The Effects of Aprotinin on Thromboelastography with Three Different Activators

2001 ◽  
Vol 95 (5) ◽  
pp. 1169-1174 ◽  
Author(s):  
Michael S. Avidan ◽  
Jorge Da Fonseca ◽  
Kiran Parmar ◽  
Emma Alcock ◽  
José Ponte ◽  
...  

Background Thromboelastography is used for assessment of hemostasis. Adherence to thromboelastography-guided algorithms and aprotinin administration each decrease bleeding and blood product usage after cardiac surgery. Aprotinin, through inhibition of kallikrein, causes prolongation of the celite-activated clotting time and the activated partial thromboplastin ratio. The aim of this study was to assess the effects of aprotinin on the thromboelastography trace. Methods Three activators were used in the thromboelastography: celite (which is widely established), kaolin, and tissue factor. Assessment was performed on blood from volunteers and from patients before and after cardiac surgery. Results The tissue factor-activated thromboelastography trace was unaffected by the addition of aprotinin. When celite and kaolin were used as activators in the presence of aprotinin, the reaction time (time to clot formation) of the thromboelastography trace was prolonged (P < 0.0001) and the maximum amplitude (clot strength) was decreased (P < 0.05). With celite as an activator, the addition of aprotinin decreased (P < 0.05) the thromboelastography alpha angle (rate of clot extension). The reaction time of the celite-activated trace correlated with the activated partial thromboplastin ratio (P < 0.01). The reaction time of the tissue factor-activated trace correlated with the international normalized ratio (P < 0.01). Conclusion The thromboelastography trace is altered in the presence of aprotinin when celite and kaolin are used as activators but not when tissue factor is the activator.

2020 ◽  
Vol 48 (1) ◽  
pp. 43-52
Author(s):  
Qi Wong ◽  
Kelly P Byrne ◽  
Scott C Robinson

TEG6s® is a new device introduced by the Haemonetics Corporation and designed to provide the same information as TEG® 5000 (Haemonetics Corporation, Braintree, MA, USA) but with much greater ease of use. We tested whether using citrated TEG6s gave reaction time, maximum amplitude and percentage of clot that had lysed at 30 minutes values similar to a non-citrated TEG5000, to allow clinical interchangeability using our current thrombelastography management algorithm for cardiac surgery. We also examined the agreement between the alpha-angle and functional fibrinogen maximum amplitude in our cardiac surgical patients.  In total, 243 paired arterial blood samples in 99 patients were tested, using TEG5000 (non-citrated) and TEG6s (citrated) after induction of anaesthesia (prior to heparin administration), following protamine administration at the end of the cardiac bypass and whenever a TEG5000 was requested after this by the attending anaesthetist. Bland–Altman plots and Lin’s concordance coefficient were used to compare agreement whereas modified Bland–Altman plots and McNemar’s test were used to illustrate the differences in management recommendations between the two thrombelastography devices.  All 243 samples were compared for reaction time and alpha-angle; 239 samples were compared for maximum amplitude; 136 samples were compared for the percentage of clot that had lysed at 30 minutes; 16 samples were compared for functional fibrinogen maximum amplitude. Lin’s concordance coefficient for these parameters was: reaction time 0.63, alpha-angle 0.39, maximum amplitude 0.5, percentage of clot that had lysed at 30 minutes 0.09 and functional fibrinogen maximum amplitude 0.31. Differences between the two devices became more marked at more abnormal values. Significant differences in median values, suggesting a fixed bias, were found for maximum amplitude and functional fibrinogen maximum amplitude. Differences in treatment recommendation could only be calculated for reaction time and maximum amplitude. Maximum amplitude was found to have a significant difference in treatment recommendation between the two devices using our current thrombelastography management algorithm for cardiac surgery with TEG6s recommending treatment in 11.5% more patients than TEG5000.  Using the TEG6s with our current TEG5000–based thrombelastography management algorithm for cardiac surgery would result in a change in treatment recommendation in at least 10% of our cardiac surgical patients. Agreement between the two thrombelastography devices appears to decrease with increasing patient coagulopathy. New algorithms will need to be developed and tested to validate TEG6s for cardiac surgical patients in our institution.


2011 ◽  
Vol 23 (6) ◽  
pp. 1109-1113 ◽  
Author(s):  
Amrita Banerjee ◽  
Shauna L. Blois ◽  
R. Darren Wood

Thromboelastography (TEG) is a point-of-care whole blood test of hemostasis. While TEG is becoming more widely used in veterinary medicine, few studies describe the use of TEG in cats. The objectives of the current study were to: 1) document the range of TEG variables produced in healthy cats using 3 sample types (citrated native, kaolin-activated, and tissue factor–activated), and 2) determine if there was a significant difference between 2 separate samples obtained from individual healthy cats on the same day. Jugular venipuncture was performed in 20 cats, and citrated blood collected for TEG. TEG analysis was performed on citrated native, kaolin-activated, and tissue factor–activated blood for each sample. Two hours later, the procedure was repeated from the opposite jugular vein, yielding a total of 120 analyses. Reaction time ( R), alpha angle (α), kappa value (κ), and maximum amplitude (MA) were recorded from each tracing. No significant differences were found between TEG tracings from the first and second venipuncture samples. Significant differences were found between sample types for R, α, κ, and MA. Means for citrated native/kaolin-activated/tissue factor–activated methods were R = 4.1/3.7/0.6 min; κ = 2.5/1.8/2.2 min; α = 59.9/65.1/70.4 degrees; MA = 47.4/49.9/44.7 mm. A limitation of this study was the small number of cats used. Thromboelastography analysis may be a suitable method of evaluating hemostasis in cats.


