A review and analysis of outcomes in randomized clinical trials of plasma transfusion in patients with bleeding or for the prevention of bleeding: The BEST collaborative study.

BACKGROUND: Previous systematic reviews have revealed an inconsistency of outcome definitions as a major barrier in providing evidence-based guidance for the use of plasma transfusion to prevent or treat bleeding. We reviewed and analyzed outcomes in randomized controlled trials (RCTs) to provide a methodology for describing and classifying outcomes. STUDY DESIGN AND METHODS: RCTs involving transfusion of plasma published after 2000 were identified from a prior review (Yang 2012) and combined with an updated systematic literature search of multiple databases (July 1, 2011 to January 17, 2023). Inclusion of publications, data extraction, and risk of bias assessments were performed in duplicate. (PROSPERO registration number is: CRD42020158581). RESULTS: In total, 5579 citations were identified in the new systematic search and 22 were included. Six additional trials were identified from the previous review, resulting in a total of 28 trials: 23 therapeutic and five prophylactic studies. An increasing number of studies in the setting of major bleeding such as in cardiovascular surgery and trauma were identified. Eighty-seven outcomes were reported with a mean of 11 (min-max. 4-32) per study. There was substantial variation in outcomes used with a preponderance of surrogate measures for clinical effect such as laboratory parameters and blood usage. CONCLUSION: There is an expanding literature on plasma transfusion to inform guidelines. However, considerable heterogeneity of reported outcomes constrains comparisons. A core outcome set should be developed for plasma transfusion studies. Standardization of outcomes will motivate better study design, facilitate comparison, and improve clinical relevance for future trials of plasma transfusion.

Training of medical students in the use of emergency whole blood collection and transfusion in the framework of a civilian walking blood.

INTRODUCTION: In this report, we describe a training program in emergency whole blood collection and transfusion for medical students at the University of Bergen. The overall aim of the program is to improve the availability of early balanced blood transfusion for the treatment of patients with life-threatening bleeding in rural health care services. STUDY DESIGN AND METHODS: The voluntary training program provides the knowledge needed to practice emergency whole blood transfusions and understand the system for emergency whole blood collection in the framework of a civilian walking blood bank (WBB). It includes theoretical and practical sessions. In-person teaching and web-based learning resources are provided. An anonymous survey of the students attending the training course in the autumn of 2022 and spring 2023 was performed. RESULTS: 128 of 178 students participated in the practical training. 88 of 128 (69%) responded to the survey. 82 (93%) performed blood typing, 71 (81%) performed donor interviews, 61 (69%) partially performed whole blood collection (up to blood in bag) and 27 (30%) participated in complete whole blood collection and performed autologous reinfusion. No complications occurred during training. The students reported that the training course increased their understanding of how to ensure access to emergency blood transfusion by the use of a WBB. DISCUSSION: Structured theoretical and practical training in emergency whole blood collection and emergency transfusion is feasible and of interest to medical students. A multidisciplinary approach to student training in emergency whole blood collection and transfusion should be considered.

Cold-stored platelets for acute bleeding in cardiac surgical patients: a narrative review.

PURPOSE: Cold-stored platelets (CSP) are an increasingly active topic of international research. They are maintained at 1-6 °C, in contrast to standard room-temperature platelets (RTP) kept at 20-24 °C. Recent evidence suggests that CSP have superior hemostatic properties compared with RTP. This narrative review explores the application of CSP in adult cardiac surgery, summarizes the preclinical and clinical evidence for their use, and highlights recent research. SOURCE: A targeted search of MEDLINE and other databases up to 24 February 2022 was conducted. Search terms combined concepts such as cardiac surgery, blood, platelet, and cold-stored. Searches of trial registries ClinicalTrials.gov and WHO International Clinical Trials Registry Platform were included. Articles were included if they described adult surgical patients as their population of interest and an association between CSP and clinical outcomes. References of included articles were hand searched. PRINCIPAL FINDINGS: When platelets are stored at 1-6 °C, their metabolic rate is slowed, preserving hemostatic function for increased storage duration. Cold-stored platelets have superior adhesion characteristics under physiologic shear conditions, and similar or superior aggregation responses to physiologic agonists. Cold-stored platelets undergo structural, metabolic, and molecular changes which appear to "prime" them for hemostatic activity. While preliminary, clinical evidence supports the conduct of trials comparing CSP with RTP for patients with platelet-related bleeding, such as those undergoing cardiac surgery. CONCLUSION: Cold-stored platelets may have several advantages over RTP, including increased hemostatic capacity, extended shelf-life, and reduced risk of bacterial contamination. Large clinical trials are needed to establish their potential role in the treatment of acutely bleeding patients.

