Fibrinogen concentration and use of fibrinogen supplementation with cryoprecipitate in patients with critical bleeding receiving massive transfusion: a bi-national cohort study

Effects of Fibrinogen Concentrate Supplementation on Postoperative Bleeding in Infants Undergoing Complex Cardiac Surgery

The use of allogeneic blood products to restore hemostasis during pediatric cardiac surgery is associated with major risks. Consequently, there has been a growing interest in new patient blood management strategies, such as those based on the use of fibrinogen concentrate (FC). Accumulating evidence has shown FC supplementation to be safe and effective. Nevertheless, no guidelines are available on using FC in the pediatric setting, and few objective evaluations have been provided in clinical practice. The endpoint of this monocenter retrospective study was the hemostatic effect of additional FC in infants undergoing complex cardiac surgery with cardiopulmonary bypass to manage persistent clinically relevant bleeding. After weaning from cardiopulmonary bypass and after protamine administration, patients were transfused with conventional allogeneic products such as packed red blood cells, fresh frozen plasma (FFP), and platelets. In the case of redo surgery, according to the institutional protocol, patients also received tranexamic acid. In case of clinically persistent relevant bleeding, according to the anesthesiologist's judgment and thromboelastography, patients received FC supplementation (group with FC) or further FFP transfusions without receiving FC supplementation (group without FC). The primary endpoint was the hemostatic effects of FC. Secondary endpoints were the functional hypofibrinogenemia threshold value (expressed as maximum amplitude fibrinogen, MA-Fib) and postoperative MA-Fib, fibrinogenemia, intraoperative transfusions, and adverse events (AEs). In total, 139 patients who underwent cardiac surgery with CPB and aged less than 2 years were enrolled: 70 patients received allogeneic blood products and FC supplementation (group FC); 69 patients received allogeneic products without FC supplementation (group without FC). Patients that received FC supplementation were characterized by a significantly longer time of extracorporeal circulation (p < 0.001) and aortic cross-clamping (p < 0.001), a significantly lower minimum temperature (p = 0.011), increased use of concentrated prothrombin complex (p = 0.016) and tranexamic acid (p = 0.010), and a significantly higher amount of packed red blood cells, platelets (p < 0.001) and fresh frozen plasma (p = 0.03). Postoperative bleeding and severe bleeding were not statistically different between patients treated with FC and those not treated with FC supplementation (p = 0.786 and p = 0.695, respectively); after adjustment, a trend toward reduced bleeding can be observed with FC (p = 0.064). Overall, 88% of patients with severe bleeding had MA-Fib < 10 mm; a moderate association between severe bleeding and MA-Fib (odds ratio 1.7, 95% CI 0.5-6.5, p = 0.425) was found. Increased MA-Fib and postoperative fibrinogen were higher in the FC group (p = 0.003 and p < 0.001, respectively) than in FFP. AEs in the FC group were comparable to those observed in less complicated surgeries. Our results suggest a potential role of FC in complex surgery in maintaining postoperative bleeding at a level comparable to less complicated surgical procedures and favoring the increase in postoperative MA-Fib and fibrinogen.

How do I implement pathogen reduced Cryoprecipitated fibrinogen complex in a tertiary Hospital's blood Bank

BACKGROUND

Kaiser-Permanente Los Angeles Medical Center (LAMC) is a 560 licensed bed facility that provides regional cardiovascular services, including 1200 open heart surgeries annually. In 2021, LAMC explored alternative therapies to offset the impact of pandemic-driven cryo AHF shortages, and implemented Pathogen Reduced Cryoprecipitated Fibrinogen Complex (also known as INTERCEPT Fibrinogen Complex or IFC). IFC is approved to treat and control bleeding associated with fibrinogen deficiency. Unlike cryo AHF, IFC has 5-day post-thaw shelf life with potential operational and clinical benefits. The implementation steps and the operational advantages to the LAMC Blood Bank are described.

STUDY DESIGN AND METHODS

Eighteen months post-implementation, the institution reviewed their product implementation experience and compared IFC with cryo AHF with a retrospective review of transfusion service and cardiac post-op data.

RESULTS

IFC significantly decreased product wastage rates and order-to-issue time. It did not significantly impact post-op product utilization or hospital length of stay (LOS) in cardiac surgery patients when compared with cryo AHF.

DISCUSSION

Implementation of IFC provides improved product supply stability, shorter turnaround times, and reduced wastage.

Does an early, balanced resuscitation strategy reduce the incidence of hypofibrinogenemia in hemorrhagic shock?

Objectives

Some centers have recommended including concentrated fibrinogen replacement in massive transfusion protocols (MTPs). Given our center's policy of aggressive early balanced resuscitation (1:1:1), beginning prehospital, we hypothesized that our rates of hypofibrinogenemia may be lower than those previously reported.

Methods

In this retrospective cohort study, patients presenting to our trauma center November 2017 to April 2021 were reviewed. Patients were defined as hypofibrinogenemic (HYPOFIB) if admission fibrinogen <150 or rapid thrombelastography angle <60. Univariate and multivariable analyses assessed risk factors for HYPOFIB. Inverse probability of treatment weighting analyses assessed the relationship between cryoprecipitate administration and outcomes.

