Clinical application of viscoelastic point-of-care tests of coagulation-shifting paradigms

Bleeding during cardiac surgery, liver transplant, trauma and post partum hemorrhage are often multifactorial and these factors are dynamic as new factors crop up during the course of management. Conventional tests of coagulation offer information of a part of the coagulation system and also is time consuming. Viscoelastic point of care tests (VE POCTs) like rotational thromboelastometry, thromboelastogram and Sonoclot, are based on analysis of the viscoelastic properties of clotting blood and provide information for the entire coagulation pathway. In this comprehensive review being presented here, we have examined the pros and cons of VE POCTs including clinical, cost and survival benefits. The recommendations of the various guidelines regarding use of VE POCTs in various scenarios have been discussed. The review also tried to offer suggestions as to their optimal role in management of bleeding during cardiac surgeries, extracorporeal membrane oxygenation, left ventricular assist devices, liver transplant and briefly in trauma and postpartum hemorrhage.

Comparison on Anticoagulation and Antiplatelet Aggregation Effects of Puerarin with Heparin Sodium and Tirofiban Hydrochloride: An In Vitro Study / 中国结合医学杂志

<p><b>OBJECTIVE</b>To detect the anticoagulation and antiplatelet effects of different concentrations of puerarin, heparin sodium and tirofiban hydrochloride on the blood samples of healthy volunteers by Sonoclot coagulation and platelet function analyzer.</p><p><b>METHODS</b>Peripheral blood samples were extracted from 20 healthy volunteers, followed by adding different concentrations of puerarin, heparin sodium and tirofiban hydrochloride. Samples were detected for activated clotting time (ACT), clot rate (CR) and platelet function (PF) by Sonoclot coagulation and platelet function analyzer instrument.</p><p><b>RESULTS</b>For puerarin and heparin sodium, the values of ACT gradually increased, and the values of CR and PF gradually decreased with increasing in drug concentration. There was a linear (or log linear) relationship between ACT, CR, PF value and drug concentration (P<0.01). Corresponding to each value, a regression equation was obtained. For tirofiban hydrochloride, the values of ACT and CR had no significant changes, while PF values gradually decreased with concentration increasing. There was also a linear relationship between PF values and concentrations of tirofiban hydrochloride (P<0.01). Under the same ACT values, the puerarin corresponding CR values (CR = e, P<2.2e-16) were always higher than the corresponding values (CR = e, P-value<2.2e-16) of heparin sodium. For high concentrations of puerarin (e.g. 3.8 mg/600 μL) and tirofiban hydrochloride (e.g. 0.8 μg/600 μL), PF values had no significant difference. However, PF values for high puerarin concentration had a larger variance.</p><p><b>CONCLUSIONS</b>Puerarin has similar anticoagulant and antiplatelet effects with the heparin sodium, and may have a lower hemorrhage risk than heparin sodium when obtained the same anticoagulation effect in the concentration range of this experiment. In addition, for high concentration, puerarin had the same antiplatelet function as tirofiban hydrochloride but with a larger individual variability.</p>

Establishment of reference intervals and transfusion criterion for Sonoclot analysis / 华中科技大学学报（医学）（英德文版）

Sonoclot analyzer has been widely used in many countries. But the reference intervals provided by the manufacturer were derived from only 45 participants, and there was no cut-off value for transfusion for Sonoclot analysis. This study aimed to establish reference intervals and transfusion criterion for Sonoclot analysis. Volunteers were recruited from healthy Chinese adults and patients undergoing cardiac surgery. Blood samples were withdrawn from forearm vein and measured for activated clotting time (ACT), clot rate (CR), platelet function (PF), activated partial thromboplastin time (APTT), fibrinogen concentration (FIB), and platelet count (PLT). The reference intervals were determined by the nonparametric method. Cut-off values were determined by the receiver operating characteristics curve. A total of 135 healthy volunteers and 281 patients were enrolled. The 95% reference intervals were 96-195 s, 22-51 signal U/min, >1.6 for ACT, CR, PF respectively. In the 281 patients, the results of APTT, FIB, PLT, ACT, CR, and PF ranged from 20.5-300.0 s, 0.28-4.11 g/L, (19.0-387.3)×109/L, 80-514 s, 2.9-74 signal U/min, and 0.1-5.1 respectively. The cut-off values for transfusion were >208, ≤14, and ≤1.3 for ACT, CR, PF respectively. The cut-off values of Sonoclot analysis were within the manufacturer's reference intervals, while they were outside the reference intervals established in this study. The results suggested that the manufacturer's reference intervals were not suitable for Chinese. The reference intervals and cut-off values established in this study will be helpful to Chinese patients.

