Evaluación preoperatoria de la hemostasia en cirugía mayor electiva / Preoperative evaluation of hemostasis in elective major surgery

Resumen: Introducción: Las pruebas de coagulación carecen de valor para determinar el riesgo de sangrado perioperatorio. Material y métodos: Se realizó un estudio observacional, descriptivo, y transversal en 2,114 pacientes en la consulta de Anestesiología del Hospital Universitario «Dr. Celestino Hernández Robau¼, los resultados se evaluaron mediante estadística descriptiva. Resultados: El tiempo de coagulación y sangrado se realizó en 100% de los casos y el conteo de plaquetas en 93.99%, mientras que el tiempo de protrombina y tiempo de tromboplastina parcial activado se efectuó en 66.27 y 55.62% de los casos respectivamente. De 8.834 exámenes realizados se encontraron 49 alterados en 0.55%. Los pacientes con exámenes alterados fueron 33 en 1.56%, los enfermos en riesgo de sangrado por exámenes de coagulación fueron 30 en 1.42% y los pacientes en riesgo sin antecedentes de sangrados detectados por exámenes de coagulación fueron tres en 0.14%. Se reportó sangrado perioperatorio en 16 pacientes en 0.76%, siete pacientes con interrogatorio positivo y exámenes normales y nueve pacientes con interrogatorio negativo y exámenes normales. Conclusiones: La historia clínica y el examen físico del paciente son las mejores herramientas para predecir el riesgo de sangrado quirúrgico y los exámenes aislados de coagulación no constituyen un buen predictor del sangrado perioperatorio.

Abstract: Introduction: Coagulation tests are no value to determine the risk of perioperative bleeding. Material and methods: An observational descriptive cross-sectional study was carried out in 2,114 patients in the anesthesiology consultation of the University Hospital «Dr. Celestino Hernández Robau¼. Results: The clotting and bleeding time was performed in 100% of cases, the platels count in 93.99%. While the prothrombin time and activated partial tromboplastin time were performed in 66.27 and 55.62% respectively. Of 8,834 tests carried out, 49 were found to be altered for 0.55%. Patients with altered tests were for 1.56%, patients at risk of bleeding from coagulation tests were 30 for 1.42% and patients at risk with no history of bleeding detected by coagulation tests were three for 0.14%. Perioperative bleeding was reported in 16 patients for 0.76%, seven patients with positive questioning and normal tests and nine patients with negative questioning and normal tests. Conclusions: The patient's medical history and physical examination are the best tools to predict the risk of surgical bleeding and isolated coagulation tests do not constitute a good predictor of perioperative bleeding.

Predictive value of thromboelastography combined with conventional coagulation tests for deep vein thrombosis in preoperative trauma patients / 中华急诊医学杂志

Objective:To analyze the relationship between preoperative deep vein thrombosis (DVT) and parameters of conventional coagulation tests (CCTs) and thromboelastography (TEG) in patients with acute trauma, and to establish a prediction model to screen out high-risk patients with preoperative DVT.Methods:The clinical data of patients with acute traumatic fracture admitted to the Emergency Intensive Care Unit of Shanghai Sixth People’s Hospital from January 2021 to June 2021 were retrospectively collected. According to whether preoperative DVT occurred, the patients were divided into the DVT group and non-DVT group. The differences of CCTs and TEG parameters at the same time were compared between the two groups. Logistic regression analysis was applied to identify independent risk factors for DVT after trauma. The receiver-operating characteristic curve analysis was employed to analyze the clinical value of those parameters to predict preoperative DVT.Results:Among 123 patients with acute traumatic fracture, 101 patients were treated with anticoagulation before operation, and 51 patients were diagnosed with DVT. There were significant differences in activated partial thromboplastin time, fibrinogen (Fib), D-Dimer, fibrinogen degradation products (FDPs), reaction time, clotting time, α angle, maximum amplitude (MA) and coagulation index between the DVT and non-DVT groups. D-Dimer and MA were independent risk factors for preoperative DVT in patients with traumatic fracture. Logistic regression equation was used to establish a prediction model: the predicting index = 0.101×D-Dimer +0.241×MA + (-18.190). The α angle (AUC=0.833, P<0.001), MA (AUC=0.904, P<0.001), coagulation index (AUC=0.914, P<0.001) of TEG versus Fib (AUC=0.684, P=0.001), D-Dimer (AUC=0.685, P<0.001) and FDPs (AUC=0.656, P=0.003) of CCTs had a higher diagnostic efficacy in developing DVT of lower extremity in patients with traumatic fracture, and of all the coagulation index was the best. However, the predictor of D-Dimer combined with MA had a better predictive value (AUC=0.926, P<0.001), and the best cut-off value was 0.32 with a sensitivity and specificity of 90.2% and 79.8%, respectively. Conclusions:Compared with CCTs, TEG has more advantages in predicting preoperative DVT in patients with traumatic fracture, and the predictor of D-Dimer combined with MA can screen out patients with high risk of DVT, which can be recommended for clinical application.

