scholarly journals Pediatric Thromboelastograph 6s and Laboratory Coagulation Reference Values

Author(s):  
Katie M. Moynihan ◽  
Kerry Johnson ◽  
Mark Rane ◽  
Andrew Norman ◽  
Susan Humphreys ◽  
...  

Context.— Specific reference intervals (RIs) facilitate accurate interpretation of results. Coagulation assay results may vary by demographics and also between reagents and analyzers used. Current Thromboelastograph 6s (TEG 6s) Hemostasis Analyzer RIs were generated from adult samples. Objective.— To generate reagent analyzer-specific pediatric RIs for TEG 6s and coagulation parameters. Design.— A prospective, observational, single-center study of healthy children undergoing general anesthesia (January 3, 2017 to January 3, 2019). Venous blood samples were obtained for TEG 6s (Kaolin, Kaolin-Heparinase, Rapid and Functional Fibrinogen assays) and coagulation parameters (activated partial thromboplastin time, prothrombin time, thrombin clotting time, Echis time, antithrombin activity, and fibrinogen concentration using Instrumentation Laboratory ACL-TOP analyzers). Differences between activated partial thromboplastin time and prothrombin time reagents were investigated using mixed-effects regression, comparing maximum coefficients-of-variation with assay-specific allowable variation. RIs (lower/upper limits 2.5th of 97.5th percentiles) were generated using the following 2 methods: within discrete age-groups (neonates [<1 month], infants [1 month–1 year], young children [1–5 years], older children [6–10 years], and adolescents [11–16 years]), and modeled as functions of age and/or sex using quantile regression, including significant fractional polynomial and interaction terms. Results.— Variation between prothrombin time and activated partial thromboplastin time assays using different reagents was clinically significant. Reagent-analyzer specific pediatric RIs were generated using data from 254 children. Discrete and model-based RIs varied by age for all coagulation parameters and TEG 6s variables in all assays. Conclusions.— We report reagent-analyzer specific pediatric RIs for TEG 6s and coagulation parameters. Observed variation reinforces recommendations for laboratory-specific RIs. These findings improve accuracy of interpretation of clinical results, provide a foundation for comparison and validation of tests in pathology and illustrate feasibility and advantages of model-based RI approaches.

Author(s):  
Э.М. Гаглоева ◽  
В.Б. Брин ◽  
С.В. Скупневский ◽  
Н.В. Боциева ◽  
Т.В. Молдован