RéSUMé: OBJECTIF: Les plaquettes conservées au froid (PCF) sont un sujet de recherche internationale de plus en plus populaire. Ces plaquettes sont maintenues à une température de 1-6 °C, contrairement aux plaquettes standard conservées à température ambiante (PTA), maintenues à 20­24 °C. Des données probantes récentes suggèrent que les PCF ont des propriétés hémostatiques supérieures aux PTA. Ce compte rendu narratif explore l'application de PCF en chirurgie cardiaque chez l'adulte, résume les données probantes précliniques et cliniques de leur utilisation, et met en évidence les recherches récentes. SOURCES: Une recherche ciblée dans MEDLINE et d'autres bases de données jusqu'au 24 février 2022 a été effectuée. Les termes de recherche combinaient des concepts en anglais tels que cardiac surgery, blood, platelet et cold-stored (soit chirurgie cardiaque, plaquette, et entreposage frigorifique). Des recherches dans les registres d'études ClinicalTrials.gov et le système d'enregistrement international des essais cliniques (ICTRP) de l'OMS ont été incluses. Les articles ont été inclus s'ils décrivaient des patient·es adultes de chirurgie en tant que population d'intérêt et une association entre les PCF et les issues cliniques. Les références des articles inclus ont fait l'objet d'une recherche manuelle. CONSTATATIONS PRINCIPALES: Lorsque les plaquettes sont conservées entre 1 et 6 °C, leur taux métabolique est ralenti, préservant la fonction hémostatique pour une durée d'entreposage accrue. Les plaquettes conservées au froid ont des caractéristiques d'adhésion supérieures dans des conditions de cisaillement physiologique et des réponses d'agrégation similaires ou supérieures aux agonistes physiologiques. Les plaquettes conservées au froid subissent des changements structurels, métaboliques et moléculaires qui semblent les « amorcer ¼ pour une activité hémostatique. Bien que préliminaires, les données probantes cliniques appuient la réalisation d'études comparant les PCF aux PTA chez la patientèle présentant des saignements liés aux plaquettes, tels que les personnes bénéficiant d'une chirurgie cardiaque. CONCLUSION: Les plaquettes conservées au froid peuvent présenter plusieurs avantages par rapport aux PTA, notamment une capacité hémostatique accrue, une durée de conservation prolongée et un risque réduit de contamination bactérienne. De grands essais cliniques sont nécessaires pour établir leur rôle potentiel dans le traitement de la patientèle en hémorragie aiguë.

Implementation of a dual platelet inventory in a tertiary hospital during the COVID-19 pandemic enabling cold-stored apheresis platelets for treatment of actively bleeding patients.

BACKGROUND: To increase preparedness and mitigate the risk of platelet shortage without increasing the number of collections, we introduced a dual platelet inventory with cold-stored platelets (CSP) with 14-days shelf life for actively bleeding patients during the COVID-19 pandemic. STUDY DESIGN AND METHODS: We collected apheresis platelet concentrates with blood type O or A. All patients receiving CSP units were included in a quality registry. Efficacy was evaluated by total blood usage and laboratory analysis of platelet count, hemoglobin, and TEG 6s global hemostasis assay. Feasibility was evaluated by monitoring inventory and a survey among laboratory staff. RESULTS: From 17 March, 2020, to 31 December, 2021, we produced 276 CSP units and transfused 186 units to 92 patients. Main indication for transfusion was surgical bleeding (88%). No transfusion reactions were reported. 24-h post-transfusion patient survival was 96%. Total outdate in the study period was 33%. The majority (75%) of survey respondents answered that they had received sufficient information and training before CSP was implemented. Lack of information about bleeding status while issuing platelets, high workload, and separate storage location was described as main reasons for outdates. DISCUSSION: CSP with 14-days shelf life is a feasible alternative for the treatment of patients with bleeding. Implementation of a dual platelet inventory requires thorough planning, including information and training of clinical and laboratory staff, continuous follow-up of practice and patients, and an easy-to-follow algorithm for use of CSP units. A dual platelet inventory may mitigate the risk of platelet shortage during a pandemic situation.

