Evaluation and comparison of coagulation factor activity in fresh-frozen plasma and 24-hour plasma at thaw and after 120 hours of 1 to 6°C storage

Use of group a thawed plasma in emergency transfusions at a pediatric quaternary care center

BACKGROUND

Balanced plasma/red blood cell transfusions have shown survival benefit in emergency scenarios. To improve plasma availability, we implemented 5-day group A thawed plasma at our pediatric hospital in February 2021.

STUDY DESIGN AND METHODS

We maintain thawed group A plasma units (5-day shelf-life) ready for immediate issue in the blood bank (since February 2021) and trauma code room (since August 2022). Group A plasma (un-titered) is issued for patients with unknown blood type during emergencies. We retrospectively reviewed records and laboratory results of recipients to assess safety and identify possible adverse events related to incompatible plasma.

RESULTS

Between February 2021 and December 2023, 173 emergency plasma requests occurred for 161 patients. Ninety-one occurred with massive transfusion protocol activations. Thirty-six patients (22.4%) were blood group B or AB, and 23 received incompatible plasma (age 0-21.3 years, weight 0.74-149.8 kg, incompatible plasma dose 4.0-428.4 mL/kg). These patients did not have any differences in survival outcomes or hospital lengths of stay (LOS) compared with compatible plasma recipients, mirroring the adult experience. None experienced adverse events related to group A plasma. No transfusion reactions were reported. No increase in wastage/outdate occurred upon thawed plasma implementation (2020 versus 2021 to 2023, 7.73% [133/1721] vs. 8.58% [497/5792], p = .284).

CONCLUSIONS

We implemented 5-day group A thawed plasma. Units are rapidly available from the blood bank and trauma code room without increased wastage. We did not identify any transfusion-associated adverse events in pediatric recipients of incompatible group A plasma.

A Contemporary Review of Blood Transfusion in Critically Ill Patients

Blood transfusion is a common therapeutic intervention in hospitalized patients. There are numerous indications for transfusion, including anemia and coagulopathy with deficiency of single or multiple coagulation components such as platelets or coagulation factors. Nevertheless, the practice of transfusion in critically ill patients has been controversial mainly due to a lack of evidence and the need to consider the appropriate clinical context for transfusion. Further, transfusion carries many risk factors that must be balanced with benefits. Therefore, transfusion practice in ICU patients has constantly evolved, and we endeavor to present a contemporary review of transfusion practices in this population guided by clinical trials and expert guidelines.

Pro-Con Debate: Viscoelastic Hemostatic Assays Should Replace Fixed Ratio Massive Transfusion Protocols in Trauma

Major trauma patients at risk of traumatic coagulopathy are commonly treated with early clotting factor replacement to maintain hemostasis and prevent microvascular bleeding. In the United States, trauma transfusions are often dosed by empiric, low-ratio massive transfusion protocols, which pair plasma and platelets in some ratio relative to the red cells, such as the "1:1:1" combination of 1 units of red cells, 1 unit of plasma, and 1 donor's worth of pooled platelets. Empiric transfusion increases the rate of overtransfusion when unnecessary blood products are administered based on a formula and not on at patient's hemostatic profile. Viscoelastic hemostatic assays (VHAs) are point-of-care hemostatic assays that provided detailed information about abnormal clotting pathways. VHAs are used at many centers to better target hemostatic therapies in trauma. This Pro/Con section will address whether VHA guidance should replace empiric fixed ratio protocols in major trauma.

The activity of labile coagulation factors and fibrinogen in thawed plasma during a 5 day storage period in the hospital blood bank refrigerator

BACKGROUND

Fresh frozen plasma (FFP) is used to treat coagulation disorders. Even though the activity of labile coagulation factors gradually decreases once thawed, it can be used up to 24 h after thawing, if stored properly. In this study, the level of coagulation factor activity was evaluated in thawed plasma during a 5 day storage period.

MATERIALS AND METHODS

This cross-sectional study was performed on 40 FFP units prepared in Yazd Blood Center. Samples were thawed in a waterbath for 20-30 min at 30-37°C and then stored in the hospital blood bank refrigerator. The level of fibrinogen concentration, as a stable factor and, coagulation factors V and VIII, as labile factors, were measured in the plasma immediately following the thawing process as well as 24 and 120 h after the process. Data analysis was performed using SPSS software 20.

RESULTS

The fibrinogen level remained stable for up to 24 h after thawing; after 120 h there was a 1.66% decrease with the mean level of 334.0 ± 53.3 mg/dl. The mean activity of factors V and VIII levels decreased by 12.3%, and 26% respectively over 120 h after thawing when compared to that after 24 h. A 120 h after thawing Factor V activity was above 70% in 87.5% of thawed plasmas and its mean activity was 81.6 ± 11.8. Factor VIII activity was above 70% in only 35% of thawed plasmas with the mean activity of 64.4 ± 17.2.

CONCLUSION

Thawed plasma can be used for up to 5 days in all therapeutic applications of FFP since it still has the essential hemostatic effects. However, in situations where higher levels of FVIII are needed, Thawed Plasma is not a suitable alternative. In such cases FFP, FVIII concentrate or cryoprecipitated antihemophilic factor should be used.

Challenging the 30-min rule for thawed plasma

BACKGROUND AND OBJECTIVES

Frozen plasma (FP) is thawed prior to transfusion and stored for ≤5 days at 1-6°C. The effect of temperature excursions on the quality and safety of thawed plasma during 5-day storage was determined.