2018 ◽  
Vol 21 (8) ◽  
pp. 708-713 ◽  
Author(s):  
Duree Shin ◽  
Aryung Nam ◽  
Kun Ho Song ◽  
Kyoung Won Seo

Objectives The aim of this study was to evaluate the effect of two differently sized butterfly catheter needles and the effect of venepuncture difficulty on thromboelastography (TEG) results in healthy cats. Methods Twenty-four healthy cats were included. Blood samples were collected from the jugular vein by syringe aspiration via direct venepuncture with 21 G and 22 G butterfly needles. The venepuncture difficulty score was classified into four categories. The first 1.5 ml blood drawn from each subject was discarded before collecting a sample for TEG analysis. TEG analyses were performed on citrated whole blood samples from 17 clinically healthy cats, using assays with kaolin as activators. Among the TEG parameters, reaction time (R), clot formation time (κ), alpha angle (α), maximum amplitude (MA) and global clot strength (G) were recorded from each tracing. Results Seven cats were excluded from the study; results were obtained for the remaining 17 cats. There were no statistically significant differences between the use of two different needles for R ( P = 0.72), κ ( P = 0.74), α ( P = 0.99), MA ( P = 0.08) and G ( P = 0.09). Samples with difficulty scores ⩾1 were not significantly different from samples with difficulty scores of 0 for R ( P = 0.24), κ ( P = 0.65), α ( P = 0.65), MA ( P = 0.72) and G ( P = 0.77). Conclusions and relevance The results of TEG in clinically healthy cats do not differ significantly when using two different gauge needles. There was no significant difference in the TEG results according to venepuncture difficulty scoring.


1995 ◽  
Vol 73 (01) ◽  
pp. 039-048 ◽  
Author(s):  
A Bierhaus ◽  
Ch J Hemmer ◽  
N Mackman ◽  
R Kutob ◽  
R Ziegler ◽  
...  

SummarySerum from patients with P. falciparum malaria at day 1 (pretherapy) induces tissue factor (TF) in cultured endothelial cells. TF induction depends on de novo transcription as shown in Nuclear Run On assays. Electrophoretic mobility shift assays demonstrated binding of AP-1 and NF- κB/Rel proteins to their recognition sites in the TF promotor. After therapy (day 28), stimulation of TF antigen by patient serum is reduced by 70%. When serum obtained before and after therapy was compared, a decrease of NF-κB activation was evident. Activation of NF-κB-like proteins was in part dependent on TNFα in patient serum, since a TNFα neutralizing antibody reduced induction of TF transcription and translation and induction of NF-κB-like proteins. Induction of TF activity was suppressed by pDTC, an inhibitor of NF-κB activation. When different promotor constructs of the TF gene were tested, induction was dependent upon the presence of the intact NF-κB-like binding site in the TF promotor. A mutant with deleted NF-κB, but intact AP-1 sites was not inducible. Mutation of the AP-1 sites did not prevent induction, but reduced inducibility by pretherapy serum. Therefore, NF-κB/Rel proteins are responsible for induction of TF transcription by pretherapy serum, but AP-1 is needed for highest inducibility. The effect of antiparasitic therapy on the induction of TF by serum from patients with complicated P. falciparum malaria is dependent on a therapy-mediated loss of activation of NF-κB-like proteins in post-treatment patient serum.


1997 ◽  
Vol 78 (04) ◽  
pp. 1202-1208 ◽  
Author(s):  
Marianne Kjalke ◽  
Julie A Oliver ◽  
Dougald M Monroe ◽  
Maureane Hoffman ◽  
Mirella Ezban ◽  
...  

SummaryActive site-inactivated factor VIIa has potential as an antithrombotic agent. The effects of D-Phe-L-Phe-L-Arg-chloromethyl ketone-treated factor VIla (FFR-FVIIa) were evaluated in a cell-based system mimicking in vivo initiation of coagulation. FFR-FVIIa inhibited platelet activation (as measured by expression of P-selectin) and subsequent large-scale thrombin generation in a dose-dependent manner with IC50 values of 1.4 ± 0.8 nM (n = 8) and 0.9 ± 0.7 nM (n = 7), respectively. Kd for factor VIIa binding to monocytes ki for FFR-FVIIa competing with factor VIIa were similar (11.4 ± 0.8 pM and 10.6 ± 1.1 pM, respectively), showing that FFR-FVIIa binds to tissue factor in the tenase complex with the same affinity as factor VIIa. Using platelets from volunteers before and after ingestion of aspirin (1.3 g), there were no significant differences in the IC50 values of FFR-FVIIa [after aspirin ingestion, the IC50 values were 1.7 ± 0.9 nM (n = 8) for P-selectin expression, p = 0.37, and 1.4 ± 1.3 nM (n = 7) for thrombin generation, p = 0.38]. This shows that aspirin treatment of platelets does not influence the inhibition of tissue factor-initiated coagulation by FFR-FVIIa, probably because thrombin activation of platelets is not entirely dependent upon expression of thromboxane A2.


