Limitations of Available Blood Products for Massive Transfusion During Mass Casualty Events at US Level 1 Trauma Centers

INTRODUCTION

Exsanguination remains a leading cause of preventable death in traumatically injured patients. To better treat hemorrhagic shock, hospitals have adopted massive transfusion protocols (MTPs) which accelerate the delivery of blood products to patients. There has been an increase in mass casualty events (MCE) worldwide over the past two decades. These events can overwhelm a responding hospital's supply of blood products. Using a computerized model, this study investigated the ability of US trauma centers (TCs) to meet the blood product requirements of MCEs.

METHODS

Cross-sectional survey data of on-hand blood products were collected from 16 US level-1 TCs. A discrete event simulation model of a TC was developed based on historic data of blood product consumption during MCEs. Each hospital's blood bank was evaluated across increasingly more demanding MCEs using modern MTPs to guide resuscitation efforts in massive transfusion (MT) patients.

RESULTS

A total of 9,000 simulations were performed on each TC's data. Under the least demanding MCE scenario, the median size MCE in which TCs failed to adequately meet blood product demand was 50 patients (IQR 20-90), considering platelets. Ten TCs exhaust their supply of platelets prior to red blood cells (RBCs) or plasma. Disregarding platelets, five TCs exhausted their supply of O- packed RBCs, six exhausted their AB plasma supply, and five had a mixed exhaustion picture.

CONCLUSION

Assuming a TC's ability to treat patients is limited only by their supply of blood products, US level-1 TCs lack the on-hand blood products required to adequately treat patients following a MCE. Use of non-traditional blood products, which have a longer shelf life, may allow TCs to better meet the blood product requirement needs of patients following larger MCEs.

Platelet to erythrocyte transfusion ratio and mortality in massively transfused trauma patients. A systematic review and meta-analysis

BACKGROUND

Platelet transfusion during major hemorrhage is important and often embedded in massive transfusion protocols. However, the optimal ratio of platelets to erythrocytes (platelet-rich plasma [PLT]/red blood cell [RBC] ratio) remains unclear. We hypothesized that high PLT/RBC ratios, as compared with low PLT/RBC ratios, are associated with improved survival in patients requiring massive transfusion.

METHODS

Four databases (Pubmed, CINAHL, EMBASE, and Cochrane) were systematically screened for literatures published until January 21, 2021, to determine the effect of PLT/RBC ratio on the primary outcome measure mortality at 1 hour to 6 hours and 24 hours and at 28 days to 30 days. Studies comparing various PLT/RBC ratios were included in the meta-analysis. Secondary outcomes included intensive care unit length of stay and in-hospital length of stay and total blood component use. The study protocol was registered in PROSPERO under number CRD42020165648.

RESULTS

The search identified a total of 8903 records. After removing the duplicates and second screening of title, abstract, and full text, a total of 59 articles were included in the analysis. Of these articles, 12 were included in the meta-analysis. Mortality at 1 hour to 6 hours, 24 hours, and 28 days to 30 days was significantly lower for high PLT/RBC ratios as compared with low PLT/RBC ratios.

CONCLUSION

Higher PLT/RBC ratios are associated with significantly lower 1-hour to 6-hour, 24-hour, 28-day to 30-day mortalities as compared with lower PLT/RBC ratios. The optimal PLT/RBC ratio for massive transfusion in trauma patients is approximately 1:1.

LEVEL OF EVIDENCE

Systematic review and meta-analysis, therapeutic Level III.

Blood product needs and transfusion timelines for the multisite massive Paris 2015 terrorist attack: A retrospective analysis

OBJECTIVE

Hemorrhage is the leading cause of death after terrorist attack, and the immediacy of labile blood product (LBP) administration has a decisive impact on patients' outcome. The main objective of this study was to evaluate the transfusion patterns of the Paris terrorist attack victims, November 13, 2015.

METHODS

We performed a retrospective analysis including all casualties admitted to hospital, aiming to describe the transfusion patterns from admission to the first week after the attack.

