Prehospital Blood Product Research Articles

Prehospital blood transfusion : Opportunities and challenges for the German emergency medical services

Exsanguination is the leading cause of preventable death in severe trauma. Immediate hemorrhage control and transfusion of blood products are critical to maintain oxygen delivery and address trauma-induced coagulopathy. While prehospital blood product transfusion (PHBT) is established in neighboring countries, the fragmented configuration of Germany's emergency medical service (EMS) infrastructure has delayed the adoption of widespread PHBT programmes. This review aims to provide an updated perspective on the evolution, international practices and research needs of PHBT within the German context. This narrative review is based on aPubMed search using the search terms "prehospital" and "blood*". From an initial 4738 articles, 333 were directly related to PHBT and were subjected to further detailed examination. The literature, including referenced studies, was categorized into areas such as history, rationale, international practices, and evidence, and analyzed for quality. The benefit of early blood transfusion in major trauma has been established since WW1, explaining the efforts to initiate this lifesaving intervention as early as possible in the care pathway, including the prehospital field. Recent randomized trials have faced design and recruitment challenges, reflecting the complexity of the research question. These trials have yielded inconclusive results regarding the survival benefits of PHBT in civilian settings. This scenario raises doubts about the capability of randomized trials to resolve questions concerning survival advantages. Despite these difficulties, there is adiscernible trend indicating potential improvements in patient outcomes. In Germany, the incidence of trauma-associated shock stands at 38per 100,000 individuals per year. It is estimated that between 300 and 1800 patients annually possibly benefit from PHBT. Prehospital Blood Transfusion appears to be promising but identifying patient groups most likely to benefit as well as the most suitable blood products remain unresolved issues. In Germany PHBT programs are not yet widely established. Paradoxically, this situation, paired with the extensive German Trauma Registry, provides aprime opportunity for comprehensive prospective cohort studies, addressing the balance between PHBT benefits, logistical feasibility, and implementation strategies. Such studies are essential for establishing guidelines and integrating PHBT efficiently into German trauma care protocols.

Outcomes of Empiric Calcium Administration with Prehospital Blood Product Administration

Outcomes of Empiric Calcium Administration with Prehospital Blood Product Administration

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.

Hypocalcaemia upon arrival (HUA) in trauma patients who did and did not receive prehospital blood products: a systematic review and meta-analysis

PurposeHypocalcaemia upon arrival (HUA) to hospital is associated with morbidity and mortality in the trauma patient. It has been hypothesised that there is an increased incidence of HUA in patients receiving prehospital transfusion as a result of citrated blood products. This research aimed to determine if there was a difference in arrival ionised calcium (iCa) levels in trauma patients who did and did not receive prehospital transfusion.MethodsWe conducted a systematic review and meta-analysis of patients with an Injury Severity Score (ISS) > / = 15 and an iCa measured on hospital arrival. We then derived mean iCa levels and attempted to compare between-group variables across multiple study cohorts.ResultsNine studies reported iCa on arrival to ED, with a mean of 1.08 mmol/L (95% CI 1.02–1.13; I2 = 99%; 2087 patients). Subgroup analysis of patients who did not receive prehospital transfusion had a mean iCa of 1.07 mmol/L (95% CI 1.01–1.14; I2 = 99%, 1661 patients). Transfused patients in the 3 comparative studies had a slightly lower iCa on arrival compared to those who did not receive transfusion (mean difference − 0.03 mmol/L, 95% CI − 0.04 to − 0.03, I2 = 0%, p = 0.001, 561 patients).ConclusionHUA is common amongst trauma patients irrespective of transfusion. Transfused patients had a slightly lower initial iCa than those without transfusion, though the clinical impact of this remains to be clarified. These findings question the paradigm of citrate-induced hypocalcaemia alone in trauma. There is a need for consensus for the definition of hypocalcaemia to provide a basis for future research into the role of calcium supplementation in trauma.

