Primary hemostatic capacity of whole blood: a comprehensive analysis of pathogen reduction and refrigeration effects over time

Blood component separation of pathogen-reduced whole blood by the PRP method produces acceptable red cells but platelet yields and function are diminished

BACKGROUND

This study evaluated blood components processed by the platelet rich plasma (PRP) method from fresh whole blood (FWB) treated with a pathogen reduction technology (PRT). The effects of storage temperature on PRT treated platelet concentrates (PCs) were also examined.

STUDY DESIGN AND METHODS

PRT was performed using riboflavin and ultraviolet light on FWB in citrate phosphate dextrose anticoagulant. Following PRT, red blood cells (RBCs), PCs, and plasma for fresh frozen plasma (FFP), were isolated by sequential centrifugation. RBCs were stored at 4°C, FFP at -80°C, and PC at 22°C or at 4°C. Components were assayed throughout their storage times for blood gases, chemistry and CBC, hemostatic function as well as platelet (PLT) and RBC integrity.

RESULTS

Component processing following PRT resulted in a significant drop in platelet recovery. Most PRT-PC bags fell below AABB guidelines for platelet count. PRT-PC also showed a decrease in clot strength and decreased aggregometry response. Platelet caspases were activated by PRT. Storage at 4°C improved platelet function. In PRT-FFP, prothrombin time and partial thromboplastin time (PT and aPTT) were prolonged; factors V, VII, VIII, and XI, protein C, and fibrinogen were significantly decreased. Free hemoglobin was elevated two-fold in PRT-RBC.

CONCLUSION

Blood components isolated by the PRP method from PRT-treated WB result in a high percentage of PC that fail to meet AABB guidelines. FFP also shows diminished coagulation capacity. However, PRT-RBC are comparable to control-RBC. PRT-WB retains acceptable hemostatic function but alternatives to the PRP method of component separation may be more suitable.

Von Willebrand factor as a thrombotic and inflammatory mediator in critical illness

The endothelial exocytosis of high-molecular-weight multimeric von Willebrand factor (vWF) may occur in critical illness states, including trauma and sepsis, leading to the sustained elevation and altered composition of plasma vWF. These critical illnesses involve the common process of sympathoadrenal activation and loss of the endothelial glycocalyx. As a prothrombotic and proinflammatory molecule that interacts with the endothelium, the alterations exhibited by vWF in critical illness have been implicated in the development and damaging effects of downstream pathologies, such as disseminated intravascular coagulation and systemic inflammatory response syndrome. Given the role of vWF in these pathologies, there has been a recent push to further understand how the molecule may be involved in the pathophysiology of related diseases, such as trauma-induced coagulopathy and acute renal injury, which are also known to develop secondarily to critical illness states. Elucidation of the role of vWF across the broader spectrum of generalized pathologies may provide a basis for the development of novel preventative and restorative measures, while also bolstering the scaffold of more widely used treatments, such as the administration of plasma-containing blood products.

Cold-stored whole blood in a Norwegian emergency helicopter service: an observational study on storage conditions and product quality

BACKGROUND

Increasing numbers of emergency medical service agencies and hospitals are developing the capability to administer blood products to patients with hemorrhagic shock. Cold-stored whole blood (WB) is the only single product available to prehospital providers who aim to deliver a balanced resuscitation strategy. However, there are no data on the safety and in vitro characteristics of prehospital stored WB. This study aimed to describe the effects on in vitro quality of storing WB at remote helicopter bases in thermal insulating containers.

STUDY DESIGN AND METHODS

We conducted a two-armed single-center study. Twenty units (test) were stored in airtight thermal insulating containers, and 20 units (controls) were stored according to routine procedures in the Haukeland University Hospital Blood Bank. Storage conditions were continuously monitored during emergency medical services missions and throughout remote and blood bank storage. Hematologic and metabolic variables, viscoelastic properties, and platelet (PLT) aggregation were measured on Days 1, 8, 14, and 21.

RESULTS

Storage conditions complied with the EU guidelines throughout remote and in-hospital storage for 21 days. There were no significant differences in PLT aggregation, viscoelastic properties, and hematology variables between the two groups. Minor significantly lower pH, glucose, and base excess and higher lactate were observed after storage in airtight containers.

CONCLUSION

Forward cold storage of WB is safe and complies with EU standards. No difference is observed in hemostatic properties. Minor differences in metabolic variables may be related to the anaerobic conditions within the thermal box.

Effect of blood flow on platelets, leukocytes, and extracellular vesicles in thrombosis of simulated neonatal extracorporeal circulation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has frequent and sometimes lethal thrombotic complications. The role that activated platelets, leukocytes, and small (0.3-micron to 1-micron) extracellular vesicles (EVs) play in ECMO thrombosis is not well understood.

OBJECTIVES

To test the effect of blood flow rate on the generation of activated platelets, leukocytes, and EVs in a simulated neonatal ECMO circuit using heparinized human whole blood.

METHODS

Simulated neonatal roller pump circuits circulated whole blood at low, nominal, and high flow rates (0.3, 0.5, and 0.7 L/min) for 6 h. Coagulopathy was defined by thromboelastography (TEG), STA® -procoagulant phospholipid clot time (STA®- Procoag-PPL), and calibrated automated thrombogram. High-resolution flow cytometry measured the cellular expression of prothrombotic phospholipids and proteins on platelets, leukocytes, and EV.

RESULTS

Despite heparinization, occlusive thrombosis halted flow in two of five circuits at 0.3 L/min and three of five circuits at 0.7 L/min. None of the five circuits at 0.5 L/min exhibited occlusive thrombosis. Phosphatidylserine (PS)-positive platelets and EVs increased at all flow rates more than blood under static conditions (P < .0002). Tissue factor (TF)-positive leukocytes and EVs increased only in low-flow and high-flow circuits (P < .0001). Tissue factor pathway inhibitor (TFPI), at 50 times more than the concentration in healthy adults, failed to suppress thrombin initiation in low-flow and high-flow circuits.

CONCLUSIONS

This in vitro study informs ECMO specialists to avoid low and high blood flow that increases TF expression on leukocytes and EVs, which likely initiate clot formation. Interventions to decrease TF generated by ECMO may be an effective approach to decrease thrombosis.

