scholarly journals Association Between Prolonged Closure Time on the Platelet Function Analyzer-200 and Risk of Perioperative Blood Transfusion

2019 ◽  
Vol 39 (3) ◽  
pp. 330-332 ◽  
Author(s):  
Kibum Jeon ◽  
Jiwon Lee ◽  
Eunyup Lee ◽  
Jeesoo Lee ◽  
Miyoung Kim ◽  
...  
Keyword(s):  
Blood Transfusion ◽  
Platelet Function ◽  
Closure Time ◽  
Function Analyzer ◽  
Platelet Function Analyzer ◽  
Perioperative Blood Transfusion

The influence of the haematocrit on primary haemostasis in vitro

2005 ◽  
Vol 94 (12) ◽  
pp. 1213-1218 ◽  
Author(s):  
Marco Eugster ◽  
Walter H. Reinhart
Keyword(s):  
Platelet Function ◽  
Type I Collagen ◽  
Inverse Correlation ◽  
Type I ◽  
Membrane Pore ◽  
Closure Time ◽  
Function Analyzer ◽  
Platelet Function Analyzer

SummaryPrimary haemostasis consists of platelet adhesion to subendothelial collagen, their activation and aggregation and finally the formation of a platelet plug. Erythrocytes are involved in this process because they flow in the center of the vessel and push platelets towards the site of action on the vessel wall and enhance shear forces, which activate platelets. In the platelet function analyzer PFA-100® (Dade Behring, Düdingen, Switzerland), the in vivo situation is simulated in vitro with blood being aspirated at high shear rates (5000s-1) through a capillary into a membrane pore with a diameter of 150 μm coated with type I collagen and either epinephrine or adenosine diphosphate. Aggregating platelets plug the pore and stop the flow, which is measured as the closure time. We analysed the influence of erythrocytes on platelet function analyzer measurements by systematic variation of the haematocrit (20,30,40,and 50%) at constant platelet counts of 289±61 ×103/μl plasma, or 152±30 ×103/μl blood, 96±9 ×103/μl blood and 54±5 ×103/μl blood, respectively. An inverse correlation was found between haematocrit and closure time under all circumstances. A decrease of the platelet count by 50 ×103 /μl could be compensated for by a 10% increase in haematocrit. The haematocrit must, therefore, be taken into consideration for the correct interpretation of PFA-100® measurements. Our data also provide a pathophysiological rationale to reduce the risk of bleeding in patients with thrombocytopenia and anaemia by normalizing the haematocrit with erythrocyte transfusions.

scholarly journals Monitoring of Clopidogrel Action: Comparison of Methods

2005 ◽  
Vol 51 (6) ◽  
pp. 957-965 ◽  
Author(s):  
Jörg Geiger ◽  
Lino Teichmann ◽  
Ralf Grossmann ◽  
Barsom Aktas ◽  
Udo Steigerwald ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Platelet Function ◽  
Significant Proportion ◽  
Coronary Intervention ◽  
Platelet Response ◽  
Closure Time ◽  
Vasp Phosphorylation ◽  
Function Analyzer ◽  
Potent Drug ◽  
Platelet Function Analyzer

Abstract Background: Clopidogrel is a potent drug for prevention of adverse effects during and after coronary intervention. Increasing experience indicates that a significant proportion of patients do not respond adequately to clopidogrel. Because failure of antiplatelet therapy can have severe consequences, there is need for a reliable assay to quantify the effectiveness of clopidogrel treatment. Methods: Of 24 healthy volunteers admitted to the study, 18 were treated for 1 week with clopidogrel (300-mg loading dose and 75-mg maintenance dose), and 6 with placebo. Platelet function was monitored by 2 assays, based on flow cytometry and enzyme immunoassay, that measure the phosphorylation status of vasodilator-stimulated phosphoprotein (VASP) and by aggregometry, flow cytometry of P-selectin, and the platelet function analyzer at baseline, on days 1–5, and on day 9 of treatment. Results: Aggregometry and VASP phosphorylation revealed a loss of platelet response to ADP within 12 h after clopidogrel intake. The phosphorylation status of VASP correlated with the inhibition of platelet aggregation. In contrast, neither P-selectin expression nor PFA-100 closure time was a clear indicator of clopidogrel effects on platelets. Conclusions: VASP phosphorylation assays are reliable for quantifying clopidogrel effects. Because the VASP assay directly measures the function of the clopidogrel target, the P2Y12 receptor, the assay is selective for clopidogrel effects rather than effects of other platelet inhibitors commonly in use.