Results

Of 29 782 patients, 6618 level 1 activations, and 1948 patients receiving emergency release blood, <1%, 2%, and 7% were HYPOFIB. HYPOFIB patients were younger, had higher head Abbreviated Injury Scale value, and had worse coagulopathy and shock. HYPOFIB had lower survival (48% vs 82%, p<0.001), shorter time to death (median 28 (7, 50) vs 36 (14, 140) hours, p=0.012), and were more likely to die from head injury (72% vs 51%, p<0.001). Risk factors for HYPOFIB included increased age (OR (95% CI) 0.98 (0.96 to 0.99), p=0.03), head injury severity (OR 1.24 (1.06 to 1.46), p=0.009), lower arrival pH (OR 0.01 (0.001 to 0.20), p=0.002), and elevated prehospital red blood cell to platelet ratio (OR 1.20 (1.02 to 1.41), p=0.03). Among HYPOFIB patients, there was no difference in survival for those that received early cryoprecipitate (within 2 hours; 40 vs 47%; p=0.630). On inverse probability of treatment weighted analysis, early cryoprecipitate did not benefit the full cohort (OR 0.52 (0.43 to 0.65), p<0.001), nor the HYPOFIB subgroup (0.28 (0.20 to 0.39), p<0.001).

Conclusions

Low rates of hypofibrinogenemia were found in our center which treats hemorrhage with early, balanced resuscitation. Previously reported higher rates may be partially due to unbalanced resuscitation and/or delay in resuscitation initiation. Routine empiric inclusion of concentrated fibrinogen replacement in MTPs is not supported by the currently available data.

Level of evidence

Level III.

Prophylactic cryoprecipitate transfusion in patients undergoing scoliosis surgery: A randomised-controlled trial

BACKGROUND

Scoliosis surgeries in adults often have a high risk of massive blood loss and significant transfusion of blood products during and after surgery. It is not known whether early cryoprecipitate therapy is useful in reducing blood loss and transfusion requirements. The objective of this randomised, prospective placebo control study was to evaluate whether prophylactic administration of cryoprecipitate would reduce blood loss and transfusion requirements during scoliosis surgery.

METHODS

Eighty adult patients scheduled to undergo elective scoliosis correction were randomly assigned to receive either ten units of cryoprecipitate before incision (cryo group) or an equivalent volume of 0.9% saline (placebo group). Blood loss, transfusion requirements, coagulation parameters and complications were assessed.

RESULTS

No significant differences were found in the volume of transfused blood products, intraoperative estimated blood loss between the intervention and placebo groups. Postoperative blood loss was significantly lower in the cry group when compared to the other group. During adult surgical correction of scoliosis, prophylactic administration of cryoprecipitate did not diminish the amount of transfused blood products or decrease intraoperative blood loss.

CONCLUSION

It could be concluded that the prophylactic administration of cryoprecipitate shows no differences in intraoperative blood loss and transfusion requirements during scoliosis surgery.

Preoperative fibrinogen level and blood transfusions in liver transplantation: A systematic review

BACKGROUND

Orthotopic liver transplantation (OLT) is a major surgery often associated with significant bleeding. We conducted a systematic review to explore the association between preoperative fibrinogen level and intraoperative blood products transfusion, blood loss and clinical outcomes in patients undergoing OLT.

METHODS

We included observational studies conducted in patients undergoing an OLT mostly for end-stage liver disease that reported an association between the preoperative fibrinogen level and our outcomes of interest. Our primary outcome was the intraoperative red blood cell (RBC) transfusion requirements. Our secondary outcomes were intraoperative blood loss, intraoperative transfusion of any blood product, postoperative RBC transfusion, postoperative thrombotic or hemorrhagic complications, and mortality. We used a standardized search strategy. We reported our results mostly descriptively but conducted meta-analyses using random-effect models when judged feasible.

RESULTS

We selected 24 cohort studies reporting at least one of our outcomes. We found that a high preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, and lower blood loss. We also found a lower overall survival in patients with a higher fibrinogen level (pooled hazard ratio [95% CI] of 1.50 [1.23 to 1.84]; 5 studies, n = 1012, I2 = 48%). Only one study formally explored a fibrinogen level threshold effect. Overall, reporting was heterogeneous, and risk of bias was variable mostly because of uncontrolled confounding.

CONCLUSION

A higher preoperative fibrinogen level was associated with fewer intraoperative RBC and other blood products transfusions, lower blood loss, and higher mortality. Further studies may help clarify observed associations and inform guidelines.

Comparison of Bacterial Risk in Cryo AHF and Pathogen Reduced Cryoprecipitated Fibrinogen Complex

Until November 2020, cryoprecipitated antihaemophilic factor (cryo AHF) was the only United States Food and Drug Administration (FDA)-approved fibrinogen source to treat acquired bleeding. The post-thaw shelf life of cryo AHF is limited, in part, by infectious disease risk. Concerns over product wastage demand that cryo AHF is thawed as needed, with thawing times delaying the treatment of coagulopathic patients. In November 2020, the FDA approved Pathogen Reduced Cryoprecipitated Fibrinogen Complex for the treatment and control of bleeding, including massive hemorrhage, associated with fibrinogen deficiency. Pathogen Reduced Cryoprecipitated Fibrinogen Complex (also known as INTERCEPT^® Fibrinogen Complex, IFC) has a five-day post-thaw room-temperature shelf life. Unlike cryo AHF, manufacturing of IFC includes broad spectrum pathogen reduction (Amotosalen + UVA), enabling this extended post-thaw shelf life. In this study, we investigated the risk of bacterial contamination persisting through the cryoprecipitation manufacturing process of cryo AHF and IFC. Experiments were performed which included spiking plasma with bacteria prior to cryoprecipitation, and bacterial survival was analyzed at each step of the manufacturing process. The results show that while bacteria survive cryo AHF manufacturing, IFC remains sterile through to the end of shelf life and beyond. IFC, with a five-day post-thaw shelf life, allows the product to be sustainably thawed in advance, facilitating immediate access to concentrated fibrinogen and other key clotting factors for the treatment of bleeding patients.