MATERIALS AND METHODS

Four plasma units were pooled, split and stored at ≤-18°C for ≤90 days. Test units T30 and T60 were exposed to 20-24°C (room temperature [RT]) for 30 or 60 min, respectively, on days 0 and 2 of storage. Negative and positive control units remained refrigerated or at RT for 5 days, respectively. On Day 5, test units were exposed once to RT for 5 h. Quality assays included stability of coagulation factors FV, FVII, FVIII, fibrinogen and prothrombin time. Bacterial growth was performed in units inoculated with ~1 CFU/ml or ~100 CFU/ml of Serratia liquefaciens, Pseudomonas putida, Pseudomonas aeruginosa or Staphylococcus epidermidis on Day 0.

RESULTS

Testing results of all quality parameters were comparable between T30 and T60 units (p < 0.05). Serratia liquefaciens proliferated in cold-stored plasma, while P. putida showed variable viability. Serratia epidermidis and P. aeruginosa survived but did not grow in cold-stored plasma. Positive and negative controls showed expected results. Overall, no statistical differences in bacterial concentration between T30 and T60 units were observed (p < 0.05).

CONCLUSION

Multiple RT exposures for 30 or 60 min do not affect the stability of coagulation factors or promote bacterial growth in thawed plasma stored for 5 days. It is therefore safe to expose thawed plasma to uncontrolled temperatures for limited periods of 60 min.

The prehospital use of younger age whole blood is associated with an improved arrival coagulation profile

INTRODUCTION

Recent in vitro data have shown that the hemostatic profile of whole blood (WB) degrades significantly after 14 days, yet the optimal storage remains debated. We hypothesized that arrival coagulation studies would be improved in patients receiving younger WB in the prehospital setting.

METHODS

This study was approved by our institutional institutional review board. We evaluated all trauma patients who received prehospital blood products by our helicopter service between July 2017 and July 2019. "Young" WB was defined as 14 days or less. Patients who received at least 1 U of young WB were classified as YOUNG, while the remainder was classified as OLD. Continuous data are presented as medians (25th-75th interquartile range) with comparisons performed using Wilcoxon rank sum. Assessments of clinical hemostatic potential included arrival platelet cell count and rapid thrombelastography. Multivariate regression analysis was also performed (Stata 12.1; College Station, TX).

RESULTS

A total of 220 patients received prehospital WB during the study period. Of these, 153 patients received YOUNG WB, while 67 were transfused only OLD WB units. There were no differences in demographics, prehospital or arrival physiology, or Injury Severity Score among the two groups. The measures of clot initiation (activated clotting time) and kinetics (k time) were improved, as were the measures of clot acceleration/fibrinogen function (angle) and platelet function (maximum amplitude). As well, arrival platelet count was higher in the YOUNG cohort. No significant differences in postarrival transfusion were noted (p = 0.220). Multivariate analysis showed the greatest differences in maximum amplitude and α angle but failed to reach significance.

CONCLUSION

Previous in vitro data have suggested deterioration of platelet function in cold-stored WB after 14 days. The current study demonstrated decreased global hemostasis by clinically available laboratory tests, especially related to fibrinogen and platelet interactions on univariate, but not multivariate analysis. This did not translate into increased transfusion requirements. Further studies are needed to determine the optimal storage duration for cold-stored WB for transfusion in the bleeding trauma patient, as well as rule out the presence of confounding variables.

LEVEL OF EVIDENCE

Therapeutic, level IV.

10 Years of Experience with the First Thawed Plasma Bank in Germany

<b><i>Background:</i></b> Plasma is stored at –30°C, which requires thawing before transfusion, causing a time delay between ordering and issuing of at least 30 min. In case of bleeding emergencies, guidelines strongly recommend a 2:1 transfusion ratio of RBCs and plasma. In addition, each minute delay in issuing of blood products in bleeding emergencies increases the mortality risk. To provide plasma in time in bleeding emergencies, a thawed plasma bank was introduced in 2011. <b><i>Summary:</i></b> The thawed plasma bank of University Medicine Greifswald has provided 18,924 thawed stored plasma units between 2011 and 2020. The workflow in the laboratory as well as in the emergency room, the operating room, and the intensive care unit have been optimized by thawed stored plasma. In case of emergencies, the stress factor for the transfusion medicine laboratory staff has been reduced substantially. The thawed plasma bank allows to transfuse patients with massive transfusion demand at a 2:1 ratio of RBCs and plasma according to guidelines. To reduce storage time, we issue all plasma requests from the thawed plasma bank except for pediatric patients. This results in a median storage time in the thawed plasma bank of 24 h. The “just in time” availability of plasma within the entire hospital based on the thawed plasma bank has reduced precautionary ordering of plasma, and hereby the unnecessary use of plasma. After introduction of the thawed plasma bank, plasma usage decreased substantially by 24% within the first year and by 60% compared to 2019/2020. However, as the overall approach to using blood products has changed over the last 10 years due to the patient blood management initiative, quantification of the effects of the thawed plasma bank in reduction of plasma transfusion is difficult. <b><i>Key Messages:</i></b> (1) A thawed plasma bank for the routine supply of blood products in a large hospital is feasible in Germany. (2) The thawed plasma bank allows to supply RBCs and plasma in a 2:1 ratio in bleeding emergencies. (3) The beneficial logistical effects of the thawed plasma bank are optimal if all plasma requests are supplied from the thawed plasma bank. This results in a median storage time of 24 h for thawed plasma.

