan. All flight medics executing the transfusions were qualified through a standardized and approved program of instruction, which included day and night skills validation, and a 90% or higher written examination score. There was no adverse reaction or out-of-standard blood product temperature despite hazardous conditions and elevated cabin temperatures. All casualties within a 10-minute flight time who met clinical indications were transfused. Utilization of a standard operating procedure with strict handling and administration parameters, a rigorous training and qualification program, an elaborate cold chain system, and redundant documentation of blood product units ensured that flight medic initiated transfusions were safe and effective. Research study is needed to refine the indications for prehospital blood transfusion and to determine the effect on outcomes in severely injured trauma patients.