The Effect of Platelet -, and Leukocyte Count on the Thrombelastograph® (TEG) Parameters.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3971-3971
Author(s):  
W.W.H. Roeloffzen ◽  
J.C. Kluin-Nelemans ◽  
Joost de Wolf
Keyword(s):  
Platelet Count ◽  
Point Of Care ◽  
Maximum Amplitude ◽  
Multiple Regression Model ◽  
Clot Strength ◽  
Normal Limits ◽  
Coagulation Tests ◽  
Plasmatic Coagulation ◽  
Sensitivity Specificity ◽  
Normal Controls

Abstract Background. The TEG is used in situations were point of care testing of hemostasis is desired, although its value is still controversially because of insufficient test validation. The main parameters of the TEG are (a) the reaction time (R), the time until the initial fibrin formation and comparable with the coagulation times PT and APTT; (b) clotting time (K), the time until a fixed level of clot firmness is reached; (c) the angle (α) is closely related to K and measures the rapidity of fibrin build up and gives information about the clot strength; R, K and α are prolonged by anticoagulants and factor deficiencies; (d) maximum amplitude (MA) is a measurement of maximum strength or stiffness of the developed clot; it is especially influenced by platelets and fibrin. Methods. We performed a multivariate analysis using the Cox multiple-regression model to study the effects of Leukocytes, Hb, and platelet count on the TEG parameters. Results. Ninety native whole blood samples from 19 patients undergoing consolidation chemotherapy were studied; in the post chemotherapy phase in which platelets decreased from normal to < 10 x 109/l samples were taken; in all these cases PT, APTT and Fibrinogen were within normal limits. Platelets significantly influenced all parameters: R (p<0.001, r=−0.5), K (p<0.001, r=−0.7), α (p<0.001, r=+0.7), MA (p<0.001, r=+0.6) whereas Leukocytes influenced MA as well (p<0.001, r=0.3). In normal controls K is 9 ± 3 min (n=110), in patients with platelet count 50–100, 25–50 and <25 x 109/l K was resp. 17 ± 9, 30 ± 13 and 46 ± 10 min. In normal controls MA was 46 ± 7 mm, in patients MA became significant smaller with platelets < 25 x 109/l: 30 ± 5 mm. In patients with leukocytes ranging from 0–0.1, 0.1–1.0, 1.0–3.5 and > 3.5 x 109/l the MA was resp. 44 ± 14, 49 ± 15, 54 ± 9, and 58 ± 8 mm. As the MA is considered the parameter most influenced by platelet count, we calculated the sensitivity, specificity, pos and neg predictive value of MA to detect a platelet count less then 50 x 109/l, they were resp. 35%, 100%, 100% and 73%. Conclusion. Firstly, platelet count not only influences MA but also the coagulation parameters R, K and α; besides leukocytes influences the clot strength; this is in agreement with the new conceptual cell based model of hemostasis; secondly, the TEG should be considered as additive to platelet count and plasmatic coagulation tests and not as a replacement.

In Normal Controls, a Lower Hb Concentration and Female Sexe Increases Coagulability on the Thrombelastograph (TEG).

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3970-3970
Author(s):  
W.W.F. Roeloffzen ◽  
J.C Kluin-Nelemans ◽  
Joost de Wolf
Keyword(s):  
Platelet Count ◽  
Point Of Care ◽  
Maximum Amplitude ◽  
Multiple Regression Model ◽  
Point Of Care Testing ◽  
Clotting Time ◽  
Clot Strength ◽  
Angle Alpha ◽  
Hb Concentration ◽  
Normal Controls