Cryoprecipitate use during massive transfusion: A propensity score analysis

INTRODUCTION

Cryoprecipitate is frequently administered as an adjunct to balanced transfusion in the setting of traumatic hemorrhage. However, civilian studies have not demonstrated a clear survival advantage, and prior observational studies noted selection bias when analyzing cryoprecipitate use. Additionally, due to the logistics involved in cryoprecipitate administration, it is inconsistently implemented alongside standardized massive transfusion protocols. This study aims to evaluate the effects of early cryoprecipitate administration on inpatient mortality in the setting of massive transfusion for exsanguinating trauma and to use propensity score analysis to minimize selection bias.

METHODS

The registry of an urban level 1 trauma center was queried for adult patients who received at least 6 units of packed red blood cells within 4 h of presentation. Univariate analysis, multiple logistic regression, and propensity score matching were performed.

RESULTS

562 patients were identified. Patients with lower median RTS (6.86 (IQR 4.09-7.84) vs 7.6 (IQR 5.97-7.84), P<0.01), decreased Glasgow coma scale (12 (IQR 4-15) vs 15 (IQR 10-15), P<0.01), and increased lactate (7.5 (IQR 4.3-10.2) vs 4.9 (IQR 3.1-7.2), P<0.01) were more commonly administered cryoprecipitate. Mortality was greater among those who received cryoprecipitate (40.2% vs 23.7%, p<0.01) on univariate analysis. Neither multiple logistic regression (OR 0.917; 95% confidence interval 0.462-1.822; p = 0.805) nor propensity score matching (average treatment effect on the treated 2.3%, p = 0.77) revealed that cryoprecipitate administration was associated with a difference in inpatient mortality.

CONCLUSIONS

Patients receiving cryoprecipitate within 4 h of presentation were more severely injured at presentation and had increased inpatient mortality. Multivariable logistic regression and propensity score analysis failed to show that early administration of cryoprecipitate was associated with survival benefit for exsanguinating trauma patients. The prospect of definitively assessing the utility of cryoprecipitate in exsanguinating hemorrhage warrants prospective investigation.

Role of Fibrinogen in Trauma-Induced Coagulopathy

BACKGROUND

Fibrinogen is the first coagulation factor to decrease after massive hemorrhage. European massive transfusion guidelines recommend early repletion of fibrinogen; however, this practice has not been widely adopted in the US. We hypothesize that hypofibrinogenemia is common at hospital arrival and is an integral component of trauma-induced coagulopathy.

STUDY DESIGN

This study entailed review of a prospective observational database of adults meeting the highest-level activation criteria at an urban level 1 trauma center from 2014 through 2020. Resuscitation was initiated with 2:1 red blood cell (RBC) to fresh frozen plasma (FFP) ratios and continued subsequently with goal-directed thrombelastography. Hypofibrinogenemia was defined as fibrinogen below 150 mg/dL. Massive transfusion (MT) was defined as more than 10 units RBC or death after receiving at least 1 unit RBC over the first 6 hours of admission.

RESULTS

Of 476 trauma activation patients, 70 (15%) were hypofibrinogenemic on admission, median age was 34 years, 78% were male, median New Injury Severity Score (NISS) was 25, and 72 patients died (15%). Admission fibrinogen level was an independent risk factor for MT (odds ratio [OR] 0.991, 95% CI 0.987-0.996]. After controlling for confounders, NISS (OR 1.034, 95% CI 1.017-1.052), systolic blood pressure (OR 0.991, 95% CI 0.983-0.998), thrombelastography angle (OR 0.925, 95% CI 0.896-0.954), and hyperfibrinolysis (OR 2.530, 95% CI 1.160-5.517) were associated with hypofibrinogenemia. Early cryoprecipitate administration resulted in the fastest correction of hypofibrinogenemia.

CONCLUSION

Hypofibrinogenemia is common after severe injury and predicts MT. Cryoprecipitate transfusion results in the most expeditious correction. Earlier administration of cryoprecipitate should be considered in MT protocols.

Management of Coagulopathy in Bleeding Patients

Early recognition of coagulopathy is necessary for its prompt correction and successful management. Novel approaches, such as point-of-care testing (POC) and administration of coagulation factor concentrates (CFCs), aim to tailor the haemostatic therapy to each patient and thus reduce the risks of over- or under-transfusion. CFCs are an effective alternative to ratio-based transfusion therapies for the correction of different types of coagulopathies. In case of major bleeding or urgent surgery in patients treated with vitamin K antagonist anticoagulants, prothrombin complex concentrate (PCC) can effectively reverse the effects of the anticoagulant drug. Evidence for PCC effectiveness in the treatment of direct oral anticoagulants-associated bleeding is also increasing and PCC is recommended in guidelines as an alternative to specific reversal agents. In trauma-induced coagulopathy, fibrinogen concentrate is the preferred first-line treatment for hypofibrinogenaemia. Goal-directed coagulation management algorithms based on POC results provide guidance on how to adjust the treatment to the needs of the patient. When POC is not available, concentrate-based management can be guided by other parameters, such as blood gas analysis, thus providing an important alternative. Overall, tailored haemostatic therapies offer a more targeted approach to increase the concentration of coagulation factors in bleeding patients than traditional transfusion protocols.

Cryoprecipitate transfusion in bleeding patients

OBJECTIVES

The management of acquired coagulopathy in multiple clinical settings frequently involves fibrinogen supplementation. Cryoprecipitate, a multidonor product, is widely used for the treatment of acquired hypofibrinogenemia following massive bleeding, but it has been associated with adverse events. We aimed to review the latest evidence on cryoprecipitate for treatment of bleeding.

METHODS

We conducted a narrative review of current literature on cryoprecipitate therapy, describing its history, formulations and preparation, and recommended dosing. We also reviewed guideline recommendations on the use of cryoprecipitate in bleeding situations and recent studies on its efficacy and safety.