The History of Fluid Resuscitation for Bleeding

Damage control resuscitation (DCR) is a bundle of care first described by Holcomb et al. that is aimed at reducing death from hemorrhage for patients with severe traumatic bleeding. DCR principles include compressible hemorrhage control; hypotensive resuscitation; rapid surgical control of bleeding; avoidance of the overuse of crystalloids and colloids, prevention or correction of acidosis, hypothermia, and hypocalcaemia; and hemostatic resuscitation (blood-based resuscitation). Remote damage control resuscitation (RDCR) is defined as the prehospital application of DCR concepts. The term RDCR was first published by Gerhardt and has been disseminated by the (Trauma Hemostasis and Oxygenation Research), or THOR Network. The history of DCR and RDCR starts well before the inception of the terms. The concepts behind the principles of DCR and RDCR stretch far back into the past. This chapter provides an outline of this history, but it is limited to the fluid resuscitation aspect of DCR/RDCR.

Effect of storage of plasma in the presence of red blood cells and platelets: re-evaluating the shelf life of whole blood

BACKGROUND

There is renewed interest in administering whole blood (WB) for the resuscitation of patients with bleeding trauma. The shelf life of WB was established decades ago based on the viability of red blood cells. However, plasma quality during WB storage is not established.

STUDY DESIGN AND METHODS

White blood cell- and platelet-reduced WB (WB-PLT) was prepared using standard processes and compared to WB processed using a platelet-sparing WBC reduction (WB + PLT) filter. WB (± PLT) was held at 2 to 6°C for 35 days alongside control units of red blood cells (RBCs) in saline, adenine, glucose, and mannitol and liquid plasma. A series of assays explored the coagulation potential and RBC quality.

RESULTS

While fibrinogen and α2-antiplasmin remained unaffected by storage, other factors varied between components or over time at 2 to 6°C. At 14 days factor V, factor VII, α₂ -antiplasmin and free protein S antigen remained on average greater than 0.50 IU/mL or 50%, as appropriate, in WB ± PLT. Factor VIII was on average 0.49 IU/mL in WB+PLT, and 0.56 IU/mL for WB-PLT. Free protein S activity decreased significantly in all arms but remained on average greater than 40% at Day 14. Contact activation was not demonstrated before Day 14. Thrombin generation in plasma remained relatively stable to Day 35 in all arms.

CONCLUSIONS

Clotting factor activity remained at or above a mean of 0.5 IU/mL, or 50%, at Day 14 for factor V, factor VII, factor VIII, free protein S, fibrinogen, and α2-antiplasmin in all arms. Further data on platelet function in WB+PLT is needed to inform its shelf life.

Thromboelastometric evaluation of coagulation profiles of cold-stored autologous whole blood: A prospective observational study

Preoperative autologous blood donation is a well-established procedure to reduce the need for allogeneic blood transfusion. We hypothesized that coagulation activity is maintained in cold-stored whole blood, because the fundamental polymerization properties of fibrin are preserved.Fifty adult patients who underwent elective cardiothoracic surgery were enrolled.Autologous whole blood collected 2 to 4 times at almost 1-week intervals before surgery was stored at approximately 4°C until reinfusion at the time of surgery. Blood samples were drawn just before reinfusion, and rotational thromboelastometry variables and fibrinogen levels were measured.A total of 158 samples were analyzed. The mean duration of cold storage was 16.7 ± 7.4 days (range: 6-33 days). Platelet counts were very low due to collection through a leukoreduction filter. The mean fibrinogen level was 2.3 ± 0.6 g/L. Amplitude at 10 minutes after CT (A10), amplitude at 20 minutes after CT (A20), and maximum clot firmness (MCF) values as determined by FIBTEM analysis were 10.8 ± 3.8, 12.2 ± 4.2, and 13.1 ± 4.7 mm, respectively. Fibrinogen levels were strongly correlated with A10, A20, and FIBTEM-MCF values (ρ = 0.83, P < .0001, ρ = 0.84, P < .0001, ρ = 0.85, P < .0001, respectively). Fibrinogen levels were not correlated with the duration of cold storage (ρ = 0.06, P = .43).The results of the present study demonstrate that fibrin polymerization occurs in cold-stored autologous whole blood, and that such activity is strongly correlated with fibrinogen levels. Furthermore, our data suggest that cold-stored leukoreduced autologous whole blood retains fibrin polymerization properties throughout 33 days.

Effect of leukoreduction and pathogen reduction on the hemostatic function of whole blood

BACKGROUND

There is renewed interest in the use of whole blood (WB) for resuscitation of patients in hemorrhagic shock. Leukoreduction with platelet-sparing filters and pathogen reduction may be used to improve the safety profile of WB, yet the effects of leukoreduction and pathogen reduction on WB hemostatic function are not well characterized.

STUDY DESIGN AND METHODS

Blood from 32 healthy group O donors was divided into treatment groups (n = 8 for each group): untreated, pathogen reduced (PR⁺ ), leukoreduced using an in-line filter (LR⁺ ), or PR⁺ LR⁺ . Units were stored without agitation for 21 days between 1° and 6°C, with sampling on days 0 (pre- and post-treatments), 1, 3, 5, 10, 15, and 21 for hemostatic function as assessed by thromboelastometry, thrombin generation, platelet activation factors, and platelet impedance aggregometry.

RESULTS

From day 3 (D3) to D15 of storage, platelet count was reduced in PR⁺ /LR⁺ units compared to PR^- /LR^- units. From D10 to D21 of storage, maximum clot firmness (MCF) was reduced in PR⁺ /LR⁺ units compared to PR^- /LR^- units. From D3 to D21 of storage, platelet aggregation was reduced in PR⁺ /LR⁺ units compared to PR^- /LR^- units. Total thrombin generation was similar in all groups from D0 to D21.

CONCLUSIONS

The combination of LR with a platelet-sparing filter and PR significantly reduces hemostatic function compared to either treatment alone or untreated WB. The clinical consequences of LR and PR of WB in patients with severe bleeding should be examined in trials before both are used in combination in patients.