Prehospital Blood Transfusion: A Cross-Sectional Study of Prehospital and Retrieval Medicine Services across Australia & Aotearoa-New Zealand

Background The frequency and type of prehospital blood product delivery across Australia and Aotearoa-New Zealand is unknown. This study aims to describe transfusion practice across different services in the two nations, as well as identifying potential barriers to the carriage of blood products. Methodology Prehospital and retrieval medicine services operating teams of doctors, specialist paramedics, and/or flight nurses out of specialty bases across Australia and Aotearoa-New Zealand were sent a standardized questionnaire regarding their base characteristics and their current blood transfusion practice. Bases that only performed inter-hospital transfers or search & rescue operations were excluded. Bases were queried on personnel, equipment, transport times, type and volume of blood products carried, frequency of use, and barriers to implementation for those without prehospital blood transfusion programs. Results 64 bases were identified and contacted, of which 5 were excluded and 45 of the remaining 59 (76.3%) responded. 62% (28/45) of respondents routinely carry prehospital blood products. 78.6% (22/28) carried packed red blood cells (PRBC) only, 14.3% (4/28) carried both PRBC and plasma, and 1 service (3.6%) carried whole blood. The mean number of units of blood product carried was 3.3 (SD 0.82). 2 bases (7.1%) carried fibrinogen concentrate. All services carried tranexamic acid and calcium. 734 patients received a blood transfusion in 2021, with trauma being the most common indication (552, 75.2%). Base characteristics varied significantly in staffing, vehicle platform and transfer times. The median transfer time from scene to hospital was 65 min (IQR of 40-92). Services without access to prehospital blood products identified multiple barriers to implementation, including training and supply chain. Conclusion Approximately two-thirds of prehospital services operating advanced teams across Australia and Aotearoa-New Zealand carried blood products and there was wide variation both in the type and number of blood products carried by each base. Multiple barriers to the carriage of blood by all bases were reported, which have implications for service equity. Transfer times are generally long in Australia and Aotearoa-New Zealand, which may impact the generalizability of overseas research performed in prehospital systems with significantly shorter transfer times to services operating in Australia and Aotearoa-New Zealand.

Resuscitation with pre-hospital blood products in adults with trauma-related haemorrhagic shock: the RePHILL RCT

Background The treatment of traumatic haemorrhagic shock has been transformed through better haemorrhage control, use of tranexamic acid and use of blood products. The improved survival seen from these strategies has stimulated an interest in pre-hospital transfusion. Objectives To determine if the clinical effectiveness of resuscitation with red blood cells and lyophilised plasma was superior to 0.9% saline for improving tissue perfusion and reducing mortality in adults with haemorrhagic shock following major trauma. Design A multi-centre, allocation concealed, open-label, parallel group, randomised controlled trial (with internal pilot). Setting The trial was conducted in four civilian pre-hospital critical care services who operated within the National Health Service (NHS) England Major Trauma Networks. Participants Adults (aged ≥16 years) who had sustained traumatic injuries, were attended by a pre-hospital emergency medical team and were hypotensive (systolic blood pressure <90 mmHg or absence of radial pulse) as a consequence of traumatic haemorrhage were eligible for inclusion. The exclusion criteria were known or apparently <16 years, blood administered on scene prior to arrival of the RePHILL team, traumatic cardiac arrest where (1) the arrest occurred prior to arrival of the team and/or (2) the primary cause is not hypovolaemia, refusal of blood product administration, known Jehovah’s Witness, pregnancy, isolated head injury without evidence of external haemorrhage, prisoners in the custody of HM Prison and Probation Service. Interventions Participants were randomised to receive up to either two units each of red blood cells and lyophilised plasma or up to 1 L 0.9% saline. Treatment was administered through the intravenous or intraosseous route. Main outcome measures The primary outcome was a composite of episode mortality and/or impaired lactate clearance. The secondary outcomes included the individual components of the primary outcome. Results From 6 December 2016 to 2 January 2021, pre-hospital medical teams randomised 432 participants to red blood cell/lyophilised plasma (n = 209) or 0.9% saline (n = 223) out of a target sample size of 490. Most participants were white (62%), males (82%), median age 38 (interquartile range 26 to 58), involved in a road traffic collision (62%) with severe injuries (median injury severity score 36, interquartile range 25 to 50). Prior to randomisation participants had received on average 430 ml crystalloid fluids and tranexamic acid (90%). The primary outcome occurred in 128/199 (64.3%) of participants randomised to red blood cell/lyophilised plasma and 136/210 (64.8%) randomised to 0.9% saline [adjusted risk difference –0.025% (95% confidence interval –9.0% to 9.0%), p = 0.996]. The event rates for the individual components of the primary outcome, episode mortality and lactate clearance were not statistically different between groups [adjusted average differences −3% (−12% to 7%); p = 0.57 and −5% (−14% to 5%), p = 0.33, respectively]. Limitations Recruitment stopped prematurely due to disruption caused by the COVID-19 pandemic. Future work Identify the characteristics of patients who may benefit from pre-hospital blood products and whether alternative transfusion regimens are superior to standard care. Conclusions The trial did not demonstrate that pre-hospital red blood cell/lyophilised plasma resuscitation was superior to 0.9% saline for trauma-related haemorrhagic shock. Trial registration This trial is registered as ISRCTN62326938. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation Programme (NIHR award ref: 14/152/14) and is published in full in Efficacy and Mechanism Evaluation; Vol. 11, No. 2. See the NIHR Funding and Awards website for further award information.