In vitro quality and hemostatic function of cold-stored CPDA-1 whole blood after repeated transient exposure to 28°C storage temperature.

BACKGROUND: Blood products are frequently exposed to room temperature or higher for longer periods than permitted by policy. We aimed to investigate if this resulted in a measurable effect on common quality parameters and viscoelastic hemostatic function of cold stored CPDA-1 whole blood. STUDY DESIGN AND METHODS: 450 ml of whole blood from 16 O Rh(D) positive donors was collected in 63 ml of CPDA-1 and stored cold. Eights bags were exposed to five weekly 4-h long transient temperature changes to 28°C. Eight bags were stored continuously at 4°C as a control. Samples were collected at baseline on day 1, after the first cycle on day 1 and weekly before each subsequent cycle (day 7, 14, 21, 28 and 35). Hemolysis, hematological parameters, pH, glucose, lactate, potassium, thromboelastography, INR, APTT, fibrinogen, and factor VIII were measured. RESULTS: CPDA-1 whole blood repeatedly exposed to 28°C did not show reduced quality compared to the control group on day 35. Two units in the test group had hemolysis of 1.1% and 1.2%, and two in the control group hemolysis of 0.8%. Remaining thromboelastography clot strength (MA) on day 35 was 51.7 mm (44.8, 58.6) in the test group and 46.1 (41.6, 50.6) in the control group (p = .023). Platelet count was better preserved in the test group (166.7 [137.8, 195.6] vs. 117.8 [90.3, 145.2], p = .018). One sample in the test group was positive for Cutibacterium acnes on day 35 + 6. CONCLUSION: Hemolysis findings warrant further investigation. Other indicators of quality were not negatively affected.

Re-introducing whole blood for transfusion: considerations for blood providers.

Whole blood is the original blood preparation but disappeared from the blood bank inventories in the 1980s following the advent of component therapy. In the early 2000s, both military and civilian practice called for changes in the transfusion support for massive haemorrhage. The 'clear fluid' policy was abandoned and replaced by early balanced transfusion of platelets, plasma and red cells. Whole blood is an attractive alternative to multi-component therapy, which offers reduced hemodilution, lower donor exposure and simplified logistics. However, the potential for wider re-introduction of whole blood requires re-evaluation of haemolysins, storage conditions and shelf-life, the need for leucocyte depletion/ pathogen reduction and inventory management for blood providers. This review addresses these questions and calls for research to define the optimal whole blood product and the indications for its use.

How do I implement a whole blood-based blood preparedness program in a small rural hospital?

Civilian and military guidelines recommend balanced transfusion to patients with life-threatening bleeding. Early start of transfusion has shown improved survival. Thus, a balanced blood inventory must be available in all levels of health care to ensure early stabilization and damage control resuscitation of patients with bleeding. Whole blood has been reintroduced as a blood product for massive bleeding situations because it affords plasma, red blood cells, and platelets in a balanced ratio in a logistically advantageous way. In this article, we describe how to establish a whole blood-based blood preparedness program in a small rural hospital with limited resources. We present an implementation tool kit, which includes discussions on whole blood program strategies and the process of developing detailed procedures on donor selection, collection, storage, and transfusion management of whole blood. The importance of training and audit of the routines is highlighted, and establishment of an emergency walking blood bank is discussed. We conclude that implementation of a whole blood program is achievable in small rural hospitals and recommend that rural health care facilities at all treatment levels enable early balanced transfusion for patients with life-threatening bleeding by establishing protocols for whole blood-based preparedness.