RESULTS

Cryoprecipitate has a relatively high fibrinogen content; however, as it is produced by pooling fresh frozen donor plasma, the fibrinogen content per unit can vary considerably. Current guidelines suggest that cryoprecipitate use should be limited to treating hypofibrinogenemia in patients with clinical bleeding. Until recently, cryoprecipitate was deemed unsuitable for pathogen reduction, and potential safety concerns and lack of standardized fibrinogen content have led to some professional bodies recommending that cryoprecipitate is only indicated for the treatment of bleeding and hypofibrinogenemia in perioperative settings where fibrinogen concentrate is not available. While cryoprecipitate is effective in increasing plasma fibrinogen levels, data on its clinical efficacy are limited.

CONCLUSIONS

There is a lack of robust evidence to support the use of cryoprecipitate in bleeding patients, with few prospective, randomized clinical trials performed to date. Clinical trials in bleeding settings are needed to investigate the safety and efficacy of cryoprecipitate and to determine its optimal use and administration.

Fibrinogen in traumatic haemorrhage

PURPOSE OF REVIEW

Recent advances in the understanding of the pathophysiological processes associated with traumatic haemorrhage and trauma-induced coagulopathy (TIC) have resulted in improved outcomes for seriously injured trauma patients. However, a significant number of trauma patients still die from haemorrhage. This article reviews the role of fibrinogen in normal haemostasis, the effect of trauma and TIC on fibrinogen levels and current evidence for fibrinogen replacement in the management of traumatic haemorrhage.

RECENT FINDINGS

Fibrinogen is usually the first factor to reach critically low levels in traumatic haemorrhage and hypofibrinogenaemia after severe trauma is associated with increased risk of massive transfusion and death. It is postulated that the early replacement of fibrinogen in severely injured trauma patients can improve outcomes. There is, however, a paucity of evidence to support this, and in addition, there is little evidence to support or refute the effects of cryoprecipitate or fibrinogen concentrate for fibrinogen replacement.

SUMMARY

The important role fibrinogen plays in haemostasis and effective clot formation is clear. A number of pilot trials have investigated different strategies for fibrinogen replacement in severe trauma. These trials have formed the basis of several large-scale phase III trials, which, cumulatively will provide a firm evidence base to harmonise worldwide clinical management of severely injured trauma patients with major haemorrhage.

Fibrinogen Early In Severe Trauma studY (FEISTY): results from an Australian multicentre randomised controlled pilot trial

Background: Haemorrhage is a major cause of death in severe trauma. Fibrinogen plays a critical role in maintaining haemostasis in traumatic haemorrhage, and early replacement using fibrinogen concentrate (FC) or cryoprecipitate (Cryo) is recommended by several international trauma guidelines. Limited evidence supports one product over the other, with widespread geographic and institutional variation in practice. Two previous trials have investigated the feasibility of rapid FC administration in severely injured trauma patients, with conflicting results. Objective: To compare the time to fibrinogen replacement using FC or Cryo in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia. Design, setting, patients and interventions: A multicentre controlled pilot trial in which adult trauma patients with haemorrhage were randomly assigned (1:1) to receive FC or Cryo for fibrinogen replacement, guided by FIBTEM A5 (functional fibrinogen assessment at 5 minutes after clot formation, using rotational thromboelastometry). Main outcome measures: The primary outcome was time to commencement of fibrinogen replacement. Secondary outcomes included effects of the intervention on plasma fibrinogen levels and clinical outcomes including transfusion requirements and mortality. Results: Of the 100 randomly assigned patients, 62 were hypofibrinogenaemic and received the intervention (n = 37) or Cryo (n = 25). Median (interquartile range [IQR]) time to delivery of FC was 29 min (23-40 min) compared with 60 min (40-80 min) for Cryo (P = 0.0001). All 62 patients were hypofibrinogenaemic before receiving FC or Cryo (FC: median FIBTEM A5, 8 mm [IQR, 7-9 mm]; Cryo: median FIBTEM A5, 9 mm [IQR, 5-10 mm]). In the FC arm patients received a median of 3 g FC (IQR, 2-4 g), and in the Cryo arm patients received a median of 8 units of Cryo (IQR, 8-14 units). Restoration of fibrinogen levels was achieved in both arms after the intervention. Blood product transfusion, fluid resuscitation and thromboembolic complications were similar in both arms. Overall mortality was 15.3%, with more deaths in the FC arm. Conclusion: Fibrinogen replacement in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia was achieved substantially faster using FC compared with Cryo. Fibrinogen levels increased appropriately using either product. The optimal method for replacing fibrinogen in traumatic haemorrhage is controversial. Our results will inform the design of a larger trial powered to assess patient-centred outcomes.

Perioperative Cryoprecipitate Waste Reduction

Improvement of operating room efficiency regarding perioperative blood product transfusion is fundamental for surgical patients. The aim of this study was to 1) assess the use of cryoprecipitate in the operating room at our institution 2) identify and address gaps in knowledge regarding the process of ordering and returning cryoprecipitate 3) aim to reduce cryoprecipitate wastage by 50% over a 14-month period. Institutional data from Dec. 2017 to April 2020 was retrieved on cryoprecipitate that was ordered, thawed, and delivered to the operating room. Additionally, data was collected regarding cryoprecipitate that was wasted. A retrospective analysis of weekly intraoperative cryoprecipitate utilization was performed to compare wastage before and after implementation of interventions. Pre-intervention (Dec 2017 - March 2019), a total of 453 units of cryoprecipitate were issued with 14 units wasted (3% wastage). Between March 2019 and April 2020, the 14 months after our intervention, there were 402 units of cryoprecipitate issued with only 1 unit wasted (0.25% wastage). The overall cryoprecipitate waste rate was reduced by 91.66%. Month-to-month comparison of pre-intervention and post-intervention data identified significant reduction in average monthly wastage (0.875 vs 0.071 units respectively, p < 0.05). Appropriately, there was not a significant change in the mean monthly cryoprecipitate issued to the operating room (28.31 vs. 28.7 units, p = 0.94). These results demonstrate that utilizing educational initiatives for optimization of blood product management can reduce unnecessary ordering, transfusions, and wastage; an outcome that could ultimately reduce costs.