Abstract Background. The TEG is used in situations were point of care testing of hemostasis is desired, although its value is still controversially because of insufficient test validation. The main parameters of the TEG are (a) the reaction time (R), the time until the initial fibrin formation and comparable with the coagulation times PT and APTT; (b) clotting time (K), the time until a fixed level of clot firmness is reached; (c) the angle (alpha) is closely related to K and measures the rapidity of fibrin build up and gives information about the clot strength; R, K and alpha are prolonged by anticoagulants and factor deficiencies; (d) maximum amplitude (MA) is a measurement of maximum strength or stiffness of the developed clot; it is especially influenced by platelets and fibrin. Methods. We performed a multivariate analysis using the Cox multiple-regression model to study the effects of sexe, age, Hb, platelet count, PT, APTT and fibrinogen on the TEG parameters. Results. Ninety nine normal controls (54 men) age 51 ± 17 years (range 19–87) were studied; no anticoagulants, antithrombotics or oral contraceptives were used. Native whole blood samples were used. The R is significantly influenced by sexe (p<0.001; r=0.4) and APTT (p<0.001; r=0.4); R is in women 19 ± 4, versus 24 ± 5 minutes in men. K is significantly influenced by Hb (p<0.001; r=0.5), fibrinogen (p<0.001; r=−0.4), platelet count (p=0.01; r=−0.3), sexe (p=0.018; r=−0.5) and APTT (p=0.009; r=0.4). The alpha is significantly influenced by the Hb (p<0.001; r=−0.5), fibrinogen (p=0.001; r=0.4), sexe (p=0.008; r=0.5) and APTT (p=0.03; r=−0.4). In normal controls with a Hb of resp.< 8, 8–9 or >=9 mmol/l the K was resp. 6.8 ± 1.7, 8.5 ± 2.5 and 10.5 ± 2.8 minutes; the alpha was resp. 31.4 ± 8.1, 26.1 ± 7 and 21.4 ± 5.8 degrees. The MA was significantly influenced by fibrinogen (p<0.001; r=0.5), age (p<0.001; r=0.5), sexe (p<0.001; r=0.4), platelet count (p=0.02; r=0.2) and PT (p0.03; r=0.1). Conclusion.. Coagulability measured in the TEG is increased in women compared to men (shortened R and K, larger alpha, increased MA) and coagulability increases with a decrease of the Hb concentration (shortened K and larger alpha).

scholarly journals Viscoelastic coagulation test for liver transplantation

2020 ◽  
Vol 15 (2) ◽  
pp. 143-151
Author(s):  
Sun Young Park
Keyword(s):  
Liver Transplantation ◽  
Management Strategy ◽  
Point Of Care ◽  
Turnaround Time ◽  
Coagulation Test ◽  
Blood Management ◽  
Coagulation Tests ◽  
Perioperative Monitoring ◽  
Plasmatic Coagulation ◽  
Hemostatic Therapy

Coagulation and transfusion management in patients undergoing liver transplantation is challenging. Proper perioperative monitoring of hemostasis is essential to predict the risk of bleeding during surgery, to detect potential causes of hemorrhage in time, and to guide hemostatic therapy. The value of conventional coagulation test is questionable in the acute perioperative setting due to their long turnaround time and the inability to adequately reflect the complex changes in hemostasis in patients with liver disease. Viscoelastic coagulation tests provide simultaneous measurement of multiple aspects of whole-blood coagulation including plasmatic coagulation and fibrinolytic factors and inhibitors that reflect most aspects of hemostasis. Coagulation initiation, mechanical clot stability, and fibrinolysis can be estimated immediately using point-of-care techniques. Therefore, viscoelastic coagulation tests including ROTEM & TEG would be useful to guide patient blood management strategy during liver transplantation.

Evaluation of a modified thromboelastography assay for the screening of von Willebrand disease

2011 ◽  
Vol 105 (06) ◽  
pp. 1091-1099 ◽  
Author(s):  
Hans-Georg Topf ◽  
Dominik Weiss ◽  
Grischa Lischetzki ◽  
Erwin Strasser ◽  
Wolfgang Rascher ◽  
...  
Keyword(s):  
Point Of Care ◽  
Area Under The Curve ◽  
Maximum Amplitude ◽  
Von Willebrand Disease ◽  
Infusion Therapy ◽  
Clot Strength ◽  
Point Of Care Test ◽  
Diagnosis And Classification ◽  
Patient Groups ◽  
Von Willebrand