Prehospital Blood Transfusion in Helicopter Emergency Medical Services: An Italian Survey

ObjectiveHemorrhage remains the most common cause of preventable death after trauma. Prehospital blood product (PHBP) administration may improve outcomes. No data are available about PHBP use in Italian helicopter emergency medical services (HEMS). The primary aim of this survey was to establish the degree of PHBP used throughout Italy. The secondary aims were to evaluate the main indications for their use, the opinions about PHBPs, and users’ experience. MethodsThe study group performed a telephone/e-mail survey of all 56 Italian HEMS bases. The questions concerned whether PHBPs were used in their HEMS bases, the frequency of transfusions, the PHBP used, and the perceived benefits. ResultsFour of 56 HEMS bases use PHBPs. Overall, 7% have prehospital access to packed red cells and only 1 to fresh plasma. In addition to blood product administration, 4 of 4 use tranexamic acid, and 3 of 4 also use fibrinogen. Seventy-five percent use PHBPs once a month and 25% once a week. The users’ experience was that PHBPs are beneficial and lifesaving. ConclusionOnly 4 of 56 HEMS in Italy use PHBPs. There is an absolute consensus among providers on the benefit of PHBPs despite the lack of evidence on PHBP use.

Prehospital Critical Care Blood Product Administration: Quantifying Clinical Benefit.

Prehospital blood transfusion has been widely practiced in the military and is drawing renewed scrutiny after many years of civilian use. The objective of this article is to quantify the benefit derived from prehospital transfusion of blood products. Deidentified data were extracted retrospectively from the flight records of a critical care transportation program between April 2018 and January 2020. Patients who were transported before a prehospital blood transfusion protocol were compared with patients after initiation of the blood transfusion protocol. Demographic data, vital signs, laboratory analytics, and other outcome measures were analyzed. Nine scene transport patients who met the transfusion criteria before a blood transfusion protocol were compared with 11 patients transported after initiation of the protocol. Identical outcome measures were analyzed. Patients who received prehospital blood transfusions had a statistically significantly longer hospital length of stay (16.5 vs 3.7 days, P = .03) and were more often taken directly to the operating room (80% vs 28%, P = .04). No statistically significant difference was identified when comparing mean arterial pressure, heart rate, respiratory rate, hemoglobin, hematocrit, or survival to hospital discharge. Trauma patients who received prehospital blood transfusion had a longer hospital length of stay and were more often taken directly to the operating room, but without improvement in survival.

An assessment of the safety, hemostatic efficacy, and clinical impact of low-titer group O whole blood in children and adolescents.