Introduction of a ROTEM protocol for the management of trauma-induced coagulopathy

Aims

Point-of-care viscoelastic tests such as rotational thrombelastometry (ROTEM) and thromboelastography (TEG) give rapid information on the kinetics of clot formation, clot strength and fibrinolysis. We developed a ROTEM algorithm for the management of trauma patients at risk of massive haemorrhage using either 5 or 10 minute EXTEM and FIBTEM ROTEM thresholds. Study aims were (a) to compare time to results for ROTEM testing versus laboratory conventional coagulation testing (CCT) and (b) to compare incidence of Trauma-induced coagulopathy (TIC) for our 5 and 10 minute ROTEM algorithms versus both the CCT-based European guideline algorithm and the ROTEM-based iTACTIC study algorithm, in both MT and non-MT patients.

Methods

Single centre, prospective, observational Emergency Department based study. All trauma patients who underwent ROTEM testing were included. Data was collected from the ROTEM Sigma machine and hospital Electronic Patient Records and analysed.

Results

Between April 2016 and May 2019, 57 trauma patients were enrolled. Mean age was 47.4 years (SD 19.4) and 44 patients (77.2%) were male. Eleven patients (19.3%) required massive transfusion (MT), 5 patients died in ED (8.8%) and overall in-hospital mortality was 22.8% (n = 13). Median time from admission to CCT result was 83 minutes (IQR 60–93) compared to 51 minutes (IQR 32-93; p = 0.0006) for ROTEM A5 results. This time difference was present for both MT and non-MT patients. Trauma-induced coagulopathy (TIC) was identified in 14 (24.5%) patients using CCT compared to 22 (38.5%) using ROTEM (p = 0.11 ns).

Conclusion

Our ROTEM Sigma based algorithm enables a coagulation result to be obtained faster than laboratory CCT and could lead to earlier clinical intervention.

Targeted cryoprecipitate transfusion in severe traumatic haemorrhage

BACKGROUND

Severe traumatic haemorrhage is the leading cause of death in young adults. Trauma Induced Coagulopathy is a complex and multifactorial phenomenon associated with severe traumatic haemorrhage. Fibrinogen is one of the first coagulation factors to become depleted in TIC and evidence suggests that severely injured trauma patients with hypofibrinogenaemia have poor outcomes. It is postulated that early fibrinogen replacement can improve clinical outcomes. This study investigated cryoprecipitate transfusion in hyopfibrinogeneamic trauma patients.

METHODS

This retrospective, single center, observational study investigated the use of cryoprecipitate in severely injured trauma patients admitted to an Australian Level I Trauma Centre. The primary outcome was time to administration of cryoprecipitate after identification of hypofibrinogenaemia using ROTEM (FIBTEM A5). Data collected included demographics, ISS, laboratory values of coagulation and blood product usage.

RESULTS

71 patients received cryoprecipitate with a median time of 61 minutes [IQR 37-93] from FIBTEM A5 result to initial cryoprecipitate administration. At 24 hours following admission to ED, Clauss Fibrinogen levels increased by 1.30g/L [IQR 0.45-1.85] and FIBTEM A5 assay increased by 8mm [IQR 3.0-11.3]. Changes in both variables were highly significant (p<0.001) and Clauss Fibrinogen versus FIBTEM A5 values showed moderate to strong correlation (R=0.75-0.80).

CONCLUSION

This study demonstrated that early administration of cryoprecipitate was both feasible and efficacious in fibrinogen replacement in severe traumatic haemorrhage. High-level evidence supporting cryoprecipitate or fibrinogen concentrate replacement with regards to efficacy and feasibility is required to guide future clinical practice. This study provided baseline data to inform the design of further clinical trials investigating fibrinogen replacement in traumatic haemorrhage.

Fibrin-based Bioinks: New Tricks from an Old Dog

For the past 10 years, the main efforts of most bioprinting research teams have focused on creating new bioink formulations, rather than inventing new printing set-up concepts. New tissue-specific bioinks with good printability, shape fidelity, and biocompatibility are based on "old" (well-known) biomaterials, particularly fibrin. While the interest in fibrin-based bioinks is constantly growing, it is essential to provide a framework of material's properties and trends. This review aims to describe the fibrin properties and application in three-dimensional bioprinting and provide a view on further development of fibrin-based bioinks.

Viscoelastic haemostatic assays and fibrinogen in paediatric acute traumatic coagulopathy: A comprehensive review

OBJECTIVE

Haemorrhage in paediatric trauma remains a significant cause of morbidity and mortality. Over recent years there has been increasing attention to the role of fibrinogen in traumatic haemorrhage and the association of low fibrinogen levels with poor patient outcomes. In addition, there has been a move towards using viscoelastic haemostatic assays (VHAs) to rapidly assess coagulation status and guide clinicians in the replacement of coagulation factors, including fibrinogen. In the paediatric population, there has been limited uptake of these principles and a paucity of data to support a change in practice. This paper summarises the available evidence in the published literature through a systematic review, presented in narrative format.

RESULTS

There is limited high-quality prospective data on the use of VHA in the management of acute traumatic coagulopathy in the paediatric population. While the use of fibrinogen early in major haemorrhage is becoming standard practice, there are currently no randomised prospective studies comparing fibrinogen concentrate to cryoprecipitate.

