Maximum Lysis Research Articles

Mechanistic modeling of the dynamics of phage attack during milk acidification in the cheese-making process

Bacteriophage attacks represent a major threat in the dairy industry. Here, an unstructured mechanistic model predicting the dynamics of milk acidification in case of phage attack was developed and experimentally validated. Multiple acidification experiments were run with different combinations of initial phage titers and bacterial concentrations and the resulting pH dynamics were recorded. The model could successfully predict the success or failure of milk acidification. Using the model, important biological parameters were deduced from simple, low-cost acidification measurements. These parameters included bacteria’s maximum growth and lysis rates, phages’ burst size, etc. Sensitivity analysis helped identify biologically relevant aspects of phage-host interactions. Growth and lysis kinetics were shown to have the most important impacts. This knowledge can be used to develop easy routine strategies to fight phage attack in the dairy industry. The model can be used to raise awareness amongst cheese makers on the importance of cleaning to avoid food and material waste.

Pharmacokinetics and pharmacodynamics of low doses of recombinant tissue plasminogen activator to establish a model for biosimilarity comparisons

BackgroundRecombinant tissue plasminogen activator (rt-PA) is a thrombolytic agent and essential in emergency medical care. Given recent supply shortages, the availability of biosimilar products is an urgent medical need. However, biosimilarity trials are difficult to perform in critically ill patients. ObjectivesThe aim of this pilot study was to investigate the pharmacokinetics and pharmacodynamics of low rt-PA doses to establish a model for testing proposed biosimilars in healthy volunteers. MethodsEight healthy volunteers received 0.02 to 0.05 mg/kg rt-PA on 3 study days; blood samples were obtained every 4 minutes after the end of the bolus infusion to measure rt-PA antigen levels by enzyme immunoassay, and the pharmacodynamics were assessed with rotational thromboelastometry. ResultsBolus infusion of low rt-PA doses was safe and well tolerated. Maximal plasma concentrations and the area under the curve increased dose-dependently. Time-concentration curves were clearly separated between the lower and the higher doses. As expected, the half-live of rt-PA was short (4.5-5 min), and representative for therapeutic doses. The intrasubject coefficient variations were moderate (<25%). Bolus infusion of rt-PA dose-dependently shortened lysis time and lysis onset time in both dose groups and caused maximum clot lysis of 100% in all participants. ConclusionIn conclusion, the pharmacokinetics of rt-PA was dose linear and displayed limited intrasubject variability even at subtherapeutic doses. The half-life and thus clearance of rt-PA was representative of full therapeutic doses. The lysis time was shortened in a dose and time-dependent fashion and was clearly distinguishable between doses. Thus, the model appears to be suitable and sensitive to test biosimilarity.

Association of hyperfibrinolysis with poor prognosis in refractory circulatory arrest: implications for extracorporeal cardiopulmonary resuscitation

BackgroundIdentifying candidates for extracorporeal cardiopulmonary resuscitation (eCPR) is challenging, and novel predictive markers are urgently needed. Hyperfibrinolysis is linked to tissue hypoxia and is associated with poor outcomes in out-of-hospital cardiac arrest (OHCA). Rotational thromboelastometry (ROTEM) can detect or rule out hyperfibrinolysis, and could, therefore, provide decision support for initiation of eCPR. We explored early detection of hyperfibrinolysis in patients with refractory OHCA referred for eCPR. MethodsWe analysed ROTEM results and resuscitation parameters of 57 adult patients with ongoing OHCA who presented to our ICU for eCPR evaluation. ResultsHyperfibrinolysis, defined as maximum lysis ≥15%, was present in 36 patients (63%) and was associated with higher serum lactate, lower arterial blood pH, and increased low-flow intervals. Of 42 patients who achieved return of circulation, 28 had a poor 30-day outcome. The incidence of hyperfibrinolysis was higher in the poor outcome group compared with patients with good outcomes (75% [21 of 28] vs 7.1% [1 of 14]; P<0.001). The ratio of EXTEM A5 to lactate concentration showed good predictive value in detecting hyperfibrinolysis (AUC of 0.89 [95% confidence interval 0.8–1]). ConclusionsHyperfibrinolysis was common in patients with refractory cardiac arrest, and was associated with poor prognosis. The combination of high lactate with early clot firmness values, such as EXTEM A5, appears promising for early detection of hyperfibrinolysis. This finding could facilitate decisions to perform eCPR, particularly for patients with prolonged low-flow duration but lacking hyperfibrinolysis.

Thromboelastometry for assessment of hemostasis and disease severity in 42 dogs with naturally-occurring heatstroke.