Optimizing whole blood storage: hemostatic function of 35-day stored product in CPD, CP2D, and CPDA-1 anticoagulants

BACKGROUND

Transitioning from whole blood (WB) to components developed from efforts to maximize donor yield. Components are advantageous for specific derangements, but treating hemorrhage with components requires significantly more volume to provide similar effects to WB. Because storage lesion and waste remain problematic, this study examined hemostatic function of refrigerated WB stored for 35 days in anticoagulants citrate-phosphate-dextrose-adenosine (CPDA-1), citrate-phosphate-dextrose (CPD), or citrate-phosphate-double dextrose (CP2D).

METHODS

Refrigerated WB units from healthy donors were sampled over 35 days. Global hemostatic parameters were measured by thromboelastometry, thrombogram, platelet aggregometry, and platelet adhesion to collagen under shear conditions. The effects of transfusion filtration and mixing 35-day stored product with fresh WB were evaluated.

RESULTS

Countable platelets declined as aggregation clusters appeared in microscopy. While gross platelet agonist-induced aggregation declined over time, normalization revealed aggregation responses in remaining platelets. Peak thrombin generation increased over time. Clot strength diminished over storage in tissue factor-activated samples (normalized by filtration of aggregates). Functional fibrinogen responses remained consistent throughout. Filtration was necessary to maintain consistent platelet adhesion to collagen beyond collection day. Few differences were observed between anticoagulants, and stored/fresh mixing studies normalized coagulation parameters.

CONCLUSIONS

WB is easier to collect, store, and transfuse. WB provides platelets, an oft-neglected, critical resuscitation component, but their individual numbers decline as aggregates appear, resulting in diminished coagulation response. WB has better performance in these assays when examined at earlier time points, but expirations designated to specific anticoagulants appear arbitrary for hemostatic functionality, as little changes beyond 21 days regardless of anticoagulant.

Lifeline for the front lines: blood products to support the warfighter

BACKGROUND

Hemorrhage is the leading cause of death on the battlefield. Damage control resuscitation guidelines in the US military recommend whole blood as the preferred resuscitation product. The Armed Services Blood Program (ASBP) has initiated low-titer group O whole blood (LTOWB) production and predeployment donor screening to make whole blood more available to military forces.

STUDY DESIGN AND METHODS

ASBP donor centers updated procedures and labeling for LTOWB production. Donors are screened according to US Food and Drug Administration regulations and standard operating procedures. Group O donors are tested for anti-A and anti-B titer levels. Additionally, military personnel notified for pending deployment coordinate with their local ASBP donor center to complete whole blood donor prescreening. The process consists of completing a donor history questionnaire, processing of blood samples for blood group and infectious disease testing, and titer determination for group O personnel.

RESULTS

Since March 2016, 7940 LTOWB units have been manufactured at ASBP donor centers and shipped in support of combat operations. Additionally, ASBP donor centers have screened several thousand service members before deployment. From these screenings, the donor low titer rate was 68% and infectious disease reactive test rate was extremely low (≤0.004).

CONCLUSION

Whole blood is now the preferred blood product for resuscitation of combat trauma patients. The ASBP partnered with combat forces to screen personnel before deployment. Additionally, LTOWB is manufactured and shipped in support of combat operations. These efforts are expanding the availability of LTOWB for the warfighter.

Evaluation of a lyophilized platelet-derived hemostatic product

BACKGROUND

Current limitations of platelet shelf life to 5 days have led to an increasingly greater demand for hemostatic agents with greater longevity. The objective of this study was to evaluate the function of a lyophilized platelet-derived hemostatic product (thrombosome [TS]) as a potential alternative to fresh platelets.

METHODS

Platelets were collected from whole blood from healthy donors. TSs were reconstituted with water and added to various configurations of reassembled whole blood (platelets, plasma, and RBCs); measures included rotational thromboelastometry (ROTEM), optical aggregometry, mitochondrial function, calibrated automated thrombogram, collagen adhesion under flow (shear flow assay), and flow cytometry.

RESULTS

In ROTEM, no differences were observed between maximum clot formation values for contact pathway activation thromboelastometry tests with TSs or platelet samples. Significantly decreased aggregation was observed in the TSs versus platelets (p < 0.001 for all agonists). Flow cytometry measures demonstrated significant decreases in glycoprotein Ib expression and increases in phosphatidylserine expression in the TS group (p < 0.01). The calibrated automated thrombogram assay was suggestive (lag time and peak thrombin) that the TSs might have some thrombogenic properties. Measurements of mitochondrial function revealed that TSs had no functional mitochondria.

CONCLUSION

In this study, TSs were shown to have nonfunctional mitochondria. ROTEM measures revealed that the TSs had no impact on clot strength. Likewise, compared to platelets, the TSs displayed minimal aggregation, had significantly more phosphatidylserine (measure of activation status), but had the ability to adhere to a collagen surface under flow conditions and contribute to clot formation and induced greater thrombin generation.

Whole Blood for Resuscitation in Adult Civilian Trauma in 2017: A Narrative Review

After a hiatus of several decades, the concept of cold whole blood (WB) is being reintroduced into acute clinical trauma care in the United States. Initial implementation experience and data grew from military medical applications, followed by more recent development and data acquisition in civilian institutions. Anesthesiologists, especially those who work in acute trauma facilities, are likely to be presented with patients either receiving WB from the emergency department or may have WB as a therapeutic option in massive transfusion situations. In this focused review, we briefly discuss the historical concept of WB and describe the characteristics of WB, including storage, blood group compatibility, and theoretical hemolytic risks. We summarize relevant recent retrospective military and preliminary civilian efficacy as well as safety data related to WB transfusion, and describe our experience with the initial implementation of WB transfusion at our level 1 trauma hospital. Suggestions and collective published experience from other centers as well as ours may be useful to those investigating such a program. The role of WB as a significant therapeutic option in civilian trauma awaits further prospective validation.

Effects of whole blood leukoreduction on platelet function and hemostatic parameters

AIMS/OBJECTIVES

The aim of this study was to evaluate the hemostatic consequences of whole blood leukoreduction (LR).

BACKGROUND

Whole blood is being used for trauma resuscitation in the military, and an increasing number of civilian trauma centres across the nation. The benefits of LR, such as decreased infectious and transfusion-related complications, are well established, but the effects on hemostatic parameters remain a concern.

