Coagulation Analyzer Research Articles

Effects of Variable Doses of Neurokinin B on Hematological and Coagulation Parameters in Adult Male Rats

Objective: To evaluate the dose-dependent effects of Neurokinin B on hematological and coagulation parameters in adult male Sprague Dawley rats. Study Design: Laboratory-based experimental study Place and Duration of Study: Gomal University and KMU Institute of Medical Sciences from February 2019 to April 2021. Methodology: Adult male Sprague Dawley rats (n=5 per group) were administered intraperitoneally with Neurokinin B at doses of 1 µg, 1 ηg and 1 ρg for 12 days consecutively. Control rats received distilled water injections. After 12 days, rats were sacrificed, and blood samples were collected from the left ventricle for hematological and coagulation analysis. Results: Bleeding time was significantly prolonged in NKB-µg (114±17.10sec) and Neurokinin B -ηg (72±22.25sec) compared to control (33±12.55sec). Clotting time (CT) was also increased (NKB-µg: 111±17.10sec; NKB-ηg: 69±17.10sec, control: 42±12.55sec), as did prothrombin time (PT) [NKB-µg: 93.60±10.92sec; NKB-ηg: 63.40±12.66sec, control: 15±4.12sec] and activated partial thromboplastin time (APTT) [NKB-µg: 94.80±14.04sec; NKB-ηg:68.60±13.74sec, control: 19.40±2.97sec]. Additionally, mean platelet volume [NKB-µg:8.94±0.36fl, control: 8.04±0.48fl] and leukocyte count (×103/µl) [NKB-µg: 12.14±0.69, control: 8.87±1.32] were significantly increased in NKB-treated animals compared to control. There was a significant increase in international normalized ratio in NKB-µg (6.86±0.80) and NKB-ηg (4.65±0.93) compared to control group (1.10±0.30). Conversely, platelet count (×103/µl) was decreased significantly in NKB-µg group (787.80±48.51) compared to the control group (960.60±58.71). Conclusion: NKB administration led to leukocytosis, thromboctopenia, and affected coagulation pathways with prolonged BT, CT, PT, APTT and INR dose-dependently.

Comparative study of hemostatic profile between conventional methods and “Sonoclot Coagulation and Platelet Function Analyzer” in patients with septicemia

Abstract: BACKGROUND: Sonoclot Coagulation and Platelet Functional Analyzer (Sonoclot) operating on the principle of micro-viscometry is known to provide comprehensive information on the entire hemostatic process. We hypothesized that performing global hemostasis assessment in patients with sepsis would identify many more patients with altered hemostasis than the conventional tests. OBJECTIVES: We compared the hemostatic status determined by Sonoclot and that by conventional hemostatic tests. METHODS: It was a prospective analytical study conducted for 18 months in a tertiary care hospital. Sixty-one cases of septicemia admitted in the intensive care units were included in the study. RESULTS: Conventional hemostatic tests (platelet count, prothrombin time [PT], international normalized ratio, and activated partial thromboplastin time [APTT]) were compared with the Sonoclot parameters. Conventional hemostatic parameter PT was prolonged in 60.7% and APTT in 31.1%. Overall, 65.6% of the patients had prolonged coagulation on assessment by conventional hemostatic parameters. Sonoclot-derived parameter-activated clotting time was prolonged in 31.1%, indicating 31.1% of cases to have a hypocoagulable state. The clot rate was increased in 93.4% of subjects, indicating 93.4% to have a hypercoagulable state. Thrombocytopenia was seen in 34.4% and thrombocytosis in 10%. Defective platelet function was observed in 92% of the cases in Sonoclot, and all of them had normal platelet counts. This finding was statistically significant. CONCLUSION: Information about hemostatic status identified by Sonoclot is significantly higher and more complete than that identified by conventional coagulation tests in septicemic patients.

A-148 Performance Evaluation ofthe Zybio EXT 4800: A Novel Optical-Magnetic Coagulation Analyzer

