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Maximum Clot Firmness (maximum + clot_firmness)

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Medical Sciences	100%

Selected Abstracts

Monitoring of haemostasis in liver transplantation: comparison of laboratory based and point of care tests

ANAESTHESIA, Issue 1 2010
F. Herbstreit
Summary During orthotopic liver transplanatation haemostasis is often disturbed and coagulation monitoring is mandatory. We compared the results obtained by whole blood prothrombin time and activated partial thromboplastin time assays (Hemochron®) and thrombelastometry (ROTEM® 05) with laboratory coagulation assays (prothrombin time, activated partial prothrombin time, fibrinogen, and platelet count) in samples obtained during orthotopic liver transplantations. Determination of prothrombin time and activated partial prothrombin time using the Hemochron device showed good correlation with laboratory coagulation assays (r = 0.912, p < 0.001, and r = 0.794, p < 0.001). Maximum clot firmness as determined by thrombelastometry correlated well with platelet count (r = 0.779, p < 0.001) and, to a lesser degree, with fibrinogen concentration (r = 0.590, p < 0.001). During orthotopic liver transplantation, prothrombin time and activated partial prothrombin time can be reliably determined by the Hemochron device, while thrombelastometry allows assessment of platelet count and fibrinogen concentration. [source]

Role of fibrinogen-, factor VIII- and XIII-mediated clot propagation in gelatin haemodilution

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2009
A. A. SCHRAMKO
Background: Gelatin solution impairs coagulation. The mechanism of coagulopathy is incompletely defined. The purpose of this study was to evaluate the capacity of single coagulation factors to reverse gelatin-promoted whole-blood coagulation disorders in vitro. Methods: Venous blood was withdrawn from 12 volunteers in a crossover study. Four percent succinylated gelatin was added to citrated whole-blood samples to make a 40 vol% end-concentration of gelatin. The baseline and 40 vol% samples, and samples with addition of fresh-frozen plasma (FFP), fibrinogen, coagulation factors XIII (FXIII) or VIII, together with the von Willebrand factor (FVIII+vWF), were analysed by thromboelastometry (ROTEM®). Coagulation was initiated by tissue thromboplastin (ExTEM®) with and without cytochalasin to determine the functional component of fibrinogen (FibTEM®). Results: Initiation of coagulation and fibrin formation were delayed at 40 vol% gelatin dilution. At this stage, the median (25th,75th percentiles) maximum clot firmness (MCF) was 76.3 (65.9,80.0) and 32.5 (27.4,45.0)% of the pre-dilution value in ExTEM® and FibTEM® thromboelastometry, respectively. Coagulation time was corrected by addition of fibrinogen and FFP in ExTEM® and FibTEM® analysis, whereas FVIII or FXIII had minimal effects. MCF was partly restored only by FFP in ExTEM®. In FibTEM® analysis, MCF improved more by fibrinogen than by FVIII+VWF, FXIII or FFP. Conclusions: Gelatin-induced whole-blood coagulation disorder in vitro is mainly dependent on the initial fibrinogen,fibrin interaction. The proposed mechanism might suggest not to reverse gelatin coagulopathy solely by fibrinogen administration. The administration of FFP, a mixture of different coagulation factors, reversed the gelatin-induced in vitro coagulopathy the best. [source]

Recombinant factor VIIa and fibrinogen display additive effect during in vitro haemodilution with crystalloids

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2009
C. FENGER-ERIKSEN
Background: Major blood loss requires fluid resuscitation for maintaining hemodynamic stability. Excessive volume infusions predispose to dilutional coagulopathy through loss, consumption and dilution of cells and proteins involved in haemostasis. Further treatment with fibrinogen concentrate and/or recombinant activated factor VII (rFVIIa) may be initiated, although the haemostatic effects in a situation with haemodilution are not fully detailed. The present study evaluates haemostatic effect of fibrinogen and rFVIIa and their combination in an in vitro model of haemodiluted whole blood with two commonly used crystalloids. Methods: Eight healthy, male volunteers were enrolled. Outcome variables were clot initiation, propagation and strength assessed by thrombelastographic parameters: clotting time, clot formation time, maximum velocity, time until maximum velocity, maximum clot firmness evaluated at dilution levels of 0% (control), 10%, 30% and 50% with isotonic saline and Ringer's lactate in a model of tissue factor-activated whole blood. Fibrinogen and rFVIIa were additional final reaction concentrations, reflecting commonly used clinically therapeutic dosages. Results: Dose-dependent coagulopathy developed following haemodilution with isotonic saline and Ringer's lactate, characterised by a prolonged clot initiation, reduced clot propagation and reduced clot strength. Fibrinogen improved clot strength and propagation phase while rFVIIa shortened clot initiation, both with a positive dose dependency. Conclusions: The combination of fibrinogen and rFVIIa displays an additive effect and improves overall in vitro whole blood clot formation in a model of in vitro crystalloid-induced haemodilution. [source]

Use of rotation thromboelastometry (ROTEM®) to achieve successful treatment of polytrauma with fibrinogen concentrate and prothrombin complex concentrate

ANAESTHESIA, Issue 2 2010
H. Schöchl
Summary Goal-directed coagulation therapy is essential in the management of trauma patients with severe bleeding. Due to the complex nature of coagulation disorders in trauma, a quick and reliable diagnostic tool is essential. We report a severely injured multiple trauma patient who received haemostatic therapy with coagulation factor concentrates, guided by rotational thromboelastometry (ROTEM®). Initial therapy consisted of fibrinogen concentrate (Haemocomplettan® P), as maximum clot firmness in the ROTEM analyses was low, whereas clotting time was normal. Later on, prothrombin complex concentrate was given to optimise thrombin generation. This approach enabled extended emergency hemihepatectomy to be performed without using fresh frozen plasma. As the EXTEM maximum clot firmness showed good clot quality, no platelets were transfused despite low platelet counts. This case shows the potential success of treatment using both fibrinogen concentrate and prothrombin complex concentrate, not only in restoring haemostasis but also in minimising requirement for transfusion of allogeneic blood products. [source]