METHODS

Twenty-four units of whole blood were assigned to one of the four groups: non-leukoreduced (NLR), leukoreduced at 1 h and a height of 33 in. (LR-1), leukoreduced at 4 h and a height of 33 in. (LR-4(33)), or leukoreduced at 4 h and a height of 28 in. (LR-4(28)). Viscoelastic parameters, platelet aggregation, cell counts, physiological parameters and thrombin potential were evaluated immediately before and after LR, and on days 1, 7, 14 and 21 following LR.

RESULTS

The viscoelastic parameters and thrombin generation potential were unchanged between the groups. Platelet aggregation was reduced in the LR-1 group compared with NLR after 7 days. The LR-4(28) group also showed a trend of reduced platelet aggregation compared with NLR. Aggregation in LR-4(33) was similar to NLR throughout the storage time. Physiological and electrolyte changes over the whole blood storage period were not affected by LR.

CONCLUSION

Our study shows that whole blood can be LR at 4 h after collection and a height of 33 in. while maintaining platelet count and without altering platelet function and hemostatic performance.

The Dead Sea needs salt water… massively bleeding patients need whole blood: The evolution of blood product resuscitation

Whole blood, that is blood that is not manufactured into its component red blood cells (RBC) plasma, and platelets (PLT) units, was the mainstay of transfusion for many years until it was discovered that the component parts of a blood donation could be stored under different conditions thereby optimizing the storage length of each product. The use of low anti-A and -B titer group O whole blood (LTOWB) has recently been rediscovered for use in massively bleeding trauma patients. Whole blood has several advantages over conventional component therapy for these patients, including simplifying the logistics of the resuscitation, being more concentrated than whole blood that is reconstituted from conventional components, and providing cold-stored PLTs, amongst other benefits. While randomized controlled trials to determine the efficacy of using LTOWB in the resuscitation of massively bleeding trauma patients are currently underway, retrospective data has shown that massively bleeding recipients of LTOWB with traumatic injury do not have worse outcomes compared to patients who received conventional components and, in some cases, recipients of LTOWB have more favourable outcomes. This paper will describe some of the advantages of using LTOWB and will discuss the emerging evidence for its use in massively bleeding patients.

Damage Control Resuscitation

Damage control resuscitation (DCR) is a strategy for resuscitating patients from hemorrhagic shock to rapidly restore homeostasis. Efforts are focused on blood product transfusion with whole blood or component therapy closely approximating whole blood, limited use of crystalloid to avoid dilutional coagulopathy, hypotensive resuscitation until bleeding control is achieved, empiric use of tranexamic acid, prevention of acidosis and hypothermia, and rapid definitive surgical control of bleeding. Patients receiving uncrossmatched Type O blood in the emergency department and later receiving cumulative transfusions of 10 or more red blood cell units in the initial 24-hour post-injury (massive transfusion) are widely recognized as being at increased risk of morbidity and mortality due to exsanguination. Ideally, these patients should be rapidly identified, however anticipating transfusion needs is challenging. Useful indicators of massive transfusion reviewed in this guideline include: systolic blood pressure <110 mmHg, heart rate > 105 bpm, hematocrit <32%, pH < 7.25, injury pattern (above-the-knee traumatic amputation especially if pelvic injury is present, multi-amputation, clinically obvious penetrating injury to chest or abdomen), >2 regions positive on Focused Assessment with Sonography for Trauma (FAST) scan, lactate concentration on admission >2.5, admission international normalized ratio ≥1.2-1.4, near infrared spectroscopy-derived StO2 < 75% (in practice, rarely available), BD > 6 meq/L. Unique aspects of out-of-hospital DCR (point of injury, en-route, and remote DCR) and in-hospital (Medical Treatment Facilities: Role 2b/Forward surgical teams - role 3/ combat support hospitals) are reviewed in this guideline, along with pediatric considerations.

Good hemostatic effect of platelets stored at 4°C in an in vitro model of massive blood loss and thrombocytopenia

This study compared the corrective effects of storage of platelets at 4°C and at 22°C in an in vitro model of massive blood loss and thrombocytopenia to provide an experimental basis for the storage of platelets for clinical applications.In vitro model of massive blood loss and thrombocytopenia were constructed by the in vitro hemodilution method and cell washing method. Using storage of platelets at 4°C (1, 3, 5, 7, 10, 14 days) and at 22°C (1, 3, 5 days) to correct the coagulation condition of the different models, by thromboelastography and by routine blood indices.①Platelets stored at 4°C (1, 3, 5,7, 10, 14 days) and at 22°C (1, 3, 5 days) to correct the in vitro model of massive blood loss. Platelet count results improved from 17 to 27 × 10/L to greater than 120 × 10/L for 4°C storage, and 20 to 27 × 10/L to greater than 120 × 10/L for 22°C storage. Thromboelastography maximum amplitude (TEG-MA) results improved from 8.8 to 15.4 mm to greater than 43 mm for 4°C storage, and 12.2 to 14.4 mm to greater than 44.8 mm for 22°C storage. Thromboelastography reaction time values decreased from 9.9-24.9 minutes to 3.8-5.5 minutes for 4°C storage, and 9.9-22.7 minutes to 4.3-4.5 minutes for 22°C storage. ②Platelets stored at 4°C (1, 3, 5,7, 10, 14 days) and at 22°C (1, 3, 5 days) to correct the in vitro model of thrombocytopenia. Platelet count results improved from 12 to 34 × 10/L to greater than 99 × 10/L for 4°C storage, and 12 to 34 × 10/L to greater than 120 × 10/L for 22°C storage. TEG-MA results improved from 21.4 to 32.1 mm to greater than 49.1 mm for 4°C storage, and 21.4 to 31.6 mm to greater than 50.5 mm for 22°C storage.Platelets stored at 4°C and 22°C have the same correcting effect for 1, 3, and 5 days. Platelets stored at 4°C for 7 to 14 days have similarly hemostatic effect on the in vitro model of massive blood loss and thrombocytopenia.

Effects of platelet-sparing leukocyte reduction and agitation methods on in vitro measures of hemostatic function in cold-stored whole blood

BACKGROUND

Agitation of platelet units stored at room temperature is performed routinely to maintain platelet function, and leukoreduction of blood products is the standard of care in many countries to reduce immune consequences of transfusion. The effect of agitation and leukoreduction on whole blood stored at 4°C requires investigation, as reductions in hemostatic capacity of whole blood may reduce its efficacy in treating trauma-induced coagulopathy and platelet dysfunction. We hypothesize that agitation of whole blood will not affect hemostatic function and that leukoreduction will reduce hemostatic function of whole blood.