Цель исследования - изучить состояние системы гемостаза при хронической интоксикации хлоридом никеля, исследовать взаимосвязь показателей гемокоагуляции с процессами липопероксидации у крыс в эксперименте. Методика. Опыты проводили на крысах-самцах Вистар (n=50, 230-250 г). Раствор NiCl2 (5 мг/кг) вводили внутрижелудочно ежедневно в течение 2 нед, 1 и 2 мес. По завершении эксперимента исследовали состояние тромбоцитарного и коагуляционного звеньев гемостаза, антикоагулянтную и фибринолитическую активность крови, а также определяли активность процессов перекисного окисления липидов и антиоксидантных ферментов. Результаты. Установлено, что через 2 нед и 1 мес интоксикации у крыс отмечались гиперкоагуляционные изменения показателей свертывающей системы крови: повышение агрегационной активности тромбоцитов, увеличение концентрации фибриногена, снижение активированного частичного тромбопластинового времени (АЧТВ) и протромбинового времени. В этот период регистрировалось увеличение антитромбиновой и фибринолитической активности крови. Через 2 мес наблюдалось подавление активности клеточного звена гемостаза - тромбоцитопения, ослабление степени АДФ-индуцируемой агрегации тромбоцитов. Выявлялась тенденция к уменьшению концентрации фибриногена. На фоне снижения АЧТВ и тромбинового времени отмечалось увеличение протромбинового времени. В то же время регистрировалось угнетение противосвертывающего звена системы гемостаза (снижалась активность антитромбина III), наблюдалось истощение резервных возможностей фибринолитического звена (замедление фXIIа-зависимого эуглобулинового лизиса) и увеличение содержания растворимых фибрин мономерных комплексов, что свидетельствует о наличии тромбинемии. Через 2 нед, один и два месяца интоксикации у животных выявлялись корреляционные связи между основными показателями системы гемостаза и активностью процессов перекисного окисления липидов и антиоксидантных ферментов. Заключение. Полученные данные подтверждают наличие взаимосвязи активности процессов липопероксидации и системы гемостаза, в том числе при хронической никелевой интоксикации. Результаты исследования позволяют рекомендовать применение антиоксидантов для разработки способов коррекции гемостатических сдвигов при воздействии на организм тяжелых металлов. The aim. To study the state of the hemostasis system in chronic nickel intoxication and to investigate the relationship between hemocoagulation indices and lipoperoxidation processes in rats. Methods. Experiments were carried out on male Wistar rats (n=50, 230-250 g). A solution of nickel chloride (5 mg/kg) was administered daily intragastrically for two weeks, one and two months. At the end of the experiments, indices of platelet and coagulation hemostasis systems, anticoagulant and fibrinolytic activity of blood plasma, and activities of lipid peroxidation and antioxidant enzymes were studied. Results. Hypercoagulative changes in indices of the coagulation system were observed in rats after two weeks and one month of intoxication, including increased platelet aggregation and fibrinogen concentration and shortened activated partial thromboplastin time and prothrombin time. During the same period, increased antithrombin and fibrinolytic activities were observed. The depressed activity of the cellular component of hemostasis evident as thrombocytopenia and impaired ADP-induced platelet aggregation was detected after two months of intoxication. A tendency to decrease in fibrinogen concentration was observed. The shortened activated partial thromboplastin time and thrombin time were associated with prolonged prothrombin time. At the same time, inhibition of the anticoagulant component of hemostasis (decreased antithrombin III activity), exhaustion of the fibrinolysis system reserve (delayed fXIIa-dependent euglobulin lysis), and a significant increase in soluble fibrin monomeric complexes indicative of thrombinemia were observed. After two weeks, one and two months of nickel intoxication, a correlation was found between the major indices of the hemostasis system and the activities of lipid peroxidation and antioxidant enzymes. Conclusion. The study confirmed a relationship between the lipid peroxidation activity and the hemostasis system, specifically in chronic nickel intoxication. This result allows to recommend the use of antioxidants in developing methods for correction of hemostatic induced affected by heavy metals.


2021 ◽  
Author(s):  
Polina Len ◽  
Gaukhar Iskakova ◽  
Zarina Sautbayeva ◽  
Aigul Kussanova ◽  
Ainur T. Tauekelova ◽  
...  

Introduction. Coagulation parameters are important determinants for COVID-19 infection. We conducted meta-analysis to assess the early hemostatic parameters in retrospective studies in association with severity of infection. Methods. Ovid, PubMed, Web of Sciences, and Google Scholar were searched for research articles that addressed clinical characteristics of COVID-19 patients and disease severity. Results were filtered using exclusion and inclusion criteria and then pooled into a meta-analysis to estimate the standardized mean difference with 95% CI for each of five coagulation parameters (D-dimers, fibrinogen, prothrombin time, platelets count, activated partial thromboplastin time). Two authors independently extracted data and assessed study quality. To explore the heterogeneity and robustness of our fundings, sensitivity and subgroup analyses were conducted. Publication bias was assessed with contour-enhanced funnel plots and Egger test by linear regression. Results. Overall, 41 original studies (17601 patients) on SARS-CoV2 were included. For the two groups of patients, stratified by severity, we identified that D-dimers, fibrinogen, activated partial thromboplastin time, and prothrombin time were significantly higher in the severe group (SMD 0.6985 with 95%CI [0.5155; 0.8815]); SMD 0.661with 95%CI [0.3387; 0.9833]; SMD 0.2683 with 95%CI [0.1357; 0.4009]; SMD 0.284 with 95%CI [0.1472; 0.4208]). In contrast, PLT was significantly lower in patients with more severe cases of COVID-19 (SMD -0.1684 with 95%CI [-0.2826; -0.0542]). Neither the analysis by the leave-one-out method nor the influence diagnostic have identified studies that solely cause significant change in the effect size estimates. Subgroup analysis showed no significant difference between articles originated from different countries but revealed that severity assessment criteria might have influence over estimated effect sizes for platelets and D-dimers. Contour-enhanced funnel plots and the Egger test for D-dimers and fibrinogen revealed significant asymmetry that might be a sign of publication bias. Conclusions. The standard coagulation laboratory parameters with exception of platelets counts are significantly elevated in patients with severe COVID-19. However, fibrinolysis shutdown requires evaluation outside conventional coagulation tests and analysis of additional specific markers related to clotting formation and PLT characteristics. We hypothesize that a proportion and parameters of immature reticulated platelets may serve as additional biomarkers for prediction of adverse events.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5248-5248
Author(s):  
Bhaumik Arvindkumar Shah ◽  
Arulselvi Subramanium ◽  
Subhadra Sharma ◽  
Deepak Agrawal ◽  
Gaurav Chhabra ◽  
...  

