Recovery of fibrinogen after administration of fibrinogen concentrate to patients with severe bleeding after cardiopulmonary bypass surgery

Relationship between perioperative cardiopulmonary bypass time, platelet count, fibrinogen level, rotational thromboelastometry data, antithrombin level, and blood loss volume and the effects of deep hypothermic circulatory arrest: An observational study

INTRODUCTION

We hypothesized that perioperative fibrinogen level, platelet count, and rotational thromboelastometry (ROTEM) data values decrease in proportion to cardiopulmonary bypass (CPB) time, particularly in patients who underwent deep hypothermic circulatory arrest (DHCA).

METHODS

A total of 160 patients were enrolled and divided into the following three groups depending on CPB time: <2-h, 2- 3-h, and >3-h groups. Blood samples were obtained during CPB weaning. Platelet count, ROTEM data, fibrinogen level, and antithrombin level were determined. For propensity matching, we selected 15 patients who underwent DHCA and 15 patients who did not undergo DHCA and used propensity scores to match CPB time and other characteristics.

RESULTS

The <2-h, 2-3-h, and >3-h groups included 74, 63, and 23 patients, respectively. No significant differences in platelet count and fibrinogen level were observed between the groups. Antithrombin level and amplitude of clot firmness at 10 min in the EXTEM and FIBTEM tests were lowest in the >3-h group. Similarly, blood loss volume and transfusion volume were highest in the >3-h group. Significant differences in platelet count, ROTEM data, lowest esophageal and bladder temperatures, and transfusion volume were observed between patients who underwent DHCA and patients who did not undergo DHCA.

CONCLUSIONS

The longer the CPB time, the greater the perioperative blood loss volume and transfusion volume, particularly if CPB time is greater than 3 hours. Sub-group analysis revealed that DHCA affects perioperative platelet count and function as well as blood loss volume.

Long-Term Safety Analysis of a Fibrinogen Concentrate (RiaSTAP®/Haemocomplettan® P)

Fibrinogen concentrate treatment is recommended for acute bleeding episodes in adult and pediatric patients with congenital and acquired fibrinogen deficiency. Previous studies have reported a low risk of thromboembolic events (TEEs) with fibrinogen concentrate use; however, the post-treatment TEE risk remains a concern. A retrospective evaluation of RiaSTAP®/Haemocomplettan® P (CSL Behring, Marburg, Germany) post-marketing data was performed (January 1986-June 2022), complemented by a literature review of published studies. Approximately 7.45 million grams of fibrinogen concentrate was administered during the review period. Adverse drug reactions (ADRs) were reported in 337 patients, and 81 (24.0%) of these patients experienced possible TEEs, including 14/81 (17.3%) who experienced fatal outcomes. Risk factors and the administration of other coagulation products existed in most cases, providing alternative explanations. The literature review identified 52 high-ranking studies with fibrinogen concentrate across various clinical areas, including 26 randomized controlled trials. Overall, a higher number of comparative studies showed lower rates of ADRs and/or TEEs in the fibrinogen group versus the comparison group(s) compared with those that reported higher rates or no differences between groups. Post-marketing data and clinical studies demonstrate a low rate of ADRs, including TEEs, with fibrinogen concentrate treatment. These findings suggest a favorable safety profile of fibrinogen concentrate, placing it among the first-line treatments effective for managing intraoperative hemostatic bleeding.

[Postpartum Hemorrhage]

Postpartum hemorrhage (PPH) affects about 4% of all deliveries in high-income countries and continues to rise, a trend attributable to the increase in caesarean section rates and maternal morbidity. Preventive measures such as the precautionary administration of uterotonics effectively reduce the risk of severe bleeding irrespective of birth mode. As a time-critical condition and a significant contributor to adverse maternal outcomes, PPH needs to be diagnosed early by measuring, not estimating, blood losses. Institutional treatment algorithms should be available to guide stage-based interdisciplinary management without delay. The main therapy goals are to identify the etiology and stop the bleeding by using uterotonics and mechanical and surgical interventions, to restore hemodynamic stability by volume and transfusion therapy and to optimize hemostasis by laboratory- and viscoelastic assay-guided factor replacement. This review highlights current recommendations for prevention, diagnosis and treatment of PPH.

Influence of Fibrinogen Concentrate on Neonatal Clot Structure When Administered Ex Vivo After Cardiopulmonary Bypass

BACKGROUND

Bleeding is a serious complication of cardiopulmonary bypass (CPB) in neonates. Blood product transfusions are often needed to adequately restore hemostasis, but are associated with significant risks. Thus, neonates would benefit from other effective, and safe, hemostatic therapies. The use of fibrinogen concentrate (FC; RiaSTAP, CSL Behring, Marburg, Germany) is growing in popularity, but has not been adequately studied in neonates. Here, we characterize structural and degradation effects on the neonatal fibrin network when FC is added ex vivo to plasma obtained after CPB.

METHODS

After approval by the institutional review board and parental consent, blood samples were collected from neonates undergoing cardiac surgery and centrifuged to yield platelet poor plasma. Clots were formed ex vivo from plasma obtained at several time points: (1) baseline, (2) immediately post-CPB, and (3) post-transfusion of cryoprecipitate. In addition, we utilized post-CPB plasma to construct the following conditions: (4) post-CPB +0.5 mg/mL FC, and (5) post-CPB +0.9 mg/mL FC. The resultant fibrin networks were imaged using confocal microscopy to analyze overall structure, fiber density, and alignment. Clots were also analyzed using a microfluidic degradation assay. Fibrinogen content was quantified for all plasma samples.

RESULTS

The addition of 0.5 or 0.9 mg/mL FC to post-CPB samples significantly enhanced the median fiber density when compared to untreated post-CPB samples (post-CPB = 0.44 [interquartile range {IQR}: 0.36-0.52], post-CPB +0.5 mg/mL FC = 0.69 [0.56-0.77], post-CPB +0.9 mg/mL FC = 0.87 [0.59-0.96]; P = .01 and P = .006, respectively). The addition of 0.9 mg/mL FC to post-CPB samples resulted in a greater fiber density than that observed after the in vivo transfusion of cryoprecipitate (post-transfusion = 0.54 [0.45-0.77], post-CPB +0.9 mg/mL FC = 0.87 [0.59-0.96]; P = .002). Median fiber alignment did not differ significantly between post-CPB samples and samples treated with FC. Degradation rates were not statistically significant from baseline values with either 0.5 or 0.9 mg/mL FC. In addition, we found a significant correlation between the difference in the baseline and post-CPB fibrinogen concentration with patient age ( P = .033) after controlling for weight.

CONCLUSIONS

Our results show that clots formed ex vivo with clinically relevant doses of FC (0.9 mg/mL) display similar structural and degradation characteristics compared to the in vivo transfusion of cryoprecipitate. These findings suggest that FC is effective in restoring structural fibrin clot properties after CPB. Future studies after the administration of FC in vivo are needed to validate this hypothesis.