Comparing modified Lee and White method against 20-minute whole blood clotting test as bedside coagulation screening test in snake envenomation victims

Abstract Background: Twenty-minute whole blood clotting test (20WBCT) and Modified Lee and White (MLW) method are the most routinely employed bedside tests for detecting coagulopathic snake envenomation. Our study compared the diagnostic utility of MLW and 20WBCT for snakebite victims at a tertiary care hospital in Central Kerala, South India. Methods: This single-center study recruited 267 patients admitted with snake bites. 20WBCT and MLW were performed simultaneously at admission along with the measurement of Prothrombin Time (PT). The diagnostic utility of 20WBCT and MLW was determined by comparing the sensitivity (Sn), specificity (Sp), positive and negative predictive values, likelihood ratios, and accuracy at admission with an INR value > 1.4. Results: Out of 267 patients, 20 (7.5%) patients had VICC. Amongst those who had venom-induced consumption coagulopathy (VICC), MLW was prolonged for 17 patients, (Sn 85% 95% confidence interval [CI]: 61.1-96.0) whereas 20WBCT was abnormal for 11 patients (Sn 55%, 95% CI: 32.04-76.17). MLW and 20WBCT were falsely positive for the same patient (Sp 99.6%, 95% CI: 97.4-99.9%). Conclusion: MLW is more sensitive than 20WBCT to detect coagulopathy at the bedside amongst snakebite victims. However, further studies are necessary for standardizing bedside coagulation tests in snakebite cases.

Efecto de las diferentes drogas anticoagulantes sobre el ensayo de fibrinógeno derivado del tiempo de protrombina / Effect of different anticoagulant drugs on the prothrombin time-derived fibrinogen assay

Resumen El objetivo de este trabajo fue comparar los niveles de fibrinógeno (FBG) obtenidos por el método de Clauss con los obtenidos por el método de fibrinógeno derivado del tiempo de protrombina (FBG PT-d), con dos tromboplastinas, en pacientes anticoagulados con distintas drogas. Se estudiaron pacientes anticoagulados consecutivos: 105 con antagonistas de la vitamina K (AVK), 55 con heparina no fraccionada (HNF), 58 con heparina de bajo peso molecular (HBPM), 60 con rivaroxabán, 45 con apixabán, 60 con dabigatrán y 100 controles normales (CN). El FBG se determinó por el método de Clauss y FBG PT-d utilizando tromboplastina de cerebro de conejo o recombinante humana; los niveles de heparina, rivaroxabán y apixabán por método cromogénico anti Xa; el dabigatrán con el ensayo de tiempo de trombina diluido. Existió un sesgo positivo (p<0,001) al comparar el FBG PT-d vs. FBG por Clauss: CN: 13,7%, AVK: 31,8%, rivaroxabán: 34,8% y apixabán: 20,0% cuando se utilizó tromboplastina de conejo. En el caso de las muestras que contenían HBPM se observó este desvío con ambas tromboplastinas. El sesgo porcentual en presencia de dabigatrán y heparina no fraccionada no fue estadísticamente distinto del obtenido en el grupo control. El ensayo de FBG PT-d no debe utilizarse en pacientes anticoagulados con rivaroxabán, apixabán, HBPM o AVK, ya que sobreestima los niveles de FBG. El porcentaje de sesgo depende del tipo de tromboplastina utilizado y fue mayor con la de cerebro de conejo en el sistema de detección utilizado.

Abstract The aim of this study was to compare fibrinogen (FBG) results obtained by Clauss method (FBG-C) and by the prothrombin time-derived fibrinogen assay (FBG PT-d) with two thromboplastins in patients under anticoagulation. Consecutive anticoagulated patients were studied: 105 vitamin-K antagonist (VKA), 55 unfractioned heparin, 58 LMWH, 60 rivaroxaban, 45 apixaban and 60 dabigatran, and 100 healthy controls (NC). FBG-C was performed by Clauss and FIB PT-d with rabbit brain and human recombinant thromboplastins, respectively. Heparins, rivaroxaban and apixaban levels were measured by antiXa; dabigatran by thrombin diluted assay. A positive bias of FBG PT-d vs. FBG-C with both thromboplastins were seen in NC (13.7 and 19.0 % for HS and RP, respectively), but bias with HS in rivaroxaban, apixaban and VKA patients were significantly higher compared to NC: 34.8%, 20.0 % and 31.8 %, respectively. LMWH presented higher BIAS compared to NC with both thromboplastins. Samples with unfraction heparin and dabigatran presented similar bias to NC. FBG PT-d should not be used in patients under anticoagulant treatment because of an important overestimation of FBG could be obtained in these patients. The percentage of bias depends on the type of thromboplastin used; it was higher with rabbit brain thromboplastin in the detection system used.