METHODS

In this in vitro randomized controlled study, 21 units of leukoreduced and 20 nonleukoreduced whole blood units were each randomly assigned into four agitation groups. Hemostatic parameters were measured using viscoelastic assays (rotational thromboelastometry-Extrinsic Screening Test (ROTEM-EXTEM) and thromboelastography (TEG) platelet mapping), impedance aggregometry (agonists-adenosine phosphate, arachidonic acid, thrombin receptor activating peptide, and collagen), and a thrombin generation assay from these whole blood units before and after filtration and on 0, 5, 10, and 15 days of storage at 4°C.

RESULTS

Leukoreduction compared to nonleukoreduction reduced platelet concentration on Day 0. Viscoelastic measures and thrombin generation parameters revealed significant reduction in hemostatic function between the leukoreduced units and the nonleukoreduced units at a few time points. Leukoreduced units consistently demonstrated reduced platelet aggregation compared to the nonleukoreduced units. Agitation methods did not significantly affect any of the hemostatic parameters examined.

CONCLUSIONS

Leukoreduction of whole blood with a platelet-sparing filter caused a moderate but significant reduction in some measures of whole blood hemostatic function most evident early in storage. The benefits of leukoreduction should be weighed against the potential reduced hemostatic function of leukoreduced units. Agitation of whole blood is not required to maintain hemostatic function.

LEVEL OF EVIDENCE

In vitro randomized controlled trial, level 1.

Hemostatic properties of cold-stored whole blood leukoreduced using a platelet-sparing versus a non-platelet-sparing filter

BACKGROUND

Whole blood (WB) is an appealing alternative to component-based transfusion in patients with significant bleeding. Historically, WB was transfused less than 48 hours after collection and was not leukoreduced (LR). However, LR components are now standard in many hospitals and LR WB is desirable. We investigated the effect of the type of LR filter used, as well as storage duration, on coagulation laboratory testing of WB.

STUDY DESIGN AND METHODS

Ten units of LR WB-5 units manufactured with a Food and Drug Administration (FDA)-approved platelet (PLT)-sparing filter (WB-PS) and 5 units manufactured with an FDA-approved non-PLT-sparing filter (WB-NPS)-underwent complete blood count, PLT function analyzer (PFA [PFA-100]), thromboelastography (TEG), prothrombin time (PT), partial thromboplastin time (PTT), Factor (F)V activity, chromogenic FVIII, thrombin generation, and microparticle quantification on Storage Days 3, 5, 7, 10, and 14.

RESULTS

WB-PS contains more PLTs than WB-NPS (mean, 71 × 10⁹ /L vs. 1 × 10⁹ /L, p < 0.001). WB-PS yielded essentially normal TEG tracings, while TEG tracings of WB-NPS were grossly abnormal (mean reaction time, 7.0 min for WB-PS vs. 9.7 min for WB-NPS, p < 0.001; mean alpha-angle 54.9° vs. 38.1°, p < 0.001; mean maximum amplitude, 54.9 mm vs. 13.9 mm, p < 0.001). PFA-100 closure was more common among units of WB-PS compared to units of WB-NPS (72% vs. 4%, p < 0.001). PT, PTT, and factor activities were not dramatically affected by the LR filter.

CONCLUSION

The choice LR filter has a major impact on the hemostatic properties of WB. Although storage of WB is associated with a rapid decline in PLT count, hemostasis as assessed by TEG and PFA-100 is not diminished over a 2-week storage period.

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

BACKGROUND

There are multiple approaches to the blood product and fluid resuscitation of a bleeding trauma patient. An in silico model of different trauma resuscitation strategies was constructed to predict their effects on the volumes of the different body fluid compartments and on several important hemostatic factors.

STUDY DESIGN AND METHODS

This multicompartment dynamic deterministic model comprised four interconnected modules (hemostatic, resuscitation, body fluid compartment, and dilutional coagulopathy). The model was divided into five resuscitation phases with simulations using six different resuscitation strategies: whole blood (WB) only, conventional component therapy (CCT) only or 10 units of WB followed by CCT, with either 1 L of crystalloid or 1.5 units of WB or red blood cells in the prehospital phase.

RESULTS

At the end of the simulations using 1 L of crystalloid fluids in the prehospital resuscitation phase, the use of WB led to a 1.4 g/dL higher hemoglobin concentration, 32 mg/dL higher fibrinogen concentration, and 0.9 L lower total extracellular fluid volume compared to CCT. Prehospital blood product transfusion in place of crystalloid resulted in higher hemoglobin and fibrinogen concentrations and a lower international normalized ratio throughout the resuscitation regardless of the resuscitation strategy used. Throughout both the prehospital crystalloid and prehospital blood product transfusion simulations, the hemoglobin and fibrinogen concentrations and platelet counts were higher, and the international normalized ratio was lower, when WB was used compared to CCT.

CONCLUSIONS

This model predicted improved hemostatic factor levels and a smaller total extracellular fluid volume volume when WB was transfused instead of CCT to bleeding trauma patients.

The effects of storage on platelet function in different blood products

OBJECTIVES

Reduced platelet (PLT) function during storage has been shown for buffy-coat-derived platelet concentrates (BCP) and apheresis platelet units (AP), while for whole blood (WB) it has not been well studied. The aim of this study was to investigate PLT function in these blood products throughout storage using a novel flow cytometric assay.

METHODS

Flow cytometric measurement of agonist-induced platelet aggregation, CD62P expression and PAC-1 binding during storage in BCP, AP (1-9 days at 20°C) and WB (1-21 days at 2-6°C).

RESULTS

PLT-aggregation capacity decreased from day 1 to day 7 for almost all product-agonist combinations (P = .004 to P = .029) with aggregation capacity of WB being similar to that of AP and BCP. WB aggregation capacity remained relatively unchanged from day 7 to day 21. For all blood products, the fraction of agonist-induced CD62P-expression remained high and the fraction of PAC-1 binding decreased during storage. WB PLTs underwent only small changes in CD62P expression and PAC-1 binding from day 7 to day 21.

