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BACKGROUND Never frozen liquid plasma (LP) has limited shelf life versus fresh frozen plasma (FFP) or plasma frozen within 24 h (PF24). Previous studies showed decreasing factor activities after Day (D)14 in thawed FFP but no differences between LP and FFP until D10. This study examined LP function through D40. STUDY DESIGN AND METHODS FFP and PF24 were stored at -20°C until assaying. LP was assayed on D5 then stored (4°C) for testing through D40. A clinical coagulation analyzer measured Factor (F)V, FVIII, fibrinogen, prothrombin time (PT), and activated partial thromboplastin time (aPTT). Thromboelastography (TEG) and thrombogram measured functional coagulation. Ristocetin cofactor assay quantified von Willebrand factor (vWF) activity. Residual platelets were counted. RESULTS FV/FVIII showed diminished activity over time in LP, while PT and aPTT both increased over time. LP vWF declined significantly by D7. Fibrinogen remained high through D40. Thrombin lagtime was delayed in LP but consistent to D40, while peak thrombin was significantly lower in LP but did not significantly decline over time. TEG R-time and angle remained constant. LP and PF24 (with residual platelets) had initially higher TEG maximum amplitudes (MA), but by D14 LP was similar to FFP. CONCLUSION Despite significant declines in some factors in D40 LP, fibrinogen concentration and TEG MA were stable suggesting stored LP provides fibrinogen similarly to frozen plasmas even at D40. LP is easier to store and prepare for prehospital transfusion, important benefits when the alternative is crystalloid.

Background The short shelf-life of fresh platelets limits their efficient inventory management and availability during a massive transfusion protocol. Risk of insufficient availability can be mitigated by building an inventory of cryopreserved platelets (CPs). Methods A comparative study of fresh apheresis platelets (FAPs) and CPs was performed. Type-O CPs were processed with DMSO frozen at -80°C and reconstituted in thawed AB plasma. All patients enrolled in the study had the following parameters evaluated on admission: vital signs (body temperature, heart rate, mean arterial pressure), blood count, prothrombin time, activated partial thromboplastin time, fibrinogen level, and, in trauma patients, international severity score. Several outcomes were evaluated: 30-day survival, adverse events, quantity of administered blood products, fibrinogen concentrate and thromboxane (TXA), and laboratory parameters after transfusion (blood count, prothrombin time, activated partial thromboplastin time, fibrinogen level). Results Twenty-five (25) patients in the study group received transfusions totaling 81 units of CPs. Twenty-one (21) patients in the control group received a total of 67 units of FAPs. There were no significant differences in patient characteristics (p > 0.05) between groups. Both groups were comparable in clinical outcomes (30-day survival, administered blood products, fibrinogen concentrate, TXA, and adverse events). Among posttransfusion laboratory parameters, platelet count was higher in the group transfused with FAPs (97.0 ×109 /L) than in the group transfused with CPs (41.5 ×109 /L), p = 0.02025. Other parameters were comparable in both groups. Conclusion The study suggests that CPs are tolerable and a feasible alternative to FAPs. However, larger randomized studies are needed to draw definitive conclusions.

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.

Background Central venous catheters are frequently inserted into patients with coagulation disorders. It is unclear whether preprocedural correction of hemostasis is beneficial. We determined the incidence of bleeding complications after central venous catheter placement in patients who had severe coagulopathy and identified potential risk factors for bleeding. Study design and methods The MEDLINE and Cochrane Library databases were systematically searched through November 2015. To be included, articles must have reported on hemorrhagic complications with specification of abnormal coagulation testing results. Severe coagulopathy was defined as a reduced platelet count of 50 × 109 /L or less, and/or an elevated international normalized ratio of 1.5 or greater, and/or a partial thromboplastin time of 45 seconds or greater. Results We included one randomized controlled trial and 21 observational studies. In total, there were 13,256 catheter insertions, including 4213 in patients with severe coagulopathy. Before 3150 central venous catheter placements, coagulopathy was not corrected. The bleeding incidence varied from 0 to 32%. The severity of coagulopathy did not predict the risk of bleeding. No study demonstrated a beneficial effect from the prophylactic administration of platelets or fresh-frozen plasma to prevent bleeding complications. Retrospective observational studies suggested that no preprocedural correction is required up to a platelet count of 20 × 109 /L and an international normalized ratio of 3.0. Conclusion The incidence of major bleeding complications after central venous catheter placement is low, even in coagulopathic patients. Based on a systematic research of the literature, strong evidence supporting the correction of hemostatic defects before central venous catheter insertion is lacking. However, well-powered randomized controlled trials will be necessary to determine the minimal platelet count, the maximal international normalized ratio, and an activated partial thromboplastin time that is safe before central venous catheter insertion.