2021 ◽  
pp. 000313482110335
Author(s):  
Alison Smith ◽  
Juan Duchesne ◽  
Matthew Marturano ◽  
Shaun Lawicki ◽  
Kevin Sexton ◽  
...  

Background Viscoelastic tests including thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are being used in patients with severe hemorrhage at trauma centers to guide resuscitation. Several recent studies demonstrated hypercoagulability in female trauma patients that was associated with a survival advantage. The objective of our study was to elucidate the effects of gender differences in TEG/ROTEM values on survival in trauma patients with severe hemorrhage. Methods A retrospective review of consecutive adult patients receiving massive transfusion protocol (MTP) at 7 Level I trauma centers was performed from 2013 to 2018. Data were stratified by gender and then further examined by TEG or ROTEM parameters. Results were analyzed using univariate and multi-variate analyses. Results A total of 1565 patients were included with 70.9% male gender (n = 1110/1565). Female trauma patients were older than male patients (43.5 ± .9 vs 41.1 ± .6 years, P = .01). On TEG, females had longer reaction times (6.1 ± .9 min vs 4.8 ± .2 min, P = .03), increased alpha angle (68.6 ± .8 vs 65.7 ± .4, P < .001), and higher maximum amplitude (59.8 ± .8 vs 56.3 ± .4, P < .001). On ROTEM, females had significantly longer clot time (99.2 ± 13.7 vs 75.1 ± 2.6 sec, P = .09) and clot formation time (153.6 ± 10.6 sec vs 106.9 ± 3.8 sec, P < .001). When comparing by gender, no difference for in-hospital mortality was found for patients in the TEG or ROTEM group ( P > .05). Multivariate analysis showed no survival difference for female patients (OR 1.11, 95% CI .83-1.50, P = .48). Conclusions Although a difference between male and females was found on TEG/ROTEM for certain clotting parameters, no difference in mortality was observed. Prospective multi-institutional studies are needed.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Zagatina ◽  
M Novikov ◽  
N Zhuravskaya ◽  
V Balakhonov ◽  
S Efremov ◽  
...  

Abstract Background Stenosis of a coronary artery results in an increase in flow velocity in the pathologic segment. Effective grafting should decrease the stenotic native coronary velocity according to hemodynamic law. The range of decreased velocity before and after cardiac surgery can hypothetically reflect the effectiveness of a graft. The aim of the study is to determine if measuring coronary flow velocity changes during coronary artery bypass grafting (CABG) can predict intraoperative myocardial infarction. Methods One hundred sixty-six (166) consecutive patients (121 men, 64±9 years old) referred for cardiac surgery, were prospectively included in the study. A standard basic perioperative transesophageal echocardiography (TEE) examination was performed with additional scans of the left main, left anterior descending (LAD), and circumflex (LCx) arteries' proximal segments. Measurements of coronary flow velocities were performed before and after grafting in the same sites of the arteries. The maximal value of cardiac troponin I (cTnI) after CABG and the additive criteria were accounted for in the analysis as it is described in the expert consensus document for Type 5 myocardial infarction (MI) definition. Results One hundred sixty-three patients (98%) had arterial hypertension, 28 patients (17%) had diabetes mellitus, 35 patients (21%) were currently smokers. The feasibility of coronary flow assessment during cardiac operations was 95%. Before grafting, the mean velocity in the left main artery was 91±49 cm/s, in LAD 101±35 cm/s, and in LCx 117±49 cm/s. There was a significant correlation between changes in coronary flow velocities during operation and the value of cTnI (R=0.34, p&lt;0.0001). Ten patients met the criteria for Type 5 MI. There were no differences in age, body mass index, number of coronary arteries with stenoses, frequency of prior MI, ejection fraction or coronary flow velocity before surgery in patients with and without Type 5 MI. The group of patients with Type 5 MI had an increase in native artery velocities during surgery in comparison with patients without MI, who had a significant decrease in coronary flow velocity after grafting (30±48 vs. −10±30 cm/s; p&lt;0.0006). Increases in native coronary velocities greater than 3 cm/s predicted Type 5 MI with 81% accuracy (sensitivity 88%, specificity 70%). Conclusion Coronary flow velocity assessment during cardiac surgery could predict an elevation of cardiac troponins and Type 5 MI. Funding Acknowledgement Type of funding source: None


2017 ◽  
Vol 27 (3-4) ◽  
Author(s):  
Hsiu‐Yun Liao ◽  
Chaw‐Chi Chiu ◽  
Ying‐Ying Ko ◽  
Hsing‐Mei Chen

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