| 1. |
- Andersson Shams Hakimi, Caroline, et al.
(författare)
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Effects of fibrinogen and platelet supplementation on clot formation and platelet aggregation in blood samples from cardiac surgery patients.
- 2014
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Ingår i: Thrombosis research. - : Elsevier BV. - 1879-2472 .- 0049-3848. ; 134:4, s. 895-900
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Tidskriftsartikel (refereegranskat)abstract
- Bleeding after cardiac surgery may be caused by surgical factors, impaired haemostasis, or a combination of both. Transfusion of blood products is used to improve haemostasis, but little is known about what combination is optimal. We hypothesized that addition of both fibrinogen and platelets to blood samples from cardiac surgery patients would improve clot formation and platelet aggregation to a greater extent than if the components were added separately.
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| 2. |
- Andersson Shams Hakimi, Caroline, et al.
(författare)
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Effects of fibrinogen and platelet transfusion on coagulation and platelet function in bleeding cardiac surgery patients.
- 2019
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Ingår i: Acta anaesthesiologica Scandinavica. - : Wiley. - 1399-6576 .- 0001-5172. ; 63:4, s. 475-482
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Tidskriftsartikel (refereegranskat)abstract
- Excessive bleeding is a significant problem in cardiac surgery. Fibrinogen and platelet concentrate transfusion are used clinically to improve haemostasis and reduce bleeding but little is known about their functional effects on coagulation and platelet function in patients with ongoing bleeding.Forty-two patients with ongoing bleeding after cardiac surgery were included in an observational study. Patients received either fibrinogen concentrate (n=16), platelet concentrate (n=12), or both fibrinogen and platelets (n=14), median doses 2g fibrinogen and 2 units platelets given at one occasion. Blood samples were collected before and after transfusion. Coagulation (clotting time and clot stability) was analysed with rotational thromboelastometry, and platelet function with impedance aggregometry. In addition, platelet count and fibrinogen concentration was measured. Chest drain output was measured before and after the transfusion.Fibrinogen infusion resulted in an increase in fibrinogen concentration and clot stability (P=0.001), but had no effect on platelet aggregation. Platelet transfusion did not significantly affect coagulation, but improved arachidonic acid- and TRAP-induced platelet aggregation (P=0.017 and 0.034 respectively) and increased platelet count. Combined fibrinogen and platelet transfusion shortened clotting time (P=0.005) and increased clot stability (P=0.001), and improved arachidonic acid- and TRAP-induced platelet aggregation (P=0.004 and 0.016 respectively), and increased fibrinogen concentration and platelet count. The median bleeding volume was 150 (25th-75th percentile 70-240)mL/h before, and 60 (40-110)mL/h after transfusion of fibrinogen and/or platelet concentrate (P<0.001).The results demonstrate improved coagulation and platelet function following fibrinogen and platelet transfusion in patients bleeding after cardiac surgery.
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| 3. |
- Andersson Shams Hakimi, Caroline
(författare)
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Fibrinogen, platelet and factor XIII supplementation in cardiac surgery: In vitro and in vivo studies
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: There is a high risk of bleeding complications in cardiac surgery. Fibrinogen and platelet concentrates are often used to treat perioperative bleeding, but there is little information about its efficacy. The overall aim of this thesis project was to study the effects of fibrinogen, platelet and factor XIII concentrates on markers of hemostasis in blood samples from cardiac surgery patients. Methods: Increasing doses of fibrinogen, platelets, and factor XIII were added to blood samples from patients or healthy volunteers (study I, III–V). In study II, blood samples from cardiac surgery patients with ongoing bleeding were analyzed before and after transfusion of fibrinogen and/or platelet concentrates. In all studies, platelet function was assessed with impedance aggregometry, and clot formation with thromboelastometry. Results: Supplementation with fibrinogen improved clot formation while platelets improved both platelet aggregation and clot formation in blood samples form cardiac surgery patients (I). Fibrinogen to patients with ongoing bleeding improved clot formation and platelets improved platelet aggregation (II). Factor XIII supplementation to blood samples from cardiac and scoliosis surgery patients improved clot formation moderately (III). Supplementation with platelets improved platelet aggregation independently of antiplatelet therapy (IV). Time-dependent changes in platelet concentrates were detected with impedance aggregometry in vitro (V). The results predicted with moderate accuracy changes in aggregation after addition of the platelet concentrates to whole blood samples. Conclusions: The results suggest that transfusion with fibrinogen or platelets improve hemostasis, whereas factor XIII should remain a secondary tool in the treatment of perioperative bleeding. Impedance aggregometry may be used to monitor the quality of stored platelet concentrates in vitro.