RESULTS

Sixty-eight of 337 admitted patients were transfused. More than three quarters of blood products were consumed in the initial phase (until November 14, 11:59 PM), where 282 packed red blood cell (pRBC) units were transfused along with 201 plasma and 25 platelet units, to 55 patients (16% of casualties). Almost 40% of these LBPs (134 pRBC, 73 plasma, 8 platelet units) were transfused within the first 6 hours after the attack. These early transfusions were massive transfusion (MT) for 20 (6%) of 337 patients, and the average plasma/red blood cell ratio was 0.8 for MT patients who received 366 (72%) of 508 LBPs.The median time from admission to pRBC transfusion was 57 (25-108) minutes and 208 (52-430) minutes for MT and non-MT patients, respectively. These same time intervals were 119 (66-202) minutes and 222 (87-381) minutes for plasma and 225 (131-289) minutes and 198 (167-230) minutes for platelets.

CONCLUSION

Our data suggest that improving transfusion procedures in mass casualty setting should rely more on shortening the time to bring LBP to the bedside than in increasing the stockpile.

LEVEL OF EVIDENCE

Epidemiological study, Therapeutic IV.

Exploring Peaks in Hospital Blood Component Utilization: A 10-Year Retrospective Study at a Large Multisite Academic Centre

Peak demand analysis is common in industries such as the energy sector, but can also be applied to the field of transfusion to characterize the nature and timing of peak days in hospital blood utilization. This information can be used to forecast future peak days or to inform hospital emergency preparedness plans. The aims of this study are to characterize peak days in red blood cell (RBC) utilization over the past 10 years at our hospital, and to compare RBC peaks with peaks in platelet, plasma, and cryoprecipitate utilization. This was a retrospective cohort study of RBC, platelet, plasma, and cryoprecipitate transfusions in the inpatient and emergency department setting between May 2009 and April 2019 at a large academic hospital, containing regional trauma and cardiovascular surgery centers. For each blood product, a peak in utilization was defined as a day with a ≥50% increase in the number of units transfused compared to the previous 90-day average. Descriptive and inferential analyses were performed to characterize peak days. There were on average 20,501 RBCs transfused per year and 56 RBCs transfused per day over the 10-year period. A total of 134 peaks in RBC utilization occurred over the study period, with an average of 14 peaks per year. RBC peak days required on average 69% more RBC units compared to nonpeak days (P< .0001). 77% of RBC peaks were caused either solely or in part by surgical bleeding, 34% were caused entirely or in part by trauma, and other causes were infrequent. RBC peaks occurred most often on Fridays and least often on weekends (P< .0001). While there were 134 RBC peaks over the study period, there was a larger number of platelet (n = 292), plasma (n = 467), and cryoprecipitate peaks (n = 579). RBC peak days often coincided with plasma peak days, but less frequently with platelet and cryoprecipitate peaks. More studies are needed to determine whether analysis of peak usage will be of value to hospital blood banks for emergency planning and blood inventory management.

Blood transfusions in mass casualty events: recent trends

BACKGROUND AND OBJECTIVES

The US AABB disaster task force recommends estimating 3 RBC units per admission (UPA) for mass casualty events (MCEs). In a previous analysis, median MCE UPA were 2·7 RBCs, 1·2 plasmas and 0·27 platelet doses (Vox Sang 2017; 112:648). Additional recent data were sought from the current era of balanced massive transfusion protocols (bMTPs).

MATERIALS AND METHODS

Publications in English from 1980 to 2020 were reviewed for MCEs using ≥50 RBCs/event and with numbers of admissions available. MCE reports were stratified by era and event-wide or trauma-centre source. The bMTP era included all MCEs since 2010 plus a 2008 bMTP military report.

STATISTICS

Mann-Whitney test.

RESULTS

Thirty-two MCEs met analysis criteria. Event-wide reports used medians [interquartile ranges] of 1·8 [1·2-3·9] RBC, 0·6 [0·3-0·9] plasma and 0·14 [0·06-0·26] platelet-dose UPA. Trauma centres transfused 3·4 [2·7-6·3] RBC, 2·4 [1·3-4·1] plasma and 0·41 [0·34-0·50] platelet-dose UPA, all P < 0·05 vs event-wide. Same-event median post-day-1 transfusions were 50% of day-1 use for RBC, 28% for plasma and 16% for platelets. Compared to prior years, the median plasma/RBC transfusion ratio rose from 0·28 to 0·67 in the bMTP era (P < 0·01). In recent mass shootings, trauma centres transfused up to 42 platelets (range 0·45-0·57 UPA) on day 1.