CONCLUSIONS

The early identification of hypo-fibrinogenemia and acute traumatic coagulopathy in paediatric trauma using VHA testing and subsequent early fibrinogen replacement with a concentrated off the shelf product is an attractive treatment option. However, there is currently insufficient high-level evidence to support the use of fibrinogen concentrate over cryoprecipitate in the paediatric trauma population. Pilot studies currently under way will go some way to addressing this important knowledge gap, and facilitate the design of larger definitive multi-centre randomised trials.

Perioperative anesthetic management for cesarean delivery of severe Wilson’s disease with liver failure: a case report

Background

Wilson’s disease is a rare autosomal recessive disorder affecting copper metabolism, which presents liver and brain dysfunction caused by abnormal copper accumulation. We report a patient who showed exacerbation of liver failure during pregnancy.

Case presentation

A 24-year-old woman with Wilson’s disease was scheduled for emergency cesarean delivery at 30 weeks of gestation. The patient exhibited severe coagulopathy and prominent body weight gain (+ 30 kg) caused by systemic edema and ascites. We decided to perform emergency cesarean delivery under general anesthesia. We used platelet concentrates, cryoprecipitate, and fibrinogen concentrate. Intraoperative hemorrhage was well controlled. On the 15th postpartum day, weight was reduced by 20 kg and liver function had improved. She and her baby were discharged without complications.

Conclusions

The appropriate continued treatment of Wilson’s disease and supplementation of coagulation factors and/or platelets when indicated greatly increase the likelihood of a successful pregnancy, even in patients with liver failure exacerbation.

Review of current transfusion therapy and blood banking practices

Transfusion Medicine is a dynamically evolving field. Recent high-quality research has reshaped the paradigms guiding blood transfusion. As increasing evidence supports the benefit of limiting transfusion, guidelines have been developed and disseminated into clinical practice governing optimal transfusion of red cells, platelets, plasma and cryoprecipitate. Concepts ranging from transfusion thresholds to prophylactic use to maximal storage time are addressed in guidelines. Patient blood management programs have developed to implement principles of patient safety through limiting transfusion in clinical practice. Data from National Hemovigilance Surveys showing dramatic declines in blood utilization over the past decade demonstrate the practical uptake of current principles guiding patient safety. In parallel with decreasing use of traditional blood products, the development of new technologies for blood transfusion such as freeze drying and cold storage has accelerated. Approaches to policy decision making to augment blood safety have also changed. Drivers of these changes include a deeper understanding of emerging threats and adverse events based on hemovigilance, and an increasing healthcare system expectation to align blood safety decision making with approaches used in other healthcare disciplines.

Does the evidence support the importance of high transfusion ratios of plasma and platelets to red blood cells in improving outcomes in severely injured patients: a systematic review and meta-analyses

BACKGROUND

Deaths by exsanguination in trauma are preventable with hemorrhage control and resuscitation with allogeneic blood products (ABPs). The ideal transfusion ratio is unknown. We compared efficacy and safety of high transfusion ratios of FFP:RBC and PLT:RBC with low ratios in trauma.

STUDY DESIGN AND METHODS

Medline, Embase, Cochrane, and Controlled Clinical Trials Register were searched. Observational and randomized data were included. Risk of bias was assessed using validated tools. Primary outcome was 24-h and 30-day mortality. Secondary outcomes were exposure to ABPs and improvement of coagulopathy. Meta-analysis was conducted using a random-effects model. Strength and evidence quality were graded using GRADE profile RESULTS: 55 studies were included (2 randomized and 53 observational), with low and moderate risk of bias, respectively, and overall low evidence quality. The two RCTs showed no mortality difference (odds ratio [OR], 1.35; 95% confidence interval [CI], 0.40-4.59). Observational studies reported lower mortality in high FFP:RBCs ratio (OR, 0.38 [95% CI, 0.22-0.68] for 1:1 vs. <1:1; OR, 0.42 [95% CI, 0.22-0.81] for 1:1.5 vs. <1:1.5; and OR, 0.47 [95% CI, 0.31-0.71] for 1:2 vs. <1:2, respectively). Meta-analyses in observational studies showed no difference in exposure to ABPs. No data on coagulopathy for meta-analysis was identified.

CONCLUSIONS

Meta-analyses in observational studies suggest survival benefit and no difference in exposure to ABPs. No survival benefit in RCTs was identified. These conflicting results should be interpreted with caution. Studies are mostly observational, with relatively small sample sizes, nonrandom treatment allocation, and high potential for confounding. Further research is warranted.

ICU Management of Trauma Patients

OBJECTIVES

To describe the current state of the art regarding management of the critically ill trauma patient with an emphasis on initial management in the ICU.

DATA SOURCES AND STUDY SELECTION

A PubMed literature review was performed for relevant articles in English related to the management of adult humans with severe trauma. Specific topics included airway management, hemorrhagic shock, resuscitation, and specific injuries to the chest, abdomen, brain, and spinal cord.

DATA EXTRACTION AND DATA SYNTHESIS

The basic principles of initial management of the critically ill trauma patients include rapid identification and management of life-threatening injuries with the goal of restoring tissue oxygenation and controlling hemorrhage as rapidly as possible. The initial assessment of the patient is often truncated for procedures to manage life-threatening injuries. Major, open surgical procedures have often been replaced by nonoperative or less-invasive approaches, even for critically ill patients. Consequently, much of the early management has been shifted to the ICU, where the goal is to continue resuscitation to restore homeostasis while completing the initial assessment of the patient and watching closely for failure of nonoperative management, complications of procedures, and missed injuries.

CONCLUSIONS

The initial management of critically ill trauma patients is complex. Multiple, sometimes competing, priorities need to be considered. Close collaboration between the intensivist and the surgical teams is critical for optimizing patient outcomes.