SummaryThromboelastography (TEG) has been shown to be a valuable point-of-care device for the rapid diagnosis of various bleeding disorders. However, TEG has thus far not been used for the screening for von Willebrand disease (VWD). We evaluated the performance of a modified TEG assay for the laboratory screening of VWD. Three hundred twenty-eight patients (148 male, 180 female, median age 8.4 years, range 0.1 – 72.7 years) were included in the study. The diagnosis and classification of patients was based on personal and familial case history, von Willebrand factor antigen, ristocetin cofactor levels, collagen binding assay, factor VIII coagulant activity and multimer analysis. The ratio of clot strength after preincubation with ristocetin, and without ristocetin, represents the component of clot strength that is formed by cross-linked fibrin fibres and is dependent on the agglutinated platelet fraction. The decrease of the maximum amplitude is a function of the ristocetin concentration and provides a diagnostic parameter able to differentiate between healthy individuals and patients having VWD. Based on a preliminary cut-off value of 25% for the area under the curve (AUC) ratio, the sensitivity varied from 53% to 100% for the different VWD patient groups. The test is suitable for use as a screening test using whole blood and has the additional benefit of being suitable as a point of care test. It appears also useful for monitoring responses to desmopressin (DDAVP) and infusion therapy.

Assessment of Changes in Coagulation in Parturients with Preeclampsia Using Thromboelastography 

1999 ◽  
Vol 90 (2) ◽  
pp. 385-390 ◽  
Author(s):  
Shiv K. Sharma ◽  
John Philip ◽  
Charles W. Whitten ◽  
Udaya B. Padakandla ◽  
Dennis F. Landers
Keyword(s):  
Platelet Count ◽  
Pregnant Women ◽  
Whole Blood ◽  
Maximum Amplitude ◽  
Study Groups ◽  
Coagulation Profile ◽  
Coagulation Tests ◽  
Active Labor ◽  
Coagulation Defects ◽  
Disposable Plastic

Background Preeclampsia is associated with a risk of abnormal hemostasis that occurs most commonly secondary to thrombocytopenia. Thromboelastography measures whole blood coagulation and has been used to manage coagulation defects in obstetric patients. The authors conducted this investigation in a large number of preeclamptic women to assess changes in coagulation using thromboelastography. Methods Thromboelastography and platelet counts were performed in 52 healthy pregnant women, 140 mild preeclamptic women, and 114 severe preeclamptic women in active labor using disposable plastic cups and pins and native whole blood. In preeclamptic patients with a platelet count &lt;100,000/mm3, conventional coagulation tests were also performed. Epidural analgesia was provided in some women when they requested pain relief. Results Fifteen percent of all preeclamptic women (38 of 254) and 2% (1 of 52) of healthy pregnant women had a platelet count &lt;100,000/mm3. The incidence of thrombocytopenia &lt;100,000/mm3 was 3% (4 of 140) and 30% (34 of 114) in mild preeclamptic patients and severe preeclamptic patients, respectively. Severe preeclamptic patients with a platelet count &lt;100,000/mm3 were significantly hypocoagulable when compared to the other study groups. Ten severe preeclamptic women with a platelet count &lt;100,000/mm3 had a maximum amplitude &lt;54 mm (the lower limit of maximum amplitude in healthy pregnant women enrolled in this investigation). None of the mild preeclamptic women had a maximum amplitude &lt;54 mm. Five severe preeclamptic women with a platelet count &lt;100,000/mm3 had an abnormal coagulation profile, whereas all four mild preeclamptic women with a platelet count &lt;100,000/mm3 had a normal coagulation profile. Conclusion This study shows that severe preeclamptic women with a platelet count &lt;100,000/mm3 are hypocoagulable when compared to healthy pregnant women and other preeclamptic women.

scholarly journals COVID-19 Seroprevalence among Healthcare Workers of a Large COVID-19 Hospital in Rome Reveals Strengths and Limits of Two Different Serological Tests

2021 ◽  
Vol 18 (5) ◽  
pp. 2650
Author(s):  
Giuseppe Vetrugno ◽  
Daniele Ignazio La Milia ◽  
Floriana D’Ambrosio ◽  
Marcello Di Pumpo ◽  
Roberta Pastorino ◽  
...  
Keyword(s):  
Blood Test ◽  
Healthcare Workers ◽  
Point Of Care ◽  
Venous Blood ◽  
Administrative Staff ◽  
Serological Tests ◽  
Predictive Values ◽  
Work From Home ◽  
Significant Difference ◽  
Sensitivity Specificity

