Fibrinogen and Hemostasis

Comparative assessment of hemostasis in septic patients and healthy controls using standard coagulation tests and whole-blood thromboelastometry

BACKGROUND

Sepsis is associated with dysregulation of procoagulant, anticoagulant, and fibrinolytic pathways.

AIMS

To compare the measurements of coagulation activation, clot formation, stabilization, and lysis between rotational thromboelastometry (ROTEM) and standard coagulation tests (SCTs) on patients with early sepsis (SP) and healthy controls (HC).

METHODS

This observational study included 30 SP and 30 HC. At study inclusion, SCTs and ROTEM analyses were conducted. A modified ROTEM with exogenous tPA was used to investigate fibrinolysis resistance.

RESULTS

SP had longer prothrombin time, higher fibrinogen levels and lower platelet count compared to HC. On ROTEM, clotting initiation was longer in SP than in HC but median clotting time maintained within reference ranges. SP had higher maximum velocity of clot formation, clot firmness, elasticity, and platelet component than HC. Clot lysis indices (CLI) were higher in EXTEM and APTEM (without and with added tPA) in SP compared to HC. The difference in CLI between APTEM and EXTEM was lower for both native and tPA-spiked samples in SP compared with HC.

CONCLUSIONS

While SCTs suggest SP are hypocoagulable, VET revealed normal coagulation initiation in more than 80 % of SP. Compared to HC, SP had increased clot propagation, firmness and elasticity, and decreased platelet-mediated clot retraction and lysis. In sepsis, VET provide more comprehensive information about hemostatic changes than SCTs.

Identification of Amino Acid Residues Critical for the Interaction of Fibrin with N-Cadherin

We recently identified N-cadherin as a novel receptor for fibrin and localized complementary binding sites within the fibrin βN-domains and the third and fifth extracellular domains (EC3 and EC5) of N-cadherin. We also hypothesized that the His16 and Arg17 residues of the βN-domains and the (Asp/Glu)-X-(Asp/Glu) motifs present in the EC3 and EC5 domains may play roles in the interaction between fibrin and N-cadherin. The primary objectives of this study were to test these hypotheses and to further clarify the structural basis for this interaction. To test our hypotheses, we first mutated His16 and Arg17 in the recombinant (β15-66)2 fragment, which mimics the dimeric arrangement of the βN-domains in fibrin, using site-directed mutagenesis. The results revealed that the mutations of both His16 and Arg17 are critical for the interaction. Next, we mutated Asp/Glu residues in the three (Asp/Glu)-X-(Asp/Glu) motifs, M1 (Asp-Phe-Glu), M2 (Glu-Ala-Glu), and M3 (Asp-Tyr-Asp), of the fibrin-binding N-cad(3-5) fragment of N-cadherin. The results showed that Asp292 and Glu294 of M1, and Asp468 and Asp470 of M3, are critical for the interaction. Our molecular modeling of the 3D structure of the EC3-EC4-EC5 domains revealed that these residues are located at the interfaces of EC3-EC4 and EC4-EC5 and that some may also be involved in calcium binding. In conclusion, our study identified amino acid residues in the fibrin βN-domains and the EC3 and EC5 domains of N-cadherin that are critical for the interaction of fibrin with N-cadherin and localized the fibrin-binding residues in the 3D structure of N-cadherin.

Safety of Fibrinogen Concentrate for Correcting Perioperative Bleeding-Associated Hypofibrinogenemia in Adults: A Single-Center Experience

Background: Surgery often leads to bleeding associated with hypofibrinogenemia. Supplementation with fibrinogen concentrate appears to be effective and safe, although findings from studies are inconsistent. The primary aim of this study was to assess the safety of fibrinogen concentrate during the perioperative period. Methods: This single-centre, prospective, observational study included adult patients undergoing scheduled or emergency surgery related to bleeding coagulopathy and the administration of fibrinogen concentrate. Patients were followed until their discharge from the institution. Comprehensive data were collected, including age, sex, type of surgery, associated comorbidities, anticoagulant and/or anti-aggregating therapy, and the number of blood transfusions. Laboratory data on plasma fibrinogen concentration, haemoglobin, and platelet count before and after surgery were also collected. The primary outcomes were the mortality rate at discharge and any reported thrombotic or thromboembolic events, including deep vein thrombosis, pulmonary embolism, and myocardial infarction. Results: The study included 91 adult patients who had undergone surgery, with 29 surgeries (32%) conducted in an emergency setting. The mean age was 59.2 years, and 53.8% were male. Major bleeding occurred in 29 cases, mainly in older males and those on anticoagulant therapy. The pre-operative fibrinogen level averaged 161 mg/dL, and the average dosage of fibrinogen concentrate administered was 2.7 g. Eight patients died (8.8%), mostly due to septic or cardiogenic shock, with deaths being more frequent in emergency settings. Thromboembolic events occurred in eight patients, none of whom died. No additional adverse events directly related to the administration of fibrinogen concentrate were reported. Conclusions: Our findings suggest a favourable safety profile for fibrinogen concentrate in surgical patients, as evidenced by a low incidence of deaths and thromboembolic events, which were primarily attributed to other factors. Future research should strive to increase statistical robustness to further illuminate clinically significant patient safety measures.

ErpY-like Protein Interaction with Host Thrombin and Fibrinogen Intervenes the Plasma Coagulation through Extrinsic and Intrinsic Pathways

The survival and proliferation of pathogenic Leptospira within a host are complex phenomena that require careful consideration. The ErpY-like lipoprotein, found on the outer membrane surface of Leptospira, plays a crucial role in enhancing the bacterium's pathogenicity. The rErpY-like protein, in its recombinant form, contributes significantly to spirochete virulence by interacting with various host factors, including host complement regulators. This interaction facilitates the bacterium's evasion of the host complement system, thereby augmenting its overall pathogenicity. The rErpY-like protein exhibits a robust binding affinity to soluble fibrinogen, a vital component of the host coagulation system. In this study, we demonstrate that the rErpY-like protein intervenes in the clotting process of the platelet-poor citrated plasma of bovines and humans in a concentration-dependent manner. It significantly reduces clot density, alters the viscoelastic properties of the clot, and diminishes the average clotting rate in plasma. Furthermore, the ErpY-like protein inhibits thrombin-catalyzed fibrin formation in a dose-dependent manner and exhibits saturable binding to thrombin, suggesting its significant role in leptospiral infection. These findings provide compelling evidence for the anticoagulant effect of the ErpY-like lipoprotein and its significant role in leptospiral infection.

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.

Implementation and early outcomes with Pathogen Reduced Cryoprecipitated Fibrinogen Complex

OBJECTIVES

Cryoprecipitated antihemophilic factor (cryo) has been used for fibrinogen replacement in actively bleeding patients, dysfibrinogenemia, and hypofibrinogenemia. Cryo has a shelf life of 4 to 6 hours after thawing and a long turnaround time in issuing the product, posing a major limitation of its use. Recently, the US Food and Drug Administration approved Pathogen Reduced Cryoprecipitated Fibrinogen Complex (INTERCEPT Fibrinogen Complex [IFC]) for the treatment of bleeding associated with fibrinogen deficiency, which can be stored at room temperature and has a shelf life of 5 days after thawing.

METHODS

We identified locations and specific end users with high cryoprecipitate utilization and waste. We partnered with our blood supplier to use IFC in these locations. We analyzed waste and turnaround time before and after implementation.

RESULTS

Operative locations had a waste rate that exceeded nonoperative locations (16.7% vs 3%) and were targeted for IFC implementation. IFC was added to our inventory to replace all cryo orders from adult operating rooms, and waste decreased to 2.2% in these locations. Overall waste of cryoprecipitated products across all locations was reduced from 8.8% to 2.4%. The turnaround time for cryoprecipitated products was reduced by 58% from 30.4 minutes to 14.6 minutes.

CONCLUSIONS

There has been a substantial decrease in waste with improved turnaround time after IFC implementation. This has improved blood bank logistics, improved efficiency of patient care, and reduced costly waste.