CONCLUSION

Based on available mass casualty data, we recommend planning for 3 RBC, 1 plasma and one-fourth platelet-dose units per admission for blood centres (event-wide), and 6, 4 and one-half UPA, respectively, for trauma centres, which have seen rising plasma usage and large mass-shooting platelet needs.

Blood bank preparedness for mass casualty incidents and disasters: a pilot study in the Piedmont region, Italy

BACKGROUND AND OBJECTIVES

Blood is a critical resource for responding to mass casualty incidents (MCI). The main framework for transfusion preparedness is the American Association of Blood Bank (AABB) Disaster Operation Handbook. A disaster preparedness plan for co-ordinated blood supply was issued in Italy in 2016.

AIM

To assess the level of preparedness of the Transfusion Centers (TS) in the Piedmont region, to evaluate the applicability of AABB checklist and to evaluate the application of the Italian plan.

MATERIALS AND METHODS

We surveyed all the Regional Transfusion Centers (TS) using the AABB checklist, addressing 74 priority action items grouped according to 16 preparedness domains. The Italian 2016 plan has been considered the regulatory cut-off and hospitals were stratified based on the type and the TS workload. A principal component analysis (PCA) was conducted to summarize the variance among centres.

RESULTS

Twenty-one out of 25 TS agreed to participate. Eighty-one % were at high and 18% were at medium level of preparedness. All but two centres were above the cut-off determined by the Italian law. A significant better preparedness was found in medium size hospitals compared to bigger and smaller hospitals. Other than that, the different TS showed a quite homogeneous distribution of preparedness variance.

CONCLUSIONS

This study demonstrated a good level of preparedness in the Piemonte TS, above the Italian law requirements in the majority of TS. The AABB checklist could be used to highlight gaps and needs in the regional TS networks in case of emergency crisis.

Single cell analysis of aged RBCs: quantitative analysis of the aged cells and byproducts

This study initially focused on characterizing the aging process of red blood cells by correlating the loss of hemoglobin and the translocation of phosphatidylserine (PS) in expired human red blood cells, hRBCs. Five pre-storage, leukoreduced hRBC units in AS-5 solution were stored between 1 and 6 °C for 42 days. Aliquots from each of these units were stained with Annexin-V FLUOS, which binds to externalized PS, and the hemoglobin within the cells was placed in a methemoglobin state with sodium nitrite, metHb. These aliquots were subsequently sorted into four sub-populations, ranging from no PS expression to high PS expression using a BD FACS ARIAIII. Each of these sub-fractions were introduced into the cell tracking velocimetry apparatus which measured both the magnetically-induced and the gravity-induced velocity. Subsequently, the samples were removed from the cell tracking velocimetry instrument and characterized using the Multisizer 4e Coulter Counter. From the magnetically-induced velocity, the amount of hemoglobin, in pg Hb per cell can be determined, and using an average value of the density of RBCs, the size can be determined. For the PS negative sub-fraction of RBCs, the size of the RBC was as expected but the average hemoglobin, Hb, content was below the threshold which defines anemia. In contrast, unexpected results were observed with the various levels of expression of PS. First, virtually all of the PS expressing cells were significantly smaller, on the order of 1 micron, than a normal RBC after 42 days of storage; yet the density of these small cells/microvesicles was such that they had settling velocities similar to normal-sized RBCs. Further, while the total amount of Hb per small cell/microvesicle was only approximately 25% of the full-sized RBCs, the volume of these small cells/microvesicles is only 1/200 of the PS negative RBCs. This suggests that these PS expressing cells are shrunken RBCs, or shrunken microvesicles from RBCs that concentrated the Hb internally. These results suggest not only a relationship between the loss of hemoglobin and the amount of PS exposed on the cellular outer wall, but also a mechanism by which these aged RBCs break down. It is not known at this time whether this is an artifact of storage or similar mechanisms occur in circulation within the human body.

Traumatic coagulopathy and massive transfusion: improving outcomes and saving blood

Introduction

Dysfunction of the coagulation system, termed trauma-induced coagulopathy (TIC), is a major problem in patients who bleed after injury. Trauma haemorrhage is considered one of the leading preventable causes of death worldwide. Deaths occur early and, despite the presence of trauma teams and large transfusions of blood products, outcomes remain poor.