Factor V activity in apheresis platelets: Implications for management of FV deficiency

BACKGROUND

Allogeneic platelet (PLT) infusion is a strategy to raise Factor V (FV) levels in patients with congenital FV deficiency. However, since FV is labile in vitro, we hypothesized that FV activity could be low in PLT units.

STUDY DESIGN AND METHODS

FV activity was tested using a prothrombin time-based platform in the supernatant and platelet lysate (PL) of apheresis PLT units (16 units stored in PLT additive solution with acetate and phosphate [PAS-C] and 10 units stored in plasma only), on post-collection days 3-6. Statistical analysis was performed using Student's t test (P < .05).

RESULTS

FV activity was severely diminished in PAS-C PLTs (N = 16) supernatant (3.70% ± 1.02%) and PL (3.26% ± 1.02%). FV activity in plasma-only PLTs (N = 10) was lower in both supernatant (44.55% ± 6.46%) and lysate (39.67% ± 6.33%) relative to normal plasma levels, but both were significantly higher (P < .0001) compared to PAS-C PLTs. In a separate set of experiments, FV activity in PAS-C PLTs examined serially over storage time (N = 3 for these experiments) showed that FV levels were reduced by day 3 and not significantly different by day 5 of storage (Day 3 supernatant 5.03% ± 1.41%; Day 5 supernatant: 3.10% ± 0.57%; P = .2; Day 3 lysate: 3.89% ± 1.03%; Day 5 lysate: 2.61% ± 0.41%; P = .4).

CONCLUSION

Plasma should be considered over PLTs as first-line therapy for non-complex FV deficiency-associated hemorrhage. If PLTs are considered for transfusion, plasma-only PLT units should be preferentially utilized, as PAS-C PLT have near-absent FV activity.

Comparing hemostatic resuscitation management of intraoperative massive bleeding with traumatic massive bleeding: a computer simulation

Background

Appropriate blood component transfusion might differ between intraoperative massive bleeding and traumatic massive bleeding in the emergency department because trauma patients initially bleed undiluted blood and replacement typically lags behind blood loss. We compared these two blood loss scenarios, intraoperative and traumatic, using a computer simulation.

Methods

We modified the multi-compartment dynamic model developed by Hirshberg and implemented it using STELLA 9.0. In this model, blood pressure changes as blood volume fluctuates as bleeding rate and transcapillary refill rate are controlled by blood pressure. Using this simulation, we compared the intraoperative bleeding scenario with the traumatic bleeding scenario. In both scenarios, patients started to bleed at a rate of 50 ml/min. In the intraoperative bleeding scenario, fluid was administered to maintain isovolemic status; however, in the traumatic bleeding scenario, no fluid was supplied for up to 30 min and no blood was supplied for up to 50 min. Each unit of packed red blood cells (PRBC) was given when the hematocrit decreased to 27%, fresh frozen plasma (FFP) was transfused when plasma was diluted to 30%, and platelet concentrate (PC) was transfused when platelet count became 50,000/ml.

Results

In both scenarios, the appropriate ratio of PRBC:FFP was 1:0.47 before PC transfusion, and the ratio of PRBC:FFP:platelets was 1:0.35:0.39 after initiation of PC transfusion.

Conclusion

The ratio of transfused blood component did not differ between the intraoperative bleeding and traumatic bleeding scenarios.

Thawed solvent/detergent-treated plasma demonstrates comparable clinical efficacy to thawed plasma

BACKGROUND

Thawed Plasma (TP), plasma thawed and refrigerated for up to 5 days, is a commonly transfused plasma product. This pilot study was conducted to determine whether Thawed Solvent/Detergent-treated Plasma stored refrigerated for up to 5-days post-thaw (T-S/D) was as efficacious as TP.

STUDY DESIGN AND METHODS

This single institution retrospective cohort analysis evaluated the efficacy of T-S/D in reversing coagulopathies in comparison to TP. Utilizing the institution's electronic medical records, transfusion data were collected in adult patients who received either TP or T-S/D. The primary outcome was the incidence of subsequent transfusions within 24 hours after first dose of either type of plasma. Secondary outcomes included the number of blood products transfused within 24 hours of first-dose plasma, correction of pre-transfusion coagulation laboratory values, volume transfused, and clinical outcomes.

RESULTS

TP was received by 301 patients and 137 received T-S/D during the first 32 months post-implementation of T-S/D. There was no difference in incidence of subsequent transfusions or number of blood products given. The median pre-INR of both the TP and T-S/D cohorts was 1.9, with a similar decrease in INR of 0.2 and 0.3 (p = 0.36), respectively, post plasma transfusion. There was no difference in correction of PT/aPTT, mortality, transfusion reactions, readmission rates, length of stay, or inpatient deep venous thrombosis. The median volume of T-S/D plasma transfused for the first dose was 126 mL less than TP (p = .0001).

CONCLUSION

T-S/D was as efficacious as TP for the treatment of coagulopathies and the reversal of coagulation laboratory values.