Recommendations on Monitoring and Replacement of Antithrombin, Fibrinogen, and Von Willebrand Factor in Pediatric Patients on Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic review informed, modified Delphi consensus regarding monitoring and replacement of specific coagulation factors during pediatric extracorporeal membrane oxygenation (ECMO) support for the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021.

STUDY SELECTION

Included studies assessed monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric ECMO support.

DATA EXTRACTION

Two authors reviewed all citations independently, with conflicts resolved by a third reviewer if required. Twenty-nine references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. A panel of 48 experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. We developed one weak recommendation and four expert consensus statements.

CONCLUSIONS

There is insufficient evidence to formulate recommendations on monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric patients on ECMO. Optimal monitoring and parameters for replacement of key hemostasis parameters is largely unknown.

Safety of Fibrinogen Concentrate in Non-Trauma and Non-Obstetric Adult Patients during Perioperative Care: Systematic Review and Meta-Analysis

Background: Low fibrinogen levels are associated with an increased risk of perioperative bleeding. However, there is an ongoing debate over the ideal treatment threshold, the benefits of prophylactic supplementation with fibrinogen concentrate, and the best source of fibrinogen. While fibrinogen concentrate supplementation is being widely used to treat bleeding related to acquired haemostatic deficiencies, there is a lack of evidence regarding its dosage, effectiveness, and safety. This systematic review provides an up-to-date summary of the relationship between fibrinogen concentrate supplementation and safety measures in the perioperative care of non-trauma, non-obstetric adult patients. Methods: A comprehensive online search was conducted on PubMed/Medline, EMBASE, Scopus, Web of Science, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials. Results: This systematic review and meta-analysis encompasses ten studies involving 1391 patients. There was a decreased risk of total thromboembolic events in patients treated with fibrinogen compared to the control (OR 0.65, 95% CI 0.43 to 0.98, I2 = 0%). In addition, when fibrinogen was used prophylactically, it resulted in shorter ICU stays (MD -1.50, 95% CI -2.64 to -0.36), when set against its therapeutic use. A sensitivity analysis on cardiovascular surgery studies did not reveal any statistically significant difference. Conclusions: The use of fibrinogen concentrate in the perioperative care of non-trauma and non-obstetric adult patients may lead to potential benefits.

A CO-releasing coating based on carboxymethyl chitosan-functionalized graphene oxide for improving the anticorrosion and biocompatibility of magnesium alloy stent materials

Due to its biofunctions similar to NO, the CO gas signaling molecule has gradually shown great potential in cardiovascular biomaterials for regulating the in vivo performances after the implantation and has received increasing attention. To construct a bioactive surface with CO-releasing properties on the surface of magnesium-based alloy to augment the anticorrosion and biocompatibility, graphene oxide (GO) was firstly modified using carboxymethyl chitosan (CS), and then CO-releasing molecules (CORM401) were introduced to synthesize a novel biocompatible nanomaterial (GOCS-CO) that can release CO in the physiological environments. The GOCS-CO was further immobilized on the magnesium alloy surface modified by polydopamine coating with Zn2+ (PDA/Zn) to create a bioactive surface capable of releasing CO in the physiological environment. The outcomes showed that the CO-releasing coating can not only significantly enhance the anticorrosion and abate the corrosion degradation rate of the magnesium alloy in a simulated physiological environment, but also endow it with good hydrophilicity and a certain ability to adsorb albumin selectively. Owing to the significant enhancement of anticorrosion and hydrophilicity, coupled with the bioactivity of GOCS, the modified sample not only showed excellent ability to prevent platelet adhesion and activation and reduce hemolysis rate but also can promote endothelial cell (EC) adhesion, proliferation as well as the expression of nitric oxide (NO) and vascular endothelial growth factor (VEGF). In the case of CO release, the hemocompatibility and EC growth behaviors were further significantly improved, suggesting that CO molecules released from the surface can significantly improve the hemocompatibility and EC growth. Consequently, the present study provides a novel surface modification method that can simultaneously augment the anticorrosion and biocompatibility of magnesium-based alloys, which will strongly promote the research and application of CO-releasing bioactive coatings for surface functionalization of cardiovascular biomaterials and devices.

Recent Advances in Topical Hemostatic Materials

Untimely or improper treatment of traumatic bleeding may cause secondary injuries and even death. The traditional hemostatic modes can no longer meet requirements of coping with complicated bleeding emergencies. With scientific and technological advancements, a variety of topical hemostatic materials have been investigated involving inorganic, biological, polysaccharide, and carbon-based hemostatic materials. These materials have their respective merits and defects. In this work, the application and mechanism of the major hemostatic materials, especially some hemostatic nanomaterials with excellent adhesion, good biocompatibility, low toxicity, and high adsorption capacity, are summarized. In the future, it is the prospect to develop multifunctional hemostatic materials with hemostasis and antibacterial and anti-inflammatory properties for promoting wound healing.

Early Goal-Directed Hemostatic Therapy for Severe Acute Bleeding Management in the Intensive Care Unit: A Narrative Review

This is a narrative review of the published evidence for bleeding management in critically ill patients in different clinical settings in the intensive care unit (ICU). We aimed to describe "The Ten Steps" approach to early goal-directed hemostatic therapy (EGDHT) using point-of-care testing (POCT), coagulation factor concentrates, and hemostatic drugs, according to the individual needs of each patient. We searched National Library of Medicine, MEDLINE for publications relevant to management of critical ill bleeding patients in different settings in the ICU. Bibliographies of included articles were also searched to identify additional relevant studies. English-language systematic reviews, meta-analyses, randomized trials, observational studies, and case reports were reviewed. Data related to study methodology, patient population, bleeding management strategy, and clinical outcomes were qualitatively evaluated. According to systematic reviews and meta-analyses, EGDHT guided by viscoelastic testing (VET) has been associated with a reduction in transfusion utilization, improved morbidity and outcome in patients with active bleeding. Furthermore, literature data showed an increased risk of severe adverse events and poor clinical outcomes with inappropriate prophylactic uses of blood components to correct altered conventional coagulation tests (CCTs). Finally, prospective, randomized, controlled trials point to the role of goal-directed fibrinogen substitution to reduce bleeding and the amount of red blood cell (RBC) transfusion with the potential to decrease mortality. In conclusion, severe acute bleeding management in the ICU is still a major challenge for intensive care physicians. The organized and sequential approach to the bleeding patient, guided by POCT allows for rapid and effective bleeding control, through the rational use of blood components and hemostatic drugs, since VET can identify specific coagulation disorders in real time, guiding hemostatic therapy with coagulation factor concentrates and hemostatic drugs with individual goals.

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.

Fibrinogen contribution to clot strength in patients with sepsis and hematologic malignancies and thrombocytopenia-a prospective, single-center, analytical, cross-sectional study

Background

Patients with hematological malignancies (HM) frequently present thrombocytopenia and higher risk of bleeding. Although transfusion is associated with higher risk of adverse events and poor outcomes, prophylactic transfusion of platelets is a common practice to prevent hemorrhagic complications. Thromboelastometry has been considered a better predictor for bleeding than isolated platelet counts in different settings. In early stages of sepsis, hypercoagulability may occur due to higher fibrinogen levels.

Objectives

To evaluate the behavior of coagulation in patients with HM who develop sepsis and to verify whether a higher concentration of fibrinogen is associated with a proportional increase in maximum clot firmness (MCF) even in the presence of severe thrombocytopenia.

Methods

We performed a unicentric analytical cross-sectional study with 60 adult patients with HM and severe thrombocytopenia, of whom 30 had sepsis (sepsis group) and 30 had no infections (control group). Coagulation conventional tests and specific coagulation tests, including thromboelastometry, were performed. The main outcome evaluated was MCF.

