Identification of heparin interaction sites on thrombin-activatable fibrinolysis inhibitor that modulate plasmin-mediated activation, thermal stability, and antifibrinolytic potential.

Background: Thrombin-activatable fibrinolysis inhibitor (TAFI) is a plasma zymogen that provides a molecular link between coagulation and fibrinolysis. Studies have shown that the presence of glycosaminoglycans accelerates TAFI activation by plasmin and stabilizes activated TAFI (TAFIa). Objectives: We aimed to define the elements of TAFI structure that allow these effects. Methods: Based on crystallographic studies and homology to heparin-binding proteins, we performed mutagenesis of surface-exposed charged residues on TAFI that putatively constitute heparin-binding sites. We determined heparin binding, kinetics of activation by plasmin in the presence or absence of heparin, thermal stability, and antifibrinolytic potential of each variant. Results: Mutagenesis of Lys211 and Lys212 did not impair heparin binding but affected the ability of TAFI to be activated by plasmin. Mutagenesis of Lys306 and His308 did not impair heparin binding, but mutation of His308 had a severe negative effect on TAFI/TAFIa function. Mutation of Arg320 and Lys324 in combination markedly decreased heparin binding but had no effect on heparin-mediated acceleration of TAFI activation by plasmin while somewhat decreasing TAFIa stabilization by heparin. Mutagenesis of Lys327 and Arg330 decreased (but did not eliminate) heparin binding while decreasing the ability of heparin to accelerate plasmin-mediated TAFI activation, stabilize TAFIa, and increase the antifibrinolytic ability of TAFIa. A quadruple mutant of Arg320, Lys324, Lys327, and Arg330 completely lost heparin-binding ability and stabilization of the enzyme by heparin. Conclusion: Basic residues in the dynamic flap of TAFIa define a functionally relevant heparin-binding site, but additional heparin-binding sites may be present on TAFI.

Catheter directed therapy in high-risk pulmonary embolism: Analysis of 9 cases. / Terapia dirigida por catéter en embolia pulmonar de alto riesgo: análisis de 9 casos.

BACKGROUND: Mechanical thrombectomy is a useful technique in patients with high-risk pulmonary embolism. It is indicated as an alternative to systemic fibrinolysis when it is contraindicated or as an adjuvant therapy when it fails. OBJECTIVE: To describe clinical characteristics, evolution and survival of patients with high-risk pulmonary embolism who have undergone mechanical thrombectomy. METHOD: Single-center retrospective descriptive study of consecutive patients who underwent mechanical thrombectomy. Demographic, clinical and survival variables were analyzed. RESULTS: 9 patients were included (56% men, 44% women). All patients had pulmonary artery pressure assessed using a Swan-Ganz catheter before thrombectomy. The median pulmonary artery pressure before the procedure was 46mmHg (51-38mmHg). Systemic fibrinolysis was also performed in 5 cases, in 2 of them in the setting of cardiorespiratory arrest, without hemorrhagic complications. No patient died during hospitalization. Survival one month after the procedure was 100%. CONCLUSIONS: In our series, mechanical thrombectomy is a useful technique as an alternative to systemic fibrinolysis or as an adjuvant therapy to it.

Unravelling the Antifibrinolytic Mechanism of Action of the 1,2,3-Triazole Derivatives.

A new family of antifibrinolytic drugs has been recently discovered, combining a triazole moiety, an oxadiazolone, and a terminal amine. Two of the molecules of this family have shown activity that is greater than or similar to that of tranexamic acid (TXA), the current antifibrinolytic gold standard, which has been associated with several side effects and whose use is limited in patients with renal impairment. The aim of this work was to thoroughly examine the mechanism of action of the two ideal candidates of the 1,2,3-triazole family and compare them with TXA, to identify an antifibrinolytic alternative active at lower dosages. Specifically, the antifibrinolytic activity of the two compounds (1 and 5) and TXA was assessed in fibrinolytic isolated systems and in whole blood. Results revealed that despite having an activity pathway comparable to that of TXA, both compounds showed greater activity in blood. These differences could be attributed to a more stable ligand-target binding to the pocket of plasminogen for compounds 1 and 5, as suggested by molecular dynamic simulations. This work presents further evidence of the antifibrinolytic activity of the two best candidates of the 1,2,3-triazole family and paves the way for incorporating these molecules as new antifibrinolytic therapies.