Prolonged (post-thaw) shelf life of -80°C frozen AB apheresis plasma

BACKGROUND

Early plasma transfusion is important in the treatment of patients with major hemorrhage. Prolonged shelf life of AB type frozen −80°C and cold‐stored (4°C) deep frozen plasma (DFP) will improve strategic stock management, minimize need for resupply, and make pre‐hospital implementation more feasible.

METHODS AND MATERIALS

Plasma products type AB of different age and origin (−30°C Fresh Frozen [(FFP], −80°C DFP [short (±1 year) and long (±7 year)] stored) were thawed (Day 0), stored at 4°C, and sampled on Days 7 and 14. Additionally, samples of plasma containing blood products (Octaplas LG®, whole blood and platelets) were compared for coagulation factor activity, phospholipid clotting time (PPL), and kaolin TEG during 4°C or 22°C storage.

RESULTS

Coagulation profiles of FFP, short‐ and long‐stored −80°C DFP were not significantly different after thaw. Cold storage did not affect fibrinogen, Protein C, and Antithrombin III activities whereas factor V, VII, VIII, and Protein S decreased in all blood products. After 14 days DFP still meets the guidelines for clinical use, except for Protein S (0.4 IU/mL). With exception of Octaplas LG®, phospholipid activity and TEG coagulation were similar between plasma containing blood components during storage.

CONCLUSION

AB DFP quality was unaffected by almost 7 years of frozen storage. Quality of thawed 14‐day stored AB DFP met, with exception of Protein S, all minimal guidelines which implies that its quality is sufficient for use in the (pre)‐hospital (military) environment for treatment of major hemorrhage.

Coagulation factor activity in units of leukoreduced and nonleukoreduced canine fresh-frozen plasma

OBJECTIVE

To evaluate coagulation factors in units of leukoreduced (LR) and nonleukoreduced (non-LR) canine fresh-frozen plasma (cFFP).

ANIMALS

8 healthy research dogs.

PROCEDURES

In a crossover study, dogs were randomly assigned to 1 of 2 groups from which blood was collected and either did or did not undergo leukoreduction. After a recovery period of ≥ 28 days, the dogs were switched between protocols. After each collection, blood samples were centrifuged, and cFFP was stored frozen for later comparative analysis of coagulation factors, antithrombin, and protein C activities (reported as comparative percentages of the corresponding activities determined in a canine pooled plasma standard); prothrombin and activated partial thromboplastin times; and fibrinogen concentration.

RESULTS

There were no significant differences detected between results for LR cFFP, compared with those for non-LR cFFP.

CONCLUSIONS AND CLINICAL RELEVANCE

Although there was variation among residual activities of coagulation factors in LR and non-LR cFFP, the variations and differences were considered unlikely to impact the efficacy of LR cFFP transfused for coagulation factor replacement in dogs. However, owing to the small sample size and high variability of results in the present study, additional research with a larger sample size is required for definitive conclusions on the effects of leukoreduction on coagulation factors in cFFP and to develop treatment guidelines for LR cFFP use in dogs with congenital and acquired coagulopathies.

Effects of storage over a 36-month period on coagulation factors in a canine plasma product obtained by use of plasmapheresis

OBJECTIVE

To evaluate stability of coagulation factors in canine plasma obtained by use of plasmapheresis and stored over a 36-month period.

SAMPLE

Canine plasma obtained by use of plasmapheresis acquired from a commercial blood bank.

PROCEDURES

Coagulation testing for fibrinogen concentration and activity of factors II, V, VII, VIII, and IX and von Willebrand factor was performed on canine plasma obtained by use of plasmapheresis. Samples were obtained for testing at 6-month intervals from plasma stored for up to 36 months.

RESULTS

A simple mixed linear regression model was created for each analysis. Median value for the fibrinogen concentration was > 150 mg/dL for all time points, except at 467, 650, and 1,015 days of storage. Median value for factor VIII was > 70% only at 650 days. Median value for factor V was > 50% through 650 days. Median value for factors VII and X was > 50% through 833 days, and median value for factors II and VII was > 50% through 1,015 days. Median value for von Willebrand factor was > 50% for the entire study (1,198 days). Median value for factor X was always < 50%.

CONCLUSIONS AND CLINICAL RELEVANCE

Coagulation factors degraded over time at variable rates, and all labile factors remained at > 50% activity for longer than 1 year. Plasma collected by plasmapheresis potentially offers prolonged life span of some clotting factors. Plasmapheresis is an acceptable form of canine plasma collection for transfusion purposes, and further studies should be performed to determine all of its benefits.

Reduction in Operating Room Plasma Waste After Evidence-Based Quality Improvement Initiative

Anesthesiologists request units of plasma in anticipation of transfusion. The amount of plasma transfused intraoperatively is less than that issued (requested, thawed, and sent). We presented institutional-specific data on plasma usage including anesthesiologist-specific ratios of plasma issued-to-transfused. In month-to-month comparisons from the year before the presentation (June-December 2015) to 7 months after (June-December 2016), plasma issued to the operating room was reduced from 434.9 ± 81 to 327.3 ± 65 units, a change of 107.6 units per month (95% confidence interval [CI], 22-193); plasma discarded by the blood bank was reduced from 109.7 ± 48 units to 69.1 ± 9 units, a change of 40.6 units per month (95% CI, 0.2-81); and plasma transfused went from 188.4 ± 42 units to 160.7 ± 52 units, a nonsignificant change of 27.7 units per month (95% CI, -27 to 83).