Resumo O objetivo deste trabalho foi comparar os níveis de fibrinogênio (FBG) obtidos pelo método de Clauss com aqueles obtidos pelo método do fibrinogênio derivado do tempo de protrombina (FBG PT-d), com duas tromboplastinas, em pacientes anticoagulados com diferentes drogas. Pacientes anticoagulados consecutivos foram estudados: 105 com antagonista da vitamina K (AVK); 55 com heparina não fracionada (UFH); 58 com heparina de baixo peso molecular (HBPM), 60 com rivaroxabana, 45 com apixabana, 60 com dabigatrana e 100 controles normais (CN). FBG foi determinado pelo método de Clauss e FBG PT-d usando tromboplastina de cérebro de coelho ou tromboplastina humana recombinante; níveis de heparina, rivaroxabana e apixabana pelo método cromogênico anti-Xa; dabigatrana com ensaio de tempo de trombina diluída. Há um viés positivo (p<0,001) ao comparar o FBG PT-d vs FBG de Clauss: CN: 13,7%; AVK: 31,8%, rivaroxabana: 34,8% e apixabana 20,0% quando foi utilizada tromboplastina de coelho. No caso das amostras contendo HBPM, esse desvio foi observado com ambas as tromboplastinas. O viés percentual na presença de dabigatrana e heparina não fracionada não foi estatisticamente diferente daquela obtida no grupo controle. O ensaio de FBG PT-d não deve ser usado em pacientes anticoagulados com rivaroxabana, apixabana, LMWH ou VKA, pois superestima os níveis de FBG. A porcentagem de viés depende do tipo de tromboplastina utilizado e foi maior com a de cérebro de coelho, no sistema de detecção utilizado.

Changes in hemostasis and clinical significance of coagulation function test in patients with liver cirrhosis / 临床肝胆病杂志

The liver plays an important role in procoagulant and anticoagulant mechanisms in human body. There are complex changes in hemostasis in patients with liver cirrhosis, with the presence of interaction between the portal venous system and the peripheral system and differences in etiology, and such patients have a dual trend of hemorrhage and thrombosis. At present, there are certain limitations in coagulation function tests commonly used in clinical practice. The primary etiology and results of various coagulation tests should be considered before initiation of anticoagulant therapy for patients with liver cirrhosis, so as to make the best clinical decisions for patients.

Efficacy of the 20-minute whole blood clotting test (WBCT20) in the diagnosis of coagulation alteration related to snakebites in a Western Brazilian Amazon hospital

Abstract Introduction: The efficacy of 20-minute whole blood clotting (WBCT20) and the Lee-White clotting time (LWCT) tests in diagnosing coagulation alterations from snakebites were compared. Methods: We evaluated 89 snakebite cases treated at the Hospital Regional do Juruá em Cruzeiro do Sul, Acre, Brazil. Results: WBCT20 results were normal in 33.7% and unclottable in 66.3% of cases, while LWCT results were normal in 23.6% and altered (prolonged or unclottable) in 76.4% of cases, with no significant differences. Conclusions: The WBCT20 is important for rapidly diagnosing coagulation alterations from snakebites. Furthermore, it is efficient, inexpensive, and can be deployed in isolated hospitals.

A Retrospective Study on Unfractionated Bovine Heparin Safety in On-Pump Cardiac Surgery

Abstract Background: Heparin decreases the risks of thrombotic phenomena in extracorporeal circulation. However, it must present a robust safety profile itself, especially for bleeding. Contamination of porcine heparin demands an alternative source and consequent assessment of safety. Objective: To evaluate the safety of unfractionated bovine heparin during on-pump cardiac surgery. Methods: Descriptive, retrospective study, evaluating medical records from all patients who had on-pump cardiac surgery over four years. We observed the occurrence of bleeding, thrombocytopenia, postoperative vasoplegia, activated clotting time values and any other coagulation phenomena as safety profile parameters. Results: We evaluated 204 medical records reporting the use of unfractionated bovine heparin. 66.18% of the patients presented thrombocytopenia, 1.04% presented bleeding of more than 2000 mL in the first 24 hours of the postoperative period. One patient presented clots in the surgical field. Median activated clotting time was 137 seconds at baseline, 803 seconds after the first dose of heparin and, after protamine, it returns to similar baseline values, that is, 149.5 seconds. Conclusion: Unfractionated bovine heparin did not present unusual adverse effects and can be considered safe for on-pump cardiac surgery.