Results

Higher levels of fibrinogen and MCF were found in sepsis group. Both fibrinogen and platelets contributed to MCF. The relative contribution of fibrin was significantly higher (60.5 ± 12.8% vs 43.6 ± 9.7%; P < .001) and that of platelets was significantly lower (39.5 ± 12.8% vs 56.4 ± 9.7%; P < .001) in the sepsis group compared with the control group.

Conclusion

Patients with sepsis and HM presented higher concentrations of fibrinogen than uninfected patients, resulting in greater MCF amplitudes even in the presence of thrombocytopenia.

CG02N Analyzer Accurately Measures Fibrinogen Level in Whole Blood in the Presence of Low- or High-Dose Heparin

Rapid fibrinogen (Fbg) evaluation is important in patients with massive bleeding during severe trauma and those undergoing major surgery. However, there are only a few studies on the point-of-care Fbg analyzer. In this study, we aimed to investigate the accuracy of Fbg level measured using CG02N, with whole blood contained in lithium-heparinized syringes with two different concentrations of heparin. Blood samples were collected in lithium-heparinized tubes, namely PREZA-PAK®II (low-dose heparin group [LG], 7 IU/mL) and Pro-Vent® Plus (high-dose heparin group [HG], 70.5 IU/mL). The Fbg levels in LG and HG were compared with those of citrated plasma Fbg (standard-Fbg). Strong correlations with respect to the Fbg level were observed between standard-Fbg and LG or HG (r = 0.968, p < 0.0001; r = 0.970, p < 0.0001, respectively). We demonstrated that the Fbg level in whole-blood samples was accurately assessed by CG02N and not affected by low- or high-dose heparin.

Hemostatic capability of ultrafiltrated fresh frozen plasma compared to cryoprecipitate

This in vitro study evaluated the potential hemostatic effect of fresh frozen plasma (FFP) ultrafiltration on clotting factors, coagulation parameters, and plasma properties. ABO-specific units of FFP (n = 40) were prepared for the concentrated FFP and cryoprecipitate. Plasma water was removed from FFP by ultrafiltration using a dialyzer with a pump running at a 300 mL/min. The aliquot of each concentrated FFP after 50, 100, 200, and 250 mL of fluid removal were measured the standard coagulation assay, clotting activity, and plasma properties to compare those parameters of cryoprecipitate. Concentrated FFP contained 36.5% of fibrinogen in FFP with a mean concentration of 7.2 g/L, lower than the cryoprecipitate level. The levels of factor VIII (FVIII), von Willebrand factor (VWF):antigen (Ag), and VWF:ristocetin cofactor (RCo) were also lower in concentrated FFP, whereas the levels of factor V, factor IX, factor XIII, antithrombin and albumin was higher in concentrated FFP. Maximum clot firmness (MCF) in thromboelastometry was approximately one-half of that in cryoprecipitate. Although the levels of VWF:Ag, VWF:RCo, and FVIII differed depending on the ABO blood types, fibrinogen levels, and MCF were not significantly different among the ABO blood groups in FFP and concentrated FFP.

A Perioperative Blood Management Algorithm Aimed at Conservation of Platelets in Clinical Practice: The Role of the Anesthesiologist in Decision-Making

Platelet dysfunction and thrombocytopenia are associated with postoperative morbidity not only from modifiable preoperative factors but also from a lack of local patient blood management algorithms. In this regard, platelet transfusions have risen after the COVID-19 pandemic. Simultaneously, there has been a shortage of donors. It is logical, therefore, that each hospital should develop a triage tool, posting their algorithm on walls. Anesthesiologists should assist in planning a strategy to minimize blood transfusions while improving tissue oxygenation. A flowchart posted in each operating theatre may be customized per patient and hospital. Clinicians need reminders to draw a prothrombin time, fibrinogen, complete blood count every hour, and the appropriate threshold to transfuse. In summary, anesthesiologists are often unable to have a discussion with a patient until the preoperative day; thus, the onus falls on our surgical colleagues to reduce risk factors for coagulopathy or to delay surgery until after proper consultants have optimized a patient. The most important problems that an individual patient has ideally should be listed in a column where an anesthesiologist can write a timeline of key steps across a row, corresponding to each problem. If a handoff in the middle of the case is required, this handoff tool is superior to simply checking a box on an electronic medical record. In summary, in the operating suite, an anesthesiologist should emphasize the importance of a multidisciplinary approach. Continuing education, regular stakeholder meetings, and posters can assist in reinforcing algorithms in clinical practice.

Bothrops venom-induced hemostasis disorders in the rat: Between Scylla and Charybdis

Hemostasis impairment represents the most threatening consequence of Viperidae envenoming, notably with Bothrops genus. In the French departments of America, B. atrox envenomation in French Guiana may lead to bleeding while B. lanceolatus envenomation in Martinique to thrombosis. Bleeding related to B. atrox envenomation is attributed to vascular damage mediated by venom metalloproteinases and blood uncoagulable state resulting from thrombocytopenia and consumptive coagulopathy. Thrombosis related to B. lanceolatus envenomation are poorly understood. We aimed to compare the effects of B. atrox and B. lanceolatus venoms in the rat to identify the determinants of the hemorrhagic versus thrombotic complications. Viscoelastometry (ROTEM), platelet count, plasma fibrinogen, thrombin generation assay, fibrinography, endothelial (von Willebrand factor, ADAMTS13 activity, ICAM-1, and soluble E-selectin), and inflammatory biomarkers (IL-1β, IL-6, TNF-α, MCP-1, and PAI-1) were determined in blood samples obtained at H3, H6, and H24 after the subcutaneous venom versus saline injection. In comparison to the control, initial fibrinogen consumption was observed with the two venoms while thrombocytopenia and reduction in the clot amplitude only with B. atrox venom. Moreover, we showed an increase in thrombin generation at H3 with the two venoms, an increase in fibrin generation accompanied with hyperfibrinogenemia at H24 and an increase in inflammatory biomarkers with B. lanceolatus venom. No endothelial damage was found with the two venoms. To conclude, our data support two-sided hemostasis complications in Bothrops envenoming with an initial risk of hemorrhage related to platelet consumption and hypocoagulability followed by an increased risk of thrombosis promoted by the activated inflammatory response and rapid-onset fibrinogen restoration.

Real-World Experience with a Human Fibrinogen Concentrate: Clinical Data from Adult and Pediatric Patients Requiring Fibrinogen for Bleeding Control and Prevention

Human fibrinogen concentrate (Fibryga) received temporary approval for fibrinogen replacement therapy in France (2017), with subsequent full approval for congenital and acquired hypofibrinogenemia. We evaluated real-world use for on-demand treatment of bleeding and prophylaxis to enhance our knowledge on fibrinogen concentrate as an option for fibrinogen replacement. Data were retrospectively collected from adult and pediatric patients with fibrinogen deficiency. The primary end point was indication for fibrinogen concentrate use; the secondary end point was treatment success for on-demand treatment/perioperative prophylaxis. The study included 150 adult (median age, 62 years; range, 18-94 years) and 50 pediatric (median age, 3 years; range, 0.01-17 years) patients with acquired fibrinogen deficiency. Fibrinogen concentrate was administered to 47.3% for nonsurgical bleeding, 22.7% for surgical bleeding, and 30.0% for perioperative prophylaxis in adult patients, and to 4.0% for surgical bleeding and 96.0% for perioperative prophylaxis in pediatric patients. Cardiac surgeries accounted for 79.5%/75.0% perioperative prophylaxis and 82.4%/100.0% surgical bleeding cases in adult/pediatric patients, respectively. The mean ± standard deviation (SD, median) total fibrinogen doses were 3.06 ± 1.69 g (32.61 mg/kg), 2.09 ± 1.36 g (22.99 mg/kg), and 2.36 ± 1.25 g (29.67 mg/kg) for adult nonsurgical bleeding, surgical bleeding, and perioperative prophylaxis, respectively; doses of 0.75 ± 0.35 g (47.64 mg/kg) and 0.83 ± 0.62 g (55.56 mg/kg) were used for pediatric surgical bleeding and perioperative prophylaxis, respectively. Treatment success was 85.7%/97.1/93.3% in adults and 50.0%/87.5% in pediatrics for nonsurgical bleeding (adults only), surgical bleeding, and perioperative prophylaxis, respectively. Fibrinogen concentrate demonstrated favorable effectiveness and safety across the age groups. This study contributes to evidence supporting fibrinogen concentrate for bleeding control/prevention in real-world clinical practice, particularly for patients with acquired fibrinogen deficiency.