The European guideline on management of major bleeding and coagulopathy following trauma: fifth edition

BACKGROUND

Severe traumatic injury continues to present challenges to healthcare systems around the world, and post-traumatic bleeding remains a leading cause of potentially preventable death among injured patients. Now in its fifth edition, this document aims to provide guidance on the management of major bleeding and coagulopathy following traumatic injury and encourages adaptation of the guiding principles described here to individual institutional circumstances and resources.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004, and the current author group included representatives of six relevant European professional societies. The group applied a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were re-examined and revised based on scientific evidence that has emerged since the previous edition and observed shifts in clinical practice. New recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated.

RESULTS

Advances in our understanding of the pathophysiology of post-traumatic coagulopathy have supported improved management strategies, including evidence that early, individualised goal-directed treatment improves the outcome of severely injured patients. The overall organisation of the current guideline has been designed to reflect the clinical decision-making process along the patient pathway in an approximate temporal sequence. Recommendations are grouped behind the rationale for key decision points, which are patient- or problem-oriented rather than related to specific treatment modalities. While these recommendations provide guidance for the diagnosis and treatment of major bleeding and coagulopathy, emerging evidence supports the author group's belief that the greatest outcome improvement can be achieved through education and the establishment of and adherence to local clinical management algorithms.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. If incorporated into local practice, these clinical practice guidelines have the potential to ensure a uniform standard of care across Europe and beyond and better outcomes for the severely bleeding trauma patient.

Efficacy of a new pathogen-reduced cryoprecipitate stored 5 days after thawing to correct dilutional coagulopathy in vitro

BACKGROUND

Fibrinogen supplementation during bleeding restores clot strength and hemostasis. Cryoprecipitate, a concentrated source of fibrinogen, has prolonged preparation time for thawing, a short shelf life resulting in frequent wastage, and infectious disease risk. This in vitro study investigated the efficacy of a new pathogen-reduced cryoprecipitate thawed and stored at room temperature for 5 days (PR Cryo) to treat dilutional hypofibrinogenemia, compared to immediately thawed standard cryoprecipitate (Cryo) or fibrinogen concentrate (FC).

STUDY DESIGN AND METHODS

Ten phlebotomy specimens from healthy volunteers were diluted 1:1 with crystalloid and supplemented with PR Cryo and Cryo (at a dose replicating transfusion of two pooled doses [10 units]) and FC at a dose replicating 50 mg/kg. Changes in clot firmness (thromboelastometry) and in coagulation factor activity were assessed at baseline, after dilution, and after supplementation.

RESULTS

Clinical dosing was used, as described above, and consequently the FC dose contained 24% and 36% more fibrinogen versus PR Cryo and Cryo, respectively. At baseline, subjects had a median FIBTEM maximum clot firmness of 13.5 mm, versus 6.5 mm after 50% dilution (p = 0.005). After supplementation with PR Cryo, a median FIBTEM maximum clot firmness of 13 mm was observed versus 9.0 mm for Cryo (p = 0.005) or 16.5 mm for FC (p = 0.005). Median factor XIII was higher after PR Cryo (64.8%) versus Cryo (48.3%) (p = 0.005). Fibrinogen activity was higher after FC (269.0 mg/dL) versus PR Cryo (187.0 mg/dL; p = 0.005) or Cryo (193.5 mg/dL; p = 0.005); the difference between PR Cryo and Cryo supplementation (p = 0.445) was not significant.

CONCLUSION

PR Cryo used 5 days after thawing effectively restores clot strength after in vitro dilution.

Effects of in-house cryoprecipitate on transfusion usage and mortality in patients with multiple trauma with severe traumatic brain injury: a retrospective cohort study

BACKGROUND

Hypofibrinogenaemia is a common complication of multiple trauma with severe traumatic brain injury (Abbreviated Injury Scale score of the head ≥4; body ≥3). In Japan, neither fibrinogen concentrate nor cryoprecipitate is permitted to treat acquired hypofibrinogenaemia with the purpose of rapidly restoring a haemostatic level of fibrinogen. The aim of this study was to investigate transfusion usage and mortality in patients with multiple trauma and severe traumatic brain injury who were given a cryoprecipitate prepared in-house, comparing those administered the product early or later.

MATERIAL AND METHODS

We prepared and produced cryoprecipitate from fresh-frozen plasma beginning in March 2013. We performed a retrospective cohort study of patients admitted to our single tertiary medical centre with severe multiple trauma with traumatic brain injury from March 2013 to June 2018, sorting them into those given the cryoprecipitate infusion within 90 minutes of admission (Early group) and those given it more than 90 minutes after admission (Late group). Clinical outcomes were compared between the two groups using chi-square or Fisher's exact tests and the Wilcoxon test as appropriate.

RESULTS

There were 26 and 16 patients in the Early and Late groups, respectively. The 24-hour mortality tended to be lower in the Early group than in the Late group (8 vs 13%, respectively). The patients were more severely anaemic and thrombocytopenic after haemostatic therapy in the Late group than in the Early group. Transfusion usage in the Early group was lower than that in the Late group (red blood cells: 7±1 units vs 17±3 units, p<0.05; fresh-frozen plasma: 9±1 units vs 16±3 units, p<0.05; platelet concentrate: 3±1 units vs 15±4 units, p<0.05, respectively).

DISCUSSION

Early administration of an in-house cryoprecipitate may reduce transfusion usage in patients with multiple trauma with severe traumatic brain injury.