BACKGROUND Patients on warfarin who present with bleeding or who require an urgent procedure are commonly treated with intravenous (IV) vitamin K, which is supplemented with repletion of the vitamin K factors using either plasma or a prothrombin complex concentrate (PCC). In some such cases, use of vitamin K alone could be adequate to achieve acceptable hemostasis. STUDY DESIGN AND METHODS An algorithm emphasizing the use of vitamin K alone in patients presenting with non–life-threatening bleeding was encouraged, with repeat testing of the international normalized ratio (INR) within 5 hours. Depending on the INR result, patients received no factor repletion or plasma or PCC, as judged by the physician. Leftover samples from a separate cohort of patients with supratherapeutic INRs (INR > 4.0) were studied for clotting factor evaluation. RESULTS A total of 46 pre- and postinfusion INRs were evaluable from 41 patients. Median INR decreased from 5.8 to 2.5, with a median dose of 5 mg after a median time of 4.0 hours postinfusion. A total of 27 of 46 (59%) postinfusion samples showed an INR of 2.5 or less. Samples from patients with the highest INR showed the greatest decline in INR. Samples from supratherapeutic INR patients showed very high Factor VIII:C (200%) and a normal activated partial thromboplastin time in 23 of 50 (46%). CONCLUSION Use of IV vitamin K as sole therapy for urgent partial reversal of warfarin for non–life-threatening bleeding may provide adequate hemostasis within 5 hours, avoiding the need for clotting factor repletion.

BACKGROUND Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder characterized by heparin-dependent antibodies that activate platelets (PLTs) via PLT FcγIIa receptors. "Autoimmune" HIT (aHIT) indicates a HIT subset where thrombocytopenia progresses or persists despite stopping heparin; aHIT sera activate PLTs strongly even in the absence of heparin (heparin-independent PLT-activating properties). Affected patients are at risk of severe complications, including dual macro- and microvascular thrombosis leading to venous limb gangrene. High-dose intravenous immunoglobulin (IVIG) offers an approach to interrupt heparin-independent PLT-activating effects of aHIT antibodies. CASE REPORT A 78-year-old male who underwent cardiopulmonary bypass for aortic dissection developed aHIT, disseminated intravascular coagulation, and deep vein thrombosis; progression to venous limb gangrene occurred during partial thromboplastin time (PTT)-adjusted bivalirudin infusion (underdosing from "PTT confounding"). Thrombocytopenia recovered with high-dose IVIG, although the PLT count increase began only after the third dose of a 5-day IVIG regimen (0.4 g/kg/day × 5 days). We reviewed case reports and case series of IVIG for treating HIT, focusing on various IVIG dosing regimens used. RESULTS Patient serum-induced PLT activation was inhibited in vitro by IVIG in a dose-dependent fashion; inhibition of PLT activation by IVIG was much more marked in the absence of heparin versus the presence of heparin (0.2 U/mL). Our literature review indicated 1 g/kg × 2 IVIG dosing as most common for treating HIT, usually associated with rapid PLT count recovery. CONCLUSION Our clinical and laboratory observations support dose-dependent efficacy of IVIG for decreasing PLT activation and thus correcting thrombocytopenia in aHIT. Our case experience and literature review suggests dosing of 1 g/kg IVIG × 2 for patients with severe aHIT.

BACKGROUND Therapeutic plasma exchange (TPE) is increasingly used for treatment of antibody-mediated rejection (AMR) after solid organ transplants. There is concern that TPE may increase risk of bleeding, although data are limited. After TPE, clot-based coagulation tests may not accurately represent the levels of coagulation factors due to the effect of citrate. We investigated protein levels of fibrinogen using antigen detection method (FibAg) and correlated results with a clot-based fibrinogen activity test (Fib). STUDY DESIGN AND METHODS Nine kidney transplant recipients who received TPE for AMR were investigated. Fib, FibAg, prothrombin time/international normalized ratio (PT/INR), partial thromboplastin time (PTT), coagulation factor X chromogenic activity (CFX), and ionized calcium (iCa) were measured at pre- and post-TPE and 1, 3, 6, 9, 24, and 48 hours after the first TPE. RESULTS Mean Fib/FibAg ratio before TPE was 1.08; therefore, all Fib values were normalized (n) by dividing by 1.08. Overall, the mean normalized Fib (nFib)/FibAg ratio at post-TPE was 0.89 and returned to close to 1.0 at 6 hours after the first TPE. Decreases in nFib, FibAg, and CFX and increases in PT/INR and PTT post-TPE were observed. The lowest Fib, FibAg, CFX, platelet, and iCa levels were still at levels that would be considered sufficient for hemostasis at all time points. CONCLUSION The mean nFib/FibAg ratio after TPE was 0.89 and normalized in 6 hours, which demonstrates a persistent effect of citrate for up to 6 hours. Therefore, similar data observed in clot-based tests of PT/INR and PTT may be falsely elevated up to 6 hours after TPE due to the citrate effect.