The diagnostic value of Sonoclot in the diagnosis of heat stoke complicated with DIC and heat stroke / 实用医学杂志

Objective To evaluate diagnostic value of Sonoclot in the diagnosis of heat stroke complicated with disseminated intravascular coagulation (DIC). Methods 43 patients with heat stroke and coagulation dysfunction were retrospectively included and divided into 2 groups according to scores by International Society of Thrombosis and Hemostasis (ISTH): DIC dominant group (22 case) and DIC non-dominant group (21case). Regular coagulation tests , routine blood test , D-dimer and Sonoclot tests were performed at admission and their clinical data were compared. Logistic regression analysis was applied to evaluate the relationships between DIC occurrence and Sonoclot parameters. ROC curves were used to evaluate diagnostic value of Sonoclot for the patients with DIC and heat stroke. Results There were no differences in age, sex, central temperature and total hospital stay between the 2 groups except ICU stay, DIC symptoms, outcome, ISTH scores and APACHEⅡscores (P <0.05). ACT and CR correlated with the occurrence of DIC (P < 0.05). The AUC of ACT and ACT combined with CR were 0.854 and 0.877 respectively. The specificity of ACT in predicting DIC was 69.2%with the sensitivity of 90.3%. When combined with CR, both the specificity and the sensitivity were increased to 80.2% and 93.5%, respectively. Conclusions Sonoclot can predict DIC quickly and is effective in the diagnosis of heat stroke patients with DIC.

Utility of Sonoclot analysis and tranexamic acid in tetralogy of Fallot patients undergoing intracardiac repair.

Sonoclot analysis is a point of care test to monitor the coagulation process, presenting a comprehensive evaluation of the clot formation and retraction as well as platelet function. This randomized double-blinded study was designed to investigate the utility of Sonoclot analysis in monitoring the coagulation profile as also the antifibrinolytic effects of tranexamic acid administered in patients with tetralogy of Fallot undergoing intracardiac repair. Eighty of a total 94 patients were randomly divided into two groups of 40 each. In the study group, TA was administered thrice at a dosage of 10 mg/kg, i.e. before CPB, on CPB and after CPB, whereas in the control group, placebo was administered at the same time intervals. Sonoclot analysis and D-dimer measurement were performed at baseline and following heparin neutralisation. An additional variable, DR 15 (diminishing rate of clot strength at 15 min postmaximal clot strength), was calculated from the Sonoclot graph and was compared with d-dimer levels as a measure of fibrinolysis. The three Sonoclot variables, i.e. activated clotting time, clot rate and platelet function, were deranged at baseline in all the patients. Post-CPB, the change in these variables was not significant. ACT, clot rate and platelet function showed no significant (P > 0.05) difference in both the groups at both the time intervals. DR 15 and d-dimer values were comparable at baseline in both the groups. However, a significant (P < 0.05) difference was seen in these variables in the control group as compared with the TA group following heparin neutralisation. To conclude, Sonoclot analysis is a useful, point of care method for the monitoring of coagulation and fibrinolysis in patients with tetralogy of Fallot undergoing intracardiac repair.

Effects of blood loss during operation on coagulation function in selective non-cardiovascular surgery patients / 解放军医学杂志

Objective To investigate the change in coagulation function in relation to different amounts of blood loss in selective non-cardiovascular surgery patients.Methods Twenty American Anesthesia Association (ASA) class I or Ⅱ patients,aged 23-57 yr,undergoing non-cardiovascular surgery with normal preoperative coagulation were chosen randomly.After general anesthesia,on the basis of adequate sedation and analgesia,patients were given Ringer's solution and Voluven (pre-warmed to 37℃,volume ratio of crystalloid/colloid was 1:2) to maintain the stability of heart rate,blood pressure and central venous pressure.Temperature and blood gas analysis were monitored to prevent potential interference induced by hypothermia and acidosis.When the ratio of blood loss/blood volume reached 10%,15%,20% and 25%,all the routine blood components analysis and coagubility parameters,and Sonoclot coagulation and platelet function parameters were observed.Results Preoperative average value of Hct was 38.1%,and when ratio of blood loss/blood volume were 10%,15%,20 % and 25%,Hct was decreased to 33.4%,31.5%,30.1% and 27.9% respectively.When the ratio reached 15% or larger,platelet count decreased significantly compared with preoperative value (P