Epidemiology of severe bleeding in children following cardiac surgery involving cardiopulmonary bypass: use of Bleeding Assessment Scale for critically Ill Children (BASIC)

OBJECTIVES

To describe the epidemiology of severe bleeding in the immediate post-operative period in children who undergo cardiopulmonary bypass surgery using the Bleeding Assessment Scale for critically Ill Children (BASIC).

STUDY DESIGN

Retrospective cohort study in a paediatric ICU from 2015 to 2020.

RESULTS

356 children were enrolled; 59% were male with median (IQR) age 2.1 (0.5-8) years. Fifty-seven patients (16%) had severe bleeding in the first 24 hours post-operatively. Severe bleeding was observed more frequently in younger and smaller children with longer bypass and cross-clamp times (p-values <0.001), in addition to higher surgical complexity (p = 0.048). Those with severe bleeding received significantly more red blood cells, platelets, plasma, and cryoprecipitate in the paediatric ICU following surgery (all p-values <0.001). No laboratory values obtained on paediatric ICU admission were able to predict severe post-operative bleeding. Those with severe bleeding had significantly less paediatric ICU-free days (p = 0.010) and mechanical ventilation-free days (p = 0.013) as compared to those without severe bleeding.

CONCLUSIONS

Applying the BASIC definition to our cohort, severe bleeding occurred in 16% of children in the first day following cardiopulmonary bypass. Severe bleeding was associated with worse clinical outcomes. Standard laboratory assays do not predict bleeding warranting further study of available laboratory tests.

Safety of Tigecycline in Patients on Antithrombotic Therapy: A Single-Center Retrospective Study

INTRODUCTION

The aims of the study were to investigate the risk factors of tigecycline-induced hypofibrinogenemia and to evaluate the safety of tigecycline with concomitant antithrombotic drugs.

METHODS

We performed a retrospective analysis of patients who received tigecycline for more than 3 days between January 2015 and June 2019. Clinical and laboratory data were collected including fibrinogen concertation, tigecycline dose, duration of treatment, disease severity, complete blood count, indicators of infection, liver and renal function. Risk factors of hypofibrinogenemia were analyzed by univariate and multivariate analysis. To evaluate the safety of tigecycline and concomitant antithrombotic drugs, bleeding events were assessed by comparing the decline in hemoglobin and the amount of red blood cell transfusion in patients with antithrombotic drugs and those without.

RESULTS

This study included a total of 68 cases, 20 of which experienced hypofibrinogenemia while receiving tigecycline treatment. Duration of treatment, cefoperazone/sulbactam combination therapy, and fibrinogen levels prior to initiation of tigecycline were risk factors associated with tigecycline-induced hypofibrinogenemia. There were 26 recorded bleeding incidents, 25 of which happened before the start of tigecycline. Antithrombotic and non-antithrombotic patients did not differ in their hemoglobin decline or need for red blood cell transfusions while taking tigecycline.

CONCLUSION

A longer treatment duration, cefoperazone/sulbactam combination therapy, and a lower level of fibrinogen before tigecycline were associated with an increased risk of tigecycline-induced hypofibrinogenemia. A combination of antithrombotic drugs and tigecycline did not aggravate the bleeding events during tigecycline treatment.

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.

Broad-Spectrum Clearance of Lipopolysaccharides from Blood Based on a Hemocompatible Dihistidine Polymer

Blood infection can release toxic bacterial lipopolysaccharides (LPSs) into bloodstream, trigger a series of inflammatory reactions, and eventually lead to multiple organ dysfunction, irreversible shock, and even death, which seriously threatens human life and health. Herein, a functional block copolymer with excellent hemocompatibility is proposed to enable broad-spectrum clearance of LPSs from whole blood blindly before pathogen identification, facilitating timely rescue from sepsis. A dipeptide ligand of histidine-histidine (HH) was designed as the LPS binding unit, and poly[(trimethylamine N-oxide)-co-(histidine-histidine)], a functional block copolymer combining the LPS ligand of HH and a zwitterionic antifouling unit of trimethylamine N-oxide (TMAO), was then designed by reversible addition-fragmentation chain transfer (RAFT) polymerization. The functional polymer achieved effective clearance of LPSs from solutions and whole blood in a broad-spectrum manner and had good antifouling and anti-interference properties and hemocompatibility. The proposed functional dihistidine polymer provides a novel strategy for achieving broad-spectrum clearance of LPSs, with potential applications in clinical blood purification.

Etiology and management of hypofibrinogenemia in trauma

PURPOSE OF REVIEW

Fibrin polymerization is essential for stable clot formation in trauma, and hypofibrinogenemia reduces hemostasis in trauma. This review considers fibrinogen biology, the changes that fibrinogen undergoes after major trauma, and current evidence for lab testing and treatment.

RECENT FINDINGS

Fibrinogen is a polypeptide that is converted to fibrin by the action of thrombin. During trauma, fibrinogen levels are consumed and reduce within the first few hours because of consumption, dilution, and fibrinolysis. Fibrinogen levels usually rebound within 48 hours of injury and can contribute to thrombotic events. The Clauss fibrinogen assay is the gold standard test for fibrinogen levels, although viscoelastic hemostatic assays are often used when a lab delay is anticipated. An evidence-based threshold for fibrinogen replacement is not well established in the literature, but expert opinion recommends maintaining a level above 150 mg/dl.

SUMMARY

Hypofibrinogenemia is an important cause of nonanatomic bleeding in trauma. Despite multiple pathologic causes, the cornerstone of treatment remains fibrinogen replacement with cryoprecipitate or fibrinogen concentrates.

The effect of sulfur baths on hemorheological properties of blood in patients with osteoarthritis

Balneotherapy is an effective treatment method in various diseases and commonly used treatment modality among patients with musculoskeletal disorders. Sulfur baths are known for healing properties however effect on rheological properties is unstudied. Thus the aim of our study was to determine the effect of sulfur balneotherapy on hemorheological blood indices. A total of 48 patients with osteoarthritis were enrolled to the study. Blood samples were collected twice, before and after 3-week time period. We evaluated complete blood count, fibrinogen, hs-CRP and blood rheology parameters such as elongation index (EI), half-time of total aggregation (T_1/2) and aggregation index (AI) analyzed with the Lorrca Maxis. Mean age of studied cohort was 67 ± 5 years. After sulfur baths WBC count was significantly decreased is studied group (p = 0.021) as well as neutrophile count (p = 0.036). Red blood cell EIs were statistically higher after sulfur baths in shear stress ranging from 8.24 to 60.30 Pa. T_1/2 was significantly higher (p = 0.031) and AI lower (p = 0.003) compared to baseline. No significant changes in fibrinogen and hs-CRP were observed. It is the first study that evaluate effect of sulfur balneotherapy on rheologic properties of blood. Sulfur water baths may improve erythrocyte deformability and aggregation parameters.

Emergency administration of fibrinogen concentrate for haemorrhage: systematic review and meta-analysis

INTRODUCTION

The occurrence of massive haemorrhages in various emergency situations increases the need for blood transfusions and increases the risk of mortality. Fibrinogen concentrate (FC) use may increase plasma fibrinogen levels more rapidly than fresh-frozen product or cryoprecipitate use. Previous several systematic reviews and meta-analyses have not effectively demonstrated FC efficacy in significantly improving the risk of mortality and reducing transfusion requirements. In this study, we investigated the use of FC for haemorrhages in emergency situations.