Low-titer group O whole blood (LTOWB) use has been associated with improved survival and less blood transfusions in adult trauma patients. Its use in pediatric trauma has been shown to be safe when using leukoreduced, LTOWB with anti-A, anti-B antibody titers of <1:50. We set out to evaluate the safety, hemostatic potential, and impact on pediatric outcomes at a center using non-leukoreduced, LTOWB with anti-A, anti-B antibody titers of <1:200. Patients younger than 18 years, who received emergency-release, uncrossed matched blood, and presented to our trauma center from November 2017 to April 2021 were included. Patients were divided into those receiving any LTOWB and those receiving only RBC and or plasma (COMP). Primary outcome was 30-day survival. One hundred sixty-four patients received emergency release blood products. Of these, 73 received at least one unit of LTOWB. The LTOWB group were younger (14 years vs. 13 years), more likely to be male (87% vs. 49%), and to have sustained penetrating trauma (44% vs. 23%); all p < 0.05. Low-titer group O whole blood patients received more blood than their COMP counterparts prior to arrival. Serial hemolysis panels (K+, bilirubin, LDH, haptoglobin) obtained at 24 hours, 48 hours, and 72 hours were similar between groups; all p > 0.05. There was no difference in survival by univariate analysis but after adjusting for inverse probability of treatment weights there was an observed association between WB administration and improved survival, with an odds ratio of 2.48 (1.15-5.47). Non-leukoreduced, LTOWB in anti-A/anti-B antibody titers of <1:200 appear safe in children and adolescents. While patients receiving LTOWB had more evidence of shock, higher torso injury severity, and received more prehospital blood products, there may be a mortality benefit with whole blood. Larger, multicenter studies are needed. Therapeutic/Care Management; Level IV.

Association of Prehospital Transfusion With Mortality in Pediatric Trauma

Optimal hemostatic resuscitation in pediatric trauma is not well defined. To assess the association of prehospital blood transfusion (PHT) with outcomes in injured children. This retrospective cohort study of the Pennsylvania Trauma Systems Foundation database included children aged 0 to 17 years old who received a PHT or emergency department blood transfusion (EDT) from January 2009 and December 2019. Interfacility transfers and isolated burn mechanism were excluded. Analysis took place between November 2022 and January 2023. Receipt of a blood product transfusion in the prehospital setting compared with the emergency department. The primary outcome was 24-hour mortality. A 3:1 propensity score match was developed balancing for age, injury mechanism, shock index, and prehospital Glasgow Comma Scale score. A mixed-effects logistic regression was performed in the matched cohort further accounting for patient sex, Injury Severity Score, insurance status, and potential center-level heterogeneity. Secondary outcomes included in-hospital mortality and complications. Of 559 children included, 70 (13%) received prehospital transfusions. In the unmatched cohort, the PHT and EDT groups had comparable age (median [IQR], 47 [9-16] vs 14 [9-17] years), sex (46 [66%] vs 337 [69%] were male), and insurance status (42 [60%] vs 245 [50%]). The PHT group had higher rates of shock (39 [55%] vs 204 [42%]) and blunt trauma mechanism (57 [81%] vs 277 [57%]) and lower median (IQR) Injury Severity Score (14 [5-29] vs 25 [16-36]). Propensity matching resulted in a weighted cohort of 207 children, including 68 of 70 recipients of PHT, and produced well-balanced groups. Both 24-hour (11 [16%] vs 38 [27%]) and in-hospital mortality (14 [21%] vs 44 [32%]) were lower in the PHT cohort compared with the EDT cohort, respectively; there was no difference in in-hospital complications. Mixed-effects logistic regression in the postmatched group adjusting for the confounders listed above found PHT was associated with a significant reduction in 24-hour (adjusted odds ratio, 0.46; 95% CI, 0.23-0.91) and in-hospital mortality (adjusted odds ratio, 0.51; 95% CI, 0.27-0.97) compared with EDT. The number needed to transfuse in the prehospital setting to save 1 child's life was 5 (95% CI, 3-10). In this study, prehospital transfusion was associated with lower rates of mortality compared with transfusion on arrival to the emergency department, suggesting bleeding pediatric patients may benefit from early hemostatic resuscitation. Further prospective studies are warranted. Although the logistics of prehospital blood product programs are complex, strategies to shift hemostatic resuscitation toward the immediate postinjury period should be pursued.