Hepatocyte Growth Factor DNA Aptamer for Prevention of Postoperative Peritoneal Adhesion via Enhancement of Fibrinolysis and Inhibition of Mesothelial Mesenchymal Transition.

Postoperative peritoneal adhesion (PPA) is a prevalent complication of abdominal surgery, posing a significant hindrance to postsurgical recovery. Although several strategies have been developed to alleviate and prevent adhesions, their efficacy remains unsatisfactory. For the first time, we studied the therapeutic effect and mechanism of our recently developed thermally stable oligonucleotide-based mimetics of hepatocyte growth factor (HGF DNA aptamer) to prevent PPA. The HGF DNA aptamer effectively inhibited canonical TGF-ß1 signaling transduction, partially suppressing mesothelial mesenchymal transition. Additionally, the aptamer, respectively, upregulated and downregulated the expression of tissue plasminogen activator and plasminogen activator inhibitor 1, thereby enhancing fibrinolytic activity. As a pleiotropic factor, the HGF DNA aptamer also enhanced the migratory and proliferative capacities of mesothelial cells. Finally, the aptamer demonstrated a higher level of effectiveness in preventing PPAs than the commercially available antiperitoneal adhesion barrier, Seprafilm. Due to its therapeutic benefits, excellent stability, biosafety, cost-effectiveness, and versatility, the HGF DNA aptamer demonstrates promise for preventing PPA in future clinical settings.

Effects of dabigatran, rivaroxaban, and apixaban on fibrin network permeability, thrombin generation, and fibrinolysis.

INTRODUCTION: There are important pharmacological differences between direct oral anticoagulants (DOAC) and a deeper knowledge of how they influence different aspects of hemostasis in patients on treatment is desirable. MATERIALS AND METHODS: Blood samples from patients on dabigatran (n = 23), rivaroxaban (n = 26), or apixaban (n = 20) were analyzed with a fibrin network permeability assay, a turbidimetric clotting and lysis assay, the calibrated automated thrombogram (CAT), plasma levels of thrombin-antithrombin complex (TAT) and D-dimer, as well as DOAC concentrations, PT-INR and aPTT. As a comparison, we also analyzed samples from 27 patients on treatment with warfarin. RESULTS: Patients on dabigatran had a more permeable fibrin network, longer lag time (CAT and turbidimetric assay), and lower levels of D-dimer in plasma, compared with patients on rivaroxaban- and apixaban treatment, and a more permeable fibrin network than patients on warfarin. Clot lysis time was slightly longer in patients on dabigatran than in patients on rivaroxaban. Warfarin patients formed a more permeable fibrin network than patients on apixaban, had longer lag time than patients on rivaroxaban (CAT assay), and lower peak thrombin and ETP compared to patients on treatment with both FXa-inhibitors. CONCLUSIONS: Results from this study indicate dabigatran treatment is a more potent anticoagulant than apixaban and rivaroxaban. However, as these results are not supported by clinical data, they are probably more related to the assays used and highlight the difficulty of measuring and comparing the effect of anticoagulants.

Thromboelastography in acute immunologic reactions: a prospective pilot study.