Healthcare workers are at the forefront against COVID-19, worldwide. Since Fondazione Policlinico Universitario A. Gemelli (FPG) IRCCS was enlisted as a COVID-19 hospital, the healthcare workers deployed to COVID-19 wards were separated from those with limited/no exposure, whereas the administrative staff were designated to work from home. Between 4 June and 3 July 2020, an investigation was conducted to evaluate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin (IgG) antibodies among the employees of the FPG using point-of-care (POC) and venous blood tests. Sensitivity, specificity, and predictive values were determined with reverse-transcription polymerase chain reaction on nasal/oropharyngeal swabs as the diagnostic gold standard. The participants enrolled amounted to 4777. Seroprevalence was 3.66% using the POC test and 1.19% using the venous blood test, with a significant difference (p < 0.05). The POC test sensitivity and specificity were, respectively, 63.64% (95% confidence interval (CI): 62.20% to 65.04%) and 96.64% (95% CI: 96.05% to 97.13%), while those of the venous blood test were, respectively, 78.79% (95% CI: 77.58% to 79.94%) and 99.36% (95% CI: 99.07% to 99.55%). Among the low-risk populations, the POC test’s predictive values were 58.33% (positive) and 98.23% (negative), whereas those of the venous blood test were 92.86% (positive) and 98.53% (negative). According to our study, these serological tests cannot be a valid alternative to diagnose COVID-19 infection in progress.

scholarly journals Rotational thrombelastometry (ROTEM) improves hemostasis assessment compared to conventional coagulation test in ACLF and Non-ACLF patients

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jessica Seeßle ◽  
Jan Löhr ◽  
Marietta Kirchner ◽  
Josefin Michaelis ◽  
Uta Merle
Keyword(s):  
Liver Cirrhosis ◽  
Test Performance ◽  
Coagulation System ◽  
Bleeding Events ◽  
Coagulation Parameters ◽  
Normal Limits ◽  
Coagulation Tests ◽  
Prospective Assessment ◽  
Patient Groups ◽  
Coagulation Assay

Abstract Background Patients with liver cirrhosis typically exhibit abnormal coagulation parameters in conventional coagulation tests (CCTs). Rotational thromboelastometry (ROTEM) is a holistic blood coagulation assay. This method provides an insight into the global hemostatic capabilities and has been suggested to provide a better overview of the coagulation system in liver cirrhosis. Methods The goal of this study was to examine hemostasis in patients with stable liver cirrhosis (Non-ACLF) and in acute-on-chronic liver failure (ACLF) by CCT and ROTEM including agreement of both tests and the prospective assessment of test performance based on clinical outcomes in ACLF patients. Therefore, ACLF patients were additionally subgrouped by bleeding events. Fifty-five Non-ACLF patients and twenty-two patients with ACLF were analysed in this prospective cohort study. Results Coagulation parameters analysed by CCT were outside the normal range in Non-ACLF and ACLF patients, but were significantly more aberrant in ACLF patients. Non-ACLF patients analysed by ROTEM revealed parameters largely within the normal limits, while significantly more ROTEM parameters in ACLF patients were affected. Maximum clot firmness (MCF) was significantly divergent between both patient groups and correlated well with levels of fibrinogen and platelet count. Using Cohen’s Kappa coefficient κ, the strength of agreement between CCT and ROTEM analyses was determined to be fair for Non-ACLF patients and moderate for ACLF patients. Bleeding events occurred significantly more often in ACLF group with significantly reduced A10 and MCF. Conclusions For assessing hemostasis in Non-ACLF and ACLF patients the underlying dataset shows advantages of ROTEM over CCT. A10 and MCF represent suitable prognostic parameters in predicting bleeding events in ACLF group.