METHODS AND ANALYSIS

In this systematic review and meta-analysis, we included controlled trials, but excluded randomized controlled trials (RCTs) in elective surgeries. The study population consisted of patients with haemorrhages in emergency situations, and the intervention was emergency supplementation of FC. The control group was administered with ordinal transfusion or placebo. The primary and secondary outcomes were in-hospital mortality and the amount of transfusion and thrombotic events, respectively. The electronic databases searched included MEDLINE (PubMed), Web of Science, and the Cochrane Central Register of Controlled Trials.

RESULTS

Nine RCTs in the qualitative synthesis with a total of 701 patients were included. Results showed a slight increase in in-hospital mortality with FC treatment (RR 1.24, 95% CI 0.64-2.39, p = 0.52) with very low certainty of the evidence. There was no reduction in the use of red blood cells (RBC) transfusion in the first 24 h after admission with FC treatment (mean difference [MD] 0.0 Unit in the FC group, 95% CI - 0.99-0.98, p = 0.99) with very low certainty of the evidence. However, the use of fresh-frozen plasma (FFP) transfusion significantly increased in the first 24 h after admission with FC treatment (MD 2.61 Unit higher in the FC group, 95% CI 0.07-5.16, p = 0.04). The occurrence of thrombotic events did not significantly differ with FC treatment.

CONCLUSIONS

The present study indicates that the use of FC may result in a slight increase in in-hospital mortality. While FC did not appear to reduce the use of RBC transfusion, it likely increased the use of FFP transfusion and may result in a large increase in platelet concentrate transfusion. However, the results should be interpreted cautiously due to the unbalanced severity in the patient population, high heterogeneity, and risk of bias.

C-reactive protein/albumin and C-reactive protein/fibrinogen ratios for the diagnosis of periprosthetic joint infection in revision total joint arthroplasty

AIM

Testing for systemic inflammation markers is considered a simpler method for diagnosing periprosthetic joint infection (PJI). Changes in the C-reactive protein/albumin ratio (CRP/Alb ratio) and C-reactive protein/fibrinogen ratio (CRP/Fib ratio) are associated with PJI. This study aimed to evaluate the application of CRP/Alb and CRP/Fib ratios as novel inflammation-based markers for the diagnosis of PJI.

METHODS

We retrospectively evaluated 445 patients who underwent total hip and knee revision arthroplasties between January 2010 and February 2021. Of these, 129 patients were also independently evaluated for PJI with coagulation-related comorbidities. The patients were divided into two groups: the aseptic revision (268 patients) and PJI revision groups (187 patients). Subsequently, we evaluated the diagnostic value of the CRP/Alb and CRP/Fib ratios compared to other inflammation-based diagnoses using the area under the curve (AUC) values.

RESULTS

The AUC values of the CRP/Alb and CRP/Fib ratios were 0.880 and 0.872, respectively, suggesting similar diagnostic potentials for PJI. The CRP/Alb and CRP/Fib ratios were better than the erythrocyte sedimentation rate (ESR), Alb, and Fib, whose AUC values were 0.765, 0.352, and 0.730, respectively, for the diagnosis of PJI. The optimal cut-off for the CRP/Alb ratio was 0.13, with good sensitivity (85.0%) and specificity (78.4%). The optimal cut-off CRP/Fib ratio was 2.04, with good sensitivity (81.3%) and specificity (80.6%). Notably, the CRP/Alb and CRP/Fib ratios had the highest sensitivity, followed by four conventional inflammatory markers, namely, CRP, ESR, Alb, and Fib, which had sensitivities of 80.2%, 67.4%, 50.8%, and 54.0%, respectively. Similar findings were observed in patients with coagulation-related comorbidities.

CONCLUSION

Both the CRP/Alb and CRP/Fib ratios were significantly higher in patients with PJI than in those with aseptic failure and showed better sensitivity and specificity for diagnosing PJI than classical inflammatory markers.

Raising the bar on fibrinogen: a retrospective assessment of critical hypofibrinogenemia in severely injured trauma patients

Objectives

Fibrinogen depletion may occur at higher levels than historically referenced. We evaluated hypofibrinogenemia and associated mortality and multiple organ failure (MOF) after severe injury.

Methods

Retrospective investigation including 417 adult patients with Injury Severity Score (ISS) >15. Demographics and injury characteristics were collected. Fibrinogen within 30 minutes of admission was described: <150 mg/dL, 150 mg/dL to 200 mg/dL and >200 mg/dL. Primary outcome: 28-day mortality. Secondary outcomes: 28-day MOF and blood product transfusion. Multivariable logistic regression model evaluated association of fibrinogen categories on risk of death, after controlling for confounding variables. Results presented as OR and 95% CIs.

Results

Fibrinogen <150 mg/dL: 4.8%, 150 mg/dL to 200 mg/dL: 18.2%, >200 mg/dL: 77.0%. 28-day mortality: 15.6%. Patients with <150 mg/dL fibrinogen had over fourfold increased 28-day mortality risk (OR: 4.9, 95% CI 1.53 to 15.7) after adjusting for age, ISS and admission Glasgow Coma Scale. Patients with lower fibrinogen were more likely to develop MOF (p=0.04) and receive larger red blood cell transfusion volumes at 3 hours and 24 hours (p<0.01).

Conclusions

Fibrinogen <150 mg/dL is significantly associated with increased 28-day mortality. Patients with fibrinogen <150 mg/dL were more likely to develop MOF and required increased administration of blood products. The optimal threshold for critically low fibrinogen, the association with MOF and subsequent fibrinogen replacement requires further investigation.

Level of evidence

Level III.

Statins and Hemostasis: Therapeutic Potential Based on Clinical Evidence

Hemostasis preserves blood fluidity and prevents its loss after vessel injury. The maintenance of blood fluidity requires a delicate balance between pro-coagulant and fibrinolytic status. Endothelial cells (ECs) in the inner face of blood vessels maintain hemostasis through balancing anti-thrombotic and pro-fibrinolytic activities. Dyslipidemias are linked to hemostatic alterations. Thus, it is necessary a better understanding of the underlying mechanisms linking hemostasis with dyslipidemia. Statins are drugs that decrease cholesterol levels in the blood and are the gold standard for treating hyperlipidemias. Statins can be classified into natural and synthetic molecules, approved for the treatment of hypercholesterolemia. The classical mechanism of action of statins is by competitive inhibition of a key enzyme in the synthesis pathway of cholesterol, the HMG-CoA reductase. Statins are frequently administrated by oral ingestion and its interaction with other drugs and food supplements is associated with altered bioavailability. In this review we deeply discuss the actions of statins beyond the control of dyslipidemias, focusing on the actions in thrombotic modulation, vascular and cardiovascular-related diseases, metabolic diseases including metabolic syndrome, diabetes, hyperlipidemia, and hypertension, and chronic diseases such as cancer, chronic obstructive pulmonary disease, and chronic kidney disease. Furthermore, we were prompted to delved deeper in the molecular mechanisms by means statins regulate coagulation acting on liver, platelets, and endothelium. Clinical evidence show that statins are effective regulators of dyslipidemia with a high impact in hemostasis regulation and its deleterious consequences. However, studies are required to elucidate its underlying molecular mechanism and improving their therapeutical actions.

Comparative retrospective study on the validity of point-of-care testing device for massive obstetrical hemorrhage: dry hematology vs thromboelastography

BACKGROUND

Early recognition of hypofibrinogenemia and prompt initiation of transfusion therapy in patients with massive obstetrical hemorrhage can improve prognosis. There are reports on the usefulness of point-of-care testing, which provides quicker test results compared with fibrinogen measurements using the conventional Clauss method.

OBJECTIVE

This study aimed to compare and investigate the diagnostic accuracy of dry hematology and thromboelastography in point-of-care testing for the diagnosis of hypofibrinogenemia.

STUDY DESIGN

A single-center, retrospective study of 126 massive obstetrical hemorrhage cases with point-of-care testing before treatment was initiated. The correlation of fibrinogen values with the Clauss method and the diagnostic accuracy for hypofibrinogenemia were compared between dry hematology and thromboelastography.