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| 4. |
- Andersson Shams Hakimi, Caroline, et al.
(författare)
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In vitro assessment of platelet concentrates with multiple electrode aggregometry.
- 2015
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Ingår i: Platelets. - : Informa UK Limited. - 0953-7104 .- 1369-1635. ; 26:2, s. 132-137
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT Storage impairs platelet function. It was hypothesized that multiple electrode aggregometry in vitro could be used to follow aggregability in platelet concentrates over time and that the results predict the efficacy of platelet transfusion in an ex vivo transfusion model. In vitro platelet aggregability was assessed in apheresis and pooled buffy coat platelet concentrates (BCs) (n = 13 each) using multiple electrode aggregometry with different agonists 1, 3, 5 and 7 days after preparation. In the ex vivo transfusion model, whole blood samples from nine healthy volunteers were collected every second day. The samples were supplemented with stored platelets (+146 × 10(9) × l(-1)) from the same unit 1, 3, 5 and 7 days after preparation. Platelet aggregability was assessed in the concentrate and in the whole blood samples before and after platelet supplementation. There was a continuous reduction in in vitro platelet aggregability over time in both apheresis and pooled BCs. The same pattern was observed after ex vivo addition of apheresis and pooled BCs to whole blood samples. The best correlation between in vitro aggregability and changes in aggregation after addition was achieved with collagen as agonist (r = 0.67, p
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| 5. |
- Andersson Shams Hakimi, Caroline, et al.
(författare)
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The Effect of Ex Vivo Factor XIII Supplementation on Clot Formation in Blood Samples From Cardiac and Scoliosis Surgery Patients.
- 2018
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Ingår i: Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis. - : SAGE Publications. - 1938-2723. ; 24:4, s. 677-683
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Tidskriftsartikel (refereegranskat)abstract
- Excessive perioperative bleeding remains a substantial problem. Factor XIII (FXIII) contributes to clot stability, and it has therefore been suggested that supplementation with FXIII concentrate may improve perioperative hemostasis. We evaluated the effects of increasing doses of FXIII, alone or in combination with fibrinogen or platelet concentrate, in blood samples from 2 considerably different groups of surgical patients: cardiac and scoliosis surgery patients. Whole-blood samples were collected immediately after operation from cardiac and scoliosis surgery patients. The samples were supplemented with 3 clinically relevant doses of FXIII concentrate (+20%, +40%, and +60%), alone or in combination with a fixed dose of fibrinogen concentrate (+1.0 g/L) or fresh apheresis platelets (+92 × 10(9)/L). Clot formation was assessed with rotational thromboelastometry (ROTEM). When the highest dose of FXIII concentrate was added, EXTEM clotting time was shortened by 10% in both cardiac and scoliosis surgery patients (95% confidence intervals: 2.4%-17% and 3.3%-17%, respectively), and FIBTEM maximum clot firmness was increased by 25% (9.3%-41%) in cardiac patients, relative to baseline. When fibrinogen was added, the dose-dependent effect of FXIII on clot stability was maintained, but the total effect was markedly greater than with FXIII alone, +150% (100%-200%) and +160% (130%-200%) for the highest FXIII dose in cardiac and scoliosis patients, respectively. Ex vivo supplementation with clinically relevant doses of FXIII improved clot formation moderately in blood samples from cardiac and scoliosis surgery patients, both alone and when given in combination with fibrinogen or platelet concentrate.
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| 6. |
- Gäbel, Jakob, 1971, et al.