Thromboelastometry (TEM) provides a comprehensive overview of the entire coagulation process and has not been evaluated in heatstroke-induced coagulopathies in dogs. To determine the diagnostic and prognostic utility of TEM in dogs with heatstroke. Forty-two client-owned dogs with heatstroke. Prospective observational study. Blood samples for intrinsic and extrinsic TEM (INTEM and EXTEM, respectively) were collected at presentation and every 12 to 24 hours for 48 hours. Coagulation phenotype (hypo-, normo-, or hypercoagulable) was defined based on TEM area under the 1st derivative curve (AUC). Case fatality rate was 31%. Median TEM variables associated with death (P < .05 for all) included longer INTEM clotting time, lower AUC at presentation and at 12 to 24 hours postpresentation (PP), lower INTEM alpha angle, maximum clot firmness, and maximum lysis (ML) at 12 to 24 hours PP, and lower EXTEM ML at 12 to 24 hours PP. Most dogs were normo-coagulable on presentation (66% and 63% on EXTEM and INTEM, respectively), but hypo-coagulable 12 to 24 PP (63% for both EXTEM and INTEM). A hypo-coagulable INTEM phenotype was more frequent at presentation and 12 to 24 PP among nonsurvivors compared to survivors (55% vs 15% and 100% vs 50%, P = .045 and .026, respectively). AKI was more frequent (P = .015) in dogs with hypo-coagulable INTEM tracings at 12 to 24 hours. Disseminated intravascular coagulation was more frequent (P < .05) in dogs with a hypo-coagulable INTEM phenotype and in nonsurvivors at all timepoints. Hypocoagulability, based on INTEM AUC, is predictive of worse prognosis and occurrence of secondary complications.

Thromboelastography in acute immunologic reactions: a prospective pilot study

BackgroundBiomarkers of fibrinolysis are elevated during acute immunologic reactions (allergic reactions and angioedema), although it is unclear whether fibrinolysis is associated with disease severity. ObjectivesWe investigated a possible association between maximum lysis (ML) measured by thromboelastography and the severity of acute immunologic reactions. MethodsWe 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. ResultsWe 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. ConclusionML, quantified by thromboelastography, is associated with the severity of acute immunologic reactions.

P204 Utility of Rotational Thrombo-Elastometry as an Objective Measure of Hypercoagulability in Patients with Ulcerative Colitis-A Prospective Case Control Study

Abstract Background Inflammatory bowel disease (IBD) has an increased risk of venous thromboembolism (VTE) with factors like hospitalization and surgery increasing this risk. Although few recent guidelines recommend anticoagulation thromboprophylaxis for hospitalised IBD patients, there is wide variation in reported practices for VTE prophylaxis. This study was aimed to evaluate Rotational Thrombo-Elastometry (ROTEM) for assessing blood coagulation status in ulcerative colitis (UC) and to evaluate the relationship between ROTEM, disease severity and response to treatment. Methods This was a prospective age- and sex-matched study with 60 patients each in UC and irritable bowel syndrome (IBS) groups, latter being controls. Clinical details, blood investigations including ROTEM and D-dimer were collected and analysed after taking informed consent. Hypercoagulable state was defined using Kaufmann’s classification. ROTEM parameters [clotting time (CT), clot formation time (CFT), alpha angle (AA), maximum clot firmness (MCF), maximum lysis (ML)] and D-dimer levels were compared between the two groups. Results Of the 60 UC patients (age: 38.6±11.64 years, 44 males); 15(25%) were in remission, 18(30%), 17(28.3%) and 10(16.7%) had mild, moderate, and severe disease respectively. The UC group had significantly more hypercoagulable ROTEM than the control group (66.7% vs. 36.7%, p=0.001). Hypercoagulable ROTEM was found in 9(60%), 8(44.4%), 14(82.3%) and 9(90%) of those in remission, with mild, moderate and severe UC respectively. Compared to controls; CT [292.36±70.45 vs 337.56±77.89, p=0.001], CFT [103.15±30.31 vs 128.61±40.18, p=0.0001], AA [69.88±5.19 vs 65.36±6.4, p=0.00004], MCF [65.75±5.64 vs 63.25±4.43, p=0.008] and D-dimer levels [329(63-2358) vs 145.5(54-1304), p=0.00001) were significantly abnormal in UC group. Among UC patients with mild, moderate and severe disease; only CFT, AA and D-dimer were significantly different between the groups. There was no significant difference in ROTEM values and D-dimer level in patients with severe UC after one week of treatment. On univariate analysis; partial Mayo score [OR: 1.49, 95% CI: 1.04-2.12, p=0.028], serum albumin [OR: 0.32, 95% CI: 0.10-0.98, p=0.04], hemoglobin [OR: 0.59, 95% CI: 0.40-0.86, p=0.007], and platelets [OR: 1, 95% CI: 1.01-1.02, p=0.035], were predictors of hypercoagulable state in active UC. On multivariate analysis; only haemoglobin [OR: 0.61, 95% CI: 0.38-0.98, p=0.04] was found to be significant independent predictor. Conclusion UC patients had hypercoagulable ROTEM regardless of activity of inflammatory process. The degree of hypercoagulability increased with disease activity. Low haemoglobin was found to predictive of hypercoagulable state in active UC patients.

