Fibrin formation is more impaired than thrombin generation and platelets immediately following cardiac surgery.
ABSTRACT Cardiac surgery performed on cardio-pulmonary bypass (CPB) may be complicated by coagulopathy and bleeding. This prospective observational study investigated the CPB-induced changes in thrombin generation, fibrin formation, and in the platelet component of the whole blood clot elasticity. The effects of haemostatic therapy with fresh frozen plasma (FFP) and platelet concentrate on these parameters were also evaluated.
In 90 cardiac surgery patients, thrombin generation was measured using the calibrated automated thrombogram, fibrin formation was assessed as the maximum clot elasticity of the fibrin-based clot in the thromboelastometry FIBTEM test (MCE(FIBTEM)), and the platelet component was defined as the difference in maximum elasticity between the whole blood clot obtained through extrinsic activation and the fibrin-based clot (MCE(EXTEM)-MCE(FIBTEM)). Blood samples were collected before surgery, immediately after CPB, and after administration of FFP or FFP and platelet concentrate.
Following CPB, the endogenous thrombin potential decreased to 93%, from median 1485 (interquartile range 1207, 1777) to 1382 (1190, 1533) nM*min (P>0.05), MCE(FIBTEM) decreased to 62%, from 21 (19, 29) to 14 (12, 19) (P<0.001), and the platelet component to 73%, from 139 (119, 174) to 101 (87, 121) (P<0.001). Administration of 11 (10, 13) ml per kg of bodyweight (ml/kgbw) FFP (40 patients), or of 13 (10, 18) ml/kgbw FFP and 7 (5, 9) ml/kgbw platelet concentrate (18 patients) brought no statistically significant changes in these parameters.
Fibrin formation is more impaired than thrombin generation and the platelet component of the whole blood clot immediately after cardiopulmonary bypass.
SourceAvailable from: Manuela Carvalho[Show abstract] [Hide abstract]
ABSTRACT: Several clinical settings are associated with specific coagulopathies that predispose to uncontrolled bleeding. With the growing concern about the need for optimizing transfusion practices and improving treatment of the bleeding patient, a group of 9 Portuguese specialists (Share Network Group) was created to discuss and develop algorithms for the clinical evaluation and control of coagulopathic bleeding in the following perioperative clinical settings: surgery, trauma, and postpartum hemorrhage. The 3 algorithms developed by the group were presented at the VIII National Congress of the Associação Portuguesa de Imuno-hemoterapia in October 2013. They aim to provide a structured approach for clinicians to rapidly diagnose the status of coagulopathy in order to achieve an earlier and more effective bleeding control, reduce transfusion requirements, and improve patient outcomes. The group highlights the importance of communication between different specialties involved in the care of bleeding patients in order to achieve better results. © The Author(s) 2014.Clinical and Applied Thrombosis/Hemostasis 11/2014; DOI:10.1177/1076029614559773 · 1.58 Impact Factor
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ABSTRACT: Introduction Patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) are susceptible to haemostatic disturbances. Monitoring the haemostatic capacity by conventional clotting tests is challenging. Materials and Methods Thrombin generation (TG) by Calibrated Automated Thrombography, clotting tests and tissue factor pathway inhibitor (TFPI) measurements were performed to describe the relationship between haemostatic changes and alterations in these tests. Blood samples were collected before, during and after CPB. Furthermore, it was investigated whether TG measured intraoperatively, is associated with increased risk of bleeding postoperatively. Results TG diminished significantly (p < 0.01) after heparinization in the presence and absence of platelets (37% and 50%) compared to baseline. After the start of CPB, TG elevated and persisted till the end of surgery but remained lower than preoperatively. Activated clotting time increased after heparinization and after the start of bypass compared to baseline (400% and 500%). Anti-FXa activity reduced on the start of CPB compared to the level after heparinization, to almost the baseline value following protamine reversal of heparin. The plasma levels of total and free TFPI elevated 9 and 14 fold during bypass and remained after protamine administration higher than preoperatively. Plasma D-dimer levels reduced (p < 0.01) when bypass started. However, a marked elevation was observed in the following time points. TG in platelet-rich plasma measured after heparinization and after the start of CPB associated (p < 0.05) with postoperative blood loss. Conclusions TG can be determined during CPB despite the high heparinization level, it reflects the haemostatic capacity better than clotting-based assays and might better predict bleeding when performed intraoperatively.Thrombosis Research 01/2013; DOI:10.1016/j.thromres.2013.12.017 · 2.43 Impact Factor
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ABSTRACT: According to limitations in blood product resources and to prevent unnecessary transfusions and afterwards complications in perioperative period of total hip arthroplasty, authors administered fibrinogen concentrate in a pilot randomized clinical trial to evaluate bleeding and need to blood transfusion in preoperative period. Thirty patients (3-75 years old) with ASA physical status class I or II and candidate for total hip arthroplasty consequently enrolled in this study and randomly assigned into two groups: taking fibrinogen concentrate and control. Two groups were similar in serum concentration of fibrinogen, hemoglobin, and platelet preoperatively. After induction of general anesthesia 30mg/kg fibrinogen concentrate was administered in the fibrinogen group. Blood loss, need to blood transfusion and probable complications were compared between two groups. The mean operation time was 3.3 ± 0.8 hours in the fibrinogen group and 2.8 ± 0.6 hours in the placebo group, and this difference was statistically significant (P=0.04). There was a significant correlation between operation time and blood loss during surgery (P=0.002). The mean transfused blood products in the fibrinogen and control group was 0.8 ± 1.01 units and 1.06 ± 1.2 units respectively (P=0.53). The mean of perioperative blood loss was 976 ± 553 ml in the fibrinogen group and 1100 ± 350 ml in the control group, but this difference was not significant between two groups. By adjusting time factor for two groups, we identified that the patients in fibrinogen group had lower perioperative bleeding after adjusting time factor for two groups (P=0.046). None of the patients had complications related to fibrinogen concentrate administration. The prophylactic administration of fibrinogen concentrate was safe and effective in reducing bleeding in the perioperative period of total hip arthroplasty.Acta medica Iranica 11/2014; 52(11):804-10.