Molecular weight of Hydroxyethyl Starch Molecules influences Coagulation Profile measured by thrombelastography

2008 ◽  
Vol 94 (1) ◽  
pp. 7-13
Author(s):  
M Felfernig ◽  
S Virmani ◽  
M Weintraud ◽  
U Oberndorfer ◽  
M Zimpfer ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydroxyethyl Starch ◽  
Platelet Activating Factor ◽  
Maximum Amplitude ◽  
Coagulation System ◽  
Trauma Patients ◽  
Platelet Activity ◽  
Ringer’S Lactate ◽  
Plasmatic Coagulation ◽  
Key Words Coagulation

SummaryBackgroundThe consensus about the ideal intravenous fluid in trauma patients remains open. However, hypertonic saline and hydroxyethyl starch (HES) seems to have advantages in terms of immuno-modulatory and haemodynamic effects. Nevertheless clotting abnormalities are frequently reported in association with the use of HES. We investigated the influence of light, medium and heavy molecular weight (MW) hydroxyethyl starch (HES) on coagulation in 29 healthy subjects.MethodsRinger’s lactate (RL) served as a control solution. Thrombelastography using Haemoscope’s Thrombelastograph® (TEG®) hemostasis system was used to assess the effect of HES polymers and RL. TEG analysis was performed using recalcified native whole blood both with and without the addition of platelet activating factor IV (PAF IV) before and immediately after infusion of one of the solutions.ResultsInfusion of RL or one of the three HES solutions exerts an anticoagulant effect as demonstrated by a increase in clot formation time (R) and a decrease in maximum amplitude (MA), and the angle. The addition of PAF IV reversed these changes.ConclusionsThis data indicate clear evidence of platelet activity per se or platelet interaction with the plasmatic coagulation system. Key words: Coagulation, thrombelastography, platelets, hydroxyethyl-starch

scholarly journals Secondary Analysis of an Electronic Surveillance System Combined with Multi-focal Interventions for Early Detection of Sepsis

2017 ◽  
Vol 26 (01) ◽  
pp. 47-66 ◽  
Author(s):  
Bonnie Westra ◽  
Sean Landman ◽  
Pranjul Yadav ◽  
Michael Steinbach
Keyword(s):  
Early Detection ◽  
Surveillance System ◽  
Point Of Care ◽  
Management Strategies ◽  
Secondary Analysis ◽  
Length Of Hospital Stay ◽  
Separate Analysis ◽  
Electronic Surveillance ◽  
Predictive Values ◽  
Sensitivity Specificity

SummarySummary: To conduct an independent secondary analysis of a multi-focal intervention for early detection of sepsis that included implementation of change management strategies, electronic surveil-lance for sepsis, and evidence based point of care alerting using the POC AdvisorTM application. Methods: Propensity score matching was used to select subsets of the cohorts with balanced covariates. Bootstrapping was performed to build distributions of the measured difference in rates/ means. The effect of the sepsis intervention was evaluated for all patients, and High and Low Risk subgroups for illness severity. A separate analysis was performed patients on the intervention and non-intervention units (without the electronic surveillance). Sensitivity, specificity, and the positive predictive values were calculated to evaluate the accuracy of the alerting system for detecting sepsis or severe sepsis/ septic shock.Results: There was positive effect on the intervention units with sepsis electronic surveillance with an adjusted mortality rate of –6.6%. Mortality rates for non-intervention units also improved, but at a lower rate of –2.9%. Additional outcomes improved for patients on both intervention and non-intervention units for home discharge (7.5% vs 1.1%), total length of hospital stay (-0.9% vs –0.3%), and 30 day readmissions (-6.6% vs –1.6%). Patients on the intervention units showed better outcomes compared with non-intervention unit patients, and even more so for High Risk patients. The sensitivity was 95.2%, specificity of 82.0% and PPV of 50.6% for the electronic surveillance alerts. Conclusion: There was improvement over time across the hospital for patients on the intervention and non-intervention units with more improvement for sicker patients. Patients on intervention units with electronic surveillance have better outcomes; however, due to differences in exclusion criteria and types of units, further study is needed to draw a direct relationship between the electronic surveillance system and outcomes.

scholarly journals Fecal Calprotectin in Combination With Standard Blood Tests in the Diagnosis of Inflammatory Bowel Disease in Children

2021 ◽  
Vol 8 ◽  
Author(s):  
Shaun S. C. Ho ◽  
Michael Ross ◽  
Jacqueline I. Keenan ◽  
Andrew S. Day
Keyword(s):  
Inflammatory Bowel Disease ◽  
Platelet Count ◽  
Bowel Disease ◽  
Predictive Value ◽  
Screening Test ◽  
Fecal Calprotectin ◽  
Non Invasive ◽  
Blood Tests ◽  
Inflammatory Bowel ◽  
Sensitivity Specificity