CONCLUSION

This study found PLT aggregation in WB stored at 4°C to be as least as good as for BCP and AP stored at 20°C. WB retained significant PLT-aggregation capacity to day 21.

Whole Blood Transfusion

Whole blood is the preferred product for resuscitation of severe traumatic hemorrhage. It contains all the elements of blood that are necessary for oxygen delivery and hemostasis, in nearly physiologic ratios and concentrations. Group O whole blood that contains low titers of anti-A and anti-B antibodies (low titer group O whole blood) can be safely transfused as a universal blood product to patients of unknown blood group, facilitating rapid treatment of exsanguinating patients. Whole blood can be stored under refrigeration for up to 35 days, during which it retains acceptable hemostatic function, though supplementation with specific blood components, coagulation factors or other adjuncts may be necessary in some patients. Fresh whole blood can be collected from pre-screened donors in a walking blood bank to provide effective resuscitation when fully tested stored whole blood or blood components are unavailable and the need for transfusion is urgent. Available clinical data suggest that whole blood is at least equivalent if not superior to component therapy in the resuscitation of life-threatening hemorrhage. Low titer group O whole blood can be considered the standard of care in resuscitation of major hemorrhage.

Vox Sanguinis International Forum on the use of prehospital blood products and pharmaceuticals in the treatment of patients with traumatic haemorrhage

While specific practices and transported blood products vary around the world, most of the respondents in this International Forum transported at least one blood product for the transfusion to bleeding patients en route to the hospital. The most commonly carried product was RBCs, while the use of whole blood will likely increase given the recent reports of its successful use in the civilian setting, and because of the change in the AABB's Standards regulating its use. It will be interesting to see if plasma use in the prehospital setting becomes more widely used given today's enhanced appreciated of the coagulopathy of trauma and plasma's beneficial effect in reversing it, and if blood products are transported to the scene of injury by more vehicles, that is, not just predominantly in helicopters. It was not surprising that TXA is being widely administered as close to the time of injury as possible given its potential benefit in these patients. This International Forum highlights the importance of focusing attention on prehospital transfusion management with a need to further high‐quality research in this area to guide optimal resuscitation strategies.

Cold storage of platelets in additive solution: the impact of residual plasma in apheresis platelet concentrates

Platelet transfusion has become essential therapy in modern medicine. Although the clinical advantage of platelet transfusion has been well established, adverse reactions upon transfusion, especially transmission of bacterial infection, still represent a major challenge. While bacterial contamination is favored by the storage of platelets at room temperature, cold storage may represent a solution for this important clinical issue. In this study, we aimed to clarify whether plasma has protective or detrimental effects on cold-stored platelets. We investigated the impact of different residual plasma contents in apheresis-derived platelet concentrates, stored at 4°C or room temperature, on platelet function and survival. We found that platelets stored at 4°C have higher expression of apoptosis marker compared to platelets stored at room temperature, leading to accelerated clearance from the circulation in a humanized animal model. While cold-induced apoptosis was independent of the residual plasma concentration, cold storage was associated with better adhesive properties and higher response to activators. Interestingly, delta (δ) granule-related functions, such as ADP-mediated aggregation and CD63 release, were better preserved at 4°C, especially in 100% plasma. An extended study to assess cold-stored platelet concentrates produced under standard care Good Manufacturing Practice conditions showed that platelet function, metabolism and integrity were better compared to those stored at room temperature. Taken together, our results show that residual plasma concentration does not have a cardinal impact on the cold storage lesions of apheresis-derived platelet concentrates and indicate that the current generation of additive solutions represent suitable substitutes for plasma to store platelets at 4°C.

Novel concepts for damage control resuscitation in trauma

PURPOSE OF REVIEW

Traumatic injuries are a major cause of mortality worldwide. Damage control resuscitation or balanced transfusion of plasma, platelets, and red blood cells for the management of exsanguinating hemorrhage after trauma has become the standard of care. We review the literature regarding the use of alternatives to achieve the desired 1 : 1:1 ratio as availability of plasma and platelets can be problematic in some environments.

RECENT FINDINGS

Liquid and freeze dried plasma (FDP) are logistically easier to use and may be superior to fresh frozen plasma. Cold storage platelets (CSPs) have improved hemostatic properties and resistance to bacterial contamination. Low titer type O whole blood can be transfused safely in civilian patients.

SUMMARY

In the face of hemorrhagic shock from traumatic injury, resuscitation should be initiated with 1 : 1 : 1 transfusion of plasma, platelets, and red blood cells with limited to no use of crystalloids. Availability of plasma and platelets is limited in some environments. In these situations, the use of low titer type O whole blood, thawed or liquid plasma, cold stored platelets or reconstituted FDP can be used as substitutes to achieve optimal transfusion ratios. The hemostatic properties of CSPs may be superior to room temperature platelets.

Blood products and procoagulants in traumatic bleeding: use and evidence

PURPOSE OF REVIEW

Death from uncontrolled haemorrhage is one of the leading causes of trauma-related mortality and is potentially preventable. Advances in understanding the mechanisms of trauma-induced coagulopathy (TIC) have focused attention on the role of blood products and procoagulants in mitigating the sequelae of TIC and how these therapies can be improved.

RECENT FINDINGS

A host of preclinical and clinical studies have evaluated blood product availability and efficacy in trauma. Recently published randomized controlled trials have investigated the ratio of platelet:plasma:red cell transfusion and the role of early cryoprecipitate in trauma. Demand for readily available plasma has led to changes particularly in the use of thawed group A plasma. Furthermore, ex-vivo and early clinical work has demonstrated variations in the haemostatic activity of different plasma, platelet and whole blood products. A number of multicentre trials are in progress aiming to answer key questions regarding tranexamic acid, procoagulant factor and fibrinogen concentrates and their effect on trauma outcomes.

SUMMARY

There are promising results from ex-vivo studies in manufacturing and storage of blood products to optimize haemostatic activity and availability, particularly with alternative plasma and platelet products and whole blood. There is an urgent need for these products needs to be tested prospectively.