BACKGROUND Massive transfusion practices have undergone several recent developments. We sought to examine institutional practices guiding hemostatic resuscitation in the setting of massive hemorrhage. STUDY DESIGN AND METHODS A 37-question online survey was sent to American Association for the Surgery of Trauma members. RESULTS A total of 191 surgeons from 125 institutions completed the survey. Level I and II centers composed 70 and 18% of responding sites, respectively. A total of 123 institutions have a massive transfusion protocol (MTP); 54% report having an MTP for less than 5 years. The number of coolers and units of red blood cells, plasma, and platelets are highly variable. Tranexamic acid is part of the MTP at 64% of centers; 26% continue to use recombinant activated Factor VII. MTP activation occurs more than five times per month at 32% of centers. MTPs are utilized for nontrauma patients in 82% of institutions. Point-of-care prothrombin time, international normalized ratio, and partial thromboplastin time testing is utilized in 37% of institutions. Only 9% routinely utilize thromboelastography or rotational thromboelastometry (TEG/ROTEM) within their MTP. Just 7% use a validated scoring system to guide MTP activation. The incorporation of TEG/ROTEM into the MTP is associated with the use of a scoring system in regression analysis (p = 0.024). CONCLUSION Most institutions regularly activate recently implemented MTPs for trauma and nontrauma indications; however, few use validated scoring systems for MTP activation. MTP content is highly variable. Few institutions use TEG, while most have incorporated tranexamic acid into their protocol. The lack of consistent practices underscores the need for outcome-based studies to guide transfusion practices.

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

BACKGROUND: Therapeutic plasma exchange (TPE) removes coagulation proteins, but its impact on therapeutic anticoagulation is unknown. We performed a systematic review of the literature to determine the coagulation effects of TPE in patients receiving systemic anticoagulation. STUDY DESIGN AND METHODS: We searched MEDLINE, CINAHL, EMBASE, and Web of Science until June 2018 for studies combining controlled vocabulary and keywords related to: therapeutic plasma exchange, plasmapheresis, anticoagulants, and therapy. The primary outcome was the effect of TPE on anti-Xa activity, activated partial thromboplastin time (aPTT), or International Normalized Ratio (INR). The secondary outcome was reports of post-TPE bleeding or thrombosis. RESULTS: 1830 references were screened and a total of eight studies identified. Our selected studies (five case reports and three case series) involved 23 patients and evaluated the effects of seven anticoagulants. Six studies of unfractionated heparin (UFH), low molecular weight heparins (LMWH), and direct oral anticoagulants (DOAC) demonstrated anti-Xa level decline. Two studies of UFH and LMWH showed aPTT increase. One study of warfarin showed a post-TPE INR increase. Reports of post-TPE bleeding occurred in two patients and thrombosis in one. CONCLUSION: In patients receiving therapeutic anticoagulation, TPE is associated with anti-Xa activity decline and aPTT and INR increase. These coagulation changes do not appear to significantly increase bleeding or thrombotic risk. Our data suggest the need for prospective studies to investigate the true clinical impact of TPE on therapeutic anticoagulation.

Background Dried plasma is logistically superior for hemostasis management because it can be transported and stored under nonfrozen conditions and quickly reconstituted at the point of care, enabling prehospital administration. Velico Medical has developed a spray-drying system to be integrated into routine blood center work streams for spray drying single donor plasma units. This study compared the quality of the spray-dried plasma (on-demand plasma [ODP]) with fresh frozen plasma (FFP). Study design and methods ODP units (n = 60) were manufactured from never frozen fresh plasma, which was pretreated with glycine-hydrochloric acid and stored at 1to 6°C. Paired aliquots were frozen and stored at -18°C or less. After 31 to 33 days, ODP samples were reconstituted with water for injection and comprehensively characterized in parallel with paired FFP. The quantities of plasma dried and rehydration fluid were predetermined, ensuring comparable total protein concentration in ODP and paired FFP. Results ODP is comparable to FFP in global coagulation function as assessed by activated partial thromboplastin time and prothrombin time and in clot formation evaluated by thrombelastography. Compared to FFP, ODP had greater than 80% levels of functional coagulation factors and related proteins and chemistry analytes except for Factor XIII (74%). Pretreatment mitigated cleavage of high-molecular-weight von Willebrand factor multimers by spray drying and resulted in 60% vWF:ristocetin cofactor activity in ODP compared to FFP. Conclusions ODP demonstrates coagulation function comparable to that of FFP. The spray drying system can be implemented in blood centers and is capable of producing units of ODP.

BACKGROUND As plasma contains procoagulant microparticles (MPs), removing MPs by 75-nm nanofiltration may decrease plasma in vitro thrombogenicity while maintaining the hemostatic activity from coagulation factors. STUDY DESIGN AND METHODS We defined conditions to nanofilter leukoreduced plasma on a 75-nm hollow-fiber membrane filter. Plasma quality was assessed by coagulation, immunochemical, and electrophoretic assays. MP removal was evaluated by biophysical (flow cytometry, dynamic light scattering, nanoparticle tracking analysis, and tunable resistive pulse sensing) and functional (thrombin generation assay [TGA; Technothrombin], prothrombinase [Zymuphen MP-activity], tissue factor [Zymuphen MP-TF], and procoagulant phospholipid-dependent clotting time [STA-Procoag-PPL] assays) methods. Spiking experiments using platelet MPs were performed to determine extent of removal by nanofiltration. RESULTS Freshly collected leukoreduced, but not previously frozen, plasma could be readily nanofiltered on a 0.01-m2 75-nm nanofilter under conditions preserving protein and lipoprotein profile, coagulation factor content, and global coagulation activity (prothrombin time, activated partial thromboplastin time). Biophysical methods confirmed an extensive removal of MPs during nanofiltration. All functional assays indicated a marked reduction of plasma in vitro thrombogenicity. There was no thrombin generation in nanofiltered plasma tested by TGA assay with “RC-low phospholipid concentration” reagent, while it was similar to that of starting and leukoreduced plasma samples when using “RC-high phospholipid concentration” reagent. More than 9 log of MPs were removed by nanofiltration. CONCLUSION Nanofiltration of 75 nm efficiently removes MPs and decreases in vitro thrombogenicity of plasma without affecting the protein content or the hemostatic activity of coagulation factors. Studies are needed to evaluate the impact of MP removal on in vivo thrombogenic risks and hemostatic efficacy.