The correlation of Rotational Thromboelastometry (ROTEM) derived parameters with severe obstetric haemorrhage

Background Prediction of severe obstetric haemorrhage may facilitate timely interventions and reduce maternal morbidity and mortality. Rotational thromboelastometry (ROTEM) provides point-of-care coagulation parameters that may identify patients at risk of severe haemorrhage. Purpose Our aim was to determine the correlation of ROTEM-derived parameters at early stages of postpartum haemorrhage. Research design Retrospective cohort study. Study Sample Patients who utilised ROTEM during postpartum haemorrhage from 2013 to 2021. Data Collection and Analysis Severe harmorrhage was defined as: (1) decrease in haemogoblin concentration &gt;4g.dL-1 within 48 h; (2) packed red blood cell transfusion of &gt;1000 mL; (3) haemostatic intervention such as angiographic embolisation, arterial ligration, or hysterectomy; or (4) death. ROTEM-derived parameters were collected accordingly. Results Data from 36 patients were analysed, of whom 29 (80.6%) developed severe haemorrhage. FIBTEM A5, A10, and A20 were highly correlated (r &gt; +/−0.7) with severe haemorrhage. There were moderate correlations (r = +/− 0.5 to 0.7) between EXTEM A5, A10, A20, maximum clot firmness, maximum lysis, and lysis index-30 with severe haemorrhage. Conclusions These findings are consistent with prior studies reporting associations between fibrinogen concentration, EXTEM A10, and FIBTEM A10 with severe haemorrhage. In conjunction with these studies, our results support the use of FIBTEM A5 and A10 as early biomarkers to predict progression to severe haemorrhage and facilitate timely implementation of appropriate medical or surgical interventions.

Impaired Whole-Blood Fibrinolysis is a Predictor of Mortality in Intensive Care Patients.

Background Altered fibrinolysis is considered to play a crucial role in the development of coagulopathy in sepsis. However, routine laboratory tests for fibrinolysis are currently very limited, and the impact of fibrinolytic capacity on clinical outcome is poorly investigated. Objectives To assess whole-blood fibrinolysis in patients admitted to the intensive care unit (ICU) and compare fibrinolysis in sepsis patients with nonsepsis patients. Further, to investigate associations between fibrinolytic capacity and 30-day mortality and venous thromboembolism (VTE). Methods This study was designed as a prospective cohort study. Adult ICU patients were included at the Aarhus University Hospital, Denmark. All patients had a blood sample obtained the morning after admission. A modified thromboelastometry (ROTEM®) analysis with tissue plasminogen activator (ROTEM®-tPA) was used to assess fibrinolysis. The primary endpoint was difference in ROTEM®-tPA lysis time between sepsis patients and nonsepsis patients. Results ROTEM®-tPA revealed fibrinolytic impairment in sepsis patients ( n = 30) compared with nonsepsis ICU controls ( n = 129), with longer lysis time (median [interquartile range] 3,600 [3,352-3,600] vs. 3,374 seconds [2,175-3,600], p < 0.01), lower maximum lysis (23 [8-90] vs. 94% [14-100], p = 0.02), and lower fibrinolysis speed (0.41 [0.0-1.4] vs. 1.6 mm/min [0.1-2.7], p = 0.01). In the composite ICU population, 61% (97/159) demonstrated prolonged lysis time indicating impaired fibrinolytic capacity. These patients had higher 30-day mortality (adjusted odds ratio [OR]: 2.26 [0.83-6.69]) and VTE risk (OR: 3.84 [0.87-17.8]) than patients with normal lysis time. Conclusion Sepsis patients showed impaired fibrinolysis measured with ROTEM®-tPA compared with nonsepsis patients and ROTEM®-tPA lysis time was associated with 30-day mortality and VTE in the entire ICU cohort.