Background: Biomarkers of fibrinolysis are elevated during acute immunologic reactions (allergic reactions and angioedema), although it is unclear whether fibrinolysis is associated with disease severity. Objectives: We investigated a possible association between maximum lysis (ML) measured by thromboelastography and the severity of acute immunologic reactions. Methods: We recruited patients with acute immunologic reactions at a high-volume emergency department. Clinical disease severity at presentation and at the end of the emergency department stay was assessed using a 5-grade scale, ranging from local symptoms to cardiac arrest. We determined ML on admission by thromboelastography (ROTEM's extrinsic [EXTEM], and aprotinin [APTEM] tests), expressed as ML%. Hyperfibrinolysis was defined as an ML of >15% in EXTEM, which was reversed by adding aprotinin (APTEM). We used exact logistic regression to investigate an association between ML% and disease severity (grades 1 and 2 [mild] vs 3-5 [severe]) and between hyperfibrinolysis and disease severity. Results: We included 31 patients (71% female; median age, 52 [IQR, 35-58] years; 10 [32%] with a severe reaction). ML% was higher in patients with severe symptoms (21 [IQR, 12-100] vs 10 [IQR, 4-17]). Logistic regression found a significant association between ML% and symptom severity (odds ratio, 1.07; 95% CI, 1.01-1.21; P = .003). Hyperfibrinolysis was detected in 6 patients and found to be associated with severe symptoms (odds ratio, 17.59; 95% CI, 1.52-991.09; P = .02). D-dimer, tryptase, and immunoglobulin E concentrations increased with the severity of immunologic reactions. Conclusion: ML, quantified by thromboelastography, is associated with the severity of acute immunologic reactions.

Methods, precision, and analytical sensitivity of a novel low-plasma-volume assay of fibrinolytic capacity utilizing the euglobulin fraction.

INTRODUCTION: Fibrinolysis is a critical aspect of the hemostatic system, with assessment of fibrinolytic potential being critical to predict bleeding and clotting risk. We describe the method for a novel low-plasma-volume assay of fibrinolytic capacity utilizing the euglobulin fraction (the "modified mini-euglobulin clot lysis assay [ECLA]"), its analytic sensitivity to alterations in key fibrinolytic substrates/regulators, and its initial applications in acute and convalescent disease cohorts. METHODS: The modified mini-ECLA requires 50 µL of plasma, a maximal read time of 3 h (with most results available within 60 min), and is entirely performed in a 96-well microplate. Assay measurements were obtained in a variety of commercial control and deficient plasmas representing clinically relevant hypo- and hyperfibrinolytic states, and in three distinct adolescent cohorts with acute or convalescent illness: critically ill, following endotracheal intubation; acute COVID-19-related illness; and ambulatory, 3 months following a venous thromboembolic event. RESULTS: In 100% and 75% deficient plasmas, hypofibrinolysis for plasminogen-deficient, fibrinolysis for alpha-2-antiplasmin-deficient, and hyperfibrinolysis for plasminogen activator inhibitor-1-deficient plasmas were observed. CONCLUSION: The modified mini-ECLA Clot Lysis Time Ratio ("CLTR") demonstrated moderate-strength correlations with the Clot Formation and Lysis (CloFAL) assay, is analytically sensitive to altered fibrinolytic states in vitro, and correlates with clinical outcomes in preliminarily-studied patient populations.

Reduced protein carbonylation on hormone therapy is associated with improved fibrinolysis in postmenopausal women: the impact of PAI-1 and TAFI activity.

Hormone therapy (HT) has been reported to reduce protein carbonylation (PC) in postmenopausal women, in whom fibrinolysis is impaired. We investigated whether PC affects fibrinolysis and if HT modulates this effect. We enrolled 150 women aged 55.5 ± 4.7 years in a randomized interventional open-label study, including 50 on standard oral HT, 50 on ultra-low-dose HT, and 50 controls. PC, along with global fibrinolysis (clot lysis time, CLT), fibrinolysis proteins, and prothrombotic markers were determined at baseline and at 24 weeks. Patients with the baseline top quartile PC (> 2.07 nM/mg protein) had 10.3% longer CLT, higher activity (but not antigen) of TAFI (+ 19.9%) and PAI-1 (+ 68.1%) compared to the remainder. No differences were observed in thrombin generation, factor VIII, plasminogen or α2-antiplasmin. On-treatment PC decreased by 16.4% (p < 0.0001), without differences related to the type of HT, compared to baseline and by 30% compared to controls, in whom PC and fibrinolysis markers remained unchanged. Patients with PC > 2.07 nM/mg had shortened CLT during HT compared to baseline, along with lower PAI-1 (-69%) and TAFI (-26%) activity. In this subgroup CLT was 5.8% shorter compared to controls with the highest PC. In postmenopausal women with increased PC, HT was accompanied by PC reduction and faster clot lysis together with decreased PAI-1 and TAFI activity.