Performance of HemosIL ReadiPlasTin, a Liquid Reagent for Prothrombin Time Measurement / 임상검사와정도관리

BACKGROUND: Prothrombin time (PT) measurement is an important test for screening blood coagulation disorders and monitoring anticoagulant therapy. In this study, we evaluated the analytical performance of HemosIL ReadiPlasTin (Instrumentation Laboratory, USA), a liquid reagent for PT measurement. METHODS: The precision of HemosIL ReadiPlasTin was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) EP5-A3 guidelines. Further, comparison with HemosIL RecombiPlasTin 2G (Instrumentation Laboratory, USA) was made according to the CLSI EP9-A3 guidelines. The reference intervals were established according to the CLSI C28-A3 guidelines. RESULTS: The coefficient of variation values for repeatability and total imprecision at two levels of control materials were lower than 1.1% and 3.4%, respectively. The performance of HemosIL ReadiPlasTin was comparable to that of HemosIL RecombiPlasTin 2G, with a high correlation (r=0.996). The reference interval for normal subjects was 10.4–13.3 seconds. CONCLUSIONS: HemosIL ReadiPlasTin showed an acceptable degree of imprecision and its performance showed high correlation with that of a conventional reagent. Therefore, it is expected to be useful for PT measurement in clinical laboratories.

Effect of different doses of low molecular weight heparin on coagulation mechanism in thoracic cancer surgery / 中国医师杂志

Objective@#To study the effect of different doses of low molecular weight heparin on coagulation mechanism after thoracic surgery.@*Methods@#A prospective randomized controlled study was conducted to select patients who underwent thoracic cancer surgery (lung cancer, esophageal cancer, cardiac cancer) from February 2015 to October 2018. According to the Caprini risk assessment model, 101 patients with high risk of deep venous thrombosis were randomly assigned to groups A, B and C. Control group A (34 cases) did not use low molecular weight heparin; group B (34 cases) used prophylactic low molecular weight heparin calcium after operation; group C (33 cases) used therapeutic low molecular weight heparin calcium after operation. The platelet count (PLT), fibrinogen (FIB), prothrombin time (PT), D-dimer (D-D), postoperative thoracic drainage and lower extremity deep vein ultrasound were observed before and after operation.@*Results@#The incidence of deep venous thrombosis (DVT) was 11.76% in group A, 2.94% in group B and 3.03% in group C, with significant difference between group B and C and group A (P<0.05), but there was no significant difference between group B and C (P>0.05). The levels of FIB and D-D after operation were significantly higher than those before operation (P<0.05), but the levels of indexes in group B and C were significantly lower than those in group A (P<0.05).@*Conclusions@#Low molecular weight heparin calcium does not increase bleeding and thoracic drainage, which is beneficial to improve the hypercoagulable state of patients and has good safety. However, the use of low molecular weight heparin calcium in different doses (prevention amount and treatment amount) has no significant effect on the occurrence of lower extremity deep vein thrombosis and coagulation index.

The comparative study between thromboelastography and conventional coagulation tests in ischemic cerebral vascular disease / 中华急诊医学杂志

Objective@#To explore the correlation and consistency between thromboelastography (TEG) and traditional coagulation tests (CCTs) in ischemic cerebral vascular disease (ICVD).@*Methods@#Totally 108 ICVD patients admitted to Nanyang Central Hospital from May 1 to October 31 2018 were enrolled. Patients’ TEG parameters (R value, K value, Angle value, MA value, CI value and G value) and CCTs parameters (PT, APTT, TT, and FIB) were collected and analyzed retrospectively. The Spearman correlation coefficient was used to explore the correlation between TEG and CCTs parameters, and Kappa (κ) to explore the consistency in determining the coagulation status of the patients. The ROC curve was used to analyze the predictive value of TEG parameters for abnormal results of CCTs, and the results of TEG and CCTs were comprehensively analyzed to evaluate the ability to predict the coagulation status of patients.@*Results@#(1) PLT was positively correlated with MA value and G value; PT and APTT were positively correlated with K value; TT was positively correlated with R value and K value; FIB was positively correlated with Angle value, MA value and G value. TT was negatively correlated with Angle value and CI value; FIB was negatively correlated with K value. (2) PT and MA values, PT and G values, FIB and MA values, FIB and G values were accordant in valuing the hypoxic state of ICVD patients. (3) PLT and Angle values, PLT and MA values, PLT and CI values, PLT and G values were accordant in assessing hypercoagulable status of ICVD patients; FIB and Angle values, FIB and MA values, FIB and CI value, and FIB and G value were consistent in evaluating the hypercoagulable state of ICVD patients. (4) For detecting TT>20 s, the AUC of K value and Angle value were 0.648, 0.651, respectively; For detecting FIB>4 g/L, the AUC of Angle value and MA value were 0.717 and 0.747, respectively; For detecting PLT>300×109/L, the AUC of MA value was 0.808 (all P<0.05).@*Conclusions@#There is weak correlation and consistency between TEG and CCTs parameters in ICVD patients. The TEG parameters have good predictive value in evaluating the abnormal results of CCTs, but cannot replace the CCTs. Combination of these two methods can better reflect the coagulation status of patients, so as to afford assistance.