RESULTS

Fibrinogen value in dry hematology showed a strong positive correlation with values measured by the Clauss method, and the diagnostic accuracy for hypofibrinogenemia was high, but there were many residuals above 100 mg/dL, and the distribution of these residuals was not uniform. Although thromboelastography cannot be used to directly measure fibrinogen values, maximum amplitude citrated functional fibrinogen, amplitude-10 citrated rapid thromboelastography, and amplitude-10 citrated functional fibrinogen showed a strong positive correlation with fibrinogen values using the Clauss method, and no significant difference in correlation or diagnostic accuracy was observed relative to dry hematology.

CONCLUSION

Dry hematology and thromboelastography were equally accurate in diagnosing hypofibrinogenemia, with results correlating well with fibrinogen values measured by the Clauss method.

Microwave assisted preparation of a hemostatic gauze with mesoporous silica through in-situ synthesis

The medical disinfection cotton gauze is the most frequently used medical consumables for wound care. Here this ordinary commercial gauze was upgraded to a hemostatic gauze, which was loaded with mesoporous silica through in-situ synthesis and further microwave treatment. The original cotton gauze was pretreated with NaOH solutions for surface activation, soaked in double-silica source precursor solution for moderate in-situ synthesis, treated with microwave for quick template removement and dehydration. The final obtained hemostatic gauze (MS-G₁) showed superior physical, biocompatible and hemostatic advantages. The newborn mesoporous silica was firmly anchored onto the cotton fiber surface with <20% leaching after 10 min of sonication. The microwave treatment not only shortened the time for template removal but also promotes the formation of mesoporous structure. The clotting blood time (CBT) of MS-G₁ were only (62.00 ± 5.56 s), which was 23.14% shorter than that of original medical gauze, and even 3.6% shorter than Combat Gauze (CG). MS-G₁ also showed excellent biocompatibility in cytotoxicity tests of L-929 cells, with a 116% proliferation rate at the concentration of 5 mg/mL. Furthermore, the hemostatic performance was explored on a rabbit wound model of hemorrhagic liver injury, and MS-G₁ showed both shorter hemostasis time (113.75 s) and less blood loss (1.69 g) than that of CG (180.00 s, 5.13 g). The hemostatic gauze anchored with mesoporous silica was expected to be an excellent prehospital hemostatic dressing for field first aid.

Does Intraoperative Fibrinogen Affect Blood Loss or Transfusion Practice After Aortic Arch Surgery: A Prematurely Ended Randomized Trial

Cardiovascular surgery is often complicated by significant bleeding due to perioperative coagulopathy. The effectiveness of treatment with fibrinogen concentrate to reduce the perioperative blood transfusion rate after thoracic aortic replacement surgery in prior studies has shown conflicting results. Therefore, we conducted a double-blind randomized controlled trial to investigate if a single dose of intraoperative fibrinogen administration reduced blood loss and allogeneic transfusion rate after elective surgery for thoracic arch aneurysm with deep hypothermic circulatory arrest. Twenty patients were randomized to fibrinogen concentrate (N = 10) or placebo (N = 10). The recruitment of study patients was prematurely ended due to a low inclusion rate. Perioperative transfusion, 5-minute bleeding mass after study medication and postoperative blood loss were not different between the groups with fibrinogen concentrate or placebo. Due to small volumes of postoperative blood loss and premature study termination, a beneficial effect of fibrinogen concentrate on the number of blood transfusions could not be established. However, treatment with fibrinogen efficiently restored fibrinogen levels and clot strength to preoperative values with a more effective preserved postoperative thrombin generation capacity. This result might serve as a pilot for further multicenter studies to assess the prospective significance of automated and standardized thrombin generation as a routine assay for monitoring perioperative coagulopathy and its impact on short- and long-term operative results.

Prophylactic Use of Antifibrinolytics During Pediatric Cardiac Surgery With Cardiopulmonary Bypass on Postoperative Bleeding and Transfusion: A Systematic Review and Meta-Analysis

OBJECTIVES

To determine the effect of intraoperative antifibrinolytics, including tranexamic acid (TXA), aminocaproic acid (EACA), or aprotinin, on bleeding in children undergoing cardiac surgery with cardiopulmonary bypass (CPB).

DATA SOURCES

Relevant articles were systematically searched from Ovid MEDLINE, Ovid EMBASE, CINAHL, Cochrane Library, and Web of Science to November 15, 2021.

STUDY SELECTION

Abstracts were screened, and full texts were reviewed using predetermined inclusion and exclusion criteria using the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline.

DATA EXTRACTION

A standardized data extraction tool was used.

DATA SYNTHESIS

Sixty-eight studies including 28,735 patients were analyzed. TXA compared with placebo resulted in a mean decrease in chest tube output of 9.1 mL/kg (95% CI, 6.0-12.3 mL/kg), I2 equals to 65.2%, p value of less than 0.001, platelet requirement of 2.9 mL/kg (95% CI, 0.1-5.8 mL/kg), I2 =72.5%, p value less than 0.001 and plasma requirement of 4.0 mL/kg (95% CI, 0.6-7.2 mL/kg), I2 equals to 94.5%, p value less than0.001. Aprotinin compared with placebo resulted in a mean decrease in chest tube output of 4.3 mL/kg (2.4-6.2 mL/kg), I2 equals to 66.3%, p value of less than 0.001, platelet transfusion of 4.6 mL/kg (95% CI, 0.6-8.6 mL/kg), I2 equals to 93.6%, p value of less than 0.001, and plasma transfusion of 7.7 mL/kg (95% CI, 2.1-13.2 mL/kg), I2 equals to 95.3%, p value of less than 0.001. EACA compared with placebo resulted in a mean decrease in chest tube output of 9.2 mL/kg (2.3-21.0 mL/kg), I2 equals to 96.4%, p value of less than 0.001, RBC transfusion of 7.2 mL/kg (95% CI, 2.4-12.1 mL/kg), I2 equals to 94.5%, p value equals to 0.002, and platelet transfusion of 10.7 mL/kg (95% CI, 2.9-18.5 mL/kg), I2 equals to 0%, p value of less than 0.001. No statistical difference was observed in chest tube output when TXA was compared with aprotinin. Subgroup analysis of cyanotic patients showed a significant decrease in chest tube output, platelet requirement, and plasma requirement for patients receiving aprotinin. Overall, the quality of evidence was moderate.

CONCLUSIONS

Antifibrinolytics are effective at decreasing blood loss and blood product requirement in children undergoing cardiac surgery with CPB although the quality of evidence is only moderate.

Prophylactic administration of tranexamic acid combined with thromboelastography-guided hemostatic algorithm reduces allogeneic transfusion requirements during pediatric resective epilepsy surgery: A randomized controlled trial

Background: Intraoperative bleeding and allogeneic transfusion remain common problems in pediatric resective epilepsy surgery. Tranexamic acid (TXA) is a widely recommended antifibrinolytic drug that reduces blood loss and transfusion requirements for bleeding patients. Thromboelastography (TEG)-guided hemostatic algorithm is commonly used in bleeding management. This trial was designed to validate the efficacy of a multimodal coagulation therapy involving continuous TXA infusion with TEG-guided hemostatic algorithm in reducing allogeneic exposure risk in pediatric resective epilepsy surgery.

Methods: Eighty-three children undergoing resective epilepsy surgery were randomized into a treatment group (Group T; n = 42) and a control group (Group C; n = 41). Group T received prophylactic TXA (10 mg/kg followed by 5 mg/kg/h) with TEG-guided hemostatic algorithm, whereas Group C received conventional coagulation management. The primary outcome was allogeneic transfusion rate during surgery, and the secondary outcomes were intraoperative blood loss, incidence of postoperative seizures, and thromboembolic events during hospitalization.