Abstract Background Coagulation analysis, crucial in clinical diagnostics, predominantly employs optical and Mechanical methods. Optical methods are preferred for their simplicity and cost-effectiveness but are susceptible to hemolysis, icterus, and lipemia interferences. Mechanical methods, considered more accurate, are hindered by higher costs and operational complexity. This study evaluates the Zybio EXT 4800, a novel analyzer integrating both technologies(U.S. Patent:US11022558 B2), to harness their collective benefits. Methods The study compared optical, mechanical, and integrated optical-mechanical detection methods for Prothrombin Time (PT) testing, particularly under interference conditions such as chyle. To ensure reagent reliability, a comprehensive open-vial stability assessment was conducted for Zybio's reagents. Additionally, a clinical correlation study compared Zybio EXT 4800 with Siemens CS-2000i Systems, covering multiple parameters. Through this rigorous methodology, the study sought to establish the accuracy, reliability, and clinical applicability of these advanced coagulation analysis technologies. Results In the presence of lipemia interferents during PT testing, notable fluctuations were observed with the optical method, resulting in deviations ranging from 80% to 104% from the set values. Conversely, when utilizing the integrated optical-mechanical approach for analysis, the instrument automatically identifies interferences in the sample, intelligently switching the detection method from optical to mechanical.This intelligent adaptation to interference exhibits strong anti-interference capabilities. The experimental results of mechanical testing show deviations ranging from 0.8% to 1.7%, while the experimental results of optical retesting after high-speed centrifugation of samples show deviations ranging from 1.1% to 2.3%. Regarding reagent stability, Zybio's reagents showcased exceptional durability. Following an accelerated aging process of 50 days at 37°C, Zybio reagents exhibited smaller relative deviations compared to the comparator reagents, underscoring the remarkable stability and reliability offered by Zybio's reagents. Furthermore, in a clinical correlation analysis between Zybio's “EXT 4800 Automated Coagulation Analyzer” and Siemens' “CS-2000i Systems,” strong correlations were observed. The R-squared values perform well, with determinations of exemplary quantitative parameters: FIB for 0.985, D-Dimer for 0.983, and AT for 0.980. These results not only validate the performance equivalence between the two systems but also highlight the advanced stability and anti-interference capabilities of the EXT 4800, positioning it as a formidable alternative to existing solutions. Conclusions The EXT 4800 coagulation analyzer effectively merges optical and mechanical methodologies, offering high sensitivity, accuracy, and reduced susceptibility to interferences. It presents as a cost-effective, reliable alternative in coagulation analysis, with strong performance correlations to established systems and superior reagent stability, making it a valuable addition to clinical laboratories.

A-162 Improved Laboratory Workflow using Automated Detection of Hemolysis, Icterus, and Lipemia for Coagulation Testing

Abstract Background Managing preanalytical variables is critical to providing quality laboratory test results. However, this can be a challenge for laboratory staff, particularly with manual detection of interfering substances and complicated workflows. For coagulation testing, we assess specimen integrity and acceptability by visual checks and quantification of interfering substance on a chemistry analyzer. To improve this subjective process, we evaluated the technical performance of a new model of coagulation analyzer with automated preanalytical specimen integrity detection. Our objective was to determine if we could reduce the number of specimens requiring visual inspection/off-analyzer interference testing in order to simplify our testing workflow. Methods Citrated plasma specimens received in the Hospital Clinical Laboratory at Mayo Clinic (Rochester, MN) were tested on the TOP ACL 500 or TOP ACL 550 Series Coagulation analyzers (Werfen, Boston, MA) according to manufacturer’s instruction. Specimens tested on the TOP 500 were visually inspected for hemolysis, icterus, and lipemia (HIL). If the technologist detected a possible interferent, an aliquot of plasma was analyzed on our cobas c501 chemistry analyzer (c501) (Roche Diagnostics, Indianapolis, IN) to obtain HIL values. Laboratory-established or manufacturer-defined interference thresholds were applied in determining specimen acceptability. For samples tested on the TOP 550, specimen integrity was assessed by the instrument’s automated interference detection module. The analyzer reported HIL as an “interference cloud” or estimated range, rather than a single value like the c501. HIL values were estimated by visual assessment of the low end of the “interference cloud”. Values were confirmed on the c501 only for specimens with an “interference cloud” at/exceeding the test-specific interference thresholds. We analyzed data from a 2-month period pre- (TOP 500) and post-implementation (TOP 550). The percent of specimens requiring quantitation/confirmation on the c501 was calculated. Statistical significance was calculated using the Chi-squared test where significance was defined as p<0.01. Correlation between c501 and TOP 550 estimated HIL values was evaluated. Results A total of 2.2% (171/7605) and 1.3% (113/8983) of specimens tested on the TOP 500 and TOP 550, respectively, required HIL measurements on the c501 (p<0.001). Of those samples, 8.2% (14/171) and 14.2% (16/113) from the TOP 500 and TOP 550, respectively, had HIL values above the interference thresholds and were rejected by the laboratory. Comparison of the estimated HIL values from the “interference cloud” and from the c501 resulted in slopes (Pearson correlation coefficients) of: H 1.56 (0.77), I 0.67 (0.97), and L 1.35 (0.99). Conclusions In comparison to our workflow with visual assessment of interference, use of the automated interference detection functionality on the TOP 550 instrument resulted in a lower percentage of specimens requiring HIL measurements on the chemistry analyzer. Agreement between interference measurements obtained on the c501 and the TOP 550 was moderate where TOP 550 overestimated the degree of hemolysis and lipemia and underestimated icterus. Implementation of automated interference detection on the TOP 550 analyzer improved our workflow by eliminating the need for tedious and subjective visual checks and reducing the percentage of specimens requiring additional HIL measurements.