Current transfusion practice and need for new blood products to ensure blood supply for patients with major hemorrhage in Europe.

New blood products are considered for treatment of patients with major hemorrhage. The aim of this report is to describe the current transfusion practices in Europe for patients with major hemorrhage and explore the need for new or modified blood products to ensure prehospital and in-hospital blood supply. The European Blood Alliance (EBA) Working Group on Innovation and New Blood Products' subgroup on major hemorrhage performed a survey among the EBA member states. The response rate was 58% (17 responses from 15 of the 26 EBA member states). Of these, sixteen (94%) provide massive transfusion packages (MTPs) with balanced ratio of red blood cells and plasma. Seven of the respondents included platelets from the start of treatment. Eleven (65%) provide prehospital blood products, mainly red cell concentrates or dried and/or thawed plasma with 5 days of extended storage. Two countries provide prehospital whole blood. Twelve respondents (71%) saw a need for implementation of new or modified blood components in their institution. The top three priorities were whole blood (12 of 12, 100%), dried plasma (8 of 12, 67%), and cold-stored platelets (7 of 12, 58%). Current national guidelines for use of blood products in patients with major hemorrhage in Europe agree on the use of balanced transfusion, however the timing and source of platelets differ. Blood products for prehospital transfusion are available in several European countries. An interest in new or modified blood products for patients with major hemorrhage was observed, especially for whole blood.

Pre-hospital blood products for hazardous area response team paramedics: A service evaluation to inform decisions on future practice

Aim To identify the number of incidents, over a 1-year period in a single UK Ambulance Service Trust, where patients attended by Hazardous Area Response Team (HART) paramedics where eligible to receive Pre-hospital Blood Products (PHBP) but did not due to the unavailability of a suitably trained clinician. Methods This was a Service Evaluation using a three-stage method of filtering data to reduce bias and improve accuracy when identifying eligible cases. These stages consisted of an initial data request, a peer review filtering stage and then finally an Expert Consensus Panel review of cases to determine whether PHBP should have been administered. Results The consensus group considered 14 cases that would have ‘Likely’ or ‘Certainly’ have received PHBP if a suitably trained clinician was available on scene. Twelve cases involved a traumatic cause whilst the remaining two were medical. Similarly, 12 cases involved patients with spontaneous circulation whilst two patients had no pulse. South Western Ambulance Service Foundation Trust (SWASFT) Bristol HART attended eight and Exeter HART six of these cases. Conclusion This study reveals that across the South West of England, there were a number of patients, being attended by HART, who may potentially benefit from PHBP but are not receiving this intervention due to the unavailability of a suitably trained clinician. This could be far more in the event of a multi or mass-casualty event. HART paramedic access to PHBPs would enable more patients to access a potentially lifesaving treatment and contribute to narrowing the care gap identified in the Manchester Arena Inquiry. The authors recommend that a local pilot trial is undertaken to explore whether a HART PHBP service is feasible, sustainable, cost-effective, appropriate, and safe.

Changing the Playing Field: A Prehospital Blood Product Pilot Project in Rural North Georgia.

In Georgia, the paramedic's scope of practice prohibited the initiation of blood products. Due to the rural landscape in Georgia, one region's Regional Trauma Advisory Committee (RTAC) advocated expanding the scope of practice for Georgia's paramedics to allow them to initiate blood products in the prehospital environment. This study evaluated the safety and feasibility of allowing paramedics to initiate blood products for hemorrhaging patients utilizing a regionally established prehospital blood pilot program. Approval was obtained from the state medical directors and the Office of EMS and Trauma. The project team addressed product selection, equipment, prehospital service selection, education, policies and procedures, monitoring, and performance improvement. Four EMS services were identified to participate. Liquid plasma was selected due to cost and availability. Equipment was secured for blood storage and temperature monitoring to ensure the hospital's blood bank could maintain standards for exchange. A transfusion guideline was created, an administrative policy was developed, and an education plan was developed. A process with the trauma center's blood bank was also instituted to minimize waste and reduce costs. The pilot project began in spring of 2020, and as of January 2023, there have been 100 field initiations and no adverse effects, demonstrating the safety of paramedics to initiate blood products in the field. A post-licensure skill for paramedics is now available in Georgia for the initiation of blood products. The repeatability of a similar project depends on the resources available, the stakeholder commitment, and the partnerships across disciplines.