Cold-stored leukoreduced CPDA-1 whole blood: in vitro quality and hemostatic properties.

BACKGROUND: Some jurisdictions require leukoreduction of cellular blood components. The only whole blood collection set with a platelet-saving filter uses citrate-phosphate-dextrose (CPD) as storage solution. Substituting CPD with citrate-phosphate-dextrose-adenine (CPDA-1) increases shelf life from 21 to 35 days. This would simplify prehospital and rural resupply and reduce wastage. We investigated in vitro quality and hemostatic properties of CPDA-1 whole blood leukoreduced with a platelet-saving filter. STUDY DESIGN AND METHODS: CPDA-1 whole blood was leukoreduced using a platelet-saving filter and stored 35 days. EDQM requirements, hematology, metabolic parameters, thromboelastography, light transmission aggregometry, fibrinogen, factor VIII, and interleukin-6 were measured on Days 0, 1, 14, 21, and 35 and compared to non-leukoreduced blood. RESULTS: All units met EDQM requirements. Leukoreduction yielded residual white blood cell count <1 × 106 and 87% platelet recovery on Day 1. It caused reduction in thromboelastography parameters, but not aggregometry response. No hemolysis >0.8% was observed. Factor VIII was higher on Day 35 in the leukoreduced group, 37.9 (95% CI: 26.0, 49.8) versus 13.8 (9.4, 18.2) IU/dL. In both groups, aggregation was significantly reduced by Day 14. Thromboelastography showed remaining platelet activity on Day 35, MA 46.9 (42.1, 51.7) in the leukoreduced and 44.3 (39.6, 49.0) mm in the non-leukoreduced group. Fibrinogen was within reference ranges at Day 35 (>2 g/dL). Interleukin-6 was not detectable. CONCLUSION: Leukoreducing CPDA-1 whole blood with a platelet-saving filter did not compromise hemostatic properties. We encourage development of a single bag CPDA-1 whole blood collection set with in-line platelet-saving filter.

Trends in platelet distributions from 2008 to 2017: a survey of twelve national and regional blood collectors.

BACKGROUND: This multi-national study evaluated changes in platelet (PLT) unit distributions at 12 national or regional blood collectors over a 10-year period. METHODS: Data on the total number of PLT distributions, the collection method, that is apheresis vs whole blood-derived (WBD), the PLT unit characteristics and post-collection modifications were obtained from 12 national or regional blood collectors from 2008 through 2017. Individual WBD PLT units were converted to apheresis equivalent units (i.e. a dose of PLTs) by dividing by 4, the typical pool size; WBD units that were pooled before distribution were counted as a single dose. RESULTS: Overall at these 12 blood collectors, the total number of PLTs distributed in 2008 was 1 373 200, which rose by 10·2% to 1 513 803 in 2017. The Japanese Red Cross, which distributes only apheresis PLTs, had a 13·4% increase in the number of distributions between the years 2008 and 2017, while the other 11 blood collectors combined demonstrated a 6·8% increase in distributions between these two years. Between the years 2008 and 2017, the changes in the proportion of apheresis, platelet-rich plasma and buffy coat PLT distributions were -29·9%, -70·7% and 80·0%, respectively. CONCLUSION: The number of PLT distributions increased during the 10-year study period despite prophylactic PLT transfusion thresholds having remained fairly consistent over the last decade. Perhaps this increase is in part driven by increased administration of platelets to patients with massive haemorrhage or an increase in stem cell transplantation. The use of buffy coat PLTs is increasing at these collectors.

Transfusion reactions: prevention, diagnosis, and treatment.

Blood transfusion is one of the most common procedures in patients in hospital so it is imperative that clinicians are knowledgeable about appropriate blood product administration, as well as the signs, symptoms, and management of transfusion reactions. In this Review, we, an international panel, provide a synopsis of the pathophysiology, treatment, and management of each diagnostic category of transfusion reaction using evidence-based recommendations whenever available.

An international investigation into O red blood cell unit administration in hospitals: the GRoup O Utilization Patterns (GROUP) study.