(författare)
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Cell saver processing mitigates the negative effects of wound blood on platelet function
- 2016
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 60:7, s. 901-909
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundWound blood is highly activated and has poor haemostatic properties. Recent data suggest that retransfusion of unwashed wound blood may impair haemostasis. We hypothesized that cell saver processing of wound blood before retransfusion reduces the negative effects. MethodsWound blood was collected from 16 cardiac surgery patients during cardiopulmonary bypass. One portion of the wound blood was processed in a cell saver and one portion left unprocessed. Increasing amounts of unprocessed blood (10% and 20% of the systemic blood volume) or corresponding volumes of processed blood were added ex vivo to whole blood samples from the same patient. Clot formation was assessed by modified thromboelastometry (ROTEM (R)) and platelet function with impedance aggregometry (Multiplate((R))). ResultsAddition of unprocessed wound blood significantly impaired clot formation and platelet aggregability. Cell saver processing before addition did not influence clot formation but abolished completely the negative effects of wound blood on platelet aggregability tested with all agonists. Median adenosine diphosphate-induced platelet aggregation was 51 (25th and 75th percentiles 42-69) when 20% processed cardiotomy suction blood was added vs. 34 (24-52) U when 20% unprocessed blood was added, P < 0.001. The corresponding figures for arachidonic acid-, thrombin receptor activating peptide- and collagen-induced aggregation was 21 (17-51) vs. 13 (10-25) U, 112 (87-128) vs. 78 (65-103) U and 58 (50-73) vs. 33 (28-44) U, respectively, all P < 0.001). ConclusionThe results suggest that cell saver processing before retransfusion mitigates the negative effects of wound blood on platelet function despite that cell saver processing reduces platelet count.
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| 7. |
- Gäbel, Jakob, 1971, et al.
(författare)
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Retransfusion of cardiotomy suction blood impairs haemostasis: Ex vivo and in vivo studies.
- 2013
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Ingår i: Scandinavian cardiovascular journal : SCJ. - : Informa UK Limited. - 1651-2006 .- 1401-7431. ; 47:6, s. 368-376
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. Cardiotomy suction blood in volumes corresponding to 10-20% of the systemic blood volume is retransfused during cardiopulmonary bypass. We hypothesized that retransfusion of unwashed cardiotomy suction blood influences coagulation and platelet function. Design. Systemic blood samples collected during cardiopulmonary bypass were supplemented ex vivo with autologous wound blood (5, 10 and 20%, respectively). Clot formation and platelet function were assessed with thromboelastometry and platelet aggregometry. In an in vivo pilot study 30 patients were randomized into a retransfusion and a no-retransfusion group. Clot formation, platelet aggregability and thrombin generation capacity were compared between the groups. Results. Cardiotomy suction blood had markedly impaired clot stability and reduced levels of fibrinogen and platelets compared with systemic blood. Ex vivo addition of 10% and 20% suction blood to systemic blood impaired platelet aggregability and clot stability. Retransfusion of small amounts of wound blood in vivo (mean volume 280 ml, corresponding to 5% of the blood volume) did not significantly influence haemostasis. Conclusions. The ex vivo results suggest that addition of unwashed cardiotomy suction blood in clinically relevant volumes impairs systemic haemostasis. Retransfusion of smaller volumes in vivo has no or limited impact. Avoiding retransfusion of larger amounts of unwashed cardiotomy suction may improve postoperative haemostasis.
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| 8. |
- Karlsson, Martin, 1978, et al.