Clotting factor activity in fresh frozen plasma after thawing with a new radio wave thawing device

BACKGROUND

Massive hemorrhage usually results in rapid need of blood products. Patients in need of fresh frozen plasma (FFP) might benefit from shorter thawing times using a novel radio wave device. So far, only one study on the prototype has been published. Activities of clotting factors after thawing FFP with the radio wave device and with a system using water cushions were compared. This is the first study analyzing the quality of FFP using the fully developed radio wave thawing device UFT100.

STUDY DESIGN AND METHODS

Thirty FFP units were thawed with the UFT100 and the Plasmatherm machine. Various clotting factors and inhibitors were analyzed before freezing, immediately after thawing, and after a 48-hour storage period at +4°C.

RESULTS

After thawing, all factor activities were within normal ranges regardless of the thawing procedure. We observed significant differences in nearly all clotting factor activities regarding time as effector, whereas thawing with the Plasmatherm machine led to a significant decrease (>10%) only in factor V activity compared to the UFT100.

CONCLUSIONS

Immediately after rapid thawing with the UFT100, all FFP units contained adequate coagulation factor activities to maintain hemostatic activity. The UFT100 does not deteriorate FFP quality compared to a conventional system. Regardless of the thawing system, the postthaw refrigerated storage caused a decrease in several clotting factors and inhibitors (factors V, VIII, and IX; von Willebrand factor activity; protein S and C activity) and a significant increase of factor XI.

Coagulation Factor Activities Changes Over 5 Days in Thawed Fresh Frozen Plasma Stored at Different Initial Storage Temperatures

Thawed plasma is fresh frozen plasma (FFP) that has been stored for 5 days at 1-6 °C. Duration of storage and different storage temperatures might affect the coagulation factor activity in thawed FFP. This study measured the changes of coagulation factor activities over 5 days in thawed FFP and stored at two different initial storage temperatures. Thirty-six units of FFP, which consisted of nine units each from blood groups A, B, AB, and O, were thawed at 37 °C. Each unit was divided into two separate groups (Group A and Group B) based on initial storage temperature. The first group was stored at 2-6 °C for 5 days (Group A). The second group was stored at 20-24 °C for initial 6 h followed by 2-6 °C for 5 days (Group B). Prothrombin time (PT), activated partial thromboplastin time (APTT), coagulation factor activities of fibrinogen, factor (F) II, FV, FVII, FVIII, FIX, FX, and von Willebrand factor antigen (vWF Ag) were assessed at baseline after thawing, at 6 h, and on days 1, 3, and 5 of storage for both groups. All coagulation factors mean activities in both storage groups decreased significantly over 5 days of storage. The mean FVIII activity at day 5 of storage was 36.9% in Group A and 39.8% in Group B. The other coagulation factors mean activities were > 50% on day 5 of storage in both groups. The coagulation factor activities of thawed FFP stored for 5 consecutive days were reduced in the two storage groups but most of the activities were still above 30%. This study suggests that thawed FFP stored for 5 days has the potential to ameliorate coagulation factor deficiencies in affected patients.

Fresh-Frozen Plasma: Ordering Patterns and Utilization in the Operating Rooms of a Tertiary Referral Hospital

BACKGROUND

Blood product transfusion is the most commonly performed hospital procedure. Intraoperative blood product utilization varies between institutions and anesthesiologists. In the United States in 2011, nearly 4 million plasma units were transfused.

METHODS

A retrospective analysis of intraoperative plasma ordering patterns and utilization (thawing and transfusing) was performed at a tertiary, academic hospital between January 2015 and March 2016.

RESULTS

Over 15 months, 46,002 operative procedures were performed. In 1540 of them, plasma was thawed or transfused: 8297 plasma units were thawed and 3306 of those units were transfused. These 3306 plasma units were transfused in 749 cases with a median of 2 plasma units (interquartile range, 2-4) transfused. The percentage of average monthly procedures with plasma thawed and none transfused was 51.3% (confidence interval, 49.0%-53.6%). The cardiac surgery service requested the greatest number of plasma units to be thawed (2143) but only transfused 712 (33.2%) of them. Of all plasma units not transfused, 45% were generated by procedures with 1 to 4 units of plasma thawed; 95.7% of these units were thawed as even integers (ie, 2, 4).

CONCLUSIONS

For operative procedures, far more plasma was thawed than was transfused and this practice occurred across surgical specialties and anesthesiologists. Considering the plasma that was not transfused, 45% occurred in procedures with 4 or fewer units of plasma requested suggesting these low-volume requests were a primary source of potential waste. Further studies are needed to examine associations between plasma utilization and clinical outcomes.

Quasi-static acoustic tweezing thromboelastometry

Essentials Blood coagulation measurement during contact with an artificial surface leads to unreliable data. Acoustic tweezing thromboelastometry is a novel non-contact method for coagulation monitoring. This method detects differences in the blood coagulation state within 10 min. Coagulation data were obtained using a much smaller sample volume (4 μL) than currently used.