Methods

We conducted a multimodal programme of work to develop our understanding of coagulopathy and its optimal management. We studied the epidemiology, management and health economics of trauma haemorrhage, including the provision of care during mass casualty events. We combined systematic reviews of the literature with a national study of trauma haemorrhage, its transfusion management and associated health-care costs. We further examined several point-of-care coagulation tools for their ability to diagnose coagulopathy and assess the response to blood component therapy. We progressively implemented our findings into practice and assessed the outcomes of trauma patients presenting to our major trauma centre. To examine different approaches to the provision of blood to casualties in a mass casualty event, we constructed a discrete event model based on data from the 2005 London bombings.

Key results

Our systematic reviews found little strong evidence for the existing diagnostic tools or the practice of delivery of blood components in trauma haemorrhage. Our national study recruited 442 patients in 22 hospitals and found that the 1-year mortality rate for massive haemorrhage approached 50%. Half of these deaths occurred in the first 24 hours after injury and half of these occurred in the first 4 hours. We identified this early time window as a period when the provision of blood component therapy was often below the recommended thresholds and blood component therapy was delivered inconsistently. Studying early TIC we determined that loss of fibrinogen and excessive fibrinolysis were key derangements. We were able to determine that rotational thromboelastometry could identify early coagulopathy within 5 minutes, a large improvement on laboratory tests. We were further able to show how existing damage control resuscitation regimens with high-dose plasma do not maintain haemostatic competency during haemorrhage. In total, the estimated cost of treating a major haemorrhage patient was £20,600 and the estimated cost of treating a massive haemorrhage patient was £24,000. Nationally, the estimated cost of trauma haemorrhage is £85M annually. In mass casualty situations, early results show that the only mutable factor that affects the provision of care to a large degree, in the initial phase of the response, is the level of blood stocks held in the receiving hospital.

Conclusions

This multimodal programme of work has led to new understandings of the epidemiology of trauma haemorrhage and its underlying mechanisms and clinical course. We have defined diagnostic tools and trigger thresholds for identification and management and increased our understanding of how blood component and other therapeutics affect coagulopathy and when they are likely to be most effective. This diagnostic work has been taken forward at an international level to produce new personalised guidelines for the management of trauma haemorrhage. The findings have had important therapeutic implications, which have led to important changes in practice that have been incorporated into new national and international guidelines.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Blood component transfusions in mass casualty events

BACKGROUND AND OBJECTIVES

Planning transfusion needs in mass casualty events (MCE) is critical for disaster preparedness. Published data on blood component usage were analysed to seek correlative factors and usage rates.

MATERIALS AND METHODS

English-language medical publications since 1980 were searched for MCEs with numbers of patient admissions and transfused RBCs. Reports were excluded from natural disasters or with total RBC use <50 units. Statistical analysis employed Mann-Whitney U-tests and Spearman's rank correlations.

RESULTS

In 24 reports, the average units per admission were 3·06 RBCs, 2·13 plasmas and 0·37 platelet doses. Five RBCs per admission would have sufficed for 87% of events. Transfusion needs involving bombings correlated with admissions (P ≤ 0·03). In the formula (massive-transfusion patients in MCE) times X = (total units for all MCE patients), the average X was 35 for RBCs (correlation P = 0·01), 17 for plasma (P = 0·10) and five for platelet doses (P = 0·06). From 67% to 84% of all components used were given in the first 24 h (event medians).

CONCLUSIONS

Blood component use in MCEs correlated with numbers of patients admitted or receiving massive transfusion. More current data are needed to better reflect emerging trauma care practices and refine predictive models of transfusion needs.

Managing the surge in demand for blood following mass casualty events: Early automatic restocking may preserve red cell supply

BACKGROUND

Traumatic hemorrhage is a leading preventable cause of mortality following mass casualty events (MCEs). Improving outcomes requires adequate in-hospital provision of high-volume red blood cell (RBC) transfusions. This study investigated strategies for optimizing RBC provision to casualties in MCEs using simulation modeling.