Background The Mirasol system has been demonstrated to effectively inactivate white blood cells (WBCs) and reduce pathogens in whole blood in vitro. The purpose of this study was to compare the safety and efficacy of Mirasol-treated fresh whole blood (FWB) to untreated FWB in an in vivo model of surgical bleeding. Study Design and Methods A total of 18 anesthetized pigs (40 kg) underwent a 35% total blood volume bleed, cooling to 33°C, and a standardized liver injury. Animals were then randomly assigned to resuscitation with either Mirasol-treated or untreated FWB, and intraoperative blood loss was measured. After abdominal closure, the animals were observed for 14 days, after which the animals were euthanized and tissues were obtained for histopathologic examination. Mortality, tissue near-infrared spectroscopy, red blood cell (RBC) variables, platelets (PLTs), WBCs, and coagulation indices were analyzed. Results Total intraoperative blood loss was similar in test and control arms (8.3 ± 3.2 mL/kg vs. 7.7 ± 3.9 mL/kg, p = 0.720). All animals survived to Day 14. Trended values over time did not show significant differences—tissue oxygenation (p = 0.605), hemoglobin (p = 0.461), PLTs (p = 0.807), WBCs (p = 0.435), prothrombin time (p = 0.655), activated partial thromboplastin time (p = 0.416), thromboelastography (TEG)–reaction time (p = 0.265), or TEG–clot formation time (p = 0.081). Histopathology did not show significant differences between arms. Conclusions Mirasol-treated FWB did not impact survival, blood loss, tissue oxygen delivery, RBC indices, or coagulation variables in a standardized liver injury model. These data suggest that Mirasol-treated FWB is both safe and efficacious in vivo.

Patients on warfarin who present with bleeding or who require an urgent procedure are commonly treated with intravenous (IV) vitamin K, which is supplemented with repletion of the vitamin K factors using either plasma or a prothrombin complex concentrate (PCC). In some such cases, use of vitamin K alone could be adequate to achieve acceptable hemostasis.An algorithm emphasizing the use of vitamin K alone in patients presenting with non-life-threatening bleeding was encouraged, with repeat testing of the international normalized ratio (INR) within 5 hours. Depending on the INR result, patients received no factor repletion or plasma or PCC, as judged by the physician. Leftover samples from a separate cohort of patients with supratherapeutic INRs (INR 4.0) were studied for clotting factor evaluation.A total of 46 pre- and postinfusion INRs were evaluable from 41 patients. Median INR decreased from 5.8 to 2.5, with a median dose of 5 mg after a median time of 4.0 hours postinfusion. A total of 27 of 46 (59%) postinfusion samples showed an INR of 2.5 or less. Samples from patients with the highest INR showed the greatest decline in INR. Samples from supratherapeutic INR patients showed very high Factor VIII:C (200%) and a normal activated partial thromboplastin time in 23 of 50 (46%).Use of IV vitamin K as sole therapy for urgent partial reversal of warfarin for non-life-threatening bleeding may provide adequate hemostasis within 5 hours, avoiding the need for clotting factor repletion.

Background The quality of whole blood (WB)-derived plasma preparations has been the subject of several studies, but there has been a lack of robust, comparative data for the different methods of processing and freezing. Study Design and Methods Six WB-derived plasma units were pooled and split (n = 16) and frozen within either 8 or 24 hours after WB collection, stored at 4°C or at room temperature (RT), and then frozen either slowly at −20°C or rapidly to below −30°C. Plasma units were tested for fibrinogen, Factor (F)V, FVII, FVIII, FXI, and von Willebrand factor (VWF), protein C (PC), protein S (PS) activity and free PS, prothrombin time, and partial thromboplastin time. Results FVIII was reduced by 9% to 19% after having been stored for 24 hours irrespective of storage temperature. Slow freezing (SF) reduced FVIII by 17% to 25% compared to rapid freezing (RF) to below −30°C. Storage temperature, but not 24-hour storage, decreased PS activity by 20% to 28%. PS activity was 8% to 17% lower in plasma units frozen slowly compared to RF. Storage and freezing had no influence on free PS. SF caused small losses of FVII and FXI activity. Conclusion Twenty-four-hour hold at RT and SF both reduce FVIII levels below 70 U/dL in many plasma units. PS activity is affected substantially by storage temperature and SF, but free PS is not. With regard to plasma quality, freezing to below −30°C within 1 hour is superior to SF at −20°C.