SUMMARY

Background Thromboelastography is widely used as a tool to assess the coagulation status of critical care patients. It allows observation of changes in material properties of whole blood, beginning with early stages of clot formation and ending with clot lysis. However, the contact activation of the coagulation cascade at surfaces of thromboelastographic systems leads to inherent variability and unreliability in predicting bleeding or thrombosis risks. Objectives To develop acoustic tweezing thromboelastometry as a non-contact method for perioperative assessment of blood coagulation. Methods Acoustic tweezing is used to levitate microliter drops of biopolymer and human blood samples. By quasi-statically changing the acoustic pressure we control the sample drop location and deformation. Sample size, deformation and location are determined by digital imaging at each pressure. Results Simple Newtonian liquid solutions maintain a constant, reversible location vs. deformation curve. In contrast, the location/deformation curves for gelatin, alginate, whole blood and blood plasma uniquely change as the samples solidify. Increasing elasticity causes the sample to deform less, leading to steeper stress/strain curves. By extracting a linear regime slope, we show that whole blood or blood plasma exhibits a unique slope profile as it begins to clot. By exposing blood samples to pro- or antithrombotic agents, the slope profile changes, allowing detection of hyper- or hypocoagulable states. Conclusions We demonstrate that quasi-static acoustic tweezing can yield information about clotting onset, maturation and strength. The advantages of small sample size, non-contact and rapid measurement make this technique desirable for real-time monitoring of blood coagulation.

Goal-directed Hemostatic Resuscitation of Trauma-induced Coagulopathy: A Pragmatic Randomized Clinical Trial Comparing a Viscoelastic Assay to Conventional Coagulation Assays

BACKGROUND

Massive transfusion protocols (MTPs) have become standard of care in the management of bleeding injured patients, yet strategies to guide them vary widely. We conducted a pragmatic, randomized clinical trial (RCT) to test the hypothesis that an MTP goal directed by the viscoelastic assay thrombelastography (TEG) improves survival compared with an MTP guided by conventional coagulation assays (CCA).

METHODS

This RCT enrolled injured patients from an academic level-1 trauma center meeting criteria for MTP activation. Upon MTP activation, patients were randomized to be managed either by an MTP goal directed by TEG or by CCA (ie, international normalized ratio, fibrinogen, platelet count). Primary outcome was 28-day survival.

RESULTS

One hundred eleven patients were included in an intent-to-treat analysis (TEG = 56, CCA = 55). Survival in the TEG group was significantly higher than the CCA group (log-rank P = 0.032, Wilcoxon P = 0.027); 20 deaths in the CCA group (36.4%) compared with 11 in the TEG group (19.6%) (P = 0.049). Most deaths occurred within the first 6 hours from arrival (21.8% CCA group vs 7.1% TEG group) (P = 0.032). CCA patients required similar number of red blood cell units as the TEG patients [CCA: 5.0 (2-11), TEG: 4.5 (2-8)] (P = 0.317), but more plasma units [CCA: 2.0 (0-4), TEG: 0.0 (0-3)] (P = 0.022), and more platelets units [CCA: 0.0 (0-1), TEG: 0.0 (0-0)] (P = 0.041) in the first 2 hours of resuscitation.

CONCLUSIONS

Utilization of a goal-directed, TEG-guided MTP to resuscitate severely injured patients improves survival compared with an MTP guided by CCA and utilizes less plasma and platelet transfusions during the early phase of resuscitation.

Quality Assessment of Established and Emerging Blood Components for Transfusion

Blood is donated either as whole blood, with subsequent component processing, or through the use of apheresis devices that extract one or more components and return the rest of the donation to the donor. Blood component therapy supplanted whole blood transfusion in industrialized countries in the middle of the twentieth century and remains the standard of care for the majority of patients receiving a transfusion. Traditionally, blood has been processed into three main blood products: red blood cell concentrates; platelet concentrates; and transfusable plasma. Ensuring that these products are of high quality and that they deliver their intended benefits to patients throughout their shelf-life is a complex task. Further complexity has been added with the development of products stored under nonstandard conditions or subjected to additional manufacturing steps (e.g., cryopreserved platelets, irradiated red cells, and lyophilized plasma). Here we review established and emerging methodologies for assessing blood product quality and address controversies and uncertainties in this thriving and active field of investigation.

Stability of Thawed Apheresis Fresh-Frozen Plasma Stored for up to 120 Hours at 1°C to 6°C

Regulations concerning the storage of transfusable plasma differ internationally. In Canada, plasma obtained from whole blood donations and frozen within 24 hours of phlebotomy (frozen plasma, FP) may be thawed and transfused within 120 hours of refrigerated storage. However, plasma frozen within 8 hours of phlebotomy following apheresis donation (FFPA) must be transfused within 24 hours of thawing and refrigeration. Our objectives were to measure coagulation factors (F) V, VII, and VIII, fibrinogen activities, and the prothrombin time (PT) in thawed refrigerated FFPA at 0, 24, and 120 hours of storage and to compare these values to those in thawed refrigerated FP. Fibrinogen activity remained unchanged over time, while mean factor levels in 28 FFPA units declined by 17% (FV), 19.7% (FVII), and 54.6% (FVIII) over 120 hours, while PT values rose to 7.6%. Factor activities were significantly higher in FFPA than FP after 120 hours of refrigerated storage. Residual FVIII activities in thawed FFPA met predefined noninferiority criteria compared to thawed FP after 120 hours. These results support a change in Canadian regulations to permit transfusion of thawed FFPA made in a closed system and refrigerated for up to 120 hours, one that could reduce wastage of transfusable plasma.