(författare)
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Sampling Conditions Influence Multiple Electrode Platelet Aggregometry in Cardiac Surgery Patients. : Platelet aggregometry in cardiac surgery
- 2013
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Ingår i: Scandinavian cardiovascular journal : SCJ. - : Informa UK Limited. - 1651-2006 .- 1401-7431. ; 47:2, s. 98-103
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT Objectives: To investigate the importance of blood sampling conditions for multiple electrode platelet aggregometry (MEA) in cardiac surgery patients. Design: Eighty-one patients undergoing first time CABG surgery were included in three prospective, observational studies. MEA was used to analyze platelet aggregability after addition of adenosine-diphosphate (ADP) or thrombin activating peptide 6 (TRAP). In substudy 1, hirudin and citrate tubes were compared. In substudy 2, samples from peripheral vein, central venous catheter and radial artery were compared and in substudy 3, the effect of surgery was investigated by analyzing pre- and postoperative samples. Results: Platelet aggregability values were 30% higher in hirudin tubes than in citrate tubes. There was a significant correlation between hirudin and citrate tubes in TRAP-induced aggregability (r=0.84, p<0.001) but not in ADP-induced aggregability (r=0.25, p=0.13). Blood sampling site did not influence platelet aggregability. Surgery reduced ADP-induced aggregability with 31% (p<0.001) and TRAP-induced aggregability with 30 % (p<0.001) with large intraindividual variations. Conclusions: MEA results in cardiac surgery patients should not be compared between samples collected in test tubes with different anticoagulants. The choice of blood sampling site does not affect the results. The operation in itself reduces markedly mean platelet aggregability.
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| 9. |
- Singh, Sukhi, 1990, et al.
(författare)
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Adrenaline Improves Platelet Reactivity in Ticagrelor-Treated Healthy Volunteers
- 2019
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Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 119:5, s. 735-743
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Administration of agents that enhance platelet reactivity may reduce the perioperative bleeding risk in patients treated with the adenosine diphosphate (ADP)-receptor antagonist ticagrelor. Adrenaline potentiates ADP-induced aggregation and activation in blood samples from ticagrelor-treated patients, but it has not previously been evaluated in vivo.METHODS: Ten healthy male subjects were included in an interventional study. A loading dose of ticagrelor (180 mg) was administered, followed 2 hours later by a gradually increased intravenous adrenaline infusion (0.01, 0.05, 0.10 and 0.15 µg/kg/min; 15 minutes at each step). Blood pressure, heart rate, platelet aggregation (impedance aggregometry), platelet activation (flow cytometry), clot formation (rotational thromboelastometry) and adrenaline plasma concentration were determined before and after ticagrelor administration and at the end of each adrenaline step.RESULTS: = 0.007).CONCLUSION: Infusion of adrenaline at clinically relevant doses improves in vivo platelet reactivity and clot formation in ticagrelor-treated subjects. Adrenaline could thus potentially be used to prevent perioperative bleeding complications in ticagrelor-treated patients. Studies in patients are necessary to determine the clinical importance of our observations.TRIAL REGISTRY NUMBER: ClinicalTrials.gov NCT03441412.
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| 10. |
- Singh, Sukhi, 1990, et al.
(författare)
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Platelet storage lesion in interim platelet unit concentrates: A comparison with buffy-coat and apheresis concentrates.
- 2017
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Ingår i: Transfusion and Apheresis Science. - : Elsevier BV. - 1473-0502. ; 56:6, s. 870-874
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Tidskriftsartikel (refereegranskat)abstract
- Platelet storage lesion is characterized by morphological changes and impaired platelet function. The collection method and storage medium may influence the magnitude of the storage lesion. The aim of this study was to compare the newly introduced interim platelet unit (IPU) platelet concentrates (PCs) (additive solution SSP+, 40% residual plasma content) with the more established buffy-coat PCs (SSP, 20% residual plasma content) and apheresis PCs (autologous plasma) in terms of platelet storage lesions. Thirty PCs (n=10 for each type) were assessed by measuring metabolic parameters (lactate, glucose, and pH), platelet activation markers, and in vitro platelet aggregability on days 1, 4, and 7 after donation. The expression of platelet activation markers CD62p (P-selectin), CD63 (LAMP-3), and phosphatidylserine was measured using flow cytometry and in vitro aggregability was measured with multiple electrode aggregometry. Higher platelet activation and lower in vitro aggregability was observed in IPU than in buffy-coat PCs on day 1 after donation. In contrast, metabolic parameters, expression of platelet activation markers, and in vitro aggregability were better maintained in IPU than in buffy-coat PCs at the end of the storage period. Compared to apheresis PCs, IPU PCs had higher expression of activation markers and lower in vitro aggregability throughout storage. In conclusion, the results indicate that there are significant differences in platelet storage lesions between IPU, buffy-coat, and apheresis PCs. The quality of IPU PCs appears to be at least comparable to buffy-coat preparations. Further studies are required to distinguish the effect of the preparation methods from storage conditions.