Effect of different doses of low molecular weight heparin on coagulation mechanism in thoracic cancer surgery / 中国医师杂志

Objective To study the effect of different doses of low molecular weight heparin on coagulation mechanism after thoracic surgery.Methods A prospective randomized controlled study was conducted to select patients who underwent thoracic cancer surgery (lung cancer,esophageal cancer,cardiac cancer) from February 2015 to October 2018.According to the Caprini risk assessment model,101 patients with high risk of deep venous thrombosis were randomly assigned to groups A,B and C.Control group A (34 cases) did not use low molecular weight heparin;group B (34 cases) used prophylactic low molecular weight heparin calcium after operation;group C (33 cases) used therapeutic low molecular weight heparin calcium after operation.The platelet count (PLT),fibrinogen (FIB),prothrombin time (PT),D-dimer (D-D),postoperative thoracic drainage and lower extremity deep vein ultrasound were observed before and after operation.Results The incidence of deep venous thrombosis (DVT) was 11.76％ in group A,2.94％ in group B and 3.03％ in group C,with significant difference between group B and C and group A (P ＜ 0.05),but there was no significant difference between group B and C (P ＞ 0.05).The levels of FIB and D-D after operation were significantly higher than those before operation (P ＜ 0.05),but the levels of indexes in group B and C were significantly lower than those in group A (P ＜ 0.05).Conclusions Low molecular weight heparin calcium does not increase bleeding and thoracic drainage,which is beneficial to improve the hypercoagulable state of patients and has good safety.However,the use of low molecular weight heparin calcium in different doses (prevention amount and treatment amount) has no significant effect on the occurrence of lower extremity deep vein thrombosis and coagulation index.

The comparative study between thromboelastograpby and conventional coagulation tests in ischemic cerebral vascular disease / 中华急诊医学杂志

Objective To explore the correlation and consistency between thromboelastograpby(TEG)and traditional coagulation tests(CCTs)in ischemic cerebral vascular disease(ICVD).Methods Totally 108 ICVD patients admitted to Nanyang Central Hospital from May 1 to October 31 2018 were enrolled.Patients' TEG parameters(R value,K value,Angle value,MA value,CI value and G value)and CCTs parameters(PT,APTT,TT,and FIB)were collected and analyzed retrospectively.The Spearman correlation coefficient was used to explore the correlation between TEG and CCTs parameters,and Kappa(κ)to explore the consistency in determining the coagulation status of the patients.The ROC curve was used to analyze the predictive value of TEG parameters for abnormal results of CCTs,and the results of TEG and CCTs were comprehensively analyzed to evaluate the ability to predict the coagulation status of patients.Results(1)PLT was positively correlated with MA value and G value; PT and APTT were positively correlated with K value; TT was positively correlated with R value and K value; FIB was positively correlated with Angle value,MA value and G value.TT was negatively correlated with Angle value and CI value; FIB was negatively correlated with K value.(2)PT and MA values,PT and G values,FIB and MA values,FIB and G values were accordant in valuing the hypoxic state of ICVD patients.(3)PLT and Angle values,PLT and MA values,PLT and CI values,PLT and G values were accordant in assessing hypercoagulable status of ICVD patients; FIB and Angle values,FIB and MA values,FIB and CI value,and FIB and G value were consistent in evaluating the hypercoagulable state of ICVD patients.(4)For detecting TT＞20 s,the AUC of K value and Angle value were 0.648,0.651,respectively;For detecting FIB＞4 g/L,the AUC of Angle value and MA value were 0.717 and 0.747,respectively; For detecting PLT＞ 300× 109/L,the AUC of MA value was 0.808(all P＜0.05).Conclusions There is weak correlation and consistency between TEG and CCTs parameters in ICVD Patients.The TEG parameters have good predictive value in evaluating the abnormal results of CCTs,but cannot replace the CCTs.Combination of these two methods can better reflect the coagulation status of patients,so as to afford assistance.