Five-day stability of thawed plasma: solvent/detergent-treated plasma comparable with fresh-frozen plasma and plasma frozen within 24 hours

BACKGROUND

Plasma stored refrigerated for up to 5 days after thawing is common practice in many US hospitals. Therefore, clotting factor activities in fresh-frozen plasma (FFP), plasma frozen within 24 hours (PF24), and solvent/detergent-treated plasma (SDP), thawed and stored at 1 to 6°C for up to 5 days, were investigated.

STUDY DESIGN AND METHODS

Five A, B, O, and AB units of FFP, PF24, and SDP were thawed and maintained for 5 days at 1 to 6°C. The activity of factor (F)V, FVII, FVIII, protein S (PS), and ADAMTS13 was determined in each unit at baseline and every 24 hours thereafter for 5 days.

RESULTS

After thaw, mean values of the variables tested were within the normal range in all three plasma products although, in SDP, FVIII activity was significantly lower (p = 0.0039). After 5 days of storage all factors significantly declined except for ADAMTS13 activity, which was stable. Mean FVIII and ADAMTS13 activity was comparable in all three plasma products and within the normal range, mean FV activity was significantly lower in FFP and PF24 (p<0.0001) compared to SDP, and mean FVII activity was significantly lower in PF24 (p<0.03) than in FFP or SDP. Mean PS activity was below the normal range in all three plasma products with the lowest values in SDP (p = 0.0001).

CONCLUSION

Over 5 days of refrigerated storage the changes in the measured coagulation factors in FFP, PF24, and SDP are comparable. Clinical follow-up is needed to assess whether slightly lower PS levels in SDP are clinically important.

Administration of 4-Factor Prothrombin Complex Concentrate as an Antidote for Intracranial Bleeding in Patients Taking Direct Factor Xa Inhibitors

OBJECTIVE

Direct factor Xa inhibitors rivaroxaban and apixaban are efficacious alternatives to warfarin and confer a lower risk of spontaneous intracranial hemorrhage (ICH); however, they lack a validated reversal strategy. We evaluated the efficacy and safety of 4-factor prothrombin complex concentrate (PCC) administration on rivaroxaban- and apixaban-mediated coagulopathy in patients with traumatic and spontaneous ICH.

METHODS

Retrospective review of patients presenting with traumatic and spontaneous ICH and concurrent use of rivaroxaban or apixaban. Demographic factors, reason for anticoagulation, hemorrhage type and location, Glasgow coma scale score, and when appropriate, ICH score, were included. Patient charts were reviewed for in-hospital mortality, thromboembolic events, pulmonary complications, worsening of hemorrhage, hemorrhagic complications after neurosurgical intervention, and 90-day modified Rankin scale score.

RESULTS

Eighteen patients met inclusion criteria; 16 used rivaroxaban and 2 used apixaban. Eight patients presented with traumatic ICH, 8 with hemorrhagic stroke, 1 with subarachnoid hemorrhage, and 1 patient with tumoral hemorrhage. Mean Glasgow coma scale score was 12.6 (range, 6-15) and mean ICH score was 2.3 (range, 0-4). After reversal with PCC, 1 patient (5.6%) demonstrated worsening of ICH on follow-up head computed tomography. PCCs were administered before emergent placement of an external ventricular drain in 1 individual, with no hemorrhagic complications. Six patients (33.3%) experienced in-hospital mortality: family withdrew care in 4 and 2 died due to pneumonia. There was 1 (5.6%) thromboembolic complication. Favorable outcomes at 90 days were seen in 6 patients (33.3%).

CONCLUSIONS

Despite no studies demonstrating the efficacy of 4-factor PCC administration for reversal of coagulopathy in patients on direct factor Xa inhibitors, our early experience demonstrates it to be safe, yet potentially reducing hemorrhagic complications and hematoma expansion in this critically ill population.

Effect of fibrinogen on blood coagulation detected by optical coherence tomography

Our previous work demonstrated that an optical coherence tomography (OCT) technique and the parameter 1/e light penetration depth (d1/e) were able to characterize the whole blood coagulation process in contrast to existing optical tests that are performed on plasma samples. To evaluate the feasibility of the technique for quantifying the effect of fibrinogen (Fbg) on blood coagulation, a dynamic study of d1/e of blood in various Fbg concentrations was performed in static state. Two groups of blood samples of hematocrit (HCT) in 35, 45, and 55% were reconstituted of red blood cells with: 1) treated plasma with its intrinsic Fbg removed and commercial Fbg added (0-8 g L(-1)); and 2) native plasma with commercial Fbg added (0-8 g L(-1)). The results revealed a typical behavior due to coagulation induced by calcium ions and the clotting time is Fbg concentration-dependent. The clotting time was decreased by the increasing amount of Fbg in both groups. Besides, the blood of lower HCT with various levels of Fbg took shorter time to coagulate than that of higher HCT. Consequently, the OCT method is a useful and promising tool for the detection of blood-coagulation processes induced with different Fbg levels.

Thawed and liquid plasma--what do we know?