METHODS

A computerized simulation model of a UK major trauma center (TC) transfusion system was developed. The model used input data from past MCEs and civilian and military trauma registries. We simulated the effect of varying on-shelf RBC stock hold and the timing of externally restocking RBC supplies on TC treatment capacity across increasing loads of priority one (P1) and two (P2) casualties from an event.

RESULTS

Thirty-five thousand simulations were performed. A casualty load of 20 P1s and P2s under standard TC RBC stock conditions left 35% (95% confidence interval, 32-38%) of P1s and 7% (4-10%) of P2s inadequately treated for hemorrhage. Additionally, exhaustion of type O emergency RBC stocks (a surrogate for reaching surge capacity) occurred in a median of 10 hours (IQR, 5 to >12 hours). Doubling casualty load increased this to 60% (57-63%) and 30% (26-34%), respectively, with capacity reached in 2 hours (1-3 hours). The model identified a minimum requirement of 12 U of on-shelf RBCs per P1/P2 casualty received to prevent surge capacity being reached. Restocking supplies in an MCE versus greater permanent on-shelf RBC stock holds was considered at increasing hourly intervals. T-test analysis showed no difference between stock hold versus supply restocking with regard to overall outcomes for MCEs up to 80 P1s and P2s in size (p < 0.05), provided the restock occurred within 6 hours.

CONCLUSION

Even limited-sized MCEs threaten to overwhelm TC transfusion systems. An early-automated push approach to restocking RBCs initiated by central suppliers can produce equivocal outcomes compared with holding excess stock permanently at TCs.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.

Profiling clinical platelet and plasma use to inform blood supply and contingency planning: PUPPY, the prospective utilization of platelets and plasma study

BACKGROUND

Demand for platelet (PLT) and plasma transfusions is increasing. Improved clinical supply and contingency planning requires greater understanding of usage profiles and urgency of clinical requirement.

STUDY DESIGN AND METHODS

This study was a random-sample survey of PLT and plasma units produced in Victoria, Australia, to determine product disposition, recipient demographics, clinical indications for transfusion, and urgency (or "deferability") of need. PLTs and fresh-frozen plasma (FFP) were tagged with a case report form before distribution.

RESULTS

A total of 1252 PLT and 1837 FFP units were tagged, comprising 8.3 and 13.3% of all products issued during the study period. The fate of 1243 PLT and 1808 FFP units was determined. Of products issued, 72.2% of PLTs and 87.8% of FFP were transfused. Hematologic and oncologic disorders accounted for 63.9% of PLT transfusions, with acute myeloid leukemia alone accounting for 26%. Conversely, surgical patients received the largest proportion of FFP (40.4%), predominantly for cardiothoracic, solid organ transplant, and vascular surgery. Approximately 15% of PLT transfusions and 35% of plasma transfusions were required within 1 hour, and 80% of PLT transfusions and 90% of FFP transfusions were required within 24 hours. Wastage rates were higher in regional blood banks.

CONCLUSION

The PUPPY study is a comprehensive and detailed population-based assessment of PLT and plasma usage, including urgency of use. It identifies specific clinical areas with high demand for PLT and FFP transfusion and demonstrates the high urgency of need for both products. These data inform clinical supply and contingency planning activities.

Going for gold: blood planning for the London 2012 Olympic Games

The Olympics is one of the largest sporting events in the world. Major events may be complicated by disruption of normal activity and major incidents. Health care and transfusion planners should be prepared for both. Previously, transfusion contingency planning has focused on seasonal blood shortages and pandemic influenzas. This article is the first published account of transfusion contingency planning for a major event. We describe the issues encountered and the lessons identified during transfusion planning for the London 2012 Olympics. Planning was started 18 months in advance and was led by a project team reporting to the Executive. Planning was based on three periods of Gamestime. The requirements were planned with key stakeholders using normal processes enhanced by service developments. Demand planning was based on literature review together with computer modelling. The aim was blood-stock sufficiency complimented by a high readiness donor panel to minimise waste. Plans were widely communicated and table-top exercised. Full transfusion services were maintained during both Games with all demands met. The new service improvements and high readiness donors worked well. Emergency command and control have been upgraded. Red cell concentrate (RCC) stock aged but wastage was not significantly increased. The key to success was: early planning, stakeholder engagement, service developments, integration of transfusion service planning within the wider health care community and conduct within an assurance framework.