Platelet function in cats with hyperthyroidism

2020 ◽  
Vol 22 (12) ◽  
pp. 1214-1218
Author(s):  
Elizabeth C Hiebert ◽  
David L Panciera ◽  
Katie M Boes ◽  
Lara Bartl
Keyword(s):  
Platelet Count ◽  
Platelet Function ◽  
Adenosine Diphosphate ◽  
Control Group ◽  
Closure Time ◽  
Function Analyzer ◽  
The Mean ◽  
Platelet Function Analyzer ◽  
Von Willebrand ◽  
Willebrand Factor

Objectives Cats with hyperthyroidism have been reported to develop thromboembolism, with and without echocardiographic abnormalities consistent with hyperthyroidism. The objective of this study was to compare platelet function in cats with hyperthyroidism with euthyroid age-matched cats. We hypothesized that cats with hyperthyroidism have shortened collagen and adenosine diphosphate (C-ADP) closure times as measured with the platelet function analyzer (PFA-100) in comparison with healthy, age-matched controls. Methods Sixteen hyperthyroid and nine euthyroid healthy cats >7 years of age were recruited from the hospital population. Platelet function, measured using the C-ADP closure times by the PFA-100, and platelet count were measured in healthy euthyroid cats and cats with hyperthyroidism. Results Mean ± SD closure times were not significantly different between control (66.3 ± 9.6 s) and hyperthyroid cats (65.9 ± 11.5 s; P = 0.75). The mean ± SD closure times of hyperthyroid cats that either were untreated or received methimazole for ⩽3 weeks (n = 6; mean 68.5 ± 15.4 s) was not different than that of cats treated for >3 weeks (n = 10; mean 64.3 ± 8.9 s; P = 0.57). The mean automated platelet count was higher in the hyperthyroid group than in the control group ( P = 0.023). Conclusions and relevance Platelet function, as measured by closure time under high shear conditions using C-ADP as an agonist, was not affected by hyperthyroidism in this group of cats. Further research is needed to determine if a hypercoagulable state exists in hyperthyroid cats and the potential roles platelets and von Willebrand factor may have.

scholarly journals Platelet function analyzer (PFA)-100R closure time in the evaluation of platelet disorders and platelet function

2006 ◽  
Vol 4 (2) ◽  
pp. 312-319 ◽  
Author(s):  
C. P. M. HAYWARD ◽  
P. HARRISON ◽  
M. CATTANEO ◽  
T. L. ORTEL ◽  
A. K. RAO ◽  
...  
Keyword(s):  
Platelet Function ◽  
Closure Time ◽  
Function Analyzer ◽  
Platelet Disorders ◽  
Platelet Function Analyzer

Platelet aggregation and platelet function analyzer 100 (PFA-100) closure time in camels—a comparative study with humans

2006 ◽  
Vol 15 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Abdel Galil M. Abdel Gader ◽  
Abeer K. Al Ghumlas ◽  
Mansour F. Hussain ◽  
Ahmed I. Al Haidary
Keyword(s):  
Platelet Aggregation ◽  
Comparative Study ◽  
Platelet Function ◽  
Closure Time ◽  
Function Analyzer ◽  
Platelet Function Analyzer

scholarly journals Establishment of reference intervals for Platelet Function Analyzer -100 closure time in Algerian adults

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249402
Author(s):  
Malika Belkacemi ◽  
Yassine Merad ◽  
Mohamed Amine Merbouh
Keyword(s):  
Platelet Function ◽  
Clinical Chemistry ◽  
Point Of Care ◽  
Reference Intervals ◽  
Primary Hemostasis ◽  
Asian Populations ◽  
Closure Time ◽  
Function Analyzer ◽  
Time Required ◽  
Platelet Function Analyzer

Introduction The Platelet Function Analyzer-100 (PFA-100) is a point of care instrument that simulates plug formation under high shear flow. The PFA-100 measures the time required to occlude the aperture in a biochemically active cartridge and is expressed in a term of closure time (CT). In Algeria, the reference values used in clinical laboratories are of Western origin. However, ethnic, genetic, dietary environmental, and diet differences between populations may affect reference intervals. We established the reference intervals of PFA-100 closure times in healthy Algerian adults according to the International Federation of Clinical Chemistry method, and we compared them with those of Western and Asian countries. Material and methods We enrolled 303 healthy blood donors in the study. 218 subjects met inclusion criteria. We analyzed the blood sample on the PFA-100 for CT with both the collagen epinephrine and collagen ADP cartridges. Results The reference intervals of PFA-100 collagen epinephrine CT and PFA-100 collagen ADP CT were 91–207 seconds and 71–144 seconds, respectively. Compared to Western and Asian populations, there were significant differences. The upper limits of CTs were higher for Algerians in this study. Our findings show that many healthy Algerians would be incorrectly identified as having a primary hemostasis abnormality according to the reference intervals of the manufacturer and scientific literature. Conclusion This report provides the first reference intervals for PFA-100 CTs in healthy Algerian adults. These results improve the accuracy of diagnosis and patient care in Algeria.

Sign in / Sign up

Export Citation Format

Share Document