Abstract Abstract 5248 In India trauma related deaths occur every 1.9 minutes. Mortality in severe traumatic injury (ISS>16) is six times higher in developing country like India. Coagulopathy is observed in almost 25– 30% of trauma patients which itself is an independent risk factor for haemorrhage. Coagulopathy detected early after injury is indicative of injury severity and itself is a prognostic factor for mortality. Aim To find out the usefulness of thromboelastography (TEG) in detecting coagulopathy in contrast to conventional methods of plasma based standard coagulation parameters (PT, aPTT, TT, fibrinogen, D-dimer) Objective To detect coagulopathy early by TEG in trauma patients within 24 hrs after injury which can be useful to guide haemostatic therapies to reduce mortality. Materials and methods Patients admitted to trauma casualty were studied within 24 hrs after injury. Native whole blood was withdrawn through venepuncture appropriately in syringe using 21G needle and TEG was performed within 2 mins. Blood was also collected in citrated tube to assess standard coagulation parameters (prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, D-dimer) and also by means of thromboelastography. Results Patients (n=87,New ISS-24.78(mean)) admitted to J.P.N Apex trauma centre casualty from 1st April,2011 to 31st July,2011 were studied. The cases included in the study were isolated head injury (n=40, NISS-25.87(mean)), multiple trauma with head injury (n=13,NISS – 30.69 (mean)) and trauma other than head injury (n=34, NISS-21.24 (mean)).Thromboelastography was performed using whole blood (n=69) and citrated blood (n=18). Coagulation tests were performed on all 87 patients using both TEG and conventional coagulation parameters. Total 52 patients showed coagulopathy by TEG and only 14 patients showed coagulopathy by standard coagulation parameters (prothrombin time, activated partial thromboplastin time). Only in 10 cases coagulopathy was detected by both methods. 4 patients showed coagulopathy only by conventional methods while 42 patients showed coagulopathy by only Thromboelastography (TEG). To find out whether there is any stastistical significance in the observed apparently better result by TEG, McNemar Test was carried out and P value was <0.0001. Conclusion Thromboelastography could be a better technique as compared to conventional measurements of PT, aPTT, TT, Fibrinogen, D-dimer in early detection of coagulopathy in trauma patients. Disclosures: No relevant conflicts of interest to declare.