Coagulation management and transfusion in massive postpartum hemorrhage

PURPOSE OF REVIEW

Excessive bleeding during and following childbirth remains one of the leading causes of maternal mortality.

RECENT FINDINGS

Current guidelines differ in definitions and recommendations on managing transfusion and hemostasis in massive postpartum hemorrhage (PPH). Insights gained from trauma-induced coagulopathy are not directly transferable to the obstetric population due to gestational alterations and a differing pathophysiology.

SUMMARY

Factor deficiency is uncommon at the beginning of most etiologies of PPH but will eventually develop from consumption and depletion in the absence of bleeding control. The sensitivity of point-of-care tests for fibrinolysis is too low and may delay treatment, therefore tranexamic acid should be started early at diagnosis even without signs for hyperfibrinolysis. Transfusion management may be initiated empirically, but is best to be guided by laboratory and viscoelastic assay results as soon as possible. Hypofibrinogenemia is well detected by point-of-care tests, thus substitution may be tailored to individual needs, while reliable thresholds for fresh frozen plasma (FFP) and specific components are yet to be defined. In case of factor deficiency, prothrombin complex concentrate or lyophilized plasma allow for a more rapid restoration of coagulation than FFP. If bleeding and hemostasis are under control, a timely anticoagulation may be necessary.

Prophylactic Fibrinogen Reduces Excessive Bleeding in Total Hip Arthroplasty Surgery: A Randomized Double-blinded Placebo-controlled Trial

Objectives

Excessive blood loss is a critical complication of total hip arthroplasty. We intended to determine whether preoperative fibrinogen administration reduces perioperative bleeding and the need for blood transfusion in total hip arthroplasty surgery.

Methods

In 4 months, 178 patients who underwent total hip arthroplasty were randomly assigned equally to intervention and placebo-control groups in a double-blinded, parallel two-arm randomized controlled trial. Both intravenously, 30 min before the start of the surgery, the intervention group received two grams of fibrinogen concentrate dissolved in 100 ml of distilled water. In contrast, the control group received 100 ml of normal saline solution. The amount of postoperative blood loss served as the main result, and the requirement for blood transfusions served as the secondary outcome.

Results

In comparison to the placebo, administering fibrinogen concentrate considerably reduced the amount of blood loss (P=0.001) and the requirement for blood transfusions (P=0.004). Patients who got fibrinogen concentrate experienced no side effects. In addition, patients in the fibrinogen group had significantly lower hemoglobin and higher fibrinogen levels in the recovery room and received lesser blood transfusions (P<0.005) than the placebo group.

Conclusion

In total hip arthroplasty, fibrinogen concentrate lessens postoperative bleeding and the requirement for blood transfusions.

Prevention and management of difficult hemostasis in acute type A aortic dissection repair

Postoperative bleeding after surgery for acute aortic dissection is one of the most common complications and has an important influence on mortality and morbidity. Therefore, various methods have been introduced to prevent or manage postoperative bleeding. In this article, we investigated the causes of bleeding after surgery for acute aortic dissection, and introduce appropriate transfusion or pharmacologic treatment, topical hemostatic agents, and local compressive maneuver to manage it.

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.

Evaluation of plasma fibrinogen levels before and after coronary artery bypass graft surgery and its association with the need for blood products

Background:

The present study investigated the plasma level of fibrinogen before and after removing the pump in coronary artery bypass graft (CABG) surgery and its relationship with the need for blood products.

Materials and Methods:

The present study was performed on 60 patients who were candidates for CABG surgery. The fibrinogen level of these patients was assessed and recorded before surgery and immediately after removing the pump. In addition, their hemoglobin level was recorded before the operation and 2 h after. In addition, the number and type of blood products transfusion were recorded intraoperatively and postoperatively and also at the intensive care unit.

Results:

Patients’ fibrinogen level after removing the pump with the mean of 130.53 ± 122.01 mg/dl decreased significantly compared to before surgery with the mean of mg/dl 224.95 ± 132.88 mg/dl (P < 0.001). In addition, the prognostic value of fibrinogen after removing the pump in determining the postoperative need of blood transfusion showed that the cut-off value of fibrinogen was < 196 mg/dl with a sensitivity of 16.82% and specificity of 80%, but it was not statistically significant (area under the curve [95% confidence interval]: 0.519 [0.350–0.689]; P = 0.825).

Conclusion:

According to the results of the present study, due to significant changes in fibrinogen levels after removing the pump compared to preoperation, it seems that this factor can play an important role in prognosis of the need to postoperative blood transfusion, although the prognostic value and the critical point mentioned in our study was not significant and it is required to do further studies.

Viscoelastic testing to assess the effects of rapid fibrinogen concentrate administration after cardiopulmonary bypass: insights from the REPLACE study

Haemorrhage during and following surgery results in increased morbidity and mortality. Low plasma fibrinogen levels have been associated with increased blood loss and transfusion requirements. Fibrinogen supplementation has been shown to reduce bleeding in coagulopathic patients. This post hoc study evaluated fibrinogen repletion and pharmacokinetic data from the REPLACE study. One hundred and fifty-two adult patients undergoing elective aortic surgery requiring cardiopulmonary bypass (CPB) with defined bleeding of 60-250 g at first 5 min bleeding mass were included in the phase III trial. Patients were randomized to receive either fibrinogen concentrate (FCH) or placebo following CPB removal. Plasma fibrinogen levels and viscoelastic testing parameters (ROTEM-based FIBTEM and EXTEM assays) were measured before, during, and after study treatment administration. A mean dose of 6.3 g FCH was administered in the FCH group, with a median infusion duration of 2 min. Immediately following completion of FCH administration, a rapid increase in plasma fibrinogen levels to near baseline (median change from baseline -0.10 g/l) was seen in the FCH group but not in the placebo group (median change from baseline -1.29 g/l). FCH administration also caused an immediate increase in FIBTEM maximum clot firmness (MCF) to 23 mm and improvements in EXTEM coagulation time and clot formation time by the end of infusion. There was a strong correlation between the plasma fibrinogen level and FIBTEM MCF. Treatment with high doses of FCH with a rapid infusion time resulted in immediate recovery to baseline levels of plasma fibrinogen and viscoelastic testing parameters.