Prolonged fibrinolysis time is a risk factor for mortality in patients with chronic kidney disease - a propensity score matched analysis

Abstract Purpose To investigate the role of fibrinolysis time and clot structure on cardiovascular mortality of patients with chronic kidney disease. Methods Clot characteristics were measured in 56 propensity score matched patients (i.e. based on gender, BMI, presence of CAD, presence of CVD and CKD stage) by a modified ROTEM assay with the addition of 175 ng/ml of tPA from the Care4HOMe study. Results In total 462 patients with CKD stage II-IV were included in the Care4HOMe study. Patients with cardiovascular death differed significantly from patients without cardiovascular mortality with respect to presence of cardiovascular disease (CVD), presence of coronary artery disease (CAD) and CKD stage (all p &amp;lt; 0.001). Therefore, to assess clot characteristics in a less confounded environment we propensity score matched patients with and without cardiovascular death in a 1:1 ratio. After matching a total of 56 patients with similar baseline characteristics remained. Interestingly, clot-formation time (CFT) and maximal lysis (ML) were significantly altered in patients that suffered cardiovascular death (CFT Event-free: 150±172sec; CFT CV-death: 80±61sec p = 0.035; ML Event-free: 30±61%; ML CV-death: 10±81% p = 0.021). To assess the prognostic importance of both parameters we stratified CFT and ML based on the median and calculated Kaplan-Meier curves and performed a Cox-proportional hazard regression analysis. Combined assessment revealed that a ML lower than the median significantly increased the cardiovascular mortality risk (HR 3.7 95%CI 1.3 – 10.3, p = 0.009; Log-rank 0.0059) while the stratified-CFT remained insignificant (HR 0.99 95%CI 0.99 – 1.00, p = 0.28, Log-rank p = 0.79). Additional C-statistic demonstrated that the predictive value of ML with respect to cardiovascular mortality in CKD patients was comparable to established CKD mortality predictors including Cystatin-C plasma levels and Urine Albumin/Creatine Ratio (UACR) (ML 0.69, 95%CI 0.53-0.86; CystatinC 0.70, 95%CI 0.51 – 0.80; UACR 0.70, 95%CI 0.56-0.84). Conclusions Prolonged fibrinolysis time may be an important prognostic parameter that links atherothrombotic risk to cardiovascular mortality in patients with chronic kidney disease.Maximum Lysis

Concentration–effect relationship for tranexamic acid inhibition of tissue plasminogen activator-induced fibrinolysis in vitro using the viscoelastic ClotPro® TPA-test

BackgroundTranexamic acid is an antifibrinolytic drug that is commonly administered for obstetric haemorrhage. Conventional viscoelastic tests are not sensitive to tranexamic acid, but the novel ClotPro® TPA-test can measure tranexamic acid-induced inhibition of fibrinolysis. We aimed to evaluate the TPA-test in pregnant and non-pregnant women. MethodsWe performed an in vitro study of whole blood samples spiked with tranexamic acid from pregnant women in the first, second, and third trimester (n=20 per group) and from non-pregnant women (n=20). We performed ClotPro TPA-tests of whole blood sample and ClotPro EX-tests, FIB-tests, and TPA-tests. ResultsClot lysis was inhibited in a concentration-dependent manner up to a tranexamic acid concentration of 6.25 mg L−1. At tranexamic acid concentrations of 12.5 mg L−1 and above, clot lysis was completely inhibited. The concentration–effect relationship of tranexamic acid did not differ in a clinically important manner in blood from pregnant women across all three trimesters or from non-pregnant controls. A median maximum lysis cut-off value of at9 least 16% (25–75th percentiles 15–18), a median clot lysis time of 3600 s (25–75th percentiles 3600–3600), or both was associated with a tranexamic acid concentration of least 12.5 mg L−1. ConclusionsThe ClotPro® TPA-test is sensitive in detecting inhibition of fibrinolysis by tranexamic acid in whole blood samples of pregnant and non-pregnant women. The concentration–effect relationship of tranexamic acid to inhibit fibrinolysis in whole blood did not differ for women in the first, second, and third trimester or for non-pregnant women.

Lomber spondilolistezis saptanan hastaların radyolojik ve klinik verilerinin karşılaştırılması