Whole Blood in Pediatric Craniofacial Reconstruction Surgery

BACKGROUND

Pediatric complex cranial vault reconstruction (CCVR) surgery is often associated with significant blood loss and transfusion. The authors recently changed our transfusion practice during CCVR to using whole blood (WB) instead of reconstituted blood (RB). The aim of this study was to assess the impact of this practice change. Our hypothesis was that replacement with WB would be as effective as RB for the outcomes of total perioperative blood donor exposures (BDEs) and the incidence of laboratory evidence of postoperative coagulopathy.

METHODS

The authors queried the Pediatric Craniofacial Surgery Perioperative Registry for children ages ≤48 months from our institution who underwent CCVR and received either RB or WB. The primary outcomes of total perioperative BDEs and the incidence of laboratory evidence of postoperative coagulopathy were compared between the 2 cohorts.

RESULTS

The query returned 59 subjects in the RB cohort and 52 subjects in the WB cohort. There were no significant differences in demographic variables between the 2 groups. Patients in the WB cohort were more likely to have ≤1 BDEs when compared to the RB cohort (62% versus 39%, respectively, P = 0.02). There was no significant difference in the incidence of postoperative coagulation laboratory test abnormalities between the WB and RB cohorts (0% versus 3.4%, respectively, P = 0.50).

CONCLUSION

There was no postoperative coagulopathy in the WB cohort. Whole blood was also associated with significantly fewer perioperative BDEs. Whole blood appears to be as effective as RB for replacement of blood loss in craniofacial surgery.

Limited Resuscitation With Fresh or Stored Whole Blood Corrects Cardiovascular and Metabolic Function in a Rat Model of Polytrauma and Hemorrhage

INTRODUCTION

We have recently shown that human whole blood stored at 4°C maintains hemostatic and platelet function. In this study, we compared restoration of hemodynamic, metabolic and hemostatic function after limited resuscitation with rat fresh whole blood, rat stored whole blood, or Lactated Ringers in traumatized rats.

METHODS

Rat whole blood was stored for 10 days at 4°C for evaluation of hemostatic function. Polytrauma was performed on isoflurane-anesthetized Sprague-Dawley rats (350-450 g) by damage to the intestines, liver, right leg skeletal muscle, and right femur fracture, followed by 40% hemorrhage. At 1 h, rats were resuscitated (20%) with either fresh whole blood (FWB), stored whole blood, 4°C for 7 days (SWB), Lactated Ringers (LR), or nothing. Blood samples were taken before and 2 h after trauma and hemorrhage to evaluate metabolic and hemostatic function.

RESULTS

Whole blood stored for 10 days showed a significant prolongation in prothrombin time (PT) and activated partial thromboplastin time (aPTT), and fall in fibrinogen concentration, but no change in Maximum Clot Firmness or speed of clot formation. Platelet function was maintained until day 7 in storage, than fell significantly. Polytrauma and hemorrhage in rats led to a fall in arterial pressure, plasma bicarbonate, fibrinogen, and platelet function, and a rise in plasma lactate, PT, aPTT, and creatinine. Resuscitation with either FWB or 7 day SWB, but not LR, returned arterial pressure, plasma lactate and plasma bicarbonate to levels similar to control, but had no effect on the fall in fibrinogen or platelet function, or the rise in PT, aPTT, or creatinine.

CONCLUSION

Hemostatic and platelet function of rat whole blood stored at 4°C is preserved for at least 7 days in vitro. Low volume resuscitation with SWB or FWB, but not LR, restores hemodynamic and metabolic function, but not the coagulopathy after severe trauma and hemorrhage.

Intravenous synthetic platelet (SynthoPlate) nanoconstructs reduce bleeding and improve 'golden hour' survival in a porcine model of traumatic arterial hemorrhage

Traumatic non-compressible hemorrhage is a leading cause of civilian and military mortality and its treatment requires massive transfusion of blood components, especially platelets. However, in austere civilian and battlefield locations, access to platelets is highly challenging due to limited supply and portability, high risk of bacterial contamination and short shelf-life. To resolve this, we have developed an I.V.-administrable 'synthetic platelet' nanoconstruct (SynthoPlate), that can mimic and amplify body's natural hemostatic mechanisms specifically at the bleeding site while maintaining systemic safety. Previously we have reported the detailed biochemical and hemostatic characterization of SynthoPlate in a non-trauma tail-bleeding model in mice. Building on this, here we sought to evaluate the hemostatic ability of SynthoPlate in emergency administration within the 'golden hour' following traumatic hemorrhagic injury in the femoral artery, in a pig model. We first characterized the storage stability and post-sterilization biofunctionality of SynthoPlate in vitro. The nanoconstructs were then I.V.-administered to pigs and their systemic safety and biodistribution were characterized. Subsequently we demonstrated that, following femoral artery injury, bolus administration of SynthoPlate could reduce blood loss, stabilize blood pressure and significantly improve survival. Our results indicate substantial promise of SynthoPlate as a viable platelet surrogate for emergency management of traumatic bleeding.

What If I Don't Have Blood? Hextend is Superior to 3% Saline in an Experimental Model of Far Forward Resuscitation After Hemorrhage

INTRODUCTION

Hypertonic crystalloid solutions, colloids, and fresh whole blood (FWB) have all been proposed for prehospital resuscitation after hemorrhage. However, there are no direct comparisons of the efficacy of these different fluids. We compared Hextend, 3% hypertonic saline (HS), and FWB in a porcine model of hemorrhagic shock.

MATERIALS AND METHODS

Female swine (n = 5/group) underwent splenectomy and pressure-controlled hemorrhage followed by resuscitation with Hextend, 3% HS, or FWB. They were maintained at a target mean arterial pressure (MAP) for 4 h, holding or infusing fluid as necessary. Sham animals for comparison underwent splenectomy alone.

RESULTS

The mean volume required to maintain target MAP was significantly higher for 3% HS (1,016 ± 386 mL) than for Hextend (346 ± 299 mL, P < 0.05). After 4 h of resuscitation, the MAP in the 3% HS group (44 ± 3 mmHg) was significantly lower than shams (56 ± 7 mmHg, P < 0.05). Three percent HS recipients had a significantly worse metabolic acidosis and anemia than shams or FWB recipients, as well as significant increases in serum sodium and chloride. Serum interleukin-6 was significantly elevated in 3% HS and FWB recipients relative to Hextend recipients (105.3 ± 58.6 and 97.2 ± 21 vs. 38.6 ± 27.1 pcg/mL, P < 0.05).