BACKGROUND: The effect of photochemical pathogen reduction (PR) methods on plasma quality has been the subject of several reports but solid comparative data for the different technologies are lacking. STUDY DESIGN AND METHODS: Plasma (n = 24) photoinactivated with methylene blue (MB), riboflavin (RF), or amotosalen (AS) was compared using a pool-and-split design. Samples were taken before and after treatment with each method and tested for coagulation factors (fibrinogen, Factor [F] II, FV, FVIII, F IX, FXI), natural coagulation inhibitors (Protein C [PC], protein S [PS], antithrombin III [AT]), prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin generation (TG). The three methods were mutually compared by repeated-measures analysis of variance. RESULTS: All three PR methods cause significant reduction (p

Background: Fresh-frozen plasma (FFP) is sometimes administered to nonbleeding preterm neonates who are judged to be at risk for bleeding because they have abnormal coagulation tests. The benefits/risks of this practice are not well defined. One limitation to progress is lack of reference intervals for the common coagulation tests, thus limiting precision about whether coagulation tests are indeed abnormal. Study Design and Methods: In a sequential observational study, fetal blood was drawn at preterm birth (≤34 weeks) from the umbilical vein near the placenta. Fibrinogen, prothrombin time, activated partial thromboplastin time, D-dimer, platelet (PLT) count, and mean PLT volume were measured. Reference intervals were constructed using 5th and 95th percentile values. Associations were then sought between abnormal coagulation values at birth and bleeding problems identified during the first week. Results: Coagulation tests were drawn at 175 preterm deliveries and the results were organized into reference intervals by gestational age. No abnormal coagulation value, either alone or in combination, predicted hemorrhage (intraventricular, gastrointestinal, or pulmonary) during the first week. However, fibrinogen exceeding the 95th percentile was associated with evidence of in utero infection/inflammation (correlations with elevated C-reactive protein, p

Increased focus on traumatic coagulopathy over the last decade has led to more aggressive use of hemostatic agents in resuscitation of the massively bleeding patient. Novel formulations of plasma factors and other therapeutics have opened for early intervention to prevent coagulopathy and may even be utilized in the prehospital setting. Careful selection of patients to receive hemostatic agents early during the resuscitation is of great importance due to the potential detrimental effects of this treatment. Several studies have identified coagulation parameters as reliable predictors of massive transfusion, even very early after trauma. Prothrombin time international normalized ratio (PT/INR), activated partial thromboplastin time (aPTT), fibrinogen concentration, and viscoelastic tests such as thrombelastography (TEG) and rotational thrombelastometry (RoTEM) have proved to be of value in predicting massive transfusion when performed in-hospital. PT/INR appears to be slightly more accurate than the other parameters, with a reported sensitivity of 84.8% and an area under the receiver operating curve of 0.87. Comparison studies on PT/INR, aPTT, and viscoelastic assays do suggest that caution should be taken when point-of-care (POC) methods, as opposed to conventional laboratory analyses, are used. Novel techniques for POC measurement of fibrinogen levels are currently being developed, and preclinical data suggest acceptable agreement with conventional methods. A number of factors should be considered regarding the feasibility of POC tests in the prehospital environment. In addition to environmental factors such as temperature, altitude, and humidity, electromagnetic interference issues and operators' skills must be taken into account. Coagulation parameters appear to be a useful tool in identifying patients with increased risk of massive bleeding at an early stage. Further studies are needed to determine if prehospital intervention based on POC analyses improves outcome.

BACKGROUND: Whole blood (WB) has been used in combat since World War I as it is readily available and replaces every element of shed blood. Component therapy has become standard; however, recent military successes with WB resuscitation have revived the debate regarding wider WB use. Characterization of optimal WB storage is needed. We hypothesized that refrigeration preserves WB function and that a pathogen reduction technology (PRT) based on riboflavin and ultraviolet light has no deleterious effect over 21 days of storage. STUDY DESIGN AND METHODS: WB units were stored for 21 days either at 4 C or 22 C. Half of each temperature group underwent PRT, yielding four final treatment groups (n = 8 each): CON 4 (WB at 4 C); CON 22 (WB at 22 C); PRT 4 (PRT WB at 4 C); and PRT 22 (PRT WB at 22 C). Testing was at baseline, Days 1-7, 10, 14, and 21. Assays included coagulation factors; platelet activation, aggregation, and adhesion; and thromboelastography (TEG). RESULTS: Prothrombin time (PT) and partial thromboplastin time increased over time; refrigeration attenuated the effects on PT (p /= 0.009). Aggregation decreased over time (p /= 0.001); losses were attenuated by refrigeration (p /= 0.001). Refrigeration preserved TEG parameters (p /= 0.001) and PRT 4 samples remained within normal limits throughout the study. Refrigeration in combination with PRT inhibited fibrinolysis (p /= 0.001) and microparticle formation (p /= 0.031). Cold storage increased shear-induced platelet aggregation and ristocetin-induced platelet agglutination (p /= 0.032), as well as GPIb-expressing platelets (p /= 0.009). CONCLUSION: The in vitro hemostatic function of WB is largely unaffected by PRT treatment and better preserved by cold storage over 21 days. Refrigerated PRT WB may be suitable for trauma resuscitation. Clinical studies are warranted.

