scholarly journals Aspirin prolongation of the template bleeding time: influence of venostasis and direction of incision

Blood ◽  
1982 ◽  
Vol 60 (5) ◽  
pp. 1139-1142 ◽  
Author(s):  
CH Jr Mielke

Abstract The template bleeding time is a measure of platelet participation in primary hemostasis. Aspirin alters platelet function through interference with prostaglandin biosynthesis. In many individuals, aspirin will consistently prolong the bleeding time. Despite this observation, normal individuals rarely develop a bleeding disorder. This prompted us to investigate the influence of technical variables on the prolongation of the bleeding time by aspirin. Both direction of incision and venostasis influenced the prolongation of the bleeding time by aspirin. A horizontal incision with venostasis produced the most pronounced prolongation, while a vertical incision without venostasis didn't prolong the bleeding time despite the characteristic changes in platelet aggregation and release. These studies suggest that the influence of aspirin on the template bleeding time is dependent on technical variables and is minimal in the normal subject.

Blood ◽  
1982 ◽  
Vol 60 (5) ◽  
pp. 1139-1142
Author(s):  
CH Jr Mielke

The template bleeding time is a measure of platelet participation in primary hemostasis. Aspirin alters platelet function through interference with prostaglandin biosynthesis. In many individuals, aspirin will consistently prolong the bleeding time. Despite this observation, normal individuals rarely develop a bleeding disorder. This prompted us to investigate the influence of technical variables on the prolongation of the bleeding time by aspirin. Both direction of incision and venostasis influenced the prolongation of the bleeding time by aspirin. A horizontal incision with venostasis produced the most pronounced prolongation, while a vertical incision without venostasis didn't prolong the bleeding time despite the characteristic changes in platelet aggregation and release. These studies suggest that the influence of aspirin on the template bleeding time is dependent on technical variables and is minimal in the normal subject.


1999 ◽  
Vol 82 (10) ◽  
pp. 1250-1254 ◽  
Author(s):  
Olga Panes ◽  
Blanca Muñoz ◽  
Edgar Pais ◽  
Rodrigo Tagle ◽  
Fernando González ◽  
...  

Summary Background: A defect in platelet function is the main determinant of the prolonged bleeding time in chronic renal failure (CRF). We previously reported a significant correlation between platelet abnormalities and elevated plasma markers of plasmin and thrombin generation. Our aim was to explore the effect of inhibiting both plasmin action with tranexamic acid (TA) and thrombin production with low molecular weight heparin (LMWH), on the bleeding time (BT) and platelet function in patients with CRF. Methods: 37 patients with CRF (mean creatinine 8.6 ± 4.4 mg/dl) under conservative treatment, with prolonged BT, entered this study and received TA during 6 days, with (n = 24) and without LMWH (n = 13). BT, platelet aggregation/secretion, platelet granule contents, von Willebrand factor and parameters of coagulation and fibrinolysis were recorded before and at the end of treatment. Results: The BT was shortened in 26/37 (67%) patients. This effect was associated with significant improvement of platelet aggregation and secretion, with decrease to a normal range of fibrin/fibrinogen degradation products, mild increase in plasmin-antiplasmin complexes and pronounced reduction of circulating plasminogen. No differences were seen among patients with or without LMWH. No serious side effects or complications were observed. Interpretation: These findings indicate that the activation of fibrinolysis plays a significant role in the defect of primary hemostasis in patients with CRF. Inhibition of plasmin activity with TA shortens the BT and improves platelet function in the majority of patients with severe disease.


1988 ◽  
Vol 60 (01) ◽  
pp. 083-087 ◽  
Author(s):  
M P Gordge ◽  
R W Faint ◽  
P B Rylance ◽  
G H Neild

SummaryBleeding time and platelet function tests were performed on 31 patients with progressive chronic renal failure (CRF) due to non-immunological (urological) causes, and compared with 22 healthy controls. Patients were classified as mild (plasma creatinine <300 μmol/l), moderate (300-600 μmol/l) or severe renal failure (>600 μmol/l). Bleeding time was rarely prolonged in mild and moderate CRF and mean bleeding time significantly elevated only in severe CRF (p <0.005). Haematocrit was the only index which correlated with bleeding time (r = -0.40). Platelet counts, collagen stimulated thromboxane generation, and platelet aggregation responses to ADP, collagen and ristocetin were all either normal or increased in all three CRF groups, but thromboxane production in clotting blood was reduced. Plasma fibrinogen, C reactive protein and von Willebrand factor (vWF) were elevated in proportion to CRF. We found no evidence that defects in platelet aggregation or platelet interaction with vWF prolong the bleeding time in patients with progressive CRF.