Thromboelastography:clinical applications and new development / 国际检验医学杂志

Under normal physiological conditions, hemostatic process is a dynamic balance process dependent on many factors.It involves interaction between primary hemostasis (vasoconstriction, platelet clot formation), secondary hemostasis (thrombin generation, fibrin polymerization) and fibrinolysis, and any abnormalities of the three may cause hemorrhagic or thrombotic diseases.Conventional coagulation tests are useful for a limited degree since they only reflect a portion of the coagulation cascade.Thromboelastography (TEG) provides a more complete picture of coagulation status, taking into account more factors involved in the clotting process, including platelet activity and clotting factors, which has been widely used in clinic.In this article, we will briefly discuss clinical applications and new development of TEG.

Utility of thromboelastography versus routine coagulation tests for assessment of hypocoagulable state in patients undergoing cardiac bypass surgery

Introduction: Peri-operative monitoring of coagulation is important to diagnose potential cause of hemorrhage, to manage coagulopathy and guide treatment with blood products in patients undergoing cardiac surgery with cardiopulmonary bypass. This study was done to evaluate usefulness of Thromboelastography (TEG) and routine coagulation tests (RCT) in assessing hemostatic changes and predicting postoperative bleeding in patients undergoing cardiac surgery with cardiopulmonary bypass. Methods: Fifty adult patients undergoing cardiac surgery with cardiopulmonary bypass were enrolled in this prospective study. Preoperative and post-operative samples were collected for routine coagulation tests and TEG. Regression analysis and test of significance using Pearson's correlation coefficient was performed to assess correlation between routine coagulation tests and corresponding TEG parameters .Regression analysis was done to study relation between blood loss at 24 hours and various coagulation parameters. Results: The Routine coagulation test i.e. PT, INR, APTT showed no significant correlation with corresponding TEG parameters in pre-operative samples. However platelet count significantly correlated (p = 0.004) with MA values in postoperative samples. A significant correlation (p = 0.001) was seen between fibrinogen levels and alpha angles as well as with MA in both baseline preoperative and postoperative samples. TEG parameters R time and MA in postoperative samples were the only parameters that predicted bleeders with fair accuracy. Conclusion: Though the techniques of RCT and TEG are different, a few RCT e.g. platelet count and fibrinogen correlated with corresponding TEG parameters i.e. MA and Alpha angle. TEG parameters (R time and MA in postoperative samples) were able to predict blood loss better than RCT.

Comparación preoperatoria entre pruebas de coagulación y tromboelastografía en pacientes con cirrosis hepática sometidos a trasplante hepático / Thromboelastography and classical coagulation tests in the preoperative period of liver transplantation

Background: Compared to standard coagulation essays (SCE), such as international normalized ratio (INR), prothrombin activated partial thromboplastin time (aPTT), or platelet count, thromboelastograhy (TEG) offers precise and real-time information about hemostasis. TEG tests both platelet function and coagulation by assaying several parameters of clot formation dynamically in whole blood. Aim: To evaluate hemostasis in cirrhotic patients undergoing liver transplantation and determine the positive and negative predictive values of SCE for alterations of TEG. Material and Methods: Preoperative SCE and TEG were prospectively analyzed in 25 patients. Results were categorized as normal, laboratory alteration or clinical alteration. SCE results were compared with TEG parameters to determine positive (PPV) and negative predictive values (NPV). Results: Hemostasis was abnormal and laboratory abnormalities were observed in all patients. One patient had clinical signs of excessive bleeding. SCE were abnormal in all patients and TEG was normal in nine patients. The most common alteration in TEG was hypocoagulability, in some cases associated with hypercoagulability and hyperfibrinolysis. Two patients had solely hypercoagulability. PPV of INR, aPTT, platelet count and fibrinogenemia were 0, 0, 0.5 and 0.17 respectively. NPV of the same tests were 1, 1, 0.34 and 1 respectively. Conclusions: Hypocoagulability was the most common laboratory alteration, however, clinical signs of coagulopathy were rarely present. SCE had a poor predictive value to diagnose o discard hemostatic abnormalities.

Extraction, physical-chemical characterization and in vitro inhibitorypotential of thrombin generation of crude sulfated polysaccharides from Brazilian tropical seaweeds / Extração, caracterização físico-química e potencial inibitório in vitro da geração detrombina de polissacarídeos sulfatados brutos de algas marinhas tropicais brasileiras