Results: The incidence of intraoperative allogeneic transfusion reduced by 34.7% with the use of a multimodal coagulation therapy (19.0% in Group T vs. 53.7% in Group C; RR 0.355, 95% CI 0.179–0.704; p = 0.001). This was mainly triggered by a significant reduction (44.1%) in intraoperative plasma transfusion (7.1% in Group T vs. 51.2% in Group C; RR 0.139, 95% CI 0.045–0.432; p = 0.000). The risk of intraoperative RBC transfusion was lower in Group T than in Group C, but the difference was not statistically significant (14.3% in Group T vs. 29.3% in Group C; RR 0.488, 95% CI 0.202–1.177; p = 0.098). No platelets were transfused in both groups. Further, 19 (45.2%) patients in Group T received fibrinogen concentrates guided by TEG data, whereas 1 (2.4%) patient in Group C received fibrinogen concentrates empirically. There were no significant differences in estimated blood loss and postoperative seizures between the two groups, and no thromboembolic events were observed after surgery.

Conclusion: Prophylactic administration of TXA combined with TEG-guided hemostatic algorithm can be an effective multimodal coagulation strategy for reducing allogeneic transfusion requirements during pediatric resective epilepsy surgery.

Clinical Trial Registration:www.chictr.org.cn/index.aspx, identifier ChiCTR1800016188.

Clinical predictive model to estimate probability of remission in patients with lupus nephritis

BACKGROUND

Lupus nephritis (LN) is a major organ complication and cause of morbidity and mortality in patients with systemic lupus erythematosus. This study aims to provide the clinician with a quantitative tool for the prediction of the individual remission probability of LN and obtain new insights for improved clinical management in LN treatment.

METHODS

A total of 301 patients with renal biopsy-proven LN were recruited and randomly divided into model construction and validation group. The least absolute shrinkage and selection operator regression analysis was conducted to select significant variables, and a multivariate Cox regression predictive model was established. The performance of the model was verified and tested with 1000-bootstrap validation in the validation group. Finally, the nomogram was constructed, and the performance was evaluated. The predictive accuracy and efficiency were verified through receiver operation characteristic and calibration curves.

RESULTS

A total of 210 and 91 patients who all received renal biopsy were included in the training and validation group, respectively. A final prognostic model was established, which included the course of LN, gender, 24h-proteinuria, creatinine, triglycerides, FIB, Complement C3, anti-dsDNA antibody, tubular atrophy and classification of kidney biopsy. Moreover, an easy-to-use nomogram was built based on the predictive model. The areas under the curve (AUC) of the 1, 2, 5-year prediction were 77.12, 77.98 and 87.01 in the training group, respectively. In the validation group, the AUC of the 1, 2, 5-year prediction were 81.42, 87.20 and 92.81 respectively, which indicated good performance in predicting the remission probability of LN.

CONCLUSION

This novel model was constructed to predict the remission probability of patients with LN for the first time. This model displayed good predictive performance and was easy to use for clinical practice.

Protein-coated nanostructured surfaces affect the adhesion of Escherichia coli

Developing new implant surfaces with anti-adhesion bacterial properties used for medical devices remains a challenge. Here we describe a novel study investigating nanotopography influences on bacterial adhesion on surfaces with controlled interspatial nanopillar distances. The surfaces were coated with proteins (fibrinogen, collagen, serum and saliva) prior to E. coli-WT adhesion under flow conditions. PiFM provided chemical mapping and showed that proteins adsorbed both between and onto the nanopillars with a preference for areas between the nanopillars. E. coli-WT adhered least to protein-coated areas with low surface nanopillar coverage, most to surfaces coated with saliva, while human serum led to the lowest adhesion. Protein-coated nanostructured surfaces affected the adhesion of E. coli-WT.

Latest advances in postpartum hemorrhage management

Hemorrhage is the leading cause of maternal mortality worldwide. A maternal health priority is improving how healthcare providers prevent and manage postpartum hemorrhage (PPH). Because anesthesiologists can help facilitate how hospitals develop approaches for PPH prevention and anticipatory planning, we review the potential utility of PPH risk-assessment tools, bundles, and protocols. Anesthesiologists rely on clinical and diagnostic information for initiating and evaluating medical management. Therefore, we review modalities for measuring blood loss after delivery, which includes visual, volumetric, gravimetric, and colorimetric approaches. Point-of-care technologies for assessing changes in central hemodynamics (ultrasonography) and coagulation profiles (rotational thromboelastometry and thromboelastography) are also discussed. Anesthesiologists play a critical role in the medical and transfusion management of PPH. Therefore, we review blood ordering and massive transfusion protocols, fixed-ratio vs. goal-directed transfusion approaches, coagulation changes during PPH, and the potential clinical utility of the pharmacological adjuncts, tranexamic acid, and fibrinogen concentrate.

Congenital afibrinogenemia in a newborn

Introduction: Congenital afibrinogenemia is a rare coagulation disorder characterized by a deficiency in the fibrinogen molecule. Fibrinogen is a hexameric glycoprotein consisting of a polypeptide chain encoded by FGB, FGA, and FGG and is required for normal hemostasis. Changes in FGA, FGB, and FGG may affect fibrinogen at different levels. As a result of these changes, fibrinogen cannot be detected in the blood. Clinical manifestations of such changes range from asymptomatic to life-threatening bleeding or thromboembolic events. Since it is an autosomal recessive disease, the risk is higher in children whose parents are related. Therefore, the disease is more common in regions where consanguineous marriage rates are high. Diagnosis is made by laboratory tests that show the absence of fibrinogen. These patients need to be treated with fibrinogen replacement therapy. Case presentation: This study reports the case of a newborn with congenital afibrinogenemia. The baby born from a first-degree consanguineous marriage was referred to our hospital due to bleeding and ecchymosis, and afibrinogenemia was diagnosed after coagulation tests were performed. Blood samples of the patient and his parents were sent to the Genetic Diseases Diagnosis Center for a genetic diagnosis of afibrinogenemia. A new homozygous mutation of FGB exon 7: c.1220c > t (p.t407 m) (p.thr407 met) was identified in the patient. The patients' parents were heterozygous for the same mutation. Prophylaxis was not recommended for our patient who was asymptomatic in the follow-up. Conclusions: We present the case of a hemorrhagic neonatal patient diagnosed with congenital afibrinogenemia and emphasize that fibrinogen testing should be included in the evaluation of such patients. Furthermore, congenital fibrinogen disorders may be more severe when caused due to unknown specific mutation genes. Therefore, a more center-involved genetic analysis is required to identify undiagnosed fibrinogen and fibrinogen mutations.

Fibrinogen and Bleeding in Adult Cardiac Surgery: A Review of the Literature

Background: Fibrinogen is a substrate for blood clots formation. In cardiac surgery, a number of different mechanisms lead to a decrease in fibrinogen levels and consequent impaired haemostasis. Patients undergoing cardiac surgery are therefore frequently exposed to blood loss and allogeneic blood transfusion, which are risk factors associated with morbidity and mortality. Thus, particular efforts in fibrinogen management should be made to decrease bleeding and the need for blood transfusion. Therefore, fibrinogen remains an active focus of investigations from basic science to clinical practice. This review aims to summarise the latest evidence regarding the role of fibrinogen and current practices in fibrinogen management in adult cardiac surgery. Methods: The PubMed database was systematically searched for literature investigating the role and disorders of fibrinogen in cardiac surgery and diagnostic and therapeutic procedures related to fibrinogen deficiency aimed at reducing blood loss and transfusion requirements. Clinical trials and reviews from the last 10 years were included. Results: In total, 146 articles were analysed. Conclusion: The early diagnosis and treatment of fibrinogen deficiency is crucial in maintaining haemostasis in bleeding patients. Further studies are needed to better understand the association between fibrinogen levels, bleeding, and fibrinogen supplementation and their impacts on patient outcomes in different clinical settings.