The Effect of Prehospital Blood Transfusion on Patient Body Temperature from the Time of Emergency Medical Services Transfusion to Arrival at the Emergency Department.

Transfusion of blood products is life-saving and time-sensitive in the setting of acute blood-loss anemia, and is increasingly common in the emergency medical services (EMS) setting. Prehospital blood products are generally "cold-stored" at 4°C, then warmed with a portable fluid-warming system for the purpose of preventing the "lethal triad" of hypothermia, acidosis, and coagulopathy. This study aims to evaluate body temperature changes of EMS patients receiving packed red blood cells (PRBC) and/or fresh frozen plasma (FFP) when using the LifeWarmer Quantum Blood & Fluid Warming System (LifeWarmer, https://www.lifewarmer.com/). From 1 January 2020 to 31 August 2021, patients who qualified for and received PRBC and/or FFP were retrospectively reviewed. Body-temperature homeostasis pre- and post-transfusion were evaluated with attention given to those who arrived to the emergency department (ED) hypothermic (<36°C). For all 69 patients analyzed, the mean initial prehospital temperature (°C) was 36.5 ± 1.0, and the mean initial ED temperature was 36.7 ± 0.6, demonstrating no statically significant change in value pre- or post-transfusion (0.2 ± 0.8, p = .09). Shock index showed a statistically significant decrease following transfusion: 1.5 ± 0.5 to 0.9 ± 0.4 (p < .001). Use of the Quantum prevents the previously identified risk of hypothermia with respect to unwarmed prehospital transfusions. The data is favorable in that body temperature did not decrease in critically ill patients receiving cold-stored blood warmed during administration with the Quantum.

Pediatric traumatic hemorrhagic shock consensus conference recommendations.

Hemorrhagic shock in pediatric trauma patients remains a challenging yet preventable cause of death. There is little high-quality evidence available to guide specific aspects of hemorrhage control and specific resuscitation practices in this population. We sought to generate clinical recommendations, expert consensus, and good practice statements to aid providers in care for these difficult patients.The Pediatric Traumatic Hemorrhagic Shock Consensus Conference process included systematic reviews related to six subtopics and one consensus meeting. A panel of 16 consensus multidisciplinary committee members evaluated the literature related to 6 specific topics: (1) blood products and fluid resuscitation for hemostatic resuscitation, (2) utilization of prehospital blood products, (3) use of hemostatic adjuncts, (4) tourniquet use, (5) prehospital airway and blood pressure management, and (6) conventional coagulation tests or thromboelastography-guided resuscitation. A total of 21 recommendations are detailed in this article: 2 clinical recommendations, 14 expert consensus statements, and 5 good practice statements. The statement, the panel's voting outcome, and the rationale for each statement intend to give pediatric trauma providers the latest evidence and guidance to care for pediatric trauma patients experiencing hemorrhagic shock. With a broad multidisciplinary representation, the Pediatric Traumatic Hemorrhagic Shock Consensus Conference systematically evaluated the literature and developed clinical recommendations, expert consensus, and good practice statements concerning topics in traumatically injured pediatric patients with hemorrhagic shock.