B-013 Improving the Workflow of Blood and Coagulation Tests in clinical laboratory through the Utilization of Laboratory Automation Track Systems

Abstract Background The Laboratory Automation Track System (TLA) is an automated system designed for executing highly repetitive tasks within a laboratory, commonly applied in biochemical and immunological testing systems. It aims to reduce human errors in specimen handling, enhance the overall process quality, and provide better Turnaround Time (TAT) from specimen collection to result reporting. For the first time in our laboratory, we have integrated the blood and coagulation systems with TLA. Consequently, we seek to evaluate the differences in the testing workflow and reporting efficiency of the blood and coagulation systems after being connected to TLA. Methods Abbott GLP systems Track was the TLA system for connecting with blood and coagulation systems. Two Sysmex XN-9100 fully automatic hematology systems and two Sysmex CS-5100 fully automatic coagulation analyzers were developed for blood and coagulation system, respectively. TUNYEN Laboratory Information System was established for Laboratory information system (LIS). Results Through the analysis of quality indicators and integration with intelligent information systems, improvements have been made, including the reduction of blood collection tube usage, efficient manpower utilization management, tracking of specimen progress and achievement of timely reporting rates.(1)Approximately 2,915 blood collection test tubes are saved every month, with a converted cost of 0.15 USD per tube, and a total saving of 437 USD. And reduce the carbon emissions of 32 kgCO2e, comply with the spirit of ESG sustainable development.(2)The TLA no longer requires staff to collect and deliver specimens as in the past,reducing staff and enhancing work efficiency.One of manpower was saved and new inspection items were developed.(3)Tracking of specimen progress:The laboratory has set up a specimen tracking system to monitor the specimen delivery location and provide timely response to the clinical status.The one-hour TAT for blood and coagulation increased from 82.0% and 76.9% before improvement to 91.8% and 93.3% after improvement respectively. Conclusions The implementation of Laboratory Automation Track Systems (TLA) leads to a reduction in medical errors and specimen sample volume, while also enhancing accuracy and precision, thereby improving the safety of laboratory staff. Although the introduction of TLA may require an initial investment, it brings the benefits of automation, offering ease and efficiency to laboratory processes.

A-168 Comparison of Two Different Lupus Anticoagulant Hexagonal Phase Phospholipid Confirmatory Assays on an Automated Coagulation Analyzer

Abstract Background Antiphospholipid syndrome (aPS) is an autoimmune disorder resulting in venous and/or arterial thrombosis, characterized by presence of lupus anticoagulants (LA) in patient plasma, also referred to as antiphospholipid antibodies. Depending on clinical history and symptoms, or if an unexpected elevated routine aPTT result is observed, LA laboratory testing would be performed, if appropriate. According to published clinical guidelines, LA tests should use aPTT-based and dRVVT-based screening (low phospholipid) and confirmatory (high phospholipid) methods, run in parallel. aPS diagnosis is confirmed from both clinical and laboratory criteria. Laboratory criteria are met if either the aPTT or dRVVT confirmatory test results are positive, and if lab positivity is confirmed following repeated testing 12 weeks following initial results. Due to the multiple tests used, and different manufacturers’ reagents, analysis of comparative performance allows users to identify the optimal tests to use. Objectives of the study were 1) compare intra-run and total precision of two different aPTT-based LA confirmatory tests on a newly available automated coagulation instrument equipped with improved pipetting methodology and preanalytical sample integrity detection and 2) correlate results from the two different aPTT-based LA confirmatory test assays. Methods CRYOcheck Hex LA (Precision BioLogic, Inc., Dartmouth, NS, Canada) and Staclot LA (Diagnostica Stago, Inc., Parsippany, NJ, USA) were run on a STA R Max3 automated coagulation analyzer (Diagnostica Stago, Inc.), using manufacturer recommended protocols. For intra-run precision and total precision analysis, replicates of 5 quality control samples were used (STA Control LA 1+2, Diagnostica Stago, Inc.). For the correlation studies, 20 different LA positive samples were used, supplied by the Specimen Access Team (SAT) from Laboratory Corporation of America Holdings, Burlington, NC, USA. LA positivity was defined as positive by CRYOcheck Hex LA delta result > 11 seconds, which was the cutoff determined at LabCorp’s facility. CRYOcheck Normal Donor Set plasmas were used for normal samples (Precision BioLogic, Inc.). Samples were run in batches containing 5 normal samples and 5 abnormal samples, with quality control run at the beginning and end of each batch. Results Intra-run precision was superior for Staclot LA compared to CRYOcheck Hex LA, with the exception of the high phospholipid “LA Correct” positive tube from CRYOcheck Hex LA. Total precision was either comparable or superior for Staclot LA compared to CRYOcheck Hex LA. In addition, correlation data showed Staclot LA recovered the same result between 3 different aliquots of the same patient mother tube, whereas CRYOcheck Hex LA recovered varying results between runs, when using manufacturer recommended cutoffs. Conclusions Analysis of intra-run and total precision, along with result correlation and recovery between multiple sample aliquots is recommended for when coagulation laboratories evaluate different manufacturers’ reagents. Our data indicate Staclot LA demonstrates superior performance to the CRYOcheck Hex LA on the STA R Max3 automated coagulation analyzer.

Extending the post-thaw shelf-life of cryoprecipitate when stored at refrigerated temperatures.