First-Line Administration of Fibrinogen Concentrate in the Bleeding Trauma Patient: Searching for Effective Dosages and Optimal Post-Treatment Levels Limiting Massive Transfusion-Further Results of the RETIC Study

Fibrinogen supplementation is recommended for treatment of severe trauma hemorrhage. However, required dosages and aimed for post-treatment fibrinogen levels remain a matter of discussion. Within the published RETIC study, adult patients suffering trauma-induced coagulopathy were randomly assigned to receive fibrinogen concentrate (FC) as first-line (n = 50) or crossover rescue (n = 20) therapy. Depending on bodyweight, a single dose of 3, 4, 5, or 6 g FC was administered and repeated if necessary (FibA10 < 9 mm). The dose-dependent response (changes in plasma fibrinogen and FibA10) was analyzed. Receiver operating characteristics (ROC) analysis regarding the need for massive transfusion and correlation analyses regarding fibrinogen concentrations and polymerization were performed. Median FC single doses amounted to 62.5 (57 to 66.66) mg·kg⁻¹. One FC single-dose sufficiently corrected fibrinogen and FibA10 (median fibrinogen 213 mg·dL⁻¹, median FibA10 11 mm) only in patients with baseline fibrinogen above 100 mg·dL⁻¹ and FibA10 above 5 mm, repeated dosing was required in patients with lower baseline fibrinogen/FibA10. Fibrinogen increased by 83 or 107 mg·dL⁻¹ and FibA10 by 4 or 4.5 mm after single or double dose of FC, respectively. ROC curve analysis revealed post-treatment fibrinogen levels under 204.5 mg·dL⁻¹ to predict the need for massive transfusion (AUC 0.652; specificity: 0.667; sensitivity: 0.688). Baseline fibrinogen/FibA10 levels should be considered for FC dosing as only sufficiently corrected post-treatment levels limit transfusion requirements.

Prophylactic fibrinogen concentrate administration in surgical correction of paediatric craniosynostosis: A double-blind placebo-controlled trial

BACKGROUND

Surgical craniosynostosis repair in children is associated with massive blood loss and significant transfusion of blood products. Fibrinogen concentrate is claimed to be useful in reducing blood loss and transfusion requirements.

OBJECTIVE

We investigated whether prophylactic administration of fibrinogen concentrate will reduce blood loss and transfusion requirements during paediatric craniofacial surgery.

DESIGN

Randomised, placebo-controlled, double-blind clinical trial.

SETTING

University medical centre.

PATIENTS

A total of 114 infants and children up to 25 months of age (median age 10 months).

INTERVENTION

Surgical craniosynostosis repair by calvarial remodelling was performed in each patient. Patients were randomised to receive prophylactic fibrinogen concentrate (Haemocomplettan P) at a mean dose of 79 mg kg-1 body weight or placebo.

MAIN OUTCOME MEASURES

Primary outcome was the volume of transfused blood products. Secondary outcomes were peri-operative blood loss, duration of surgery, length of stay in the paediatric ICU, length of hospital stay, postoperative complications and adverse effects of fibrinogen concentrate infusion.

RESULTS

No significant differences (P < 0.05) were found in the volume of transfused blood products (median 29 ml kg-1 body weight vs. 29 ml kg-1 body weight), intra-operative estimated blood loss (45 vs. 46 ml kg-1), calculated blood loss (57 vs. 53 ml kg-1), or postoperative blood loss (24 vs. 24 ml kg-1) between the intervention and placebo groups. In addition, duration of surgery, length of stay in the paediatric ICU, hospital stay and complications were not significantly different between the two groups.

CONCLUSION

During surgical craniosynostosis repair in young children, prophylactic administration of high-dose fibrinogen concentrate did not reduce the amount of transfused blood products or decrease peri-operative blood loss.

TRIAL REGISTRATION

National Trial Register (NTR2975) and EudraCT (2011-002287-24).

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 prophylaxis for reducing perioperative bleeding in patients undergoing radical cystectomy: A double-blind placebo-controlled randomized trial

OBJECTIVE

Excessive bleeding is an important complication of radical cystectomy. We aimed to assess whether preoperative administration of fibrinogen decreases perioperative bleeding and improves the outcome of radical cystectomy.

DESIGN

Double-blinded randomized trial with two parallel arms.

SETTING

The study was conducted in the department of surgery at a teaching hospital affiliated with a University of Medical Sciences.

PATIENTS

In total, 70 men undergoing radical cystectomy were randomized to fibrinogen (n = 35) and placebo-control groups. Mean (SD) age was 64.7 (7.4) years.

INTERVENTIONS

The intervention group received 2 g fibrinogen concentrate diluted in 100 ml distilled water, and the control group received 100 ml normal saline; both intravenously 15 ̶ 30 min before the start of the surgery.

OUTCOME MEASURES

The primary outcome was the amount of perioperative blood loss. The secondary outcomes were hemodynamic features and vital signs.

MAIN RESULTS

Fibrinogen significantly decreased the volume of blood loss (p < 0.001) and the total number of transfused packed-cell units per group (38 vs. 115 units); and compensated the decrease of HCO3 (p = 0.030), the mean arterial pressure (p < 0.001), hemoglobin O2 saturation (p = 0.001), heart rate (p < 0.001), and temperature (p < 0.001) throughout the surgery compared with the placebo. Patients in the fibrinogen group had shorter Intensive Care Unit (p = 0.001) and hospital (p < 0.001) stay. We did not find any adverse reaction in our patients receiving fibrinogen concentrate.

CONCLUSION

Fibrinogen concentrate reduces perioperative bleeding and the need for blood transfusion in radical cystectomy. It improves the outcomes of the surgery and decreases patients' length of stay in the healthcare system following radical cystectomy.

REGISTRATION

Iranian Registry of Clinical Trials (IRCT) http://www.irct.ir/, reference number: IRCT20191013045091N1.

ETHICS CODE

Shahid Beheshti University of Medical Sciences, reference number: IR.SBMU.RETECH.REC.1398.033.

Therapeutic Application of Fibrinogen in Spine Surgery: A Review Article

BACKGROUND

The aim of this review is to investigate current uses of fibrinogen as a tool to reduce operative and postoperative blood loss in different surgical fields especially orthopedic spine surgery. This is a systematic review.

METHODS

MEDLINE (via Ovid 1946 to June 1, 2020) and Embase (via Ovid 1947 to June 1, 2020) were searched using the keywords "fibrinogen", "surgery", and "spine" for relevant studies. The search strategy used text words and relevant indexing to identify articles discussing the use of fibrinogen to control surgical blood loss.

RESULTS

The original literature search yielded 407 articles from which 68 duplications were removed. Three hundred thirty-nine abstracts and titles were screened. Results were separated by surgical specialties.

CONCLUSIONS

Multiple studies have looked at the role of fibrinogen for acute bleeding in the operative setting. The current evidence regarding the use of fibrinogen concentrate in spine surgery is promising but limited, even though this is a field with the potential for severe hemorrhage. Further trials are required to understand the utility of fibrinogen concentrate as a first-line therapy in spine surgery and to understand the importance of target fibrinogen levels and subsequent dosing and administration to allow recommendations to be made in this field.

Pediatric Fibrinogen PART II-Overview of Indications for Fibrinogen Use in Critically Ill Children

Bleeding is frequently seen in critically ill children and is associated with increased morbidity and mortality. Fibrinogen is an essential coagulation factor for hemostasis and hypofibrinogenemia is an important risk factor for bleeding in pediatric and adult settings. Cryoprecipitate and fibrinogen concentrate are often given to critically ill children to prevent bleeding and improve fibrinogen levels, especially in the setting of surgery, trauma, leukemia, disseminated intravascular coagulopathy, and liver failure. The theoretical benefit of fibrinogen supplementation to treat hypofibrinogenemia appears obvious, yet the evidence to support fibrinogen supplementation in children is sparce and clinical indications are poorly defined. In addition, it is unknown what the optimal fibrinogen replacement product is in children and neonates or what the targets of treatment should be. As a result, there is considerable variability in practice. In this article we will review the current pediatric and applicable adult literature with regard to the use of fibrinogen replacement in different pediatric critical care contexts. We will discuss the clinical indications for fibrinogen supplementation in critically ill children and the evidence to support their use. We summarize by highlighting current knowledge gaps and areas for future research.

