Measurement Of Coagulation Parameters Research Articles

Coagulation parameters abnormalities and their relation to clinical outcomes in hospitalized and severe COVID-19 patients: prospective study

There has been growing attention toward the predictive value of the coagulation parameters abnormalities in COVID-19. The aim of the study was to investigate the role of coagulation parameters namely Prothrombin concentration (PC), activated Partial thromboplastin Time (aPTT), D-Dimer (DD), Anti Thrombin III (ATIII) and fibrinogen (Fg) together with hematological, and biochemical parameters in predicting the severity of COVID-19 patients and estimating their relation to clinical outcomes in hospitalized and severe COVID-19 Patients. In a prospective study, a total of 267 newly diagnosed COVID-19 patients were enrolled. They were divided into two groups; hospitalized group which included 144 patients and non-hospitalized group that included 123 patients. According to severity, the patients were divided into severe group which included 71 patients and non-severe group that included 196 patients who were admitted to ward or not hospitalized. Clinical evaluation, measurement of coagulation parameters, biochemical indices, outcome and survival data were recorded. Hospitalized and severe patients were older and commonly presented with dyspnea (P ≤ 0.001). Differences in coagulation parameters were highly significant in hospitalized and severe groups in almost all parameters, same for inflammatory markers. D-dimer, AT-III and LDH showed excellent independently prediction of severity risk. With a cut-off of > 2.0 ng/L, the sensitivity and specificity of D dimer in predicting severity were 76% and 93%, respectively. Patients with coagulation abnormalities showed worse survival than those without (p = 0.002). Early assessment and dynamic monitoring of coagulation parameters may be a benchmark in the prediction of COVID-19 severity and death.

Rapid Assessment of Coagulation at the Point of Care With the Hemochron Signature Elite System

Real-time point-of-care (POC) measurement of coagulation parameters, including activated clotting time (ACT), activated partial thromboplastin time, and prothrombin time with calculated international normalized ratio can improve patient outcomes in clinical settings, such as surgical and minimally invasive cardiac procedures, critical care units, and emergency departments. Point-of-care analyzers used in these settings must be small, portable, robust, and easy to use. The Hemochron Signature Elite system (Instrumentation Laboratory) offers 6 types of single-use disposable coagulation test cartridges, ACT+ (to measure high to moderate unfractionated heparin concentrations), ACT-LR (to measure moderate to low unfractionated heparin concentrations), activated partial thromboplastin time (citrate or whole-blood samples), and prothrombin time/international normalized ratio (citrate or whole-blood samples). Using a mechanical clot-detection technology, 1 to 2 drops of blood are mixed with an assay-specific reagent. Results are analyzed, displayed, and archived within minutes of testing. An integral barcode reader scans patient and operator IDs, and reagent lot details for documentation and traceability. The system supports remote connectivity (POCT01-A–compliant) and POC management of data, operators, and analyzers with GEMweb Plus 500 Custom Connectivity solution (Instrumentation Laboratory). The Hemochron Signature Elite system provides rapid and reliable testing with the broadest coagulation test menu of any POC instrument.

Biomarkers of Hemostatic Activation and Inflammation Are Associated with Altered Coagulation Parameters in Sepsis Patients