The post-thaw shelf-life of cryoprecipitate is 6 h, leading to high wastage. Storage of thawed cryoprecipitate at refrigerated temperatures may be feasible to extend the shelf-life. This study aimed to evaluate the quality of thawed cryoprecipitate stored at 1-6°C for up to 14 days. Cryoprecipitate (mini- and full-size packs derived from both apheresis and whole blood [WB] collections) was thawed, immediately sampled and then stored at 1-6°C for up to 14 days. Mini-packs were sampled at 6, 24, 48 and 72 h, day 7 and 14; full-size cryoprecipitate was sampled on day 3, 5 or 7. Coagulation factors (F) II, V, VIII, IX, X and XIII, von Willebrand factor (VWF) and fibrinogen were measured using a coagulation analyser. Thrombin generation was measured by calibrated automated thrombogram. FVIII decreased during post-thaw storage; this was significant after 24 h for WB (p = 0.0002) and apheresis (p < 0.0001). All apheresis and eight of 20 WB cryoprecipitate met the FVIII specification (≥ 70 IU/unit) on day 14 post-thaw. Fibrinogen remained stable for 48 h, and components met the specification on day 14 post-thaw. There were no significant differences in VWF (WB p = 0.1292; apheresis p = 0.1507) throughout storage. There were small but significant decreases in thrombin generation lag time, endogenous thrombin potential and time to peak for both WB and apheresis cryoprecipitate. Whilst coagulation factors in cryoprecipitate decreased after post-thaw storage, the thawed cryoprecipitate met the Council of Europe specifications when stored at refrigerated temperatures for 7 days.

An Automated pre-Dilution Setup for Von Willebrand Factor Activity Assays.

Accurate quantification of von Willebrand factor ristocetin cofactor activity (VWF:RCo) is critical for the diagnosis and classification of von Willebrand disease, the most common hereditary and acquired bleeding disorder in humans. Moreover, it is important to accurately assess the function of von Willebrand factor (VWF) concentrates within the pharmaceutical industry to provide consistent and high-quality biopharmaceuticals. Although the performance of VWF:RCo assay has been improved by using coagulation analyzers, which are specialized devices for blood and blood plasma samples, scientists still report a high degree of intra- and inter-assay variation in clinical laboratories. Moreover, high, manual sample dilutions are required for VWF:RCo determination of VWF concentrates within the pharmaceutical industry, which are a major source for assay imprecision. For the first time, we present a precise and accurate method to determine VWF:RCo, where all critical pipetting and mixing steps are automated. A pre-dilution setup was established on CyBio FeliX (Analytik-Jena) liquid handling system, and an adapted VWF:RCo method on BCS-XP analyzer (Siemens) is used. The automated pre-dilution method was executed on three different, most frequently used coagulation analyzers and compared to manual pre-dilutions performed by an experienced operator. Comparative sample testing revealed a similar assay precision (coefficient of variation = 5.9% automated, 3.1% manual pre-dilution) and no significant differences between the automated approach and manual dilutions of an expert in this method. While no outliers were generated with the automated procedure, the manual pre-dilution resulted in an error rate of 8.3%. Overall, this operator-independent protocol enables standardization and offers an efficient way of fully automating VWF activity assays, while maintaining the precision and accuracy of an expert analyst. Key features • Automated pre-dilution setup for von Willebrand factor concentrates of various natures. • Combination of a liquid handling system (CyBio FeliX) with a coagulation analyzer (BCS-XP). • Simplifies method transfer to other laboratories. • Basic training for CyBio FeliX and BCS-XP is required. Graphical overview VWF:RCo assay principle and measurement setup. Platelets (yellow ellipsoids) with negative surface charge (- - -) are treated with formaldehyde, which partly denatures the cell surface and thus stabilizes platelets for use as assay reagents. Stabilized platelets (dark-yellow-framed yellow ellipsoids) are then brought in contact with ristocetin A (chemical structure shown; black dots), which binds to the platelet surface and facilitates binding of VWF (green circles). The graphs show an example of quantitative determination of platelet agglutination by measurement of light transmission, where increasing amounts of VWF increase light transmission over time. The photo in the left-bottom corner shows the CyBio FeliX setup for VWF sample dilution and the photo in the right-bottom corner displays the BCS-XP system, which is used for VWF:RCo measurements.

Clot waveform analysis of prolonged activated partial thromboplastin time in various disorders.

The prolongation in APTT reflects various disorders affecting the blood coagulation system. Automated coagulation analyzers such as ACL TOP, help in evaluating the clotting cascade by displaying clot reaction curves or waveforms. The fibrin formation curve forms S-shaped curve showing the changes in the absorbance on X-axis and time in seconds on Y-axis. The clotting data is processed to obtain derivatives. This observational study analyzed 80 samples including 20 samples from normal healthy individuals as control. The parameters studied were time (secs), height (mAbs), and width (secs) of first derivative (FD), fibrin clot time at ½ height, height (mAbs), and width (secs) of both first and second peaks of second derivative (SD). Hemophilia (n = 13) that consisted of factor VIII deficiency (n = 11) and factor IX deficiency (n = 2) showed biphasic patterns in both first DC and second DC. Cases with thrombosis (n = 8) showed marked elevation in first DC. Various other disorders (n = 39) that consisted of mainly hepatic dysfunction (n = 24) showed prolongation in fibrin formation, first DC, and second DC peak time. The atypical derivative curve analysis helps in determining the interferences in clotting cascade. It gives significant information and provides direction for further testing.