BACKGROUND: Use of liquid plasma (LP) has been reported as early as the mid 1930s. Unlike fresh-frozen plasma (FFP), LP is maintained at 1 to 6°C for up to 40 days after collection and processing. Despite its approved use by the US Food and Drug Administration, the coagulation profile of LP is incompletely described. In this study we evaluate the coagulation profile of LP stored up to 30 days. STUDY DESIGN AND METHODS: LP was prepared by removing plasma from nonleukoreduced whole blood within 24 hours of collection. Three LP units from each ABO group were collected and stored at 1 to 6°C. Plasma aliquots were obtained at Postcollection Days 1 to 5, 10, 15, 20, 25, and 30 and then stored at −70°C. Each aliquot was tested for prothrombin time, activated partial thromboplastin time, and other coagulation and fibrinolytic factors. RESULTS: There was a significant decrease in Factor (F)V, FVII, FVIII, von Willebrand factor (VWF), protein S (PS) activity, and endogenous thrombin potential on Day 15 compared with Day 1. No significant difference was observed for PS antigen, D-dimer, or thrombin-antithrombin complex. At least 50% activity of all measured factors was noted on Day 15, compared to Day 1. Considerable heterogeneity was observed between the different blood groups for FVII, FVIII, and VWF. CONCLUSION: These data demonstrate that LP maintains at least 50% of factor activity and thrombin-generating capacity up to 15 days of refrigerated storage. It may be more appropriate to limit LP storage and supplement with FFP when used for management of massively bleeding patients.

BACKGROUND: Massive transfusion protocols (MTPs) with fixed ratios of blood products may improve outcomes in coagulopathic adult trauma patients. However, there is a paucity of data on transfusion support protocols for pediatric trauma patients, whose mechanisms of injury may differ from those seen in adults. We hypothesized that an MTP would improve outcomes in children, through a balanced blood product resuscitation. STUDY DESIGN AND METHODS: A pediatric trauma MTP, with a fixed ratio of red blood cells (RBCs) : fresh-frozen plasma (FFP) : platelets : cryoprecipitate in quantities based on the patient's weight, was initiated at a pediatric hospital. Data on clinical status, resuscitation volumes, and hospital course were collected and compared to data from pre-MTP trauma patients requiring transfusion. RESULTS: Fifty-three patients were enrolled over a 15-month period and compared to 49 pre-MTP patients. Seventy-two percent of MTP patients had at least one coagulation value outside of the normal range upon emergency department (ED) arrival, and the median time to FFP transfusion decreased fourfold after MTP implementation (p

BACKGROUND: Massive transfusion (MTP) protocol design is hindered by lack of accurate assessment of coagulation. Rapid thrombelastography (r-TEG) provides point-of-care (POC) analysis of clot formation. We designed a prospective study to test the hypothesis that integrating TEG into our MTP would facilitate goal-directed therapy and provide equivalent outcomes compared to conventional coagulation testing. STUDY DESIGN AND METHODS: Thiry-four patients who received more than 6 units of red blood cells (RBCs)/6 hours who were admitted to our Level 1 trauma center after r-TEG implementation (TEG) were compared to 34 patients admitted prior to TEG implementation (Pre-TEG). Data are presented as mean ± SEM. RESULTS: Emergency department pre-TEG versus TEG shock, and coagulation indices, were not different: systolic blood pressure (94 mmHg vs.101 mmHg), temperature (35.3°C vs. 35.9°C), pH (7.16 vs. 7.11), base deficit (−13.0 vs. −14.7), lactate (6.5 vs. 8.1), international normalized ratio (INR; 1.59 vs. 1.83), and partial thromboplastin time (48.3 vs. 57.9). Although not significant, patients with Injury Severity Score range 26 to 35 were more frequent in the pre-TEG group. Fresh-frozen plasma (FFP) : RBCs, platelets : RBCs, and cryoprecipitate (cryo) : RBC ratios were not significantly different at 6 or 12 hours. INR at 6 hours did not discriminate between survivors and nonsurvivors (p = 0.10), whereas r-TEG “G” value was significantly associated with survival (p = 0.03), as was the maximum rate of thrombin generation (MRTG; mm/min) and total thrombin generation (TG; area under the curve) (p = 0.03 for both). Patients with MRTG of more than 9.2 received significantly less components of RBCs, FFP, and cryo (p = 0.048, p = 0.03, and p = 0.04, respectively). CONCLUSION: Goal-directed resuscitation via r-TEG appears useful for management of trauma-induced coagulopathy. Further experience with POC monitoring could result in more efficient management leading to a reduction of transfusion requirements.