Thromboelastography and Thromboelastometry in Assessment of Fibrinogen Deficiency and Prediction for Transfusion Requirement: A Descriptive Review

Fibrinogen is crucial for the formation of blood clot and clinical outcomes in major bleeding. Both Thromboelastography (TEG) and Rotational Thromboelastometry (ROTEM) have been increasingly used to diagnose fibrinogen deficiency and guide fibrinogen transfusion in trauma and surgical bleeding patients. We conducted a comprehensive and comparative review on the technologies and clinical applications of two typical functional fibrinogen assays using TEG (FF TEG) and ROTEM (FIBTEM) for assessment of fibrinogen level and deficiency, and prediction of transfusion requirement. Clot strength and firmness of FF TEG and ROTEM FIBTEM were the most used parameters, and their associations with fibrinogen levels as measured by Clauss method ranged from 0 to 0.9 for FF TEG and 0.27 to 0.94 for FIBTEM. A comparison of the interchangeability and clinical performance of the functional fibrinogen assays using the two systems showed that the results were correlated, but are not interchangeable between the two systems. It appears that ROTEM FIBTEM showed better associations with the Clauss method and more clinical use for monitoring fibrinogen deficiency and predicting transfusion requirements including fibrinogen replacement than FF TEG. TEG and ROTEM functional fibrinogen tests play important roles in the diagnosis of fibrinogen-related coagulopathy and guidance of transfusion requirements. Despite the fact that high-quality evidence is still needed, the two systems are likely to remain popular for the hemostatic management of bleeding patients.

Outcomes of patients receiving a massive transfusion for major trauma

BACKGROUND

The benefits of high transfusion ratios (plasma to red blood cells and platelets to red blood cells) on survival in injured patients who receive massive transfusions remain uncertain. This study aimed to assess the association between transfusion ratios and adverse events and survival in patients undergoing massive transfusion for major trauma.

METHODS

A retrospective observational study was conducted on patients who had major trauma using a Japanese national administrative database. The associations between transfusion ratios and outcomes (in-hospital mortality and incidence of adverse events) were analysed using a non-linear logistic generalized additive model (GAM). In a logistic generalized estimating equation model, adjusted for patient and hospital-level confounders, transfusion ratios were included as continuous or categorical variables (low, transfusion ratio 0·75 or less; intermediate, over 0·75 to 1·25; high, over 1·25).

RESULTS

Some 1777 patients were included in the analysis, of whom 602 died in hospital. GAM plots of the transfusion ratios for in-hospital mortality demonstrated a downward convex unimodal curve. In-hospital mortality was similar with increasing transfusion ratios for plasma (adjusted odds ratio (OR) 1·13, 95 per cent c.i. 0·82 to 1·55; P = 0·446) and platelets (adjusted OR 0·84, 0·66 to 1·08; P = 0·171). Both plasma to red blood cell ratio (adjusted OR 1·77, 1·32 to 2·37; P < 0·001) and platelet to red blood cell ratio (adjusted OR 1·71, 1·35 to 2·15; P < 0·001) were significantly associated with a higher incidence of adverse events. No significant differences in in-hospital mortality were observed between the three transfusion categories (low, medium and high).

CONCLUSION

In this study, transfusion strategies with high plasma to red blood cell and platelet to red blood cell ratios did not have survival benefits, but were associated with an increase in adverse events.

The Role of Plasma Transfusion in Massive Bleeding: Protecting the Endothelial Glycocalyx?

Massive hemorrhage is a leading cause of death worldwide. During the last decade several retrospective and some prospective clinical studies have suggested a beneficial effect of early plasma-based resuscitation on survival in trauma patients. The underlying mechanisms are unknown but appear to involve the ability of plasma to preserve the endothelial glycocalyx. In this mini-review, we summarize current knowledge on glycocalyx structure and function, and present data describing the impact of hemorrhagic shock and resuscitation fluids on glycocalyx. Animal studies show that hemorrhagic shock leads to glycocalyx shedding, endothelial inflammatory changes, and vascular hyper-permeability. In these animal models, plasma administration preserves glycocalyx integrity and functions better than resuscitation with crystalloids or colloids. In addition, we briefly present data on the possible plasma components responsible for these effects. The endothelial glycocalyx is increasingly recognized as a critical component for the physiological vasculo-endothelial function, which is destroyed in hemorrhagic shock. Interventions for preserving an intact glycocalyx shall improve survival of trauma patients.

Do we still need cryoprecipitate? Cryoprecipitate and fibrinogen concentrate as treatments for major hemorrhage - how do they compare?

INTRODUCTION

Major hemorrhage is a source of significant mortality and morbidity worldwide. Identification and characterization of coagulation impairment associated with major hemorrhage has suggested a key role for fibrinogen deficiency, however the optimum mode of replacement of fibrinogen remains unclear, and standardized major hemorrhage protocols may overlook context-dependent variations in individual patients' clotting derangement. Areas covered: This paper examines the current practice and evidence regarding the role of different modes of fibrinogen replacement in major hemorrhage in 3 distinct clinical settings: trauma, obstetric hemorrhage, and gastrointestinal hemorrhage with associated liver disease. A literature search was carried out electronically using Athens access to the National Health Service evidence health information resources, primarily PubMed and Google Scholar. Expert commentary: Two key questions need to be addressed. First, what is the role of concentrated fibrinogen (by comparison to no fibrinogen), and second, which concentrated source or product is more effective (or cost-effective)? Current practice and concept is derived largely from small pilot trials in the trauma setting, but results from larger studies are awaited. More comparative data on changes to clotting profiles in different groups of bleeding patients are needed to help delineate differences and guide interventional treatment studies.

Massive transfusions for critical bleeding: is everything old new again?

Massive transfusion or major haemorrhage protocols have been widely adopted in the treatment of critically bleeding patients. Following evidence that higher ratios of transfused plasma and platelets to red blood cells may offer survival benefits in military trauma patients, these ratios are now commonly incorporated into massive transfusion protocols. They more closely resemble the effects of whole blood transfusion, which in the second half of last century was largely replaced by individual blood component transfusion based on laboratory-guided indicators. However, high-quality evidence to guide transfusion support for critically bleeding patients across the range of bleeding contexts is lacking, including for both trauma and non-trauma patients. More data on major haemorrhage support and clinical outcomes are needed to inform guidelines and practice.