Background: Spondylolisthesis is a deformity in which the upper segment is displaced anteriorly or posteriorly in the spine relative to the lower segment. In this pathology, which often causes instability, surgical treatment may be required. Also, patient’s radiological images should be evaluated carefully before treatment. We aimed to analyze clinical and radiological data with spinopelvic angles of the lumbar spondylolisthesis patients in our research.&#x0D; &#x0D; Material Method: 6593 patients who applied to the neurosurgery outpatient clinic with complaints of low back pain between January 2020 - December 2023 were retrospectively analyzed. The radiological findings of patients with spondylolisthesis, whose lumbar MRI and lumbar CT were obtained appropriately along with X-ray were evaluated in detail. Age, gender, listhesis level and degree, Cobb angle, pelvic incidence, pelvic tilt, sacral slope angle, Modic degeneration, vacuum phenomenon, annulus rupture, schmorl nodule, facet hypertrophy, osteophyte, maximum AP central canal diameter and joint lysis has been examined in these patient tests. The relationships of these data with each other were evaluated statistically.&#x0D; &#x0D; Results: 58 female and 5 male patients were found to be eligible for the study. Mean age was 59 (min 22, max 81). Grade 1 listhesis was detected in 52 of the patients. Listhesis was observed at the level of L5-S1 in 31 patients, L4-L5 in 24 patients and L3-L4 in 8 patients. A direct correlation was found between age with vacuum phenomenon, osteophyte, presence of L5-S1 listesis and lysis. Similar correlation was between pelvic incidence with sacral slop angle, facet hypertrophy and modic type 2 degeneration. Also, there was a direct correlation between pelvic incidence with pelvic tilt; between facet hypertrophy with vacuum phenomenon and lysis; ligamentum hypertrophy with vacuum phenomenon; and facet hypertrophy with lower level listesis (p 0.05).&#x0D; &#x0D; Discussion and Conclusion: Spondylolisthesis is an important problem that requires treatment in spine surgery. Radiologically determined parameters can give important findings about the severity of this pathology. These findings should be taken into consideration in the treatment of spondylolisthesis.

A comparative analysis of tranexamic acid dosing strategies in traumatic major hemorrhage.

Tranexamic acid (TXA) is a life-saving treatment for traumatic hemorrhage, but the optimal dosing regimen remains unknown. Different doses and treatment strategies have been proposed, including single bolus, repeated bolus, or bolus plus infusion. The aim of this study was to determine the effect of different TXA dosing strategies on clinical outcomes in bleeding trauma patients. Secondary analysis of a perpetual cohort study from a UK Level I trauma center. Adult patients who activated the local major hemorrhage protocol and received TXA were included. The primary outcome was 28-day mortality. Secondary outcomes were 24-hour mortality, multiple organ dysfunction syndrome, venous thromboembolism, and rotational thromboelastometry fibrinolysis. Over an 11-year period, 525 patients were included. Three dosing groups were identified: 1 g bolus only (n = 317), 1 g bolus +1 g infusion over 8 hours (n = 80), and 2 g bolus (n = 128). Demographics and admission physiology were similar, but there were differences in injury severity (median Injury Severity Score, 25, 29, and 25); and admission systolic blood pressure (median Systolic Blood Pressure, 99, 108, 99 mm Hg) across the 1-g, 1 g + 1 g, and 2-g groups. 28-day mortality was 21% in each treatment group. The incidence of multiple organ dysfunction syndrome was significantly higher in the bolus plus infusion group (84%) vs. 1 g bolus (64%) and 2 g bolus (62%) group, p = 0.002, but on multivariable analysis was nonsignificant. Venous thromboembolism rates were similar in the 1-g bolus (4%), 2 g bolus (8%) and bolus plus infusion groups (7%). There was no difference in rotational thromboelastometry maximum lysis at 24 hours: 5% in both the 1-g and 2-g bolus groups vs. 4% in bolus plus infusion group. Clinical outcomes and 24-hour fibrinolysis state were equivalent across three different dosing strategies of TXA. Single bolus administration is likely preferable to a bolus plus infusion regimen. Therapeutic/Care Management; Level III.

CFD and experimental microfluidic study of the interaction between a natural compound nanoemulsion and E. coli bacterium considering reaction-diffusion-convection model

Essential oils have recently emerged as potent natural antibacterial agents that are effective against pathogenic bacteria. The antibacterial efficacy of a stabilized nanoemulsion of carvacrol (with a mean droplet size of 123.51 nm ± 4.2 nm) on a Gram-negative Escherichia coli (E. coli ATCC 25922) was experimentally and numerically studied utilizing a continuous-flow microfluidic system. The morphology of the destroyed bacteria was examined visually and, bacteria lysis was confirmed by measuring the release of cellular contents. After establishing the antibacterial capability kinetics of the carvacrol nanoemulsions, the acquired data from the time killing assay was used to characterize the E. coli lysis. Moreover, a computational fluid dynamics (CFD) model was implemented to evaluate the influence of altering key parameters such as the Reynolds number, flow rate ratio and inlet carvacrol concentration on the unlysed bacteria percentage at the outlet (Y1) and the mass flow rate (μg/s) of the lysed bacteria at the outlet (Y2). The maximum lysis reaction rate observed in the device was 0.96s-1 corresponding to an inlet carvacrol nanoemulsion concentration of 160μg/mL. The reaction rate (r) was established based on the carvacrol concentration (Aμg/mL) as r=-0.149A0.373. The results obtained from numerical simulations indicated that the Reynolds number causes the most changes in the average value of Y1, while carvacrol concentration impacted most on the average value of Y2 response. The findings presented in this article provide insight into the probable kinetics of carvacrol nanoemulsion antibacterial activity in the microfluidics system.