BACKGROUND: Transfusion of group O blood to non-O recipients, or transfusion of D- blood to D+ recipients, can result in shortages of group O or D- blood, respectively. This study investigated RBC utilization patterns at hospitals around the world and explored the context and policies that guide ABO blood group and D type selection practices. STUDY DESIGN AND METHODS: This was a retrospective study on transfusion data from the 2013 calendar year. This study included a survey component that asked about hospital RBC selection and transfusion practices and a data collection component where participants submitted information on RBC unit disposition including blood group and D type of unit and recipient. Units administered to recipients of unknown ABO or D group were excluded. RESULTS: Thirty-eight hospitals in 11 countries responded to the survey, 30 of which provided specific RBC unit disposition data. Overall, 11.1% (21,235/191,397) of group O units were transfused to non-O recipients; 22.6% (8777/38,911) of group O D- RBC units were transfused to O D+ recipients, and 43.2% (16,800/38,911) of group O D- RBC units were transfused to recipients that were not group O D-. Disposition of units and hospital transfusion policy varied within and across hospitals of different sizes, with transfusion of group O D- units to non-group O D- patients ranging from 0% to 33%. CONCLUSION: A significant proportion of group O and D- RBC units were transfused to compatible, nonidentical recipients, although the frequency of this practice varied across sites.

Detection of specific immunoglobulin E antibodies toward common airborne allergens, peanut, wheat, and latex in solvent/detergent-treated pooled plasma.

BACKGROUND: Allergic transfusion reactions (ATRs) present with a broad range of symptoms probably caused by mediators released from mast cells and basophil granulocytes upon activation. Passive immunoglobulin (Ig)E sensitization may yield clinical symptoms and positive allergy tests. Unexpected findings of IgE antibodies in pooled solvent/detergent (S/D)-treated plasma (Octaplas, Octapharma) during routine analysis initiated an investigation of serum proteins. STUDY DESIGN AND METHODS: Consecutive batches of S/D-plasma transfused during September 2014 through March 2015 were investigated for IgE, IgG, IgA IgM, C3, C4, haptoglobin, anti-nuclear antibodies (ANAs), and red blood cell (RBC) antibodies. RESULTS: During the study period, 4203 S/D-plasma units were transfused. Nineteen (14 Octaplas A and five Octaplas AB) of 20 batches of S/D-plasma were included, representing 99.9% of total number of plasma units. A total of 0.4% of units and five batches reported ATRs. Concentrations of total IgE higher than expected values in adults (<120 kU/L) were observed in 18 of the 19 (95%) batches investigated (median concentration [quartiles], 161 [133-183]). Specific IgE antibodies (expected < 0.35 kilounits antigen [kUA]/L) against house dust mite (2.52 [1.01-5.09]), timothy (2.83 [2.48-3.24]), cat (1.13 [0.58-1.52]), dog (0.83 [0.50-1.05]), mugwort (0.69 [0.53-0.97]), birch (0.62 [0.28-0.92]), peanut (0.52 [0.29-075]), wheat (0.46 [0.33-0.69]), and latex (0.32 [0.21-0.53]) were also detected. IgG, IgA, IgM, C3, C4, and haptoglobin were within or below normal ranges. No RBC antibodies were observed, but 18% of batches showed low levels of ANA (anti-RNP). CONCLUSION: Specific IgE antibodies against airborne allergens, food allergens, and latex were detected in S/D-treated pooled plasma.

Estimating the within-subject (CVI ) and between-subject (CVG ) biological variation of serum tryptase.