The biotechnological value of macroalgae for screening assays of thrombin generation-TG using sulfated polysaccharides-SPs as substitutes to heparin has been poorly explored. Five Brazilian species of macroalgae (Gracilaria birdiae, Acanthophora muscoides, Halymenia sp., Caulerpa cupressoides and C. racemosa) wereanalyzed and compared for their abundance, physical-chemical characteristics and in vitro anticoagulant assays of activated partial thromboplastin time-APTT, prothrombin time-PT and TG. Papain extraction yielded (p 100 kDa. These procedures,combined with the use of Stains-All, also indicated nonSPs. APTTs ranged from 2.81 (A. muscoides) to 21.30 IU(Halymenia sp.) vs. heparin (193 IU), and were dependent on sulfation of the crude SPs. PT was not altered. Withrespect to TG assay, crude SPs modified concentration-dependent and independently from molecular mass TGby both intrinsic/extrinsic pathways in 60-fold diluted human plasma, with total intrinsic inactivation using crudeSPs from A. muscoides in parallel to heparin (p < 0.05). Thrombosis in vitro is differentially modulated by distinctcrude SPs from Brazilian seaweeds.

O valor biotecnológico das macroalgas para ensaios de varredura de geração de trombina-GT pouco tem sido explorado usando polissacarídeos sulfatados-PSs como substitutos à heparina. Foramanalisadas e comparadas cinco espécies brasileiras de macroalgas (Gracilaria birdiae, Acanthophora muscoides, Halymenia sp., Caulerpa cupressoides e C. racemosa) quanto à abundância, às característicasfísico-químicas e os ensaios anticoagulantes in vitro de tempo de tromboplastina parcial ativada-TTPA, aotempo de protrombina-TP e a GT. A extração com papaína rendeu (p 100 kDa. Esses procedimentos,combinados ao uso de azul de toluidina/Stains-All, indicaram também polissacarídeos-não sulfatados. OsTTPAs foram dependentes da sulfatação dos PSs brutos e variaram de 2,81 (A. muscoides) a 21,30 UI (Halymenia sp.) vs. heparina (193 UI). O TP não foi alterado. Com respeito ao ensaio de GT, os PSs brutos modificaram, dependente de concentração e independentemente de massa molecular, GT pelas viasintrínseca/extrínseca no plasma humano diluído 60 vezes, com inativação intrínseca total usando PSs brutosde A. muscoides em paralelo à heparina (p < 0,05). A trombose in vitro é modulada diferencialmente porPSs brutos distintos de algas marinhas brasileiras.

Viscoelastic Coagulation Test Guided Therapy for a Strategy to Reduce Transfusions / 대한수혈학회지

Viscoelastic coagulation tests provide simultaneous measurements of multiple aspects of whole-blood coagulation, including interactions between the plasma components and cellular components of the coagulation cascade. This can be carried out immediately using a point of care technique. Viscoelastic tests could predict the patient's outcome, including mortality, and detect coagulopathy more sensitively, resulted in reduced blood loss. The transfusion strategy based on the viscoelastic parameters rather than a conventional coagulation test has been shown to reduce the transfusion requirements. Although there are concerns about the reliability and accuracy of this method, viscoelastic tests, including ROTEM, would be a useful method to guide patient blood management strategies.

Value of thrombelastography in monitoring coagulation state of trauma patients with lower limb venous thrombosis / 中华创伤杂志

Objective To investigate the efficacy of thrombelastography (TEG) in monitoring the coagulation state of trauma patients with lower limb venous thrombosis.Methods A total of 64 trauma patients surgically treated from March 2015 to April 2015 were analyzed by retrospective case-control study.There were 32 males and 32 females,with an age range of 17-79 years (mean,53.44 years).None had significant vascular damage.The average time between injury and surgery was 8.8 days (range,2-20 days).The patients were divided into lower limb venous thrombosis group (thrombosis group,n =10) and non-venous-thrombosis group (non-thrombosis group,n =54) according to the diagnosis of color Doppler ultrasound.The causes of trauma included tumbling in 33 cases,fall from height in 8,traffic accident in 15,and compression injury in 8.The data were reviewed including variables of TEG [reaction time (R value),clot formation time (K value),α angle,maximum amplitude (MA)],platelet (PLT) count and variables of conventional coagulation tests (CCTs) [plasma prothrombin time (PT),activated partial thromboplastin time (APTT),and international normalized ratio (INR)].The correlation between R,K and CCTs and the correlation between α angle,MA and PLT were investigated.The variations of the two methods between two groups were investigated by receiver operating characteristic curve (ROC).Area under the curve (AUC),sensitivity and specificity of R value,K value,PT and APTT were analyzed.Results R value of thrombosis group was lower than that in non-thrombosis group [5.55 (4.78,5.85) min vs.6.20 (5.30,7.03) min] (P ＜ 0.05).There was no significant difference between the two groups in aspects of K value,o angle,MA,PT,APTT,INR,and PLT (P ＞ 0.05).The R value was positively correlated PT (r =0.65,P ＜ 0.05) and INR (r =0.69,P ＜ 0.05),but had no significant correlation with APTT or PLT count.The K value was not significantly correlated with PT,APTT,INR or PLT count,and PLT was not significantly correlated with α angle or MA.AUC was 0.73 in R value,0.66 in K value,0.58 in PT,and 0.60 in APIT.The sensitivity values to detect lower limb venous thrombosis in trauma patients were 87.04％ in R value (＜5 min),79.63％ in K value (＜1.00 min),0.00％ in PT (＜11.4 s),and 90.74 in APTT (＜27.4 s).The specificity values were 40.00％ in R value (＜5 min),40.00％ in K value (＜ 1.00 min),100.00％ in PT (＜ 11.4 s),and 20.00％ in APTT (＜ 27.4 s).Conclusion TEG is considered to be much more sensitive than CCTs for monitoring the coagulation state,and can be selected as the supplementary screening test for trauma patients with lower limb venous thrombosis.