Background : Sepsis is characterized by a simultaneous activation of inflammation and hemostasis in response to microbial infection. This systemic inflammatory response is due to the release of pro-inflammatory cytokines, pro-coagulants and adhesion molecules from immune cells and/or damaged endothelial tissue. Simultaneous activation of coagulation and fibrinolysis leads to consumption coagulopathy and severe vascular dysfunction. Profiling of biomarkers of hemostatic activation and inflammation along with the measurement of coagulation parameters has provided useful data in the understanding of the pathogenesis of sepsis. This study was designed to profile biomarkers of hemostatic activation, inflammation and endothelial dysfunction along with the measurement of coagulation parameters in a defined clinically confirmed sepsis population in conjunction with an IRB approved clinical trial. Materials & Methods: Citrated blood samples were collected from sepsis patients with suspected or confirmed infection, and organ dysfunction as defined by a SOFA ³ baseline. Plasma samples from septic shock patients were collected in citrated tubes within 72 hours of ICU admission under an IRB approved protocol in conjunction with an ongoing trial at the University of Utah and Veteran's Affair FFC Health Care System VAMC. Normal controls were comprised of commercially available 25 male and 25 female citrated plasma samples (George King Biomedical, Overland Park, Kansas City). Such biomarkers as CRP, PAI-1, D-Dimer, vWF and microparticle tissue factor complex (MP-TF) were measured using a commercially available sandwich ELISA methods. Nitric oxide (NO) levels were measured using a commercially available Griess reaction based colorimetric method. PT/INR, aPTT and fibrinogen measurements were based on clot based assays. All results were compiled as mean ± SD and SEM. Correlation analysis was carried out to determine relevance between different parameters. Results: Most of the biomarkers of hemostatic activation and inflammation were elevated in patients with sepsis as shown on table 1a, CRP (66 fold) and D-Dimer (23 fold) showed the most pronounced increase in comparison to the control. Other parameters also showed increase levels including MP-TF (5.3 fold), PAI-1 (3.5 fold), vWF (3.1 fold) and NO (3.0 fold). Clotting parameters such as PT/INR (2.0 fold), aPTT (2.5 fold) and fibrinogen (2.0 fold) were also significantly elevated in the sepsis patients. These differences were significant (p value ≤0.0009) for all of the parameters except for NO (p value 0.0937) and fibrinogen (p value 0.4694). As shown on table 1b, there was no correlation between various biomarkers and fibrinogen in the sepsis patients. Summary & Conclusion: In comparison to the control group, the sepsis patients showed wide variations in all of the parameters investigated in this study. The marked prolongation of PT and aPTT are suggestive of both the extrinsic and intrinsic pathway defects and consumption of clotting factors. The aPTT data showed wider scatter in comparison to PT data. The fibrinogen levels were also elevated and nearly 1/3 of the patients showed >1000 mg/dL levels. The markedly higher level of CRP in the sepsis group are indicative of severe inflammatory response. Marked elevation of D-Dimer is indicative of endogenous fibrin formation and its consumption consistent with activation of secondary fibrinolysis. MP-TF, vWF and PAI-1 were also increased in the sepsis patients suggesting marked endothelial dysfunction. This is consistent with increased NO levels which may be due to induction of iNOS in the endothelial lining of sepsis patients. These results further underscore the multifactorial pathophysiology of sepsis which results in the dysregulation of hemostasis, upregulation of inflammatory responses and generalized endothelialopathy. Profiling of the biomarkers included in this study and coagulation parameters may be helpful in the risk stratification and clinical management of patients with sepsis and related disorders. Disclosures No relevant conflicts of interest to declare.

[Vergleichende Bestimmung von Gerinnungsparametern in Blutproben verschiedener Wild- und Ziervogelspezies].

Information about the influence of species variety or diseases on coagulation values in avian blood is rare. The aim of this study was to assess the influence of species on measurements of coagulation parameters in avian plasma samples using commercially available reagents and to investigate potential influences of selected diseases on clotting times. Prothrombin time (PT), activated partial thromboplastin time (aPTT) and thrombin time (TT) were measured in citrated plasma of healthy individuals collected from eight different wild and captive avian species applying currently commercially available reagents prepared for use in humans, which were preselected in preliminary studies. The same parameters were tested in plasma samples from birds affected by aspergillosis, atherosclerosis, neoplasia and traumata. PT and aPTT showed a high interspecies variety. Irrespective of species, aPTTs were extremely long and partially exceeded the measurement range limit. Minor variations between species were seen in TT measurements. Clotting times obtained from birds affected by aspergillosis, atherosclerosis and neoplasia were not significantly different when compared to healthy birds. Plasma obtained from traumatised individuals showed significantly shorter PT and aPTT than that in healthy birds. Differences between species must be considered in diagnostic coagulation measurements in avian blood. Regardless of the avian species, aPTT measurements on avian samples appear to be of limited value. Lower PT and aPTT values reflect coagulation activation in traumatised birds.