Vortex-ultrasound for microbubble-mediated thrombolysis of retracted clots.

Endovascular sonothrombolysis has gained significant attention due to its benefits, including direct targeting of the thrombus with sonication and reduced side effects. However, the small aperture of endovascular transducers restricts the improvement of their potential clinical efficiency due to inefficient acoustic radiation. Hence, in an earlier study, we used vortex ultrasound with an endovascular ultrasound transducer to induce shear stress and enhance the clot lysis. In this study, the vortex acoustic transduction mechanism was investigated using numerical simulations and hydrophone tests. Following this characterization, we demonstrated the performance of the vortex ultrasound transducer in thrombolysis of retracted clots in in vitro tests. The test results indicated that the maximum lysis rates were 79.0% and 32.2% with the vortex ultrasound for unretracted and retracted clots, respectively. The vortex ultrasound enhanced the efficiency of the thrombolysis by approximately 49%, both for retracted and unretracted clots, compared with the typical non-vortex ultrasound technique. Therefore, the use of endovascular vortex ultrasound holds promise as a potential clinical option for the thrombolysis of retracted clots.

A new global fibrinolysis capacity assay for the sensitive detection of hyperfibrinolysis and hypofibrinogenemia in trauma patients

BackgroundConventional clotting tests are not expeditious enough to allow timely targeted interventions in trauma, and current point-of-care analyzers, such as rotational thromboelastometry (ROTEM), have limited sensitivity for hyperfibrinolysis and hypofibrinogenemia. ObjectivesTo evaluate the performance of a recently developed global fibrinolysis capacity (GFC) assay in identifying fibrinolysis and hypofibrinogenemia in trauma patients. MethodsExploratory analysis of a prospective cohort of adult trauma patients admitted to a single UK major trauma center and of commercially available healthy donor samples was performed. Lysis time (LT) was measured in plasma according to the GFC manufacturer’s protocol, and a novel fibrinogen-related parameter (percentage reduction in GFC optical density from baseline at 1 minute) was derived from the GFC curve. Hyperfibrinolysis was defined as a tissue factor–activated ROTEM maximum lysis of >15% or LT of ≤30 minutes. ResultsCompared to healthy donors (n = 19), non–tranexamic acid-treated trauma patients (n = 82) showed shortened LT, indicative of hyperfibrinolysis (29 minutes [16-35] vs 43 minutes [40-47]; p < .001). Of the 63 patients without overt ROTEM-hyperfibrinolysis, 31 (49%) had LT of ≤30 minutes, with 26% (8 of 31) of them requiring major transfusions. LT showed increased accuracy compared to maximum lysis in predicting 28-day mortality (area under the receiver operating characteristic curve, 0.96 [0.92-1.00] vs 0.65 [0.49-0.81]; p = .001). Percentage reduction in GFC optical density from baseline at 1 minute showed comparable specificity (76% vs 79%) to ROTEM clot amplitude at 5 minutes from tissue factor–activated ROTEM with cytochalasin D in detecting hypofibrinogenemia but correctly reclassified >50% of the patients with false negative results, leading to higher sensitivity (90% vs 77%). ConclusionSevere trauma patients are characterized by a hyperfibrinolytic profile upon admission to the emergency department. The GFC assay is more sensitive than ROTEM in capturing hyperfibrinolysis and hypofibrinogenemia but requires further development and automation.

Hypofibrinolysis in pediatric patients with veno-occlusive disease in hematopoietic stem cell transplantation