BACKGROUND: Tryptase is used as a biomarker to support the diagnosis of anaphylaxis and hematologic diseases. In the event of a mast cell activation during anaphylaxis, a temporary increase in the concentration of tryptase may be seen. On the basis of clinical studies, an increase of 2 µg/L + 20% from basis level has been proposed as significant. To evaluate the increase in tryptase levels, the within-subject (CVI ) and between-subject (CVG ) biological variations should be known. This study was conducted to estimate the biological variation of tryptase and to identify the reference change value (RCV). METHODS: Blood samples were collected from healthy volunteers once a week consecutively over a 10-week period. Tryptase was measured by the use of a fluoroenzyme immunoassay (ImmunoCAPTM ; Thermo Fisher Scientific), and linear mixed-effects models were used to calculate the biological variation and RCV for both nontransformed and log-transformed tryptase. RESULTS: Fourteen presumably healthy young adults (six males and eight females, age 23-35 years) were included. The CVI was 5.6% and the CVG was 31.5% (nontransformed data). Log-transformed data showed similar results. The analytical variation (CVA ) was 6.3% and the RCV was 23.5%. CONCLUSIONS: Young healthy adults without ongoing allergic reactions show low within-subject biological variation. Higher biological variation was observed between subjects.

Therapeutic efficacy of platelet transfusion in patients with acute leukemia: an evaluation of methods.

BACKGROUND: Clinical effect of platelet (PLT) transfusion is monitored by measures of PLT viability (PLT recovery and survival) and functionality. In this study we evaluate and compare transfusion effect measures in patients with chemotherapy-induced thrombocytopenia due to treatment of acute leukemia. STUDY DESIGN AND METHODS: Forty transfusions (28 conventional gamma-irradiated and 12 pathogen-inactivated photochemical-treated PLT concentrates [PCs]) were investigated. PC quality was analyzed immediately before transfusion. Samples were collected from thrombocytopenic patients at 1 and 24 hours for PLT increments and thromboelastography (TEG) with assessments of bleeding score and intertransfusion interval (ITI). Data were analyzed by Spearman's correlation. Patient and PC variables influencing the effect of transfusion were analyzed by use of a mixed-effects model. RESULTS: PLT dose, storage time, and pathogen inactivation correlated with PLT recovery but not with PLT survival (including ITI), TEG, or clinical bleeding. Fever was negatively correlated with PLT survival but did not affect PLT recovery. After 1 and 24 hours, strong correlations were observed within measures of PLT viability and between PLT increment and the TEG value maximal amplitude (MA). Negative correlation was observed between late MA increment and clinical bleeding status after transfusion (r = -0.494, p = 0.008). PLT count increments did not correlate to clinical bleeding status. CONCLUSIONS: PLT dose and quality of PCs are important for optimal immediate transfusion response, whereas duration of transfusion effect is influenced mainly by patient variables. The TEG value MA correlates with PLT count increments and bleeding, thus reflecting both PLT viability and functionality.

Effects of the COVID-19 pandemic on supply and use of blood for transfusion.

The COVID-19 pandemic has major implications for blood transfusion. There are uncertain patterns of demand, and transfusion institutions need to plan for reductions in donations and loss of crucial staff because of sickness and public health restrictions. We systematically searched for relevant studies addressing the transfusion chain-from donor, through collection and processing, to patients-to provide a synthesis of the published literature and guidance during times of potential or actual shortage. A reduction in donor numbers has largely been matched by reductions in demand for transfusion. Contingency planning includes prioritisation policies for patients in the event of predicted shortage. A range of strategies maintain ongoing equitable access to blood for transfusion during the pandemic, in addition to providing new therapies such as convalescent plasma. Sharing experience and developing expert consensus on the basis of evolving publications will help transfusion services and hospitals in countries at different stages in the pandemic.

Risk of Harm Associated With Using Rapid Sequence Induction Intubation and Positive Pressure Ventilation in Patients With Hemorrhagic Shock.

Based on limited published evidence, physiological principles, clinical experience, and expertise, the author group has developed a consensus statement on the potential for iatrogenic harm with rapid sequence induction (RSI) intubation and positive-pressure ventilation (PPV) on patients in hemorrhagic shock. "In hemorrhagic shock, or any low flow (central hypovolemic) state, it should be noted that RSI and PPV are likely to cause iatrogenic harm by decreasing cardiac output." The use of RSI and PPV leads to an increased burden of shock due to a decreased cardiac output (CO)2 which is one of the primary determinants of oxygen delivery (DO2). The diminishing DO2 creates a state of systemic hypoxia, the severity of which will determine the magnitude of the shock (shock dose) and a growing deficit of oxygen, referred to as oxygen debt. Rapid accumulation of critical levels of oxygen debt results in coagulopathy and organ dysfunction and failure. Spontaneous respiration induced negative intrathoracic pressure (ITP) provides the pressure differential driving venous return. PPV subsequently increases ITP and thus right atrial pressure. The loss in pressure differential directly decreases CO and DO2 with a resultant increase in systemic hypoxia. If RSI and PPV are deemed necessary, prior or parallel resuscitation with blood products is required to mitigate post intervention reduction of DO2 and the potential for inducing cardiac arrest in the critically shocked patient.