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| 11. |
- Stolt, Henrik, et al.
(författare)
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A comparison of the in vitro effects of three fibrinogen concentrates on clot strength in blood samples from cardiac surgery patients
- 2021
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 65:10, s. 1439-1446
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Tidskriftsartikel (refereegranskat)abstract
- Background Fibrinogen concentrate is used clinically to improve hemostasis in bleeding patients. We investigated and compared the efficacy of three commercially available fibrinogen concentrates to improve clot strength in blood samples from cardiac surgery patients. Objectives Postoperative blood samples were collected from 23 cardiac surgery patients. Samples were each divided into four vials, each supplemented with 1.125 mg of fibrinogen of one of three fibrinogen concentrates (RiaSTAP(R), Fibryga(R), FibCLOT(R)), or placebo. The fibrinogen dose corresponded to 2.5 g per 70 kg of body weight. Clot strength after supplementation was assessed in duplicate with rotational thromboelastometry (ROTEM(R)) using FIBTEM maximum clot firmness, EXTEM clot formation time, and maximum clot firmness assays. Results In vitro fibrinogen concentrate supplementation of the samples resulted in higher plasma fibrinogen concentrations and improved clot strength with all three concentrates. Supplementation with FibCLOT increased FIBTEM maximum clot firmness (+46% [25th-75th percentile 35-55] compared to placebo) significantly more than did supplementation with Fibryga (+26% [21-35]) and RiaSTAP (+29% [22-47], p < .001). FibCLOT supplementation also shortened EXTEM clot formation time and increased EXTEM maximum clot firmness to a greater extent than did the other concentrates (both p < .001). Conclusions At the selected dose, FibCLOT was more effective than Fibryga and RiaSTAP in restoring clot strength in postoperative blood samples from cardiac surgery patients. These results may have implications for the choice of fibrinogen concentrate and dosing.
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| 12. |
- Waldén, Katarina, 1983, et al.
(författare)
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Effects of fibrinogen supplementation on clot formation in blood samples from cardiac surgery patients before and after tranexamic acid administration
- 2019
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Ingår i: Transfusion Medicine. - : Wiley. - 0958-7578 .- 1365-3148. ; 29:5, s. 319-324
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate if supplementation with fibrinogen concentrate to blood samples collected after tranexamic acid administration improve clot formation more than what can be achieved with fibrinogen in the absence of tranexamic acid. Background: It is not known if the combination of fibrinogen and tranexamic acid has additional effects than what can be achieved individually. Methods: Four blood samples were collected from 15 coronary artery bypass patients. Two samples were collected before surgery, before and after 2g tranexamic acid was administered. The preoperative samples were diluted to haematocrit 21%. Two samples were collected after surgery, before and after a second dose of 2g tranexamic acid. Fibrinogen concentrate corresponding to a dose of 3g in a 70-kg patient was added to the samples. Platelet-independent clotting time and maximum clot firmness assessed by thromboelastometry (ROTEM-FIBTEM®) were compared between the samples. Results: Administration of tranexamic acid shortened clotting time marginally (−6%) before surgery, P=0·029) but did not influence clot firmness. Fibrinogen concentrate shortened clotting time (−14% before and −12% after surgery, both P=0·003) and increased clot firmness (+51 and +39%, both P<0·001). The effects of fibrinogen did not differ before and after tranexamic acid administration. Fibrinolysis was not detected in any sample. Conclusions: The results of this in vitro study suggest that the enhancing effects of fibrinogen on clot firmness in blood samples from cardiac surgery patients are not further increased in the presence of tranexamic acid. Further studies on patients with ongoing bleeding and/or hyperfibrinolysis are necessary to validate the results. © 2019 British Blood Transfusion Society
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