Evaluation of a whole blood point-of-care coagulation analyzer in dogs.

To compare the accuracy of a point-of-care coagulation analyzer (POCCA) with a reference laboratory coagulation analyzer (LabCA) and to evaluate for confounding factors that could alter the performance of the POCCA. Prospective, observational study. Two university veterinary teaching hospitals. Forty-three client-owned dogs undergoing coagulation testing between April 2020 and June 2021. Samples were obtained from dogs undergoing coagulation testing as part of a diagnostic workup. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) were measured on the POCCA and on the LabCA. PCV, platelet count, total plasma protein, hyperbilirubinemia, hemolysis, lipemia, and autoagglutination were recorded. Moderate correlation was seen for PT and strong correlation was seen for aPTT between the POCCA and the LabCA (PT: 0.59, P<0.0001; aPTT: 0.71, P<0.0001). The POCCA results were consistent with normal or hypocoagulable samples for 30 of 38 PT and 33 of 37 aPTT results, as identified by the LabCA. Samples with PCV of 30%-55% were moderately correlated (PT: 0.63, P=0.0004; aPTT: 0.63, P=0.0003), but those outside that range were more likely to register an error message on the POCCA or provide disparate results. When hemolysis was present, there was a weak correlation between the POCCA and the LabCA for PT (rho: 0.38 [95% confidence interval: 0.19-0.76], P=0.18) and a strong correlation for aPTT (rho: 0.86 [95% confidence interval: 0.62-0.95], P<0.0001). Samples with hyperbilirubinemia were strongly correlated for PT (0.97, P=0.002) but not for aPTT. Lipemia and autoagglutination were not observed. There was an acceptable correlation in patients with PCV within the manufacturer's recommended reference range; however, measurements on samples with PCV outside the reference range were inconsistent with the LabCA. Caution should be used when using the POCCA in patients with coagulopathy and anemia or other potential confounders.

Reduce energy consumption in your laboratory – switch ultra-low temperature freezers from – 80 °C to –70 °C. A pilot study on short term storage of plasma samples for coagulation testing

It is common practice in laboratories to store biological samples in ultra-low temperature (ULT) freezers. There is growing interest in raising the temperature of ULT freezers in order to save energy and reduce expenses, as energy conservation becomes increasingly important and sustainable laboratory practices gain popularity. In our laboratory, plasma samples are stored for three months for diagnostic purposes. We therefore took the opportunity to investigate the effect of two different storage temperatures (−70 °C vs −80 °C), on activated partial thromboplastin time (APTT), factor VIII (FVIII), international normalized ratio (INR) and factor VII (FVII) measurements on paired plasma samples collected from 26 individuals after three months of storage. Automated coagulation analysers CS-5100 and ACL TOP were used to perform the tests. We found no consistent difference between the two storage temperatures for any of the four coagulation parameters (all p-values > 0.05). We conclude that the temperature of ULT freezers used to store plasma samples for APTT, FVIII, INR, and FVII measurements can be safely increased from −80 to −70 °C without affecting the stability of the samples.

Trauma induced coagulopathy is limited to only one out of four shock induced endotheliopathy (SHINE) phenotypes among moderate-severely injured trauma patients: an exploratory analysis

BackgroundTrauma induced coagulopathy remains to be an important cause of high transfusion requirements and mortality and shock induced endotheliopathy (SHINE) has been implicated.MethodsEuropean multicenter observational study of adult trauma patients with injury severity score ≥ 16 arriving within 2 h from injury to the trauma centers. Admission blood samples obtained were used for analysis of the SHINE biomarkers (syndecan-1, soluble thrombomodulin, adrenaline) and extensive analysis of coagulation, -and fibrinolytic factors together with collection of clinical data. Hierarchical clustering of the SHINE biomarkers was used to identify the SHINE phenotypes.ResultsThe 313 patients clustered into four SHINE phenotypes. Phenotype 2, having the highest glycocalyx shedding, encompassing 22% of the whole cohort, had severe coagulopathy with lower levels of prothrombin, FV, IX, X, XI and severe hyperfibrinolysis with higher plasmin – alpha 2-antiplasmin (PAP) – and tPA levels and lower alpha2 – antiplasmin levels. This phenotype had significantly higher transfusion requirements and higher mortality (39% vs. 23%, 15% and 14%) but similar injury severity score (ISS) compared to the others phenotypes.ConclusionsHierarchical clustering identified four SHINE phenotype in a cohort of trauma patients. Trauma induced coagulopathy was confined to only one of the SHINE phenotypes, encompassing 22% of the total cohort. This phenotype was characterized by severe hypocoagulability and hyperfibrinolysis, which translated to significantly higher transfusion requirements and higher mortality compared to the other SHINE phenotypes with similar injury severity, warranting further investigation.