BACKGROUND: Coagulopathy after cardiopulmonary bypass (CPB) is caused by multiple perturbations in cellular and humoral elements of coagulation. A timely and comprehensive method to evaluate hemostasis would be helpful in the management of bleeding patients after CPB. The assessment of whole blood coagulation using rotation thromboelastometry (ROTEM) was compared to coagulation tests routinely performed during cardiac surgery. STUDY DESIGN AND METHODS: Blood was obtained from 26 patients undergoing CPB surgery at baseline, at 60 minutes on CPB, at the end of CPB, and on admission to intensive care unit. ROTEM tests (extrinsically activated [EXTEM], intrinsically activated [INTEM], specific clot formation [FIBTEM]), prothrombin time, activated partial thromboplastin time, platelet (PLT) count, fibrinogen, prothrombin level, antithrombin level, and thrombin generation (TG) measurement were performed. RESULTS: We observed strong correlations between FIBTEM-amplitude at 10 minutes (A10) and fibrinogen level (r = 0.87; p

BACKGROUND: Little data are available on the suitability of frozen plasma for transfusion when stored outside its normal temperature, which is the focus of investigation in this study. STUDY DESIGN AND METHODS: Plasma was pooled and split to create 10 identical units on each of 24 occasions (12 Group A and O). Plasma was frozen and stored at −40°C for 2 weeks and then one of each of the 10 identical units was subjected to one of the following deviations in storage temperature: −18°C for 1 week, 1 month, or 2 months; −10°C for 1 week, 1 month, or 2 months; 4°C for 4, 24, or 72 hours; or stored at −40°C (control) before returning all units to −40°C. RESULTS: Factor VIII was only significantly reduced when plasma was stored at 4°C for 24 hours or more or −10°C for 1 week. For all other arms of the study, the majority of units of plasma (>75%) remained above 0.70 IU/mL and more than 95% were above the lower limit of normal (0.50 IU/mL). The prothrombin time ratio only increased after storage at −10°C for 1 month or more, and the activated partial thromboplastin time ratio after storage at 4°C for 24 hours. None of the deviations in storage resulted in a decrease in fibrinogen activity. CONCLUSION: These data suggest that plasma that has been stored at −40°C and exposed to storage temperatures and times of up to 4 hours at 4°C, 1 week at −10°C or 2 months at −18°C meets EU guidelines and is suitable for transfusion.

BACKGROUND: Several groups have reported that a fraction of severely injured patients have abnormal coagulation tests at presentation to trauma centers, even in the absence of significant crystalloid resuscitation. These patients have high mortality, but their prevalence in trauma populations is not clear from the reports. STUDY DESIGN AND METHODS: Records of all patients admitted to a large urban trauma center during 2000 through 2006 were searched for early measures of common coagulation tests and in-hospital mortality. RESULTS: Abnormal coagulation tests were increasingly frequent with increasing injury severity, ranging from 5 to 43 percent for the prothrombin time as the injury severity scores (ISSs) increased from 5 to more than 45 and 4 to 18 percent for platelet counts of less than 150 × 109 per L. Abnormal coagulation tests were associated with excess mortality even below conventional transfusion triggers and this was especially true for the partial thromboplastin time. CONCLUSIONS: Abnormal coagulation tests are common in severely injured patients. Even in the moderately injured, they are associated with higher mortality.

BACKGROUND: Early identification of patients with increased risk of excessive bleeding and transfusion after cardiac surgery offers the possibility to initiate countermeasures. Fibrinogen is a key protein in the coagulation cascade and thus a potential biomarker for bleeding. We investigated the relationship between preoperative fibrinogen plasma concentration and postoperative bleeding and transfusion after coronary artery bypass grafting (CABG). STUDY DESIGN AND METHODS: A total of 170 patients (mean age, 67 ± 9 years; 75% men) undergoing isolated CABG were included in a prospective observational study. Patient variables (age, sex, operation time, anticoagulation therapy), preoperative laboratory variables (platelet [PLT] count, activated partial thromboplastin time, prothrombin time, and fibrinogen), postoperative bleeding volume, and transfusions during hospital stay were registered. Independent predictors of bleeding volume and transfusion were identified with multiple regression models. RESULTS: Postoperative bleeding volume correlated univariately with preoperative fibrinogen concentration (r = −0.53, p < 0.001) and PLT count (r = −0.26, p = 0.001) but only preoperative fibrinogen concentration was an independent predictor of postoperative bleeding volume. Twenty-nine of the 170 patients (17%) received transfusions with blood products. Independent predictors of transfusion were preoperative fibrinogen concentration (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.1-3.7 per 1-unit decrease; p = 0.027), female sex (OR, 5.0; 95% CI, 1.8-14.7; p = 0.002), and aortic cross-clamp time (OR, 1.03; 95% CI, 1.01-1.06 per minute; p = 0.013). CONCLUSION: The results indicate that preoperative fibrinogen concentration (even within the normal range) is a limiting factor for postoperative hemostasis. Preoperative measurement of fibrinogen concentration provides information about bleeding volume and transfusion requirements after CABG.