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.

Pediatric Fibrinogen PART I-Pitfalls in Fibrinogen Evaluation and Use of Fibrinogen Replacement Products in Children

Fibrinogen is a key coagulation protein, playing a critical role in hemostasis. It is the first factor to decrease to critical levels during bleeding. Hypofibrinogenemia is an important risk factor for bleeding in clinical settings, including pediatric surgery. Yet, the optimal measurement of fibrinogen levels is subject to debate, as is the critical threshold for intervention. Fibrinogen replacement may be provided by cryoprecipitate and fibrinogen concentrate. Whilst both products contain fibrinogen, they are not equivalent, each has its own advantages and disadvantages, especially for pediatric use. Unfortunately, medical literature to support fibrinogen replacement in children is limited. In this article we review the current diagnostic tools to measure fibrinogen, with respect to their use in the pediatric critical care setting. Secondly, we evaluate the different fibrinogen replacement therapies, focusing on cryoprecipitate and fibrinogen concentrate and examine their individual product characteristics, associated risks and benefits, different dosing strategies and specific pitfalls for use in children. We summarize by highlighting current knowledge gaps and areas for future research.

Early administration of fibrinogen concentrate in patients with polytrauma with thromboelastometry suggestive of hypofibrinogenemia: A randomized feasibility trial

OBJECTIVE

To evaluate the clinical effects of early administration of fibrinogen concentrate in patients with severe trauma and hypofibrinogenemia.

METHODS

We conducted an open randomized feasibility trial between December 2015 and January 2017 in patients with severe trauma admitted to the emergency department of a large trauma center. Patients presented with hypotension, tachycardia, and FIBTEM findings suggestive of hypofibrinogenemia. The intervention group received fibrinogen concentrate (50 mg/kg), and the control group did not receive early fibrinogen replacement. The primary outcome was feasibility assessed as the proportion of patients receiving the allocated treatment within 60 min after randomization. The secondary outcomes were transfusion requirements and other exploratory outcomes. Randomization was performed using sequentially numbered and sealed opaque envelopes. ClinicalTrials.gov: NCT02864875.

RESULTS

Thirty-two patients were randomized (16 in each group). All patients received the allocated treatment within 60 min after randomization (100%, 95% confidence interval, 86.7%-100%). The median length of intensive care unit stay was shorter in the intervention group (8 days, interquartile range [IQR] 5.75-10.0 vs. 11 days, IQR 8.5-16.0; p=0.02). There was no difference between the groups in other clinical outcomes. No adverse effects related to treatment were recorded in either group.

CONCLUSION

Early fibrinogen replacement with fibrinogen concentrate was feasible. Larger trials are required to properly evaluate clinical outcomes.

The role of exogenous Fibrinogen in cardiac surgery: stop bleeding or induce cardiovascular disease

The surgical treatment contributes to broad variety of cardiovascular diseases (CVD). Due to many involved factors in preoperative bleeding, it is almost difficult to perform better Haemostatic approach. Fibrinogen is a major blood glycoprotein and a coagulation factor which decreases postoperative bleeding. It has a potential role in platelet activation and bleeding inhibition; it may reflect the inflammatory responses and be related to the endothelial dysfunction. Fibrinogen can act as a pro-inflammatory element via increasing some inflammatory markers including IL-6, tumor necrosis factor-α (TNF-α), monocyte chemo attractant protein (MCP-1), macrophage inflammatory protein-1 (MIP-1a and b), matrix metalloproteinase (MMP-1 and MMP-9) and Toll-like Receptors (TLRs); through activation of these factors, fibrinogen may induce some inflammatory mechanisms such as focal adhesion kinase (FAK), mitogen-activated protein kinases (MAPK) and nuclear factor κB (NF-κB) pathways. It may cause endothelial dysfunction by increasing P and E-selection, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) levels which activate MAPK and NF-κB pathways. This factor is also associated with increased exocytosed von Willebrand factor (vWF) as well as activation of Rho-GTPase mechanism. All of these data demonstrate the dual role of fibrinogen in cardiac surgeries, bleeding inhibition and CVD. Therefore, identifying the CVD factors is helpful for designing preventive strategies and alternative drugs.

Thromboelastometry and a hemostasis management system are most beneficial for guiding hemostatic therapy in cardiac surgery patients with a EuroSCORE II of ≥1.83%: a randomized controlled two-step trial

PURPOSE

We evaluated the efficacy of hemostatic therapy based on point-of-care (POC) testing in patients undergoing cardiac surgery.

METHODS

This was a single-institution, prospective, randomized, double-blinded study. In step 1, 90 patients scheduled for elective cardiac surgery underwent complete blood count and fibrinogen measurements at baseline, after cardiopulmonary bypass (CPB) initiation (CPB start), just after CPB end, and in the intensive care unit (ICU). In step 2, 72 patients scheduled for elective cardiac surgery underwent conventional laboratory coagulation tests (control group) or POC coagulation tests (POC group). Transfusions were prepared using the fibrinogen and platelet values at mainly "CPB start" for the control group, and using the ROTEM values at mainly "CPB end" for the POC group. Consequently, the step 2 patients were divided into high- and low-risk subgroups based on the EuroSCORE II by logistic regression analysis; transfusion data and bleeding volumes were compared between the control and POC groups within the high- and low-risk subgroups.

RESULTS

In step 1, all blood components were significantly decreased at CPB start compared with baseline, and platelet and fibrinogen levels remained almost constant from CPB start to end. In step 2, the transfusion rates and perioperative bleeding volumes did not significantly differ between the control and POC groups. Subgroup analysis suggested that only the high-risk subgroup significantly differed regarding perioperative red blood cell transfusion and total bleeding volume in the ICU.

CONCLUSIONS

POC testing is beneficial for cardiac surgery patients with a EuroSCORE II of ≥1.83%.

The prophylactic use of fibrinogen concentrate in high-risk cardiac surgery

BACKGROUND

Perioperative blood loss is a major contributor to morbidity and mortality in cardiac surgery. Plasma fibrinogen levels play an essential role in hemostasis and deplete quickly during hemorrhage. The objective of this study was to determine whether prophylactic fibrinogen concentrate administration lowers overall blood product transfusion requirements in high-risk cardiac surgery in patients with low fibrinogen plasma levels.

METHODS

The study was performed in a prospective, randomized, and double-blinded design. The investigation included 62 patients undergoing elective, high-risk cardiac surgery. After weaning from cardiopulmonary bypass and reversal of heparin patients received either fibrinogen concentrate or placebo. The primary outcome variable was overall blood product usage 24 hours after intervention.