2016 ◽  
Vol 19 (2) ◽  
pp. 359-364
Author(s):  
A. Snarska ◽  
P. Sobiech

Abstract The aim of the study was to evaluate the megakaryocyte lineage of bone marrow and coagulation parameters in fallow deer during the last month of pregnancy. The animals were managed in the barn-feeding system. Twenty female fallow deer, aged 2-3 years, divided into 2 groups were used in the study. Group 1 comprised the females in the last month of pregnancy, and the non-pregnant females were used as the control. All the animals were clinically healthy. Coagulation parameters were measured in all the deer: thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), and plasma concentrations of fibrinogen, D-dimer, and antithrombin III. A quantitative assessment of bone marrow was carried out for the erythroblastic, myeloid, lymphoid, monocyte-macrophage, and megakaryopoietic cell lines. A detailed analysis of megakaryocyte lineage was performed after whole blood and platelet count. There were no significant differences in the erythroblast, granulocyte, monocyte-macrophage and lymphoid systems between the animal groups. Thrombocyte count in the pregnant deer was lower than that found in the control group. Bone marrow smears revealed a slightly decreased megakaryocyte count, while the megakaryoblast and promegakaryocyte counts were unchanged. The analysis of coagulation parameters showed increased levels of fibrinogen, thrombin time, prothrombin time and activated partial thromboplastin time in the pregnant animals. The study suggested a hyperactivation of the coagulation system with a slight reduction in the megakaryocyte count in bone marrow, and a reduction in platelet count in peripheral blood at the end of pregnancy.


2009 ◽  
Vol 21 (5) ◽  
pp. 674-678 ◽  
Author(s):  
Stefania Casella ◽  
Claudia Giannetto ◽  
Francesco Fazio ◽  
Elisabetta Giudice ◽  
Giuseppe Piccione

The aim of the present study was to assess the effect of different storage conditions on prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen concentration in clinical samples from healthy horses. A total of 100 healthy horses of varying breeds and gender, ranging in age from 4 to 18 years, with a mean body weight of 480 + 70 kg, were used. Blood was collected by jugular venipuncture, and a hemochrome-cytometric examination was conducted on all samples. All blood samples were centrifuged and divided into 4 different aliquots to assess clotting parameters by means of a coagulometer. The first aliquots were analyzed 1 hr after collection, the second aliquots were refrigerated at 8°C for 6 hr, the third aliquots were frozen at −20°C for 24 hr, and the fourth aliquots were frozen at −20°C for 48 hr. Significant differences ( P < 0.05) were determined by one-way analysis of variance with repeated measures, and statistical analysis showed a significant effect of the experimental conditions on all parameters studied. In particular, the results demonstrated that coagulation tests can be done within 6 hr when samples are stored at 8°C because the short-term refrigeration does not change the result of analyses; storage at −20°C is acceptable only after 24 hr for PT, aPTT, and fibrinogen measurements because after 48 hr, freezing alters the values of clotting parameters. Therefore, the results of this investigation indicate that clotting parameters remain stable only up to 24 hr in horses without adversely affecting hemostasis test results.


Author(s):  
N. V. Galeeva ◽  
I. E. Kravchenko

Goal of the study is to reveal the particular features of hemostasis in patients with chronic hepatitis C in dynamics of natural course of disease. Materials and methods. The indices of hemostasis in 535 patients with chronic hepatitis C were assessed by the number of platelets, degree of their aggregation with the use of inductor of adenosine triphosphate and without it (spontaneous aggregation of platelets). Coagulative hemostasis was analyzed by the activated partial thromboplastin time, antitrombin III, prothrombin ratio, prothrombin time, fibrinogen concentration in plasma and international normalized ratio. Based on the number of Tr, typical for the disseminated intravascular coagulation syndrome, conditionally the patients were divided into 3 groups: I group - hypercoagulability; II - transient phase between hyper and hypocoagulation and III- hypocoagulation, which also included patients with liver cirrhosis. Results and discussion. Independent on the phase of disseminated intravascular coagulation syndrome, increase of aggregation of Tr with the growth of maximal amplitude was observed. The main part of studied indices of coagulative hemostasis indicated at the condition of hypocoagulation in patients with chronic hepatitis C - this is significant increase of activated partial thromboplastin time, prothrombin time, international normalized ratio and decrease of fibrinogen concentration in the studied groups by the phases of disseminated intravascular coagulation syndrome. Value of antitrombin III changed oppositely, it decreased, so that plasma hemostasis tends to the hypercoagulation. Conclusion. Under the chronic hepatitis C all phases of disseminated intravascular coagulation syndrome were observed with the disorder of thrombocytic coagulative hemostasis. There was followed up multidirectional change of hemostasis which obtained in the most cases character of delitescent course of disseminated intravascular coagulation syndrome.


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