Evaluation of Point-of-Care-Directed Coagulation Management in Pediatric Cardiac Surgery.

Coagulatory alterations are common after pediatric cardiac surgery and can be addressed with point-of-care (POC) coagulation analysis. The aim of the present study is to evaluate a preventive POC-controlled coagulation algorithm in pediatric cardiac surgery. This single-center, retrospective data analysis included patients younger than 18 years who underwent cardiac surgery with cardiopulmonary bypass (CPB) and received a coagulation therapy according to a predefined POC-controlled coagulation algorithm. Patients were divided into two groups (<10 and >10 kg body weight) because of different CPB priming strategies. In total, 173 surgeries with the use of the POC-guided hemostatic therapy were analyzed. In 71% of cases, target parameters were achieved and only in one case primary sternal closure was not possible. Children with a body weight ≤10 kg underwent surgical re-evaluation in 13.2% (15/113), and respectively 6.7% (4/60) in patients >10 kg. Hemorrhage in children ≤10 kg was associated with cyanotic heart defects, deeper intraoperative hypothermia, longer duration of CPB, more complex procedures (RACHS-1 score), and with more intraoperative platelets, and respectively red blood cell concentrate transfusions (all p-values < 0.05). In children ≤10 kg, fibrinogen levels were significantly lower over the 12-hour postoperative period (without revision: 3.1 [2.9-3.3] vs. with revision 2.8 [2.3-3.4]). Hemorrhage in children >10 kg was associated with a longer duration of CPB (p = 0.042), lower preoperative platelets (p = 0.026), and over the 12-hour postoperative period lower platelets (p = 0.002) and fibrinogen (p = 0.05). The use of a preventive, algorithm-based coagulation therapy with factor concentrates after CPB followed by POC created intraoperative clinical stable coagulation status with a subsequent executable thorax closure, although the presented algorithm in its current form is not superior in the reduction of the re-exploration rate compared to equivalent collectives. Reduced fibrinogen concentrations 12 hours after surgery may be associated with an increased incidence of surgical revisions.

Evaluation of an automated platelet aggregation method for detection of congenital or acquired platelet function defects.

Light transmission aggregometry (LTA) is the most widely used laboratory method for an initial screening of patients with a suspected platelet function defect (PFD), and its use has also been proposed for assessing the efficacy of antiplatelet treatment (APT). An automated LTA method has been developed by Sysmex (Kobe, Japan) on a routine coagulation analyzer (CS-2400), together with a new research parameter called PAL (platelet aggregation level) to evaluate patients on APT. We evaluated the performance of CS-2400 compared to a stand-alone lumi-dual-aggregometer device in the diagnosis of PFD and in assessing the efficacy of APT. For these purposes, the study population was represented by a cohort of 23 patients with a previous diagnosis of PFD and a cohort of 28 patients on APT. Compared to healthy volunteers, patients with PFD showed a statistically significant reduction (p<0.05) in the maximal %light transmission, irrespective of the agonist used, both with the CS-2400 and the lumi-dual-aggregometer. As regards PFD patients, CS-2400 was effective in identifying the more severe defects, with a good sensibility and specificity, but less effective in identifying milder forms of PFD, such as platelet secretion defects. Patients on APT showed a statistically significant (p=0.001) reduced median %light transmission and PAL scores compared to healthy controls. Thanks to this LTA technology, CS-2400, a routine coagulation analyzer widely available in routine laboratories, could prove useful for initial assessment of patients with a suspected PFD. Moreover, the PAL scores were a fairly accurate reflection of the platelet response to APT.

Intravenous lipid emulsion interference in coagulation testing: an ex vivo analysis

Introduction Intravenous lipid emulsion is used in the rescue treatment of certain poisonings. A complication is interference with laboratory analyses. The aim of this study was to determine the impact of intravenous lipid emulsion on routine laboratory analysis of coagulation parameters ex vivo and determine if any of the analytical techniques remain reliable. Methods Samples were obtained from 19 healthy volunteers and divided in triplicate. One sample served as a control, and the other two were diluted to simulate the treatment of an average adult with Intralipid® 20 per cent Fresenius Kabi 100 mL (dilution-1) or 500 mL (dilution-2). Coagulation tests performed were prothrombin time, activated prothrombin time, D-dimer concentration and fibrinogen. Coagulation testing was performed by three techniques. Test-1 was performed on a Sysmex CN6000 analyzer. Test-2 was performed with a manual mechanical endpoint method using the semi-automated Stago KC4 Delta. Test-3 involved high-speed centrifugation before repeat testing on the Sysmex CN6000 analyzer. Results For test-1, only nine (47 per cent) samples in dilution-1 could be analyzed for coagulation tests, and no coagulation tests could be analyzed for dilution-2 because of lipaemia. For test-2 and test-3, all samples could be analyzed, and all results of both testing methods fell within the limits of the laboratory reference range. Discussion Difficulties in laboratory analysis of patients having received intravenous lipid emulsion are due to multiple factors. Most automated coagulation analyzers use optical measurements, which can be unreliable in the presence of a high intravenous lipid concentration. By altering the lipaemia in the testing solution using high-speed centrifugation or by using manual mechanical endpoint detection, we were able to obtain reliable results. These findings are limited by the use of an ex vivo method and healthy volunteers. Conclusions This ex vivo model confirms that Intralipid® interferes with routine coagulation studies. It is important that clinicians are aware and inform their laboratories of its administration.