Multiple electrode aggregometry and thromboelastography in thrombocytopenic patients with haematological malignancies.

BACKGROUND: In thrombocytopenic patients better assessment of bleeding risk than that provided by platelet count alone is required. Multiplate® aggregometry and thromboelastography (TEG) could be used, but information on their role in such patients is limited. The primary aim of this study was to investigate the feasibility of Multiplate® analyses in patients with haematological malignancies. A secondary aim was to explore whether a multiple logistic regression model combining Multiplate®, TEG, clinical and laboratory variables was associated with risk of bleeding. MATERIALS AND METHODS: This was an exploratory, prospective observational study of thrombocytopenic patients with haematological malignancies. Total platelet count (TPC), white blood cell count, C-reactive protein (CRP) level, temperature and bleeding status were recorded daily. TEG and Multiplate® analyses with four agonists were performed on weekdays. RESULTS: Ten patients were enrolled into the study. The median number of days in a study period was 21. Bleeding was observed on 64 of 298 study days. TPC <20×109/L and <10×109/L occurred on 119 and 25 days, respectively. When TPC was <33×109/L, many samples showed no aggregation, regardless of bleeding status. Despite this, the odds of World Health Organization (WHO) grade 2 bleeding decreased significantly as aggregation increased and Multiplate® had a negative predictive value (NPV) of 96% and a positive predictive value (PPV) of 19% for significant bleeding. In the multiple logistic regression model collagen-activated Multiplate® aggregation, TEG angle, TEG reaction time and CRP significantly affected the odds of WHO grade 2 bleeding. The combined model had a NPV of 99% and a PPV of 19%. DISCUSSION: Our findings suggest that the markers of platelet function and haemostasis provided by Multiplate® aggregometry and TEG may add information to support prediction of bleeding, although platelet count still remains the most accessible analysis for routine testing.

Preparation of leukoreduced whole blood for transfusion in austere environments; effects of forced filtration, storage agitation, and high temperatures on hemostatic function.

BACKGROUND: Damage control resuscitation principles advocate the use of blood to treat traumatic hemorrhage. Hemorrhage is a leading cause of preventable death on the battlefield, but making blood components available far forward presents logistical challenges due to shelf life and storage requirements. Whole blood simplifies logistics and enables collection in the field but can cause leukocyte-related transfusion reactions. A field-adapted leukoreduction system must be fast and safe, and storage of whole blood should preserve hemostatic function. METHODS: Blood was collected using Imuflex WB-SP and leukoreduced at 0, 150, or 300 mm Hg. Additional bags were stored at 4°C for 21 days unagitated, mixed daily, agitated or head-over-heel rotated, at 22°C for 3 days, or 32°C for 2 hours. Hematology, coagulation, CD62P/CD42b, thromboelastography (TEG)/thromboelastometry (ROTEM), and Multiplate was performed. RESULTS: Filtration time was 35 ± 1, 14 ± 0, and 9 ± 0 minutes at 0, 150, and 300 mm Hg, respectively. One of 10 units at 150 mm Hg and 4 of 11 at 300 mm Hg had residual whole blood cells greater than 5.0 × 10 per unit. One of 11 at 300 mm Hg had platelet recovery of less than 80%. Hemolysis was less than 0.2%. Filtration decreased thromboelastography/thromboelastometry and Multiplate aggregation response. Stored at 4°C, α and MA/MCF moderately decreased regardless of mixing. Significant loss of aggregation response and increased CD62P expression was seen by Day 10. By Day 3, storage at 22°C caused loss of most aggregation. Two-hour storage at 32°C did not significantly affect hemostatic capacity. CONCLUSION: Forced filtration reduced leukoreduction time, but increased residual whole blood cells reduced hemostatic function. Aggregation response deteriorated early in storage, while viscoelastic assays decreased more gradually. Mixing showed no benefits. LEVEL OF EVIDENCE: Diagnostic study, level IV.