Are all fibrinogen concentrates the same? The effects of two fibrinogen therapies in an afibrinogenemic patient and in a fibrinogen deficient plasma model. A clinical and laboratory case report.

The choice of treatments for inherited, or acquired, fibrinogen deficient states is expanding and there are now several fibrinogen concentrate therapies commercially available. Patients with the rare inherited bleeding disorder, afibrinogenemia, commonly require life-long replacement therapy with fibrinogen concentrate to prevent hemorrhagic complications. Recent reports in the setting of acquired bleeding, namely trauma hemorrhage, have highlighted the potential importance of the different compositions of fibrinogen supplements, including cryoprecipitate and the various plasma- derived concentrates. Clot strength and the subsequent susceptibility of a clot to lysis is highly dependent on the amount of fibrinogen as well as its structural composition, the concentration of pro- and anti-coagulant factors, as well as fibrinolytic regulators, such as factor XIII (FXIII). This report details the effects of two commercially available fibrinogen concentrates (Riastap®, CSL Behring and Fibryga®, Octapharma) on important functional measures of clot formation and lysis in a patient with afibrinogenemia. Our report offers insights into the differential effects of these concentrates, at the clot level, according to the variable constituents of each product, thereby emphasizing that the choice of fibrinogen concentrate can influence the stability of a clot in vivo. Whether this alters clinical efficacy is yet to be understood.

Abnormalities of Coagulation and Fibrinolysis Assessed by Thromboelastometry in an Endotoxic Shock Model in Piglets Treated with Nitric Oxide and Hydrocortisone.

This is an animal model study to investigate changes in hemostasis during endotoxemic shock and to determine whether the combination of inhaled nitric oxide (iNO) + intravenous hydrocortisone had an effect on clot formation and fibrinolysis. iNO selectively decreases pulmonary artery pressure, without affecting cardiac index or systemic vascular resistance; however, the results of studies on the possible consequences of iNO administration on coagulation are inconsistent and require further research. Thirty-four piglets were included. Administering endotoxin caused severe hypodynamic shock. Half of the animals received iNO (30 ppm) + hydrocortisone, starting 3 h after endotoxin infusion and continuing to the end of the study. All animals developed coagulation disorders, manifested by a tendency to hypocoagulation; at the same time, fibrinolysis was impaired. Coagulation and fibrinolysis disorders persisted after endotoxin infusion was discontinued, with worse severity in the animals that died before the study was terminated. Administering iNO + hydrocortisone did not cause further changes in coagulation and fibrinolysis parameters, either during or after the endotoxin challenge, suggesting that potential therapeutic interventions with iNO to lower pulmonary arterial pressure will not affect hemostasis.

Acute myocardial infarction and ischaemic stroke: differences and similarities in reperfusion therapies-a review.

Acute ST-elevation myocardial infarction (STEMI) and acute ischaemic stroke (AIS) share a number of similarities. However, important differences in pathophysiology demand a disease-tailored approach. In both conditions, fast treatment plays a crucial role as ischaemia and eventually infarction develop rapidly. Furthermore, in both fields, the introduction of fibrinolytic treatments historically preceded the implementation of endovascular techniques. However, in contrast to STEMI, only a minority of AIS patients will eventually be considered eligible for reperfusion treatment. Non-invasive cerebral imaging always precedes cerebral angiography and thrombectomy, whereas coronary angiography is not routinely preceded by non-invasive cardiac imaging in patients with STEMI. In the late or unknown time window, the presence of specific patterns on brain imaging may help identify AIS patients who benefit most from reperfusion treatment. For STEMI, a uniform time window for reperfusion up to 12 h after symptom onset, based on old placebo-controlled trials, is still recommended in guidelines and generally applied. Bridging fibrinolysis preceding endovascular treatment still remains the mainstay of reperfusion treatment in AIS, while primary percutaneous coronary intervention is the strategy of choice in STEMI. Shortening ischaemic times by fine-tuning collaboration networks between ambulances, community hospitals, and tertiary care hospitals, optimizing bridging fibrinolysis, and reducing ischaemia-reperfusion injury are important topics for further research. The aim of this review is to provide insights into the common as well as diverging pathophysiology behind current reperfusion strategies and to explore new ways to enhance their clinical benefit.