Hypothermia in the Combat Trauma Population

Background The MARCH (Massive hemorrhage, Airway, Respirations, Circulation, and Hypothermia/Head injuries) algorithm taught to military medics includes interventions to prevent hypothermia. As possible sequelae from major trauma, hypothermia is associated with coagulopathy and lower survival. This paper sought to define hypothermia within our combat trauma population using an outcomes-based method, and determine clinical variables associated with hypothermia. Methods This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry focused on casualties who received prehospital care. A receiver operating curve was constructed and Youden’s index was used to define hypothermia within the predetermined population based on mortality risk. A multivariable regression model was used to identify associations. Results There were 23,243 encounters that met the inclusion criteria for this study with patients having received prehospital care and documentation of at least one emergency department temperature. An optimal threshold of 36.2° C was found to predict mortality; 3,159 casualties had temperatures below this threshold (14%). Survival to discharge was lower among casualties with hypothermia (91% versus 98%). Hypothermic casualties were less likely to undergo blanket application (38% versus 40%). However, they had higher proportions with Hypothermia Prevention and Management Kit application (11% versus 7%) and radiant warming (2% versus 1%). On multivariable regression modeling, none of the hypothermia interventions were associated with a decreased likelihood of hypothermia. Non-hypothermia interventions associated with hypothermia included prehospital intubation (OR 1.57, 95% CI 1.45–1.69) and blood product administration. Conclusions Hypothermia, including a single recorded low temperature in the patient care record, was associated with worse outcomes in this combat trauma population. Prehospital intubation was most strongly associated with developing hypothermia. Prehospital warming interventions were not associated with a reduction in hypothermia risk. Our dataset suggests that current methods for prehospital warming are inadequate.

Pre-hospital blood products and calcium replacement protocols in UK critical care services: A survey of current practice

IntroductionIn the United Kingdom, prehospital blood products are increasingly carried for the early resuscitation of hypovolaemia in patients who are shocked or in cardiac arrest. There is an association between hypocalcaemia and mortality in trauma patients, but no current national guidelines on the timing or dose of calcium replacement exist. The objective of this study was to establish the availability of prehospital blood products, and the current calcium replacement protocols used by UK prehospital services. MethodsA cross sectional survey of all UK air ambulances and additional prehospital critical care organisations was conducted in April-May 2022 via an on-line questionnaire. The survey asked 11 questions about availability of prehospital blood products, calcium replacement for patients requiring prehospital blood products, and the use of point of care testing. ResultsThere was a 100% response rate with 20/22 UK air ambulances carrying blood products and five additional prehospital services identified. There were 15 different combinations of prehospital blood products. 23/25 services had a standard operating procedure for the replacement of calcium. This was recommended before any blood product administration in 5 services (22%), during or after the 1st unit in 5 services (22%), during or after the 2nd unit in 6 services (26%) and during or after the 4th unit in 7 services (30%). Only six services carried point of care testing and no services routinely used this to measure calcium levels in patients requiring prehospital blood products. ConclusionIn 2022, 91% of UK air ambulances carry prehospital blood products and there is significant variation between services in the combination of blood products provided. There is no consensus on the timing or dose of calcium replacement. Further prospective research should examine the association between traumatic bleeding and ionized calcium levels before and during blood product transfusion in order to produce more robust guidelines for routine calcium replacement.

Prehospital plasma is associated with survival principally in patients transferred from the scene of injury: A secondary analysis of the PAMPer trial

BackgroundWe sought to characterize if prehospital transfer origin from the scene of injury (SCENE) or from a referral emergency department (REF) alters the survival benefit attributable to prehospital plasma resuscitation in patients at risk of hemorrhagic shock. MethodsWe performed a secondary analysis of data from a recently completed prehospital plasma clinical trial. All of the enrolled patients from either the SCENE or REF groups were included. The demographics, injury characteristics, shock severity and resuscitation needs were compared. The primary outcome was a 30-day mortality. Kaplan-Meier analysis and Cox-hazard regression were used to characterize the independent survival benefits of prehospital plasma for transport origin groups. ResultsOf the 501 enrolled patients, the REF group patients (n = 111) accounted for 22% with the remaining (n = 390) originating from the scene. The SCENE group patients had higher injury severity and were more likely intubated prehospital. The REF group patients had longer prehospital times and received greater prehospital crystalloid and blood products. Kaplan-Meier analysis revealed a significant 30-day survival benefit associated with prehospital plasma in the SCENE group (P < .01) with no difference found in the REF group patients (P = .36). The Cox-regression verified after controlling for relevant confounders that prehospital plasma was independently associated with a 30-day survival in the SCENE group patients (hazard ratio 0.59; 95% confidence interval 0.39–0.89; P = .01) with no significant relationship found in the REF group patients (hazard ratio 1.03, 95% confidence interval 0.4–3.0). ConclusionImportant differences across the SCENE and REF cohorts exist that are essential to understand when planning prehospital studies. Prehospital plasma is associated with a survival benefit primarily in SCENE group patients. The results are exploratory but suggest transfer origin may be an important determinant of prehospital plasma benefit.