An in vitro study of coagulation evaluation in obstetric hemorrhage for pregnancy-induced hypertension with coagulation and platelet function analyzer

ABSTRACT This study aimed to establish in vitro hemodilution and resupplementation assays for obstetric hemorrhage in pregnancy-induced hypertension (PIH) and to monitor the coagulation function dynamically using a coagulation and platelet function analyzer. Forty-seven singleton pregnant women were divided into normal (n = 24) and PIH (n = 23) groups. Peripheral blood samples were used to construct the assays, and the activated clotting time (ACT), clotting rate (CR), and platelet function index (PF) were measured. The results showed that the baseline ACT was higher in the PIH group (p < 0.01). Hemodilution assays showed decreased ACT and increased CR and PF, with ACT changes significantly lower in the PIH group (p < 0.05). CR changed most in both groups at lower dilution ratios (35% to 50%), while ACT changed most at a higher dilution ratio (75%). In the resupplementation assay, ACT exhibited the most significant response. The analyzer effectively detected differences between pregnant women with and without PIH. Thus, we need to pay more attention to the changes of ACT in the actual clinical application to assess the coagulation status of parturients.

Effects of Salvianolate Injection on the Pharmacodynamics and Pharmacokinetics of Warfarin in Rats In vivo

Background:: Both Salvianolate Injection and warfarin are widely prescribed in patients with cardiovascular diseases, but the interaction between them is unknown and needs to be investigated. Objective:: This research aims to study the effects and mechanism of Salvianolate Injection on the pharmacodynamics and pharmacokinetics of warfarin in rats. Methods:: Male Wistar rats were intraperitoneally injected Salvianolate Injection (18 mg/kg) with or without oral administration of warfarin (0.2 mg/kg). A coagulation analyzer evaluated prothrombin time (PT) and activated partial thromboplastin time (APTT). International normalized ratio (INR) was calculated based on PT. UPLC-MS/MS combined with a chiral column was used to separate and measure the plasma concentration of R-warfarin and S-warfarin. Agilent SB-C18 column (1.8 μm, 2.1 mm × 50 mm) was used for separation, column temperature at 20°C. The isocratic mobile phase was acetonitrile-aqueous ammonium acetate (5 mM, pH 4) at a flow rate of 0.2 mL/min and 11.5 min for each injection. Pharmacokinetic parameters were calculated using DAS 2.0 software. Results:: Salvianolate Injection increased PT and INR (p &lt; 0.05), while APTT was unaffected (p &gt; 0.05). Compared with the warfarin group, the co-administration of Salvianolate Injection and singledose warfarin enlarged PT and INR (p &lt; 0.05). Similar increases in pharmacokinetic parameters of R-warfarin and S-warfarin, including Cmax, AUC0-t, AUC0-∞, t1/2, and CL/F (p &lt; 0.05), were observed in the co-administration group. A steady-state study of warfarin indicated that PT and INR in the coadministration group are longer than those in the warfarin group (p &lt; 0.05). On days 7th and 8th of warfarin treatment (two and three days after Salvianolate Injection treatment), the plasma concentration of R-warfarin increased by 47.22% and 50.16% (p &lt; 0.05), and plasma concentration of Swarfarin increased by 32.39% and 45.99% (p &lt; 0.05), respectively. Conclusion:: Salvianolate Injection exhibits an anticoagulation effect in rats. Salvianolate Injection can enhance the anticoagulant effect of warfarin by slowing metabolism and increasing the concentration of both enantiomers. These results suggest that the combination of Salvianolate Injection and warfarin should be avoided or closely monitored in case of increasing bleeding risk.

Does in vitro hemolysis affect measurements of plasma apixaban concentration by UPLC-MS and anti-Xa assay?