Coagulation and fibrinolytic markers offer utility when distinguishing between benign and malignant gallbladder tumors: A cross-sectional study.

BACKGROUND: The metabolic or proliferative abnormalities that are characteristic of tumor cells can lead to abnormal fibrinolysis or coagulation system activity, with certain tumors exhibiting hypercoagulability or existing in a fibrinolytic state. However, the utility of biomarkers of coagulation and fibrinolysis when seeking to differentiate between benign gallbladder disease and malignant gallbladder tumors remains uncertain. METHODS: This study included a total of 81 patients with benign gallbladder polyps and 94 patients with malignant gallbladder tumors. Pre-biopsy or pretreatment levels of PT, APTT, FIB, D-dimer, FDP, PLT, PIC, TAT, TM, and t-PAIC from these patients were compared using Mann-Whitney tests. The baseline data of the patients were analyzed using chi-square tests, and the diagnostic utility of these biomarkers in distinguishing between benign and malignant gallbladder lesions was evaluated using ROC curves, and Spearman correlation analysis was employed to assess the correlation between these indicators and tumor parameters. RESULTS: The average age of malignant gallbladder tumor group was higher than benign gallbladder polyp group. And the base line analysis showed that there was a statistic difference in age, history of smoking, drinking, biliary tract disease, BMI of over weight between these two groups. In patients with malignant gallbladder tumors, FIB, D-dimer, FDP, PIC, TAT, TM, and t-PAIC levels were significantly elevated relative to those in patients affected by benign gallbladder polyp. The AUC for FIB, D-dimer, and FDP was 0.8469, 0.6514, 0.5950, while for PIC, TAT, TM, t-PAIC and four biomarker combined diagnosed was 0.8455, 0.6554, 0.7130, 0.6806, and 0.8859. Among these, TM was associated with the vascular invasion of tumor patients; TAT and t-PAIC were associated with neural invasion; D-dimer and FDP were related to the maximum tumor diameter; and FDP had a certain correlation with the tumor stage. CONCLUSIONS: In gallbladder tumor patients, conventional coagulation metrics like FIB, D-dimer, and FDP, as well as newer thrombotic indicators such as PIC, TAT, TM, and t-PAIC, were obviously increased. Correlations with tumor parameters suggested their potential as biomarkers to distinguish benign from malignant gallbladder growths.

Daytime plasma cortisol and cortisol response to dexamethasone suppression are associated with a prothrombotic state in hypertension.

Background and aims: A prothrombotic state was demonstrated in patients with Cushing's syndrome and is involved in the development and progression of cardiovascular and renal damage in hypertensive patients. This study was designed to examine the relationships between cortisol secretion and the hemostatic and fibrinolytic systems in hypertension. Methods: In 149 middle-aged, nondiabetic, essential hypertensive patients free of cardiovascular and renal complications, we measured hemostatic markers that express the spontaneous activation of the coagulation and fibrinolytic systems and assessed daily cortisol levels (8 AM, 3 PM, 12 AM; area under the curve, AUC-cortisol) together with the cortisol response to dexamethasone overnight suppression (DST-cortisol). Results: Plasma levels of D-dimer (D-dim), prothrombin fragment 1 + 2 (F1 + 2), and von Willebrand factor (vWF) were progressively and significantly higher across tertiles of AUC-cortisol and DST-cortisol, whereas no differences were observed in fibrinogen, tissue plasminogen activator, plasminogen activator inhibitor-1, antithrombin III, protein C, and protein S. D-dim, F1 + 2, and vWF were significantly and directly correlated with age and both AUC-cortisol and DST-cortisol. Multivariate regression analysis showed that both AUC-cortisol and DST-cortisol were related to plasma D-dim, F1 + 2, and vWF independently of age, body mass index, blood pressure, and renal function. Conclusion: Greater daily cortisol profile and cortisol response to overnight suppression are independently associated with a prothrombotic state in hypertensive patients and might contribute to the development of organ damage and higher risk of cardiovascular complications.