Introduction: Fecal calprotectin (FC) is a useful non-invasive screening test but elevated levels are not specific to inflammatory bowel disease (IBD). The study aimed to evaluate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FC alone or FC in combination with other standard blood tests in the diagnosis of IBD.Methods: Children aged &lt;17 years who had FC (normal range &lt;50 μg/g) measured and underwent endoscopy over 33 months in Christchurch, New Zealand were identified retrospectively (consecutive sampling). Medical records were reviewed for patient final diagnoses.Results: One hundred and two children were included; mean age was 12.3 years and 53 were male. Fifty-eight (57%) of the 102 children were diagnosed with IBD: 49 with Crohn's disease, eight with ulcerative colitis and one with IBD-unclassified. FC of 50 μg/g threshold provided a sensitivity of 96.6% [95% confident interval (CI) 88.3–99.4%] and PPV of 72.7% (95% CI 61.9–81.4%) in diagnosing IBD. Two children with IBD however were found to have FC &lt;50 μg/g. Sensitivity in diagnosing IBD was further improved to 98.3% (95% CI 90.7–99.1%) when including FC &gt;50 μg/g or elevated platelet count. Furthermore, PPVs in diagnosing IBD improved when FC at various thresholds was combined with either low albumin or high platelet count.Conclusion: Although FC alone is a useful screening test for IBD, a normal FC alone does not exclude IBD. Extending FC to include albumin or platelet count may improve sensitivity, specificity, PPV and NPV in diagnosing IBD. However, prospective studies are required to validate this conclusion.

scholarly journals Identification of hypercoagulability with thrombelastography in patients with hip fracture receiving thromboprophylaxis

2021 ◽  
Vol 64 (3) ◽  
pp. E324-E329
Author(s):  
Daniel You ◽  
Leslie Skeith ◽  
Robert Korley ◽  
Paul Cantle ◽  
Adrienne Lee ◽  
...  
Keyword(s):  
Hip Fracture ◽  
Point Of Care ◽  
Common Complication ◽  
Maximal Amplitude ◽  
Clot Strength ◽  
Hip Fracture Surgery ◽  
Point Of Care Test ◽  
Trochanteric Region ◽  
Fracture Surgery ◽  
Over Time

Background: Venous thromboembolism (VTE) is the second most common complication after hip fracture surgery. We used thrombelastography (TEG), a whole-blood, point-of-care test that can provide an overview of the clotting process, to determine the duration of hypercoagulability after hip fracture surgery. Methods: In this prospective study, consecutive patients aged 51 years or more with hip fractures (trochanteric region or neck) amenable to surgical treatment who presented to the emergency department were eligible for enrolment. Thrombelastography, including calculation of the coagulation index (CI) (combination of 4 TEG parameters for an overall assessment of coagulation) was performed daily from admission until 5 days postoperatively, and at 2 and 6 weeks postoperatively. All patients received 28 days of thromboprophylaxis. We used single-sample t tests to compare mean maximal amplitude (MA) values (a measure of clot strength) to the hypercoagulable threshold of greater than 65 mm, a predictor of in-hospital VTE. Results: Of the 35 patients enrolled, 11 (31%) were hypercoagulable on admission based on an MA value greater than 65 mm, and 29 (83%) were hypercoagulable based on a CI value greater than 3.0; the corresponding values at 6 weeks were 23 (66%) and 34 (97%). All patients had an MA value greater than 65 mm at 2 weeks. Patients demonstrated normal coagulation on admission (mean MA value 62.2 mm [standard deviation (SD) 6.3 mm], p = 0.01) but became significantly hypercoagulable at 2 weeks (mean 71.6 mm [SD 2.6 mm], p < 0.001). There was a trend toward persistent hypercoagulability at 6 weeks (mean MA value 66.2 mm [SD 3.8 mm], p = 0.06). Conclusion: More than 50% of patients remained hypercoagulable 6 weeks after fracture despite thromboprophylaxis. Thrombelastography MA thresholds or a change in MA over time may help predict VTE risk; however, further study is needed.

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