There is increasing interest in the use of liquid or frozen plasma thawed and stored for extended periods (>24 h) to reduce wastage and to improve rapid availability of plasma in massive transfusion protocols advocating the early use of plasma in trauma by some centres. There is now a body of studies that have assessed individual coagulation factors during storage of thawed plasma. These show that factor VIII (FVIII) is the worst affected factor and that its activity is mainly lost during the first 24 h following thawing. However, for most factors studied, there is a continual decline during further storage. The few studies that have assessed thrombin generation in thawed plasma have shown variable results. Extended storage of plasma is associated with an increase in levels of DEHP in the component and could theoretically increase the risk of bacterial contamination, although the latter does not appear to have been an issue in countries that have adopted the use of thawed plasma. There are no clinical studies relating to the efficacy of extended-thawed plasma, and therefore, the potential reduction in its efficacy must be balanced with the clinical need for the component.

Clinical Applications of 4-Factor Prothrombin Complex Concentrate: A Practical Pathologist's Perspective

A 4-factor prothrombin complex concentrate (4F-PCC), containing therapeutic doses of vitamin K–dependent coagulation factors, was recently licensed in the United States for reversal of vitamin K antagonist therapy. However, given the emergence of several oral anticoagulants for which there are no specific reversal agents, and the existence of many other complex bleeding disorders, it is likely that clinicians will seek to use 4F-PCCs for any number of off-label indications. Thus, the goal of this review is to explore practical issues regarding 4F-PCC, with an emphasis on issues relevant to blood bankers and pathologists. Specifically, our aims are to (1) examine the role of 4F-PCC in vitamin K antagonist reversal, (2) review its potential use in the treatment of hemorrhage due to novel oral anticoagulants, and (3) explore potential uses in liver disease, trauma-associated bleeding, and rare coagulopathies. Safety and other practical considerations of 4F-PCCs will also be discussed.

Storage and handling of blood components – perspectives

The storage and handling conditions of cellular blood components and plasma are often rigorous, which is causing extensive discard of components that may be of acceptable quality as the rules for “out of optimal storage conditions” seem to be based more on tradition than scientific investigations. This short review summarizes some of the key papers indicating that it should be time for reconsideration of these rules, and some new suggestions are carefully indicated. Red cell concentrates, platelet concentrates and FFP are considered;lyophilized plasma and never-frozen liquid plasma are not included in this paper.

Coagulation factor and hemostatic protein content of canine plasma after storage of whole blood at ambient temperature

Background

Standard practice in canine blood banking is to produce fresh frozen plasma (FFP) by separating and freezing plasma produced from blood within 8 hours of collection. Within canine blood donation programs, this can limit the number of units collected.

Hypothesis/Objectives

The aim was to compare the coagulation factor and hemostatic protein content (CF&HPC) of plasma produced from blood stored at ambient temperature for 8, 12, and 24 hours. Another aim was to compare the CF&HPC between Greyhound types and other breeds.

Animals

None.

Methods

In vitro study. A convenience sample of 58 units of canine blood from a blood donor pool was processed to prepare and freeze plasma 8, 12, or 24 hours following collection.

Results

Regardless of time of processing, the units contained therapeutic CF&HPC. Frozen plasma prepared after 24 hours had significantly higher factor VIII (P = .014) and factor X (P = .03) when compared with the frozen plasma prepared at 8 hours. Factor X (P < .01), fibrinogen (P < .01), and vWF (P = .04) were significantly lower in plasma collected from Greyhound types than in plasma collected from other breeds.

Conclusions and Clinical Importance

Storing whole blood for up to 24 hours is a suitable method for producing FFP. Lower values for some coagulation factors and hemostatic proteins in plasma produced from Greyhound types would not preclude these dogs as FFP donors.

Effects of storage time and temperature on coagulation tests and factors in fresh plasma

Coagulation tests and factors measurements have been widely applied in clinical practice. Pre-analytical conditions are very important in laboratory assessment.Here,we aim to determine the effects of storage time and temperature on activated partial thromboplastin time (APTT), fibrinogen (Fbg), prothrombin time (PT), the international normalized ratio (INR), thrombin time (TT), factor VIII activity (FVIII:C), and factor IX activity (FIX:C) in fresh plasma. Seventy-two blood samples were tested after storage for 0 (baseline), 2, 4, 6, 8, 12, and 24 h at 25°C (room temperature) and 4°C (refrigeration) in two centers. The mean percentage change of greater than 10% and the numbers of samples with greater than 10% percentage changes more than 25% were used to determine clinically relevant difference. We demonstrated that samples for Fbg, PT/INR, and TT could be safely stored for ≤24 h; FVIII:C for ≤2 h; FIX:C for ≤4 h both at 4°C and 25°C; and APTT for ≤12 h at 4°C and ≤8 h at 25°C.

Plasma in the PICU: why and when should we transfuse?

Whereas red blood cell transfusions have been used since the 19th century, plasma has only been available since 1941. It was originally mainly used as volume replacement, mostly during World War II and the Korean War. Over the years, its indication has shifted to correct coagulation factors deficiencies or to prevent bleeding. Currently, it remains a frequent treatment in the intensive care unit, both for critically ill adults and children. However, observational studies have shown that plasma transfusion fail to correct mildly abnormal coagulation tests. Furthermore, recent epidemiological studies have shown that plasma transfusions are associated with an increased morbidity and mortality in critically ill patients. Therefore, plasma, as any other treatment, has to be used when the benefits outweigh the risks. Based on observational data, most experts suggest limiting its use either to massively bleeding patients or bleeding patients who have documented abnormal coagulation tests, and refraining for transfusing plasma to nonbleeding patients whatever their coagulation tests. In this paper, we will review current evidence on plasma transfusions and discuss its indications.