Documento de posición para la mejora en la reperfusión del infarto agudo de miocardio con elevación del ST en Latinoamérica / Position statement for improvement in reperfusion of ST-elevation myocardial infarction in Latin America

Resumen El tratamiento del infarto agudo de miocardio con elevación del segmento ST tiene barreras dependiendo de la región geográfica. La angioplastia coronaria primaria es el tratamiento de elección, siempre y cuando sea realizada dentro de tiempo y por operadores experimentados. Sin embargo, cuando no está disponible, la administración de fibrinólisis y el envío para angioplastia de rescate, en caso de reperfusión negativa, es la mejor estrategia. De la misma manera, la angioplastia coronaria, como parte de una estrategia farmacoinvasiva, es la mejor alternativa cuando hay reperfusión positiva. El desarrollo de redes de tratamiento del infarto aumenta el número de pacientes reperfundidos dentro de los tiempos recomendados y mejora los desenlaces. En América Latina, los programas nacionales para el tratamiento del infarto deben centrarse en mejorar los resultados y el éxito a largo plazo depende de trabajar hacia objetivos definidos y obtener métricas de rendimiento, por lo tanto, estos deben desarrollar métricas para cuantificar su desempeño. El siguiente documento discute todas estas alternativas y sugiere oportunidades de mejora.

Abstract The treatment of ST-segment elevation myocardial infarction has barriers depending on the geographic region. Primary coronary angioplasty is the treatment of choice, if it is performed on time and by experienced operators. However, when it is not available, the administration of fibrinolysis and referral for rescue angioplasty, in case of negative reperfusion, is the best strategy. In the same way, coronary angioplasty, as part of a pharmacoinvasive strategy, is the best alternative when there is positive reperfusion. The development of infarct treatment networks increases the number of patients reperfused within the recommended times and improves outcomes. In Latin America, national myocardial infarction treatment programs should focus on improving outcomes, and long-term success depends on working toward defined goals and enhancing functionality, therefore programs should develop capacity to measure their performance. The following document discusses all of these alternatives and suggests opportunities for improvement.

Connecting impaired fibrinolysis and dyslipidemia.

A State of the Art lecture entitled "Connecting Fibrinolysis and Dyslipidemia" was presented at the International Society on Thrombosis and Haemostasis Congress 2023. Hemostasis balances the consequences of blood clotting and bleeding. This balance relies on the proper formation of blood clots, as well as the breakdown of blood clots. The primary mechanism that breaks down blood clots is fibrinolysis, where the fibrin net becomes lysed and the blood clot dissolves. Dyslipidemia is a condition where blood lipid and lipoprotein levels are abnormal. Here, we review studies that observed connections between impaired fibrinolysis and dyslipidemia. We also summarize the different correlations between thrombosis and dyslipidemia in different racial and ethnic groups. Finally, we summarize relevant and new findings on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress. More studies are needed to investigate the mechanistic connections between impaired fibrinolysis and dyslipidemia and whether these mechanisms differ in racially and ethnically diverse populations.

Plasminogen Activator Inhibitor-1 4G/5G Promoter Polymorphism in Indian Patients with Deep Vein Thrombosis.