RESULTS

The fibrinogen group received numerically fewer total units of blood products than the placebo group, but the difference was not statistically or clinically significant (for groups n = 27; n = 29 and 19 vs 37 units, respectively, P = .908). The overall transfusion rate in both groups was significantly lower than the institutional average suggested (fibrinogen group 26%, placebo group 28%). The fibrinogen group showed significantly higher fibrinogen levels (2.38 vs 1.83 g/L (end of surgery), P < .001; 3.33 vs 2.68 g/L (12 hours after intervention), P = .003) and improved viscoelastic coagulation parameters (FIBTEM MCF, 27 vs 23 mm, P = .022).

CONCLUSION

This randomized, controlled trial demonstrates that point-of-care guided and prophylactic treatment with fibrinogen concentrate does not reduce transfusion of blood products in a setting of unexpectedly low transfusion rate as tested in this cohort, but may improve coagulation parameters in the setting of high-risk cardiac surgery.

Antifibrinolytics and cardiac surgery: The past, the present, and the future

Cardiac surgery is usually associated with significant blood loss, which often necessitates blood transfusion. In order to decrease the risks associated with the latter, pharmacological as well as nonpharmacological strategies have been used to reduce blood loss. Among the pharmacological approaches, antifibrinolytic drugs are the mainstay. Aprotinin, which was the first ubiquitously used drug, fell into disrepute only to re-emerge after much debate. The decline of aprotinin paved the way for the lysine analogs. However, we must be aware with the side effects of these drugs as well as the dose modification required in special situations. Nonsaccharide glycosaminoglycans have been under investigation to overcome the drawbacks of the lysine analogs. It remains to be seen whether these drugs can replace the traditional antifibrinolytics.

Efficacy of fibrinogen concentrate in major abdominal surgery - A prospective, randomized, controlled study in cytoreductive surgery for pseudomyxoma peritonei

BACKGROUND

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei (PMP) is associated with excessive bleeding and acquired fibrinogen deficiency. Maintaining plasma fibrinogen may support hemostasis.

OBJECTIVES

To compare hemostatic efficacy and safety of human fibrinogen concentrate (HFC) vs cryoprecipitate as fibrinogen sources for bleeding patients with acquired fibrinogen deficiency undergoing PMP CRS.

METHODS

FORMA-05 was an off-label single-center, prospective, randomized, controlled phase 2 study. Patients undergoing PMP surgery with predicted intraoperative blood loss ≥2 L received human fibrinogen concentrate (HFC; 4 g) or cryoprecipitate (two pools of 5 units, containing approximately 4.0-4.6 g fibrinogen), repeated as needed. The primary endpoint was a composite of intraoperative and postoperative efficacy, graded using objective 4-point scales and adjudicated by an independent committee.

RESULTS

One hundred percent of patients receiving HFC (95% confidence interval: 83.9-100.0, n = 21) or cryoprecipitate (84.6-100.0, n = 22) achieved hemostatic success. HFC demonstrated noninferior efficacy (P = .0095; post hoc) and arrived in the operating room 46 minutes faster. There were significantly greater mean increases with HFC vs cryoprecipitate in plasma fibrinogen (0.78 vs 0.35 g/L; P < .0001) and FIBTEM A20 (3.33 vs 0.93 mm; P = .003). Factor XIII, factor VIII, and von Willebrand factor activity were maintained throughout surgery. Only red blood cells were transfused intraoperatively (median units: HFC group, 1.0; cryoprecipitate group, 0.5). Thromboembolic events were detected with cryoprecipitate only. Safety was otherwise comparable between groups.

CONCLUSIONS

Human fibrinogen concentrate was hemostatically efficacious in patients undergoing major abdominal PMP surgery, with a favorable safety profile. These results are relevant to other surgical settings where bleeding and acquired fibrinogen deficiency occur.

Correlation between Maximum Clot Firmness in FIBTEM and Fibrinogen Level in Critical Trauma Patients

Background

Both fibrinogen level and rotational thromboelastometry (ROTEM®) are accurate tests to demonstrate a bleeding tendency. FIBTEM® is one type of ROTEM test to determine the function of fibrinogen. An advantage of FIBTEM is helping physicians make proper decisions for blood component transfusions. However, the correlation between fibrinogen level and FIBTEM is still unclear.

Objective

The aim of this study was to demonstrate a correlation between maximum clot firmness (MCF) in FIBTEM and fibrinogen level in critical trauma patients.

Methods

Data were retrospectively collected from 87 patients who visited the emergency department between May 2017 and January 2019 in Songklanagarind Hospital. Blood specimens were sent for both ROTEM evaluation and fibrinogen level. The data were analysed with STATA program version 12.1.

Results

Eighty-seven patients were enrolled in the study over the 21-month period. The patients consisted of 73 males (83.9%) with a median age of 40 years. Seventy-three patients (83.9%) were still alive. The following equation from FIBTEM MCF was used to predict fibrinogen level: fibrinogen level = 138 + (15.2 × FIBTEM MCF) (Lin's concordance correlation coefficient of 0.52, P < 0.001). The results showed a good correlation of FIBTEM MCF to predict patients with hypofibrinogenemia (area under ROC curve = 0.81). Patients with normal fibrinogen levels received significantly fewer units of all types of blood components.

Conclusion

FIBTEM MCF had poor prediction of fibrinogen level; however, it can help to identify patients who have hypofibrinogenemia.

Rotation thromboelastometry (ROTEM) enables improved outcomes in the pediatric trauma population

Objective

We evaluated the role of rotation thromboelastometry (ROTEM) in managing acute traumatic coagulopathy in pediatric patients with trauma.

Methods

A retrospective cohort of pediatric patients with trauma from six institutes was studied during a 10-year period from 2007 to 2017. The associations between ROTEM-guided, goal-directed coagulation therapy and clinical outcomes were determined.

Results

Three hundred thirty-two pediatric patients (age < 15 years) who were treated with ROTEM-guided, goal-directed coagulation therapy were matched to 332 control pediatric patients with conventional plasmatic coagulation tests. The ROTEM protocol was associated with a significant reduction in the interval for admission to acute traumatic coagulopathy treatment, less plasma transfusions in the first 24 hours of admission, and a favorable coagulopathy recovery. Furthermore, the median number of total hospital days was significantly shorter for patients who had the ROTEM protocol than for control patients.

Conclusions

There are significant favorable outcomes, including rapid acute traumatic coagulopathy treatment and a lower 24-hour blood product requirement, following ROTEM-guided, goal-directed coagulation therapy among pediatric patients with blunt trauma.

Randomized evaluation of fibrinogen vs placebo in complex cardiovascular surgery (REPLACE): a double-blind phase III study of haemostatic therapy

BACKGROUND

Single-dose human fibrinogen concentrate (FCH) might have haemostatic benefits in complex cardiovascular surgery.

METHODS

Patients undergoing elective aortic surgery requiring cardiopulmonary bypass were randomly assigned to receive FCH or placebo. Study medication was administered to patients with a 5 min bleeding mass of 60-250 g after separation from bypass and surgical haemostasis. A standardized algorithm for allogeneic blood product transfusion was followed if bleeding continued after study medication.