PurposeVeno-occlusive disease (VOD) is a serious complication of hematopoietic stem cell transplantation (HSCT) with a high incidence in pediatric patients. This study aimed to detect signs of hypofibrinolysis using thrombelastography.MethodsIn this prospective single-center study, thrombelastographic measurements (EX and TPA tests) were taken during HSCT to detect signs of impaired coagulation, clot formation, or hypofibrinolysis.ResultsOf 51 patients undergoing allogeneic and autologous HSCT, five (9.8%) developed VOD and received defibrotide treatment. Thrombelastography measurements were also obtained from 55 healthy children as a control group. The results show that clot lysis was prolonged in VOD patients compared to other HSCT patients and control group (lysis time, TPA test: day + 14 to + 21: VOD: 330 ± 67 s vs. HSCT: 246 ± 53 s; p = 0.0106; control: 234 ± 50 s; control vs. VOD: p = 0.0299). The maximum lysis was reduced in HSCT patients compared to controls (EX test: control: 8.3 ± 3.2%; HSCT: day 0 to + 6: 5.3 ± 2.6%, p < 0.0001; day + 7 to + 13: 3.9 ± 2.1%, p < 0.0001; day + 14 to d + 21: 4.1 ± 2.3%, p < 0.0001).ConclusionThese results suggest that HSCT patients exhibit reduced fibrinolytic capacities and patients diagnosed with VOD show signs of hypofibrinolysis. This prospective study shows that fibrinolysis can be assessed in a rapid and accessible way via thrombelastography. Thrombelastography might be a parameter to support the diagnosis of a VOD and to serve as a follow-up parameter after the diagnosis of a VOD.

No Differences in Rotational Thromboelastometry Measurements between Portal and Peripheral Circulation in Cirrhotic Patients Undergoing TIPS

In patients with liver cirrhosis, transjugular intrahepatic portosystemic shunt (TIPS) is considered a standardized treatment of refractory ascites or variceal bleeding. TIPS thrombosis (TT) and/or portal vein thrombosis (PVT) are possible complications during/after TIPS placement. Previous studies suggested increased clotting activity in portal circulation (PORC). This pilot study aimed to evaluate alterations and differences of coagulation function in PORC and in peripheral circulation (PERC) via rotational thromboelastometry during TIPS. Blood samples were collected from cirrhotic patients (n = 13; median Model of End Stage Liver Disease, MELD Score: 12; median age: 60 years) undergoing TIPS (10/13 TIPSs were elective procedures due to refractory ascites) as follows: median cubital vein (MCV; PERC)-confluence of the three hepatic veins to the inferior cava vein (HV/ICV; PORC)-portal vein (PV; PORC)-TIPS (PORC). This research utilized four variables of the extrinsic test EXTEM, i.e., clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF), and maximum lysis (ML). EXTEM results [mean, M (range) ± standard deviation, SD (range)] showed no significant differences for CT [M (70-73) ± SD (9-13); p = 0.93] or CFT [M (137-155) ± SD (75-112); p = 0.97] or MCF [M (51-54) ± SD (9-10); p = 0.90] or ML [M (9-10) ± SD (4-5); p = 0.89] between the compartments, i.e., MCV vs. HV/ICV vs. PV vs. TIPS. Overall, we detected no differences in coagulation function between PERC and PORC. These results are in contrast to previous reports suggesting increased clotting activity in PORC vs. PERC in association with liver cirrhosis. Rotational thromboelastometry-based evaluation of coagulation function in PERC appears to reliably reflect coagulation function in PORC with respect to risk estimation for TT and/or PVT in cirrhotic patients undergoing TIPS.

Acquired Factor XIII Deficiency in Patients with Multiple Trauma

IntroductionFibrin stabilizing factor (FXIII) plays a crucial role in blood clotting, tissue repair, and immune defense. FXIII deficiency after trauma can lead to prolonged wound healing due to persistent infections or coagulation disorders.The aim of this study was to describe the prevalence of acquired FXIII deficiency after trauma and to provide a description of the time-course changes of important coagulation parameters in relation to FXIII activity. In this context, patient characteristics, laboratory data, and treatment modalities were examined with respect to their influence on FXIII activity. Furthermore, the effects of in vitro administration of FXIII on clot firmness and outcomes in patients with severe traumatic brain injury were investigated. Patients and MethodsTwo trauma cohorts (A and B) were examined prospectively in a two-center study, and another (cohort C) was examined retrospectively. In cohort A (trauma patients, n=880) routine laboratory tests were conducted, and FXIII activity was measured. In cohort B (polytrauma patients, n=26), additional clinical parameters were collected, and in-vitro FXIII administration and rotational thromboelastometry (ROTEM) analyses were performed. In cohort C (polytrauma patients with severe traumatic brain injury [sTBI], n=84), the impact of initially measured FXIII activity on clinical outcomes after sTBI was investigated using the modified Rankin Scale (mRS) at least 6 months after trauma. ResultsThe prevalence of FXIII activity <70% in cohort A was 12.4%, with significant differences in age, Hb, fibrinogen, and Hct levels, platelet count, aPTT, and INR (vs. prevalence of FXIII activity >70%). Cohort B showed a decrease in FXIII activity from 85% to 58% after 7 days. FXIII deficiency correlated with time after trauma, aPTT, and fibrinogen level, lactate, and Hb levels. In-vitro administration of FXIII showed a positive influence on clot firmness due to improved maximum clot firmness (MCF in FIBTEM) and reduced maximum lysis (ML in EXTEM). Finally, a significant difference in FXIII activity between patients after sTBI with good and poor clinical outcomes was observed 6 months after trauma. ConclusionWe demonstrated that trauma-associated FXIII deficiency is a common coagulation disorder, with FXIII deficiency increasing further in the first 7 days after trauma, the period of early surgical care. In vitro administration of FXIII was able to demonstrate significant clot stabilizing effects. For trauma patients with sTBI, FXIII activity could serve as a prognostic parameter, as it differed significantly between patients with good and poor clinical outcomes.