Multi-Scale Photoacoustic Assessment of Wound Healing Using Chitosan-Graphene Oxide Hemostatic Sponge

Hemostasis is vital to save lives, reducing risks of organ failure and hemorrhagic shock. Exploring novel hemostatic materials and precise monitoring of the hemostatic status is of great importance for efficient hemostasis. We present the development of chitosan-graphene oxide-based hemostatic composite and multi-scale photoacoustic evaluation of the hemostatic performance. The hemostatic sponge can quickly and efficiently absorb the blood with its porous cavity and specific surficial property. We inspect the hemostatic performance via an in vitro blood absorption test and in vivo mouse bleeding injury experiments. Results show that the synthesized hemostatic sponge can not only absorb plasma in blood fast with its interior porous structure but also stimulate the interfacial reaction with erythrocytes and platelets. The superiority of multi-scale photoacoustic imaging for guiding, monitoring, and evaluating the hemostatic stages of sponges is demonstrated with high spatial resolution and great sensitivity at depths. Photoacoustic evaluation of a chitosan-graphene oxide-based hemostatic sponge has the potential to be transferred toward the clinical assessment of wound healing.

Lower Mortality with Cryoprecipitate During Massive Transfusion in Penetrating but Not Blunt Trauma

BACKGROUND

Balanced blood product transfusion improves the outcomes of trauma patients with exsanguinating hemorrhage, but it remains unclear whether administering cryoprecipitate improves mortality. We aimed to examine the impact of early cryoprecipitate transfusion on the outcomes of the trauma patients needing massive transfusion (MT).

METHODS

All MT patients 18 years or older in the 2017 Trauma Quality Improvement Program (TQIP) were retrospectively reviewed. MT was defined as the transfusion of ≥10 units of blood within 24 hours. Propensity score analysis (PSA) was used to 1:1 match then compare patients who received and those who did not receive cryoprecipitate in the first 4 hours after injury. Outcomes included in-hospital mortality, 1-day mortality, in-hospital complications and transfusion needs at 24 hours.

RESULTS

Of 1,004,440 trauma patients, 1,454 MT patients received cryoprecipitate and 2,920 did not. After PSA, 877 patients receiving cryoprecipitate were matched to 877 patients who did not. In-hospital mortality was lower among patients who received cryoprecipitate (49.4% v. 54.9%, P = 0.022), as was 1-day mortality. Sub-analyses showed that mortality was lower with cryoprecipitate in patients with penetrating (37.5% versus. 48%, adjusted P = 0.008), but not blunt trauma (58.5% versus. 59.8%, adjusted P = 1.000). In penetrating trauma, the cryoprecipitate group also had lower 1-day mortality (21.8% versus. 38.6%, P <0.001) and a higher rate of hemorrhage control surgeries performed within 24 hours (71.4% versus. 63.3%, P = 0.018).

CONCLUSIONS

Cryoprecipitate in MT is associated with improved survival in penetrating, but not blunt, trauma. Randomized trials are needed to better define the role of cryoprecipitate in MT.

Pro-Con Debate: Fibrinogen Concentrate or Cryoprecipitate for Treatment of Acquired Hypofibrinogenemia in Cardiac Surgical Patients

Cryoprecipitate has been the gold standard for treating acquired hypofibrinogenemia in cardiac surgery for nearly 50 years. More recently, fibrinogen concentrate has been used off-label in the United States and is the standard in European countries and Canada to treat the acquired hypofibrinogenemia during cardiac surgery. Fibrinogen concentrate has multiple potential advantages including rapid reconstitution, greater dose predictability, viral inactivation during processing, and reduced transfusion-related adverse events. However, because fibrinogen concentrate lacks the other components contained in the cryoprecipitate, it may not be the "ideal" product for replacing fibrinogen in all cardiac surgical patients, particularly those with longer cardiopulmonary bypass duration. In this Pro-Con commentary article, we discuss the advantages and disadvantages of using fibrinogen concentrate and cryoprecipitate to treat acquired hypofibrinogenemia in cardiac surgical patients.

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.

Effect of Whole-Body Cryotherapy on Morphological, Rheological and Biochemical Indices of Blood in People with Multiple Sclerosis

The aim of this study was to examine and assess the impact of a series of 20 whole-body cryotherapy (WBC) treatments on the biochemical and rheological indices of blood in people with multiple sclerosis. In this prospective controlled study, the experimental group consisted of 15 women aged 34-55 (mean age, 41.53 ± 6.98 years) with diagnosed multiple sclerosis who underwent a series of whole-body cryotherapy treatments. The first control group consisted of 20 women with diagnosed multiple sclerosis. This group had no intervention in the form of whole-body cryotherapy. The second control group consisted of 15 women aged 30-49 years (mean age, 38.47 ± 6.0 years) without neurological diseases and other chronic diseases who also underwent the whole-body cryotherapy treatment. For the analysis of the blood indices, venous blood was taken twice (first, on the day of initiation of whole-body cryotherapy treatments and, second, after a series of 20 cryotherapy treatments). The blood counts were determined using an ABX MICROS 60 hematological analyzer (USA). The LORCA analyzer (Laser-Optical Rotational Cell Analyzer, RR Mechatronics, the Netherlands) was used to study the aggregation and deformability of erythrocytes. The total protein serum measurement was performed using a Cobas 6000 analyzer, Roche and a Proteinogram-Minicap Sebia analyzer. Fibrinogen determinations were made using a Bio-Ksel, Chrom-7 camera. Statistically significant differences and changes after WBC in the levels of red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), elongation index, total extend of aggregation (AMP), and proteins (including fibrinogen) were observed. However, there was no significant effect of a series of 20 WBC treatments on changes in blood counts, rheology, and biochemistry in women with multiple sclerosis. Our results show that the use of WBC has a positive effect on the rheological properties of the blood of healthy women.

Congenital Fibrinogen Deficiency in India and Role of Human Fibrinogen Concentrate

Congenital fibrinogen deficiency is an inherited disorder due to genetic mutations with diverse presentations arising from reduced fibrinogen levels (hypofibrinogenemia), absence of fibrinogen in circulation (afibrinogenemia), abnormal functioning (dysfibrinogenemia) or both reduced levels and abnormal functioning (hypodysfibrinogenemia) of fibrinogen. The decreased fibrinogen concentration in congenital fibrinogen deficiency necessitates fibrinogen replacement therapy with fresh frozen plasma, cryoprecipitate, or human fibrinogen concentrate. However, the use of fresh frozen plasma and cryoprecipitate is limited owing to their longer transfusion time, requirement of high doses, volume overload, risk of viral transmission, and other safety concerns. The availability of human fibrinogen concentrate has made it the preferred replacement alternative due to its reduced risk of viral transmission, smaller infusion volume, and accurate dosing. The hemostatic efficacy and safety of human fibrinogen concentrate in congenital fibrinogen deficiency is well established in the literature. We review the prevalence of congenital fibrinogen deficiency in India and the current role of human fibrinogen concentrate in its management.

Trauma-induced coagulopathy

Uncontrolled haemorrhage is a major preventable cause of death in patients with traumatic injury. Trauma-induced coagulopathy (TIC) describes abnormal coagulation processes that are attributable to trauma. In the early hours of TIC development, hypocoagulability is typically present, resulting in bleeding, whereas later TIC is characterized by a hypercoagulable state associated with venous thromboembolism and multiple organ failure. Several pathophysiological mechanisms underlie TIC; tissue injury and shock synergistically provoke endothelial, immune system, platelet and clotting activation, which are accentuated by the 'lethal triad' (coagulopathy, hypothermia and acidosis). Traumatic brain injury also has a distinct role in TIC. Haemostatic abnormalities include fibrinogen depletion, inadequate thrombin generation, impaired platelet function and dysregulated fibrinolysis. Laboratory diagnosis is based on coagulation abnormalities detected by conventional or viscoelastic haemostatic assays; however, it does not always match the clinical condition. Management priorities are stopping blood loss and reversing shock by restoring circulating blood volume, to prevent or reduce the risk of worsening TIC. Various blood products can be used in resuscitation; however, there is no international agreement on the optimal composition of transfusion components. Tranexamic acid is used in pre-hospital settings selectively in the USA and more widely in Europe and other locations. Survivors of TIC experience high rates of morbidity, which affects short-term and long-term quality of life and functional outcome.