RESULTS

519 patients from 34 centres were randomized, of whom 152 (29%) met inclusion criteria for study medication. Median (IQR) pretreatment 5 min bleeding mass was 107 (76-138) and 91 (71-112) g in the FCH and placebo groups, respectively (P=0.13). More allogeneic blood product units were administered during the first 24 h after FCH, 5.0 (2.0-11.0), when compared with placebo, 3.0 (0.0-7.0), P=0.026. Fewer patients avoided transfusion in the FCH group (15.4%) compared with placebo (28.4%), P=0.047. The FCH immediately increased plasma fibrinogen concentration and fibrin-based clot strength. Adverse event rates were comparable in each group.

CONCLUSIONS

Human fibrinogen concentrate was associated with increased allogeneic blood product transfusion, an unexpected finding contrary to previous studies. Human fibrinogen concentrate may not be effective in this setting when administered according to 5-minute bleeding mass. Low bleeding rates and normal-range plasma fibrinogen concentrations before study medication, and variability in adherence to the complex transfusion algorithm, may have contributed to these results.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier no. NCT01475669; EudraCT trial no. 2011-002685-20.

Short-term recovery pattern of plasma fibrinogen after cardiac surgery: A prospective observational study

Low plasma fibrinogen level is common after cardiopulmonary bypass (CPB). Current substitution practice with fibrinogen concentrate generally follows a single measurement and cut-off values from the literature, whereas early postoperative endogenous fibrinogen kinetics is incompletely described and widely disregarded. The aim of this study was to determine the short-term recovery pattern of plasma fibrinogen after CPB weaning. Our hypothesis was that in the absence of surgical bleeding, CPB-induced hypofibrinogenemia would resolve spontaneously and predictably within a few hours. In a prospective, observational study of 26 patients undergoing conventional CPB (cCPB) or minimally invasive extracorporeal circulation (MiECC), Clauss fibrinogen level (C-FIB) was determined at 10 closely spaced time points after protamine administration. Primary endpoint was the time to recovery of post-CPB fibrinogen levels to ≥1.5 g/L. C-FIB reached its nadir after protamine administration corresponding to 62 ± 5% (mean ± SD) of the baseline level after cCPB and 68 ± 7% after MiECC (p = 0.027 vs. cCPB). C-FIB recovered spontaneously at a nearly constant rate of approximately 0.08 g/L per hour. In all patients, C-FIB was ≥1.5 g/L at 4 hours and ≥2.0 g/L at 13 hours after CPB weaning. Following cardiac surgery with CPB and in the absence of surgical bleeding, spontaneous recovery of normal endogenous fibrinogen levels can be expected at a rate of 0.08 g/L per hour. Administration of fibrinogen concentrate triggered solely by a single-point measurement of low plasma fibrinogen some time after CPB is not justified.

The role of fibrinogen in trauma-induced coagulopathy

Fibrinogen plays an essential role in clot formation and stability. Importantly it seems to be the most vulnerable coagulation factor, reaching critical levels earlier than the others during the course of severe injury. A variety of causes of fibrinogen depletion in major trauma have been identified, such as blood loss, dilution, consumption, hyperfibrinolysis, hypothermia and acidosis. Low concentrations of fibrinogen are associated with an increased risk of diffuse microvascular bleeding. Therefore, repeated measurements of plasma fibrinogen concentration are strongly recommended in trauma patients with major bleeding. Recent guidelines recommend maintaining plasma fibrinogen concentration at 1.5–2 g/l in coagulopathic patients. It has been shown that early fibrinogen substitution is associated with improved outcome.

Current use of factor concentrates in pediatric cardiac anesthesia

Excessive bleeding following pediatric cardiopulmonary bypass is associated with increased morbidity and mortality, both from the effects of hemorrhage and the therapies employed to achieve hemostasis. Neonates and infants are especially at risk because their coagulation systems are immature, surgeries are often complex, and cardiopulmonary bypass technologies are inappropriately matched to patient size and physiology. Consequently, these young children receive substantial amounts of adult-derived blood products to restore adequate hemostasis. Adult and pediatric data demonstrate associations between blood product transfusions and adverse patient outcomes. Thus, efforts to limit bleeding after pediatric cardiopulmonary bypass and minimize allogeneic blood product exposure are warranted. The off-label use of factor concentrates, such as fibrinogen concentrate, recombinant activated factor VII, and prothrombin complex concentrates, is increasing as these hemostatic agents appear to offer several advantages over conventional blood products. However, recognizing that these agents have the potential for both benefit and harm, well-designed studies are needed to enhance our knowledge and to determine the optimal use of these agents. In this review, our primary objective was to examine the evidence regarding the use of factor concentrates to treat bleeding after pediatric CPB and identify where further research is required. PubMed, MEDLINE/OVID, The Cochrane Library and the Cochrane Central Register of Controlled Trials (CENTRAL) were systematically searched to identify existing studies.

Comparison of Thrombelastography-Derived Fibrinogen Values at Rewarming and Following Cardiopulmonary Bypass in Cardiac Surgery Patients

BACKGROUND

The inflated costs and documented deleterious effects of excess perioperative transfusion have led to the investigation of targeted coagulation factor replacement strategies. One particular coagulation factor of interest is factor I (fibrinogen). Hypofibrinogenemia is typically tested for using time-consuming standard laboratory assays. The thrombelastography (TEG)-based functional fibrinogen level (FLEV) provides an assessment of whole blood clot under platelet inhibition to report calculated fibrinogen levels in significantly less time. If FLEV values obtained on cardiopulmonary bypass (CPB) during rewarming are similar to values obtained immediately after the discontinuation of CPB, then rewarming values could be used for preemptive ordering of appropriate blood product therapy.

METHODS

Fifty-one cardiac surgery patients were enrolled into this prospective nonrandomized study to compare rewarming fibrinogen values with postbypass values using TEG FLEV assays. Baseline, rewarming, and postbypass fibrinogen values were recorded for all patients using both standard laboratory assay (Clauss method) and FLEV. Mixed-effects regression models were used to examine the change in TEG FLEV values over time. Bland-Altman analysis was used to examine bias and the limits of agreement (LOA) between the standard laboratory assay and FLEVs.

RESULTS

Forty-nine patients were included in the analysis. The mean FLEV value during rewarming was 333.9 mg/dL compared with 332.8 mg/dL after protamine, corresponding to an estimated difference of -1.1 mg/dL (95% confidence interval [CI], -25.8 to 23.6; P = 0.917). Rewarming values were available on average 47 minutes before postprotamine values. Bland-Altman analysis showed poor agreement between FLEV and standard assays: mean difference at baseline was 92.5 mg/dL (95% CI, 71.1 to 114.9), with a lower LOA of -56.5 mg/dL (95% CI, -94.4 to -18.6) and upper LOA of 242.4 mg/dL (95% CI, 204.5 to 280.3). The difference between assays increased after CPB and persisted after protamine administration.