In vitro evaluation of platelet concentrates during storage: Platelet counts and markers of platelet destruction.

BACKGROUND: Differences in platelet counts are observed by use of automated haematology analyzers making interlaboratory comparison difficult. MATERIALS AND METHODS: Twenty-eight single-donor platelet concentrates (PCs) were collected. Platelet concentration and markers of platelet destruction were investigated during storage for 11/12 days. RESULTS: Increasing impedance-immunoplatelet ratio was observed during storage, correlating to platelet fragments, large platelets, platelet density and cell-lysis. High variability was observed for optical-immunoplatelet ratio. CONCLUSION: Immunoplatelet count or correction factor calculated by impedance-immunoplatelet ratio should be used to confirm that platelet unit meets platelet count requirements or to compare results from clinical trials. Optical platelet count is not recommended.

Coagulation function of stored whole blood is preserved for 14 days in austere conditions: A ROTEM feasibility study during a Norwegian antipiracy mission and comparison to equal ratio reconstituted blood.

BACKGROUND: Formulation of a medical preparedness plan for treating severely bleeding casualties during naval deployment is a significant challenge because of territory covered during most missions. The aim of this study was to evaluate the concept of "walking blood bank" as a supportable plan for supplying safe blood and blood products. METHODS: In 2013, the Royal Norwegian Navy conducted antipiracy operations from a frigate, beginning in the Gulf of Aden and ending in the Indian Ocean. Crews were on 24-hour emergency alert in preparation for an enemy assault on the frigate. Under an approved command protocol, a "walking blood bank," using crew blood donations, was established for use on board and on missions conducted in rigid-hulled inflatable boats, during which freeze-dried plasma and leukoreduced, group O low anti-A/anti-B titer, cold-stored whole blood were stored in Golden Hour Boxes. Data demonstrating the ability to collect, store, and provide whole blood were collected to establish feasibility of implementing a whole blood-focused remote damage-control resuscitation program aboard a naval vessel. In addition, ROTEM data were collected to demonstrate feasibility of performing this analysis on a large naval vessel and to also measure hemostatic efficacy of cold-stored leukoreduced whole blood (CWB) stored during a period of 14 days. ROTEM data on CWB was compared with reconstituted whole blood. RESULTS: Drills simulating massive transfusion activation were conducted, in which 2 U of warm fresh whole blood with platelet sparing leukoreduction were produced in 40 minutes, followed by collection of two additional units at 15-minute increments. The ROTEM machine performed well during ship-rolling, as shown by the overlapping calculated and measured mechanical piston movements measured by the ROTEM device. Error messages were recorded in 4 (1.5%) of 267 tests. CWB yielded reproducible ROTEM results demonstrating preserved fibrinogen function and platelet function for at least 3.5 weeks and 2 weeks, respectively. The frequency of ROTEM tests were as follows: EXTEM (n = 88), INTEM (n = 85), FIBTEM (n = 82), and APTEM (n = 12). CWB results were grouped. Compared with Days 0 to 2, EXTEM maximum clot firmness was significantly reduced, beginning on Days 10 to 14; however, results through that date remained within reference ranges and were comparable with the EXTEM maximum clot firmness for the reconstituted whole blood samples containing Day 5 room temperature-stored platelets. CONCLUSION: A "walking blood bank" can provide a balanced transfusion product to support damage-control resuscitation/remote damage-control resuscitation aboard a frigate in the absence of conventional blood bank products. ROTEM analysis is feasible to monitor damage-control resuscitation and blood product quality. ROTEM analysis was possible in challenging operational conditions. LEVEL OF EVIDENCE: Therapeutic study, level V.