New under the sun: ClotPro's ECA-test detects hyperfibrinolysis in a higher number of patients, more frequently and 9 min earlier.

Liver diseases result in a re-balanced state of the haemostatic system with decreased haemostatic reserves. Increased fibrinolytic activity is commonly seen during liver transplants. The aim of this study was to assess whether ClotPro's ECA-test is able to detect hyperfibrinolysis earlier and with higher frequency than ClotPro's conventional viscoelastic assays for the intrinsic and the extrinsic coagulation pathway. From 25 liver transplant recipients, systemic blood samples were collected during surgery. Viscoelastic haemostatic assays with ClotPro's IN-test, EX-test and ECA-test were performed simultaneously from each blood sample. Hyperfibrinolysis was defined on the basis of the manufacturer's prespecified threshold value (maximal lysis >15%). The incidence of hyperfibrinolysis detected with each test was compared with the McNemar test. For each assay, lysis detection time (LDT) was calculated and analysed with the nonparametric Kruskal-Wallis test. A total of 125 tests were performed simultaneously. Compared with the IN-test and the EX-test, the ECA-test detected hyperfibrinolysis in significantly ( P < 0.001) higher number of patients (9; 11; 14, respectively) and in more measurement points (14; 18; 28, respectively). The analysis of LDT values revealed significant superiority of the ECA-test to the IN-test ( P = 0.046) and to the EX-test ( P = 0.035), indicating the profibrinolytic state of the haemostasis 8.9 ± 0.65 and 8.7 ± 0.17 min earlier, respectively. These are preliminary results of the study NCT0424637. ClotPro's ECA-test appeared to detect fibrinolysis in a higher number of patients, more frequently, and the mean time of detection was 9 min earlier than that of the IN-test and the EX-test.

Conventional and Pro-Inflammatory Pathways of Fibrinolytic Activation in Non-Traumatic Hyperfibrinolysis.

Hyperfibrinolysis (HF) frequently occurs after severe systemic hypoperfusion during major trauma and out-of-hospital cardiac arrest (OHCA). In trauma-induced HF, hypoperfusion, the activation of protein C (APC), and the release of tissue plasminogen activator (t-PA) have been identified as the driving elements of premature clot breakdown. The APC pathway also plays a role in inflammatory responses such as neutrophil extracellular trap formation (NETosis), which might contribute to lysis through cleavage of fibrin by neutrophil elastases. We investigated whether the APC and the plasminogen pathway were general drivers of HF, even in the absence of a traumatic incident. Additionally, we were interested in inflammatory activation such as the presence of NETs as potential contributing factors to HF. A total of 41 patients with OHCA were assigned to a HF and a non-HF group based on maximum lysis (ML) in thromboelastometry. Thrombin-antithrombin (TAT)-complex, soluble thrombomodulin (sTM), APC-PC inhibitor complex, t-PA, PAI-1, t-PA-PAI-1 complex, plasmin-antiplasmin (PAP), d-dimers, neutrophil elastase, histonylated DNA (hDNA) fragments, and interleukin-6 were assessed via immunoassays in the HF group vs. non-HF. APC-PC inhibitor complex is significantly higher in HF patients. Antigen levels of t-PA and PAI-1 do not differ between groups. However, t-PA activity is significantly higher and t-PA-PAI-1 complex significantly lower in the HF group. Consistent with these results, PAP and d-dimers are significantly elevated in HF. HDNA fragments and neutrophil elastase are not elevated in HF patients, but show a high level of correlation, suggesting NETosis occurs in OHCA as part of inflammatory activation and cellular decay. Just as in trauma, hypoperfusion, the activation of protein C, and the initiation of the plasminogen pathway of fibrinolysis manifest themselves in the HF of cardiac arrest. Despite features of NETosis being detectable in OHCA patients, early pro-inflammatory responses do not appear be associated with HF in cardiac arrest.