CONCLUSIONS

Our results revealed negligible change in FLEV values from the rewarming to postbypass periods, with a CI that does not include clinically meaningful differences. These findings suggest that rewarming samples could be utilized for ordering fibrinogen-specific therapies before discontinuation of CPB. Mean FLEV values were consistently higher than the reference standard at each time point. Moreover, bias was highly heterogeneous among samples, implying a large range of potential differences between assays for any 1 patient.

Adjuncts to Blood Component Therapies for the Treatment of Bleeding in the Intensive Care Unit

Patients who are critically ill following surgical or traumatic injury often present with coagulopathy as a component of the complex multisystem dysfunction that clinicians must rapidly diagnose and treat in the intensive care environment. Failure to recognize coagulopathy while volume resuscitation with crystalloid or colloid takes place, or an unbalanced transfusion strategy focused on packed red blood cell transfusion can all significantly worsen coagulopathy, leading to increased transfusion requirements and poor outcomes. Even an optimized transfusion strategy directed at correcting coagulopathy and maintaining clotting factor levels carries the risk of a number of transfusion reactions including transfusion-related acute lung injury, transfusion-related circulatory overload, anaphylaxis, and septic shock. A number of adjunctive strategies can be used either to augment a balanced transfusion approach or as alternatives to blood component therapy. Coupled with an appropriate and timely laboratory testing, this approach can quickly diagnose a patient's specific coagulopathy and work to correct it as quickly as possible, minimizing the requirement of blood transfusion and the pathophysiologic effects of excessive bleeding and fibrinolysis. We will review the literature supporting this approach and provide insight into how these approaches can be best used to care for bleeding patients in the intensive care unit. Finally, the increasing use of several novel oral anticoagulants, novel antiplatelet drugs, and low-molecular weight heparin to clinical practice has complicated the care of the coagulopathic patient when these drugs are involved. Many clinicians familiar with heparin and warfarin reversal are not familiar with the optimal way to reverse the action of these new drugs. Patients treated with these drugs for a wide variety of conditions including atrial fibrillation, stroke, coronary artery stent, deep venous thrombosis, and pulmonary embolism will present for emergency surgery and will require management of pharmacologically induced postoperative coagulopathy. We will discuss optimized strategies for reversal of these agents and strategies that are currently under development.

Fibrinogen Early In Severe Trauma studY (FEISTY): study protocol for a randomised controlled trial

BACKGROUND

Haemorrhage is a leading cause of death in severe trauma. Fibrinogen plays a critical role in maintaining haemostasis in traumatic haemorrhage. Early fibrinogen replacement is recommended by several international trauma guidelines using either fibrinogen concentrate (FC) or cryoprecipitate (Cryo). There is limited evidence to support one product over the other with widespread geographic and institutional variation in practice. This pilot trial is the first randomised controlled trial comparing FC to Cryo in traumatic haemorrhage.

METHODS/DESIGN

The Fibrinogen Early In Severe Trauma studY (FEISTY) is an exploratory, multicentre, randomised controlled trial comparing FC to Cryo for fibrinogen supplementation in traumatic haemorrhage. This trial will utilise thromboelastometry (ROTEM®) to guide and dose fibrinogen supplementation. The trial will recruit 100 trauma patients at four major trauma centres in Australia. Adult trauma patients with evidence of haemorrhage will be enrolled on arrival in the trauma unit and randomised to receiving fibrinogen supplementation with either FC or Cryo. The primary outcome is the differential time to fibrinogen supplementation. There are a number of predetermined secondary outcomes including: effects of the intervention on plasma fibrinogen levels, feasibility assessments and clinical outcomes including transfusion requirements and mortality.

DISCUSSION

The optimal method for replacing fibrinogen in traumatic haemorrhage is fiercely debated. In this trial the feasibility and efficacy of fibrinogen supplementation using FC will be compared to Cryo. The results of this pilot study will facilitate the design of a larger trial with sufficient power to address patient-centred outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02745041 . Registered 4 May 2016.

[Hemorrhage treatment: Evaluation of the proper use of fibrinogen concentrate]

An increase in fibrinogen concentrate prescriptions was noticed in 2015 after several guidelines regarding their use were published. We tried to evaluate if they were used appropriately. To evaluate the conformity of the prescriptions to these guidelines, we searched for each prescription if a dosage of blood fibrinogen was made, if its result was below the limit recommended to prescribe fibrinogen concentrate, and if the posology was in line with the recommendations. Effect and security of the treatment was also evaluated. We analyzed 202 prescriptions for 117 patients. The indications are respected except for one prescription for which we could not find it. The blood fibrinogen is measured for 76% of the prescriptions, 59% of the results are below the limit recommended to prescribe. The posology is conforming to the guidelines for 73% of the prescriptions, it is below the dose recommended for 20%. Patients who were prescribed low doses seemed less at risk than the others which questions the necessity of the prescriptions. The guidelines respect depends on the emergency of the prescription situation. It would be interesting to conduct a prospective study to better explain why doses below those recommended are prescribed.

Introduction of thromboelastometry-guided administration of fresh-frozen plasma is associated with decreased allogeneic blood transfusions and post-operative blood loss in cardiopulmonary-bypass surgery

BACKGROUND

Cardiac surgery is frequently associated with excessive blood loss requiring multiple blood transfusions which are, in turn, associated with increased morbidity and mortality. We evaluated the effectiveness of rotational thromboelastometry (ROTEM^®)-guided administration of fresh-frozen plasma (FFP) with regards to blood loss, transfusion requirements, and major post-operative complications.

MATERIALS AND METHODS

Coagulation management in 68 prospective patients undergoing cardiac surgery with cardiopulmonary bypass was based on a treatment algorithm guided by ROTEM^® measurements. The primary end-point was blood loss at 24 hours after surgery. Secondary end-points were: (i) need for allogeneic blood products after cardiopulmonary bypass and 24 hours post-operatively, and (ii) post-operative complications until discharge. The results were compared with those of a retrospective, control group of 69 patients who received empirical coagulation management before implementation of the ROTEM^®-guided algorithm.

RESULTS

Although patients with significantly lower haemoglobin levels received less packed red blood cells (PRBC) (840 vs 1,120 mL; p=0.031) and FFP (480 vs 720 mL; p=0.007) after introduction of the ROTEM^® algorithm, the intra-operative blood loss and post-operative haemoglobin levels were similar in the ROTEM^® and the retrospective control groups. In addition to significantly reduced blood loss and decreased requirements for PRBC (30.8 vs 62.3%; p<0.001) and FFP (25.0 vs 56.5%; p<0.001), the amounts of PRBC (315 vs 840 mL; p<0.001) and FFP (480 vs 840 mL; p=0.001) received during the first 24 hours after surgery were significantly reduced in the ROTEM^® group, as was the duration of post-operative hospitalisation.

DISCUSSION

Compared with empirical treatment, timely ROTEM^®-guided FFP administration during cardiac surgery can reduce not only overall blood product use and blood loss but also the duration of hospitalisation.