Nationwide estimates of the need for prehospital blood products after injury.

Prehospital blood product resuscitation after injury significantly decreases risk of mortality. However, the number of patients who may potentially benefit from this life-saving intervention is currently unknown. The primary objective of this study was to estimate the number of patients who may potentially benefit from prehospital blood product resuscitation after injury in the United States. The secondary objective was to estimate the amount of blood products needed for prehospital resuscitation of injured patients. Patients ≥16 years with blunt/penetrating injuries included in National Emergency Medical Services Information System 2019 were identified and classified into four separate cohorts of hemodynamic instability: Cohort 1 (systolic blood pressure [SBP] <90 mmHg), Cohort 2 (SBP <90 and/or heart rate [HR] >120), Cohort 3 (SBP <90 and HR >108 or SBP <70), and Cohort 4 (shock index ≥1). The need for prehospital blood was estimated by multiplying number of patients in each cohort with average number of blood products used for prehospital resuscitation. After exclusions, 3.7 million adult trauma patients were included. The number of patients who may potentially benefit from prehospital blood products was estimated as 89,391 (Cohort 1), 901,346 (Cohort 2), 54,160 (Cohort 3), and 300,475 (Cohort 4). Assuming 1 unit of whole blood is needed per patient, a lower-bound estimate of 54,160 additional whole blood units (0.6% of current collections) will be need for prehospital resuscitation of the injured. Annually, between 54,000 and 900,000 patients may potentially benefit from prehospital blood product resuscitation after injury in the United States. Prehospital blood utilization and collection of blood products will need to be increased to scale-up this life-saving intervention nationwide.

Initial experiences of prehospital blood product transfusions between 2016 and 2020 in Päijät-Häme hospital district, Finland

BackgroundTreating hemorrhaging patients with prehospital blood product transfusions (PHBT) narrows transfusion delays and potentially benefits the patient. We describe our initial experiences of PHBT in a ground-based emergency medical service (EMS), where the transfusion protocol covers both traumatic and nontraumatic hemorrhaging patients.MethodsA descriptive retrospective analysis was performed on the records of all the patients receiving red blood cells, freeze-dried plasma, or both during prehospital care from September 2016 to December 2020. The delays of PHBT and the effects on patients’ vital signs were analyzed and reported as the median and interquartile range (IQR) and analyzed using a Wilcoxon Signed rank test.Results65 patients received prehospital blood product transfusions (PHBT), 29 (45%) were non-traumatic, and 36 (55%) traumatic. The main two reasons for PHBT were blunt trauma (n = 30, 46%) and gastrointestinal hemorrhage (n = 20, 31%). The median time from the emergency call to the start of PHBT was 54 min (IQR 38), and the transfusion began on a median of 61 min (IQR 42) before arrival at the hospital. The median systolic blood pressure improved from a median 76.5 mmHg (IQR 36.5) before transfusion to a median of 116.60 mmHg (IQR 26.5) (p < 0.001) on arrival to the hospital. No transfusion-related severe adverse events were noted.ConclusionsStarting PHBT in ground-based EMS is a feasible and viable option. The PHBT began significantly earlier than it would have started on arrival to the hospital, and it seems to be safe and improve patients’ physiology.Study approvalD/2603/07.01.04.05/2019.