CONCLUSIONS

HS performed inferiorly to Hextend as a volume expanding resuscitative fluid after hemorrhage. On the basis of our data, we would recommend the use of Hextend over 3% saline in far forward resuscitation after hemorrhage.

How do I implement a whole blood program for massively bleeding patients?

Building on the successful military experience, interest has been rekindled in transfusing whole blood (WB) early in the resuscitation of traumatically injured civilians, often before their ABO group is known. WB efficiently provides treatment for shock and coagulopathy, as well as platelet hemostatic function, to patients losing large volumes of blood. Unlike group O uncrossmatched red blood cells (RBCs), group O WB contains a substantial amount of plasma, which is incompatible with the RBCs of all non-group O recipients. Thus, when implementing a WB program, it is important to decide how to mitigate the risk of immune-mediated hemolysis. Other questions that a hospital needs to answer before implementing a WB program include determining which patients will be eligible for this product, how many units eligible patients can receive, for how long it should be stored and under what conditions, and how to monitor for adverse events. The donor center needs to consider if the WB should be leukoreduced, how to comply with the AABB's transfusion-related acute lung injury risk mitigation standard, and into which storage solution it should be collected. This report describes the multidisciplinary approach taken to implementing a civilian WB program at a multihospital health care system in the United States.

In vitro Analysis of the Hemostatic Properties of Whole Blood Products Prepared with a Platelet-Sparing Leukoreduction Filter

Background

Warm fresh whole blood (WFWB) is an ideal resuscitation fluid for exsanguinating patients but there are myriad logistic and infectious issues associated with its use. Cold whole blood (CWB) may be an acceptable alternative to the reconstituted whole blood (RWB), the current standard of care. A leukoreduction filter has been developed which maintains platelet count while eliminating white blood cells but its effect on platelet function is unknown. We hypothesize that CWB will retain an acceptable functional coagulation profile after filtration and over time.

Study Design and Methods

WFWB and CWB samples were obtained from eight donors and four units of RWB were created. The quantitative and qualitative in vitro coagulation profiles of WFWB, RWB, and CWB over time were compared.

Results

Filtration was successful at removing white blood cells (5.5 ± 1.2 vs. 0.3 ± 0.3 × 10⁶/L) while retaining an adequate platelet count (172.0 ± 47.0 to 166.0 ± 42.3 × 10⁹/L) and hemoglobin concentration (13.7 ± 0.5 vs. 13.0 ± 0.7 g/dL). Rotational Thromboelastography (ROTEM) results revealed a similar clotting time (CT) before and after filtration (64.9 ± 5.1 vs. 64.1 ± 6.8 s) but a decreased maximum clot firmness (MCF) (58.6 ± 4.2 vs. 54.9 ± 4.6 mm). Platelet aggregation decreased substantially (28.8 ± 6.7 vs. 9.3 ± 2.1 ohm) immediately after filtration. CWB function continued to diminish over time.

Conclusion

CWB holds great promise as a surrogate for WFWB, but use of a platelet-sparing LR filter diminishes platelet function almost immediately after filtration.

Biomaterials and Advanced Technologies for Hemostatic Management of Bleeding

Bleeding complications arising from trauma, surgery, and as congenital, disease-associated, or drug-induced blood disorders can cause significant morbidities and mortalities in civilian and military populations. Therefore, stoppage of bleeding (hemostasis) is of paramount clinical significance in prophylactic, surgical, and emergency scenarios. For externally accessible injuries, a variety of natural and synthetic biomaterials have undergone robust research, leading to hemostatic technologies including glues, bandages, tamponades, tourniquets, dressings, and procoagulant powders. In contrast, treatment of internal noncompressible hemorrhage still heavily depends on transfusion of whole blood or blood's hemostatic components (platelets, fibrinogen, and coagulation factors). Transfusion of platelets poses significant challenges of limited availability, high cost, contamination risks, short shelf-life, low portability, performance variability, and immunological side effects, while use of fibrinogen or coagulation factors provides only partial mechanisms for hemostasis. With such considerations, significant interdisciplinary research endeavors have been focused on developing materials and technologies that can be manufactured conveniently, sterilized to minimize contamination and enhance shelf-life, and administered intravenously to mimic, leverage, and amplify physiological hemostatic mechanisms. Here, a comprehensive review regarding the various topical, intracavitary, and intravenous hemostatic technologies in terms of materials, mechanisms, and state-of-art is provided, and challenges and opportunities to help advancement of the field are discussed.

Bio-inspired nanomedicine strategies for artificial blood components

Blood is a fluid connective tissue where living cells are suspended in noncellular liquid matrix. The cellular components of blood render gas exchange (RBCs), immune surveillance (WBCs) and hemostatic responses (platelets), and the noncellular components (salts, proteins, etc.) provide nutrition to various tissues in the body. Dysfunction and deficiencies in these blood components can lead to significant tissue morbidity and mortality. Consequently, transfusion of whole blood or its components is a clinical mainstay in the management of trauma, surgery, myelosuppression, and congenital blood disorders. However, donor-derived blood products suffer from issues of shortage in supply, need for type matching, high risks of pathogenic contamination, limited portability and shelf-life, and a variety of side-effects. While robust research is being directed to resolve these issues, a parallel clinical interest has developed toward bioengineering of synthetic blood substitutes that can provide blood's functions while circumventing the above problems. Nanotechnology has provided exciting approaches to achieve this, using materials engineering strategies to create synthetic and semi-synthetic RBC substitutes for enabling oxygen transport, platelet substitutes for enabling hemostasis, and WBC substitutes for enabling cell-specific immune response. Some of these approaches have further extended the application of blood cell-inspired synthetic and semi-synthetic constructs for targeted drug delivery and nanomedicine. The current study provides a comprehensive review of the various nanotechnology approaches to design synthetic blood cells, along with a critical discussion of successes and challenges of the current state-of-art in this field. WIREs Nanomed Nanobiotechnol 2017, 9:e1464. doi: 10.1002/wnan.1464 For further resources related to this article, please visit the WIREs website.