Factor XIII Deficiency and Thrombocytopenia Are Frequent Modulators of Postoperative Clot Firmness in a Surgical Intensive Care Unit

OBJECTIVE

Fibrinogen and factor XIII (FXIII) have been shown to critically influence clot firmness in the intraoperative setting and thus likely influence intraoperative bleeding. We were interested to identify potential modulators of postoperative clot firmness in a tertiary care hospital surgical intensive care unit setting, independent of their clinical course during surgery.

METHODS

272 day-shift consecutive patients were evaluated for whole blood clot firmness evaluated by the ROTEM® EXTEM thrombelastometric assay and various potential modulators of clot firmness upon arrival at the surgical intensive care unit (SICU).

RESULTS

Maximum clot firmness on the SICU was found to be independently influenced by the amount of colloids given during surgery as well as by platelet count, fibrinogen concentration, and FXIII activity at the time of SICU admission. In patients with lowest clot firmness, FXIII activity was the most important independent modulator of clot firmness; in patients with the highest clot firmness, platelet count and fibrinogen concentration were the most important modulators of clot firmness. Deficiencies (i.e., results below normal range) of these modulators of clot firmness were most prevalent for FXIII (activity < 70%: 45% of cases), which was significantly more frequent than thrombocytopenia (<150 × 10⁹/l: 32%) or fibrinogen deficiency (<1.5 g/l: 6%).

CONCLUSIONS

Postoperative clot firmness as evaluated by whole blood thrombelastometry (ROTEM EXTEM assay) is independently and frequently modulated though FXIII activity and the platelet count, while fibrinogen concentration is also an independent but much less frequent modulator. Different modulators show different influences, depending on the clot firmness being present. Colloids infused during surgery also independently modulate postoperative clot firmness. Based on our data, strategies can be developed to improving postoperative care of patients with bleedings or at risk for bleeding.

Fibrinogen in traumatic haemorrhage: A narrative review

Haemorrhage in the setting of severe trauma is associated with significant morbidity and mortality. There is increasing awareness of the important role fibrinogen plays in traumatic haemorrhage. Fibrinogen levels fall precipitously in severe trauma and the resultant hypofibrinogenaemia is associated with poor outcomes. Hence, it has been postulated that early fibrinogen replacement in severe traumatic haemorrhage may improve outcomes, although, to date there is a paucity of high quality evidence to support this hypothesis. In addition there is controversy regarding the optimal method for fibrinogen supplementation. We review the current evidence regarding the role of fibrinogen in trauma, the rationale behind fibrinogen supplementation and discuss current research.

Coagulation Management in Jersey Calves: An ex vivo Study

OBJECTIVE

Jersey calves are frequently used as an experimental animal model for in vivo testing of cardiac assist devices or orthopedic implants. In this ex vivo study, we analyzed the coagulation system of the Jersey calves and the potential of human-based coagulation management to circumvent perioperative bleeding complications during surgery. Experimental Procedure: Blood from 7 Jersey calves was subjected to standard laboratory tests and thromboelastometry analysis. An ex vivo model of dilutional coagulopathy was used to study the effects of fibrinogen or prothrombin complex concentrate supplementation. Fibrinolysis was induced with tissue plasminogen activator to identify potential therapeutic strategies involving tranexamic acid or aprotinin. Furthermore, anticoagulation strategies were evaluated by incubating the blood samples with dabigatran or rivaroxaban.

RESULTS

Baseline values for thromboelastometry and standard laboratory parameters, including prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin III, and D-dimers, were established. Fifty percent diluted blood showed a statistically significant impairment of hemostasis. The parameters significantly improved after the administration of fibrinogen or prothrombin complex concentrate. Tranexamic acid and aprotinin ameliorated tissue plasminogen activator-induced fibrinolysis. Both dabigatran and rivaroxaban significantly prolonged the coagulation parameters.

CONCLUSIONS

In this ex vivo study, coagulation factors, factor concentrate, antifibrinolytic reagents, and anticoagulants regularly used in the clinic positively impacted coagulation parameters in Jersey calf blood.

Role of Coagulation Factor Concentrates in the Operating Room

The use of fresh frozen plasma, cryoprecipitate, and platelets has been the mainstay of approaches to correct coagulopathies that can arise in the perioperative setting. Limitations include the time delay from obtaining results of coagulation screens to the availability of thawed fresh frozen plasma and the potential of fluid overload. With advances in both global haemostatic testing and concentrates of coagulation factors, there are increasing opportunities for innovative practice. However, there remains a paucity of studies that can provide good quality, unbiased evidence. These issues are elaborated here to form the basis for future study.

Therapeutic plasma exchange in heart transplantation: role of coagulation assessment with thromboelastometry

Therapeutic plasma exchange (TPE) is a potentially life-saving procedure which effectively removes donor-specific human leukocyte antigen (HLA) antibodies from the bloodstream, allowing critically ill heart transplant recipients to receive a donor organ with less wait time, and reducing the risk of acute organ rejection. The bulk of coagulation factors is initially removed from the blood during TPE using albumin and is later replaced with allogeneic plasma. Coagulopathy may develop during TPE and then can persist due to intraoperative blood loss and hemodilution during surgery and cardiopulmonary bypass. We hereby describe the utility of rotational thromboelastometry to assess rapid coagulation changes during TPE and subsequent heart transplant (HT) surgery.

Comparing efficacy and safety of fibrinogen concentrate to cryoprecipitate in bleeding patients: a systematic review

BACKGROUND

Bleeding is associated with the depletion of fibrinogen, thus increasing the risk of coagulopathy, further bleeding and transfusion requirements. Both fibrinogen concentrate and cryoprecipitate replenish low plasma fibrinogen levels. This systematic review aims to identify and evaluate evidence of efficacy and safety of fibrinogen concentrate and cryoprecipitate in bleeding patients.

METHOD

Cochrane Central Register of Controlled Trials (CENTRAL), Medline, EMBASE up to 2nd of March 2015 were among the electronic search strategies of randomized controlled trials and non-randomized studies with meta-analysis employed. Studies for inclusion required bleeding patients being treated with either fibrinogen concentrate or cryoprecipitate. Mortality was the primary endpoint. Secondary outcomes included bleeding, coagulopathy, transfusion requirements and clinical complications related to the intervention. PRISMA methodology, a data-extraction form and the Cochrane risk of bias tool were all employed.

RESULTS

Four studies were eligible for inclusion in this systematic review; one randomized controlled trial (RCT) consisting of 66 patients and three observational studies involving 218 patients in total. No mortality was reported in the published papers. There were no differences in fibrinogen-level increase, bleeding, RBC transfusions or thromboembolic complications. The RCT showed a possible increased functional improvement of haemostasis after cryoprecipitate therapy compared to fibrinogen concentrate.

CONCLUSION

The available evidence directly comparing fibrinogen concentrate to cryoprecipitate is sparse and with high risk of bias. Recommendation of one product over the other for fibrinogen substitution in the bleeding patient with acquired hypofibrinogenaemia is currently not possible. Future research should guide us towards evidence-based decisions of product superiority.