Investigate on reference intervals of five indexes of blood coagulation tests among infants and children in Chongqing / 重庆医学

Objective To establish children's independent normal reference intervals of five coagulation indexes in Chongqing,in order to better provide references for clinic.Methods The plasma samples of 5 119 healthy children were collected and used to detecting prothrombin time (PT),activated partial thromboplastin time (APTT) and fibrinogen (FIB),thrombin time (TT) and D-Dimer (D-D) via Sysmex CS5100 and Sysmex CSA2000.According to ages,the children were divided into 6 groups:newborn (at 0 to less than 15 days of age),newborn (at 15 days to less than 1 month of age),infant (at 1 to less than 7 months of age),children (at 7 months to less than 3 years of age),children (at 3 to less than 7 years of age),children (at 7 to 15 years of age),and comparatively analysed.For normal distribution data,(x)± 1.96s was used to calculate the reference intervals;while for skewness distribution data,the reference intervals was calculated by 95 ％ reference interval according to the percentile of P2.5 and P97.5.Results The normal reference intervals of five coagulation indexes in this clinical laboratory were as follows:PT 11.1-20.2 s (at 0 to less than 15 days of age),10.7-15.8 s (at 15 days to less than 1 month of age),9.9-13.5 s (at 1 month to 15 years of age);APTT 28.8-91.6 s (at 0 to less than 15 days of age),33.3-64.2 s (at 15 days to less tha 1 month of age),24.0-53.2 s (at 1 to less than 7 months of age),21.2-39.2 s (at 7 months to less tha 15 years of age);FIB 1.45-3.52 g/L (at 0 to less than 3 years of age),1.50-3.52 g/L (at 3 to 15 years of age);TT 15.4-26.3 s (at 0 to less than 15 days of age),14.9-21.4 s (at 15 days to less than 7 months of age),14.7-20.1 s (at 7 months to less than 3 years of age),14.9-19.3 s (at 3 to 15 years of age);D-D 0.1-5.1 mg/L (at 0 to less than 15 days of age),0.2-2.2 mg/L (at 15 days to less than 1 month of age),0.1-1.1 mg/L (at 1 to less tha 7 months of age),0.1-1.4 mg/L (at 7 months to less than 3 years of age),0.1-1.3 mg/L (at 3 to less than 7 years of age),0-1.0 mg/L (at 7 to 15 years of age).Conclusion The normal reference intervals of five coagulation indexes,including PT,APTT,FIB,TT and D-D,are established,which provide more accurate references for the diagnosis of related diseases in infants and children in this area.

Evaluation of the targeted uncertainty in routine coagulation assay using EQA data / 中华检验医学杂志

Objective To establish the target measurement uncertainty(MU)of the routine coagulation assay according to the External Quality Assessment data(EQA)of routine coagulation assay. Methods Beijing Center for Clinical Laboratory(BCCL)established the target measurementuncertainty for routine coagulation assayswith the"up-down"methodon the basis of 93 clinical laboratoriesEQA datain BeijingThese assays includedActivated partial thromboplastine time(APTT), Fibrinogen(FBG), International Normalized Ratio(INR), Prothrombin time(PT), Thrombin time(TT)and D-dimer, Compared with CLIA′88,the proficiency of current coagulation assayswas observed.Results The MU of six routine coagulation assayscompared with CLIA ′88 showed that: The 90th percentile MU met the creteriain APTTof group B,FBG of group A&B&C,INR of group B and D-dimer of group B.The 75th percentile MU met the creteriainINR of group A&C,PT of group C.The medium met the creteriainAPTT of group A&C,PT of group A and INR of group D.Conclusions Target Measurement Uncertainty was establishedin routine coagulation assay by using EQA data only,whichcan simplify the procedure of determining MU and continuously update MU according to the frequency of EQA.It has good clinical practical value.However, the applicability of this method should also be considered.