Background The aim of this study was to investigate the effect of gamma irradiation with 30 Gy on the coagulation system in leukoreduced fresh-frozen plasma (FFP). Study design and methods In 74 FFP units that had been stored for 352 +/- 103 days below -30 degrees C, the following variables were determined in parallel in an irradiated and not irradiated half: prothrombin time (PT); activated partial thromboplastin time (APTT); thrombin time; antithrombin III; protein C; protein S; von Willebrand factor antigen; ristocetin cofactor; plasminogen-alpha(2)-antiplasmin; the coagulation factors fibrinogen, factor (F)II, FV, FVII, VIII, F IX, FX, FXI, FXII, FXIII, and activated factor XII (FXIIa); D-dimer; fibrin monomer; thrombin-antithrombin complex; prothrombin fragment 1 + 2 (F1+2); plasmin-alpha(2)-antiplasmin complexes (PAPs); and platelet factor 4. The FVII activity ratio was assayed to quantify activation of FVII. Results Irradiation with 30 Gy resulted in a reduction of APTT (35.0 +/- 4.1 sec vs. 34.4 +/- 4.1 sec; p = 0.00000006) and PT (89.8 +/- 8.2% vs. 90.7 +/- 8.0%; p = 0.002) and a significant increase of the activities of the coagulation factors FII, FV, FVII, F IX, FX, and FXII. FVIII activity decreased from 118 +/- 31 to 116 +/- 32 percent (p = 0.02). Activation of the coagulation system was shown by an increase in the FVII activity ratio (1.19 +/- 0.29 vs. 1.31 +/- 0.34; p = 0.0000001), FXIIa (0.81 +/- 0.50 ng/mL vs. 0.90 +/- 0.51 ng/mL; p = 0.006), and F1+2 (1.19 +/- 0.20 nmol/L vs. 1.24 +/- 0.20 nmol/L; p = 0.000005) after irradiation with 30 Gy, whereas an increase of PAP (16.2 +/- 11.5 ng/mL vs. 20.2 +/- 12.0 ng/mL; p = 0.0004) demonstrated activation of the fibrinolytic system. No negative influence of irradiation with 30 Gy on inhibitors of coagulation was observed. Conclusion Gamma irradiation of leukoreduced FFPs with 30 Gy results in a significant but very weak activation of the coagulation and fibrinolytic system in FFPs.

BACKGROUND: Continued hemorrhage remains a major contributor of mortality in massively transfused patients and those who survive have a higher platelet (PLT) count and a shorter prothrombin time and activated partial thromboplastin time (APTT) than nonsurvivors. It was considered that early substitution with PLTs and fresh-frozen plasma (FFP) would prevent development of coagulopathy and thus improve survival. STUDY DESIGN AND METHODS: Survival of patients undergoing surgery for a ruptured abdominal aortic aneurysm (rAAA) was compared after implementing a proactive transfusion therapy encompassing two pooled buffy-coat PLT concentrates (PBPCs) immediately when a rupture of the aorta was suspected and again 30 minutes before aortic unclamping together with FFP administered in a 1:1 ratio to the amount of red blood cells (RBCs) with that of a control group receiving transfusion therapy according to existing recommendations. RESULTS: The intervention group (n = 50) had a higher PLT count at arrival at the intensive care unit compared to the control group (n = 82; 155 × 109/L vs. 69 × 109/L; p

BACKGROUND: Fresh-frozen plasma (FFP) is frequently transfused to patients with mild prolongation of coagulation values under the assumption that FFP will correct the coagulopathy. There is little evidence to support this practice, however. To determine the effect of FFP on coagulation variables and correlation with bleeding in patients with mildly prolonged coagulation values, a prospective audit of all FFP transfusions at the Massachusetts General Hospital between September 2, 2004, and September 30, 2005, was performed. STUDY DESIGN AND METHODS: All patients transfused with FFP for a pretransfusion prothrombin time (PT) between 13.1 and 17 seconds (international normalized ratio [INR], 1.1-1.85) and with a follow-up PT-INR within 8 hours of transfusion were included. Of 1091 units of FFP transfused, follow-up coagulation values within 8 hours were available for 121 patients (324 units). RESULTS: Transfusion of FFP resulted in normalization of PT-INR values in 0.8 percent of patients (95% confidence interval [CI], 0.0020-0.045) and decreased the PT-INR value halfway to normalization in 15.0 percent of patients (95% CI, 0.097-0.225). Median decrease in PT was 0.20 seconds (median decrease in INR, 0.07). Pretransfusion PT-INR, partial thromboplastin time, platelet count, and creatinine values had no correlation with red blood cell loss. CONCLUSION: It is concluded that transfusion of FFP for mild abnormalities of coagulation values results in partial normalization of PT in a minority of patients and fails to correct the PT in 99 percent of patients.

BACKGROUND: Photochemical treatment (PCT) with amotosalen HCl (S-59) was developed to inactivate pathogens and white blood cells in plasma (PCT-FFP) used for transfusion support. STUDY DESIGN AND METHODS: An open-label, multicenter trial was conducted in patients with congenital coagulation factor deficiencies (factors [F]I, FII, FV, FVII, FX, FXI, and FXIII and protein C) to measure the kinetics of specific coagulation factors, hemostatic efficacy, and safety of PCT-FFP. Posttransfusion prothrombin time (PT), partial thromboplastin time (PTT), and clinical hemostasis were evaluated before and after PCT-FFP transfusions. RESULTS: Thirty-four patients received 107 transfusions of PCT-FFP for kinetic studies or therapeutic indications (mean dose, 12.8 ± 8.5 mL/kg). Incremental factor recoveries ranged from 0.9 to 2.4 IU per dL per IU per kg (FII, FV, FVII, FX, FXI, and protein C). Mean pretransfusion PT (20.7 ± 22.2 sec) corrected after PCT-FFP (13.8 ± 2.4 sec, p