A single guanosine deletion/insertion (4G/5G) polymorphism in the promoter region of plasminogen activator inhibitor-1 (PAI-1) gene encoding PAI-1 protein has been investigated in deep vein thrombosis (DVT) patients. The association between PAI-1 4G/5G polymorphism and increased risk of DVT has been reported in some studies, while others have reported a lack of association. The present study aimed to investigate if the PAI-1 4G/5G polymorphism is associated with an increased risk of DVT in the Indian population and to assess its association with thrombophilic risk factors. Fifty-two adult patients with a history of chronic or recurrent DVT and 52 healthy adult controls were genotyped for PAI-1 4G/5G polymorphism. Plasma levels of PAI-1 and other thrombophilic risk factors were also measured. PAI-1 4G/5G polymorphism was not significantly associated with an increased risk of DVT. Protein C deficiency was significantly associated with the 4G/4G genotype. Patients with the 4G/4G genotype had significantly reduced PAI-1 levels as compared to the controls. PAI-1 4G/5G polymorphism did not significantly contribute to an increased risk of DVT in the Indian population. However, in the presence of thrombophilic risk factor abnormalities, the risk of DVT is increased in individuals with the 4G/4G genotype in the Indian cohort. Supplementary Information: The online version contains supplementary material available at 10.1007/s12288-023-01660-3.

Revolutionizing trauma care: advancing coagulation management and damage control anesthesia.

Despite advances in emergency transfer systems and trauma medicine, the incidence of preventable deaths due to massive hemorrhage remains high. Recent immunological research has elucidated key mechanisms underlying trauma-induced coagulopathy in the early stages of trauma, including sympathoadrenal stimulation, shedding of the glycocalyx, and endotheliopathy. Consequently, the condition progresses to fibrinogen depletion, hyperfibrinolysis, and platelet dysfunction. Coexisting factors such as uncorrected acidosis, hypothermia, excessive crystalloid administration, and a history of anticoagulant use exacerbate coagulopathy. This study introduces damage-control anesthetic management based on recent insights into damage-control resuscitation, emphasizing the importance of rapid transport, timely bleeding control, early administration of antifibrinolytics and fibrinogen concentrates, and maintenance of calcium levels and body temperature. Additionally, this study discusses brain-protective strategies for trauma patients with brain injuries and the utilization of cartridge-based viscoelastic assays for goal-directed coagulation management in trauma settings. This comprehensive approach may provide potential insights for anesthetic management in the fast-paced field of trauma medicine.

Improved outcome with individualised antifibrinolytic therapy: what is the evidence?

Viscoelastic haemostatic testing (VHT) has been used to determine hyperfibrinolysis and hypofibrinolysis. When modified by addition of tissue plasminogen activator (tPA), VHT has been suggested to assess responses to antifibrinolytic therapy and to estimate the concentration of tranexamic acid in patients undergoing cardiac surgery. Despite some evidence that tPA-modified VHT might allow individualisation of antifibrinolytic therapy, further studies are warranted to prove its clinical benefit for postsurgical bleeding, transfusion of blood products, and thromboembolic events.

Codon switching of conserved Ser residues in coagulation and fibrinolytic proteases.

BACKGROUND: Unique among all amino acids, Ser is encoded by 2 sets of codons, TCN and AGY (N = any nucleotide, Y = pyrimidine), that cannot interconvert through single nucleotide substitutions. Both codons are documented at the essential residues S195 and S214 within the active site of serine proteases. However, it is not known how the codons interconverted during evolution because replacement of S195 or S214 by other amino acids typically results in loss of activity. OBJECTIVE: To characterize the prevalence of codon switching among essential and non-essential Ser residues in coagulation and fibrinolytic proteases from different vertebrate lineages. METHODS: TCN and AGY codon usage was analyzed in >550 sequences. RESULTS: Evolutionary pressure to preserve the codon of S195 is absolute, with no evidence of interconversion. Pressure to preserve the codon of S214 is also strong, but an AGY↔TCN interconversion is observed in factor VII-inactive and protein C from ray-finned fish. In both cases, the interconversion occurred in genes that were rapidly evolving. In contrast, codon switching at nonessential Ser residues in the kringle domains of coagulation and fibrinolytic proteases is quite common and could be identified in half of the kringles analyzed. CONCLUSION: Codon interconversion of essential Ser residues of coagulation and fibrinolytic proteases only occurred in genes that were rapidly evolving and that-at least in some cases-evolved following genome duplication. Interconversion is common at nonessential Ser residues as found in kringle domains.