Hemolytic interference may impact various laboratory tests, including coagulation analyses. Apixaban is the most commonly used direct oral anticoagulant in Norway, and there is lacking knowledge on how apixaban concentration measurements might be influenced by hemolysis. Moreover, hemolysis-induced alterations in apixaban levels could potentially impact the risk of bleeding in specific clinical scenarios. We wanted to study whether hemolysis would increase apixaban concentration and investigate the impact of hemolytic interference on apixaban concentration measurements. Blood samples from 20 apixaban-treated patients and 8 healthy controls were hemolyzed in vitro by a freeze method. The degree of hemolysis was measured with plasma free hemoglobin (PfHb) at baseline and two levels of hemolysis. Apixaban concentration was measured in plasma using both the chromogenic anti-Xa method and the ultraperformance liquid chromatography mass spectrometry (UPLC-MS). Thrombin generation assay was performed to assess coagulability. UPLC-MS measurements showed a mean concentration change of -1.66% (±3.2%, p = 0.005) and anti-Xa assay showed a mean concentration change of 3.37% (±6.5%, p = 0.09) with increasing hemolysis. Thrombin generation lagtime decreased, and endogenous thrombin potential and peak thrombin increased with increasing hemolysis in both the control group and the apixaban group. Apixaban concentration measurements by anti-Xa assay and UPLC-MS were not affected by hemolysis to a clinically relevant extent. Furthermore, hemolysis did not lead to hypocoagulability when assessed by thrombin generation.

The clinical significance of TAT, PIC, TM, and t-PAIC in vascular events of BCR/ABL-negative myeloproliferative neoplasms

Predicting the likelihood vascular events in patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN) is essential for the treatment of the disease. However, effective assessment methods are lacking. Thrombin-antithrombin complex (TAT), plasmin-α2- plasmininhibitor complex (PIC), thrombomodulin (TM), and tissue plasminogen activator-inhibitor complex (t-PAIC) are the new direct indicators for coagulation and fibrinolysis. The aim of this study was to investigate the changes of these four new indicators in thrombotic and hemorrhagic events in BCR/ABL1-negative MPN. The study cohort of 74 patients with BCR/ABL negative myeloproliferative disorders included essential thrombocythemia, polycythemia vera, and primary myelofibrosis (PMF). A panel of 4 biomarkers, including TAT, PIC, TM, and t-PAIC were determined using Sysmex HISCL5000 automated analyzers, whereas fibrin/fibrinogen degradation products (FDP), D-dimer and Antithrombin III (ATIII) were analyzed using Sysmex CS5100 coagulation analyzer. A total of 24 (32.4%) patients experienced thrombotic events and hemorrhagic events occurred in 8 patients (10.8%). Compared to patients without hemorrhagic-thrombotic events, patients with thrombotic events had higher fibrinogen (FIB) level, FDP level and lower ATIII activity, while patients with hemorrhagic events had lower white blood cell count and hemoglobin level, higher FDP level (P < 0.05). Patients with a JAK2V617F mutation were more likely to experience thrombotic events (P < 0.05). In addtion, patients with thrombotic events had higher TAT, PIC, TM, and t-PAIC levels than patients without hemorrhagic-thrombotic events (P < 0.05), whereas patients with hemorrhagic events had a lower median value in TAT and TM (no statistical difference, P > 0.05). Patients with higher TAT, TM and t-PAIC were more likely to experience thrombotic events (P < 0.05), and only TAT was positively correlated with thrombotic events (Spearman r =0.287, P = 0.019). TAT, PIC, TM, and t-PAIC combined with ATIII and FDP have a certain value for predicting thrombosis in patients with BCR/ABL1-negative MPN. These 6 parameters are worth further exploration as predictive factors and prognostic markers for early thrombotic events.

Comparative studies between humans and golden Syrian hamsters via thromboelastography.

Thromboelastography (TEG) is a widely utilized clinical testing method for real-time monitoring of platelet function and the thrombosis process. Lipid metabolism disorders are crucial risk factors for thrombosis. The lipid metabolism characteristics of hamsters resemble those of humans more closely than mice and rats, and their relatively large blood volume makes them suitable for studying the mechanisms of thrombosis related to plasma lipid mechanisms. Whole blood samples from golden Syrian hamsters and healthy humans were obtained following standard clinical procedures. TEG was employed to evaluate coagulation factor function, fibrinogen (Fib) function, platelet function, and the fibrinolytic system. The whole blood from hamster or healthy human was isolated following the clinical procedure, and TEG was employed to evaluate the coagulation factor function, Fib function, platelet function, and fibrinolytic system. Coagulation analysis used ACLTOP750 automatic coagulation analysis pipeline. Blood routine testing used XN-2000 automatic blood analyzer. TEG parameters revealed that hamsters exhibited stronger coagulation factor function than humans (reaction time [R], p = 0.0117), with stronger Fib function (alpha angle, p < 0.0001; K-time [K], p < 0.0001). Platelet function did not differ significantly (maximum amplitude [MA], p = 0.077). Hamsters displayed higher coagulation status than humans (coagulation index [CI], p = 0.0023), and the rate of blood clot dissolution in hamsters differed from that in humans (percentage lysis 30 min after MA, p = 0.02). Coagulation analysis parameters indicated that prothrombin time (PT) and activated partial thromboplastin time (APTT) were faster in hamsters than in humans (PT, p = 0.0014; APTT, p = 0.03), whereas the Fib content was significantly lower in hamsters than in humans (p < 0.0001). No significant difference was observed in thrombin time (p = 0.1949). In summary, TEG could be used to evaluate thrombosis and bleeding parameters in whole blood samples from hamsters. The platelet function of hamsters closely resembled that of humans, whereas their coagulation function was significantly stronger.