Author(s):  
Richard C. Becker ◽  
Frederick A. Spencer

Platelet antagonists play an important role in both primary and secondary prevention of atherothrombotic events. Despite their proven benefit, individual response (and protection) varies considerably, emphasizing the importance of developing monitoring tools (tested prospectively in clinical trials) that can better determine the degree of platelet inhibition that is both safe and effective. Platelet function studies were developed originally for the evaluation of patients with unexplained bleeding and have contributed greatly to the understanding, diagnosis, and management of hereditary abnormalities such as von Willebrand disease and Glanzmann’s thrombasthenia (platelet glycoprotein [GP] IIb/IIIa receptor deficiency). Although conventional platelet function studies (turbidimetric aggregometry) have technical limitations that preclude their routine use for gauging antithrombotic therapy, they may provide guidance when hemorrhagic complications arise and in determining pretreatment risk in individuals suspected of having an intrinsic platelet abnormality. The bleeding time, considered an indicator of primary hemostasis (platelet plug formation), is defined as the time between making a small standardized skin incision and the precise moment when bleeding stops. The test is performed with a template, through which the medial surface of the forearm is incised under 40 mmHg standard pressure. A normal bleeding time is between 6 and 10 minutes. Although considered a “standardized” test of platelet function, the bleeding time can be influenced by a variety of factors, including platelet count, qualitative abnormalities, and features intrinsic to the blood vessel wall (George and Shattil, 1991). Platelet adhesion is the initiating step in primary hemostasis. Although platelet binding is an important component of this process, there are many others, including blood flow rate, endothelial cell function, adhesive proteins, and the subendothelial matrix. The original test used for assessing adhesion, platelet retention, was based on adherence to glass bead columns. The current laboratory evaluation of platelet function is based predominantly on turbidimetric platelet aggregometry (also known as light transmission aggregometry). This test is performed by preparing platelet-rich plasma (with platelet-poor plasma as a control) and eliciting an aggregation response with adenosine diphosphate, epinephrine, collagen, arachidonic acid, and ristocetin (Born, 1962).


Blood ◽  
1984 ◽  
Vol 64 (1) ◽  
pp. 229-236 ◽  
Author(s):  
KS Sakariassen ◽  
M Cattaneo ◽  
A v.d. Berg ◽  
ZM Ruggeri ◽  
PM Mannucci ◽  
...  

Abstract The effect of intravenous 1-deamino (8-D-arginine)vasopressin (DDAVP) administration on platelet interaction with human artery subendothelium was investigated with flowing blood from five normal individuals and 12 patients with von Willebrand's disease (vWD). Three of the patients were diagnosed as vWD subtype I, four as subtype IIa, and five as subtype IIb. DDAVP administration to normals enhanced platelet adherence, in parallel with increasing plasma levels of factor VIII- related antigen ( FVIIIR :Ag) and ristocetin cofactor activity ( FVIIIR :RCF). Platelet aggregate formation was transiently increased within 90 minutes. Platelet adherence in patient blood before DDAVP infusion was subnormal. In patients with subtype I, administration of DDAVP normalized the bleeding time, enhanced the platelet adherence, and transiently improved the platelet aggregate formation. The platelet adherence was more corrected than would have been expected on the basis of the FVIIIR :Ag and FVIIIR :RCF levels. In patients with subtype IIa, infusion of DDAVP increased the FVIIIR :Ag levels approximately threefold, without affecting the FVIIIR :RCF levels, and in only two of four patients was a transiently enhanced platelet adherence with a corresponding shortening of the bleeding time observed. In patients with subtype IIb, administration of DDAVP increased the FVIIIR :Ag levels about threefold and the FVIIIR :RCF levels five to tenfold, but decreased the platelet adherence significantly. The bleeding time values were not normalized. A close association between the bleeding time values and corresponding platelet adherence values before and after DDAVP infusion was observed. Normalization of the bleeding time was paralleled with normalization of platelet adherence. We conclude that DDAVP improves the primary hemostasis by causing enhanced FVIII- vWF-mediated platelet adherence. DDAVP has little or no effect on the bleeding time in patients with subtype IIa and subtype IIb, because the platelet adherence is not normalized.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2112-2112
Author(s):  
Ivana Ninkovic ◽  
James G. White ◽  
Kenyatta W. Stephens ◽  
Artur Rangel-Fihlo ◽  
Francsisca C. Wu ◽  
...  

Abstract Platelet dense granule storage pool disease (SPD) is a bleeding disorder characterized by a lack of normal platelet dense granule function, as evidenced by decreased platelet aggregation in response to ADP, epinephrine and collagen. Platelet SPD has been studied most extensively in humans and rodents with Hermansky-Pudlak syndrome (HPS), whose phenotype is a result of defects in granule trafficking, leading to oculocutanous albinism, lysosomal storage diseases, and platelet dysfunction. We have been characterizing the fawn-hooded hypertensive (FHH) rat, which has been previously shown to have a bleeding disorder consistent with a platelet SPD and some of the features of HPS. While the platelets in the FHH rat have normal alpha granules and lysosomes, they lack dense granules as assessed by transmission electron microscopy. Platelet flow cytometric analysis of GPIb and GPIIb indicated that the FHH platelets have normal surface expression of these adhesion proteins. The FHH rat has a mutation in the Rab38 gene at the ATG start site, which is associated with the bleeding disorder. Rab38 is part of a large family of GTPases, which are involved in granule formation and secretion. Western blotting of FHH tissues revealed that there is no expression of Rab38 protein. We have used confocal immunomicroscopy to assess Rab38 in platelet formation and function. In normal rat and human platelets, there was punctate expression of Rab38. There was no Rab38 staining detected in FHH platelets. In human megakaryocytic cell lines, Dami and HEL cells, there was punctate staining of Rab38 that was mainly in the periphery of the cells, with a variable amount of perinuclear staining. There was partial colocalization of Rab38 with serotonin and VWF, and with Lamp-3, a marker of lysosomes. The degree of colocalization varied between cells. There was no clear association of Rab38 with actin and tubulin in megakaryocytes. We also examined a cohort of patients with SPD, but not HPS, for mutations in Rab38. The entire coding region and intron-exon boundaries of the Rab38 gene were sequenced in 18 patient samples collected at Emory University for the CDC Women with Bleeding Disorders and Menorrhagia Study. Ten of the patients had platelet function defects documented by standard platelet aggregation studies, and eight had no identifiable platelet function defect. No mutations in Rab38 were detected. Whereas numerous known polymorphisms were identified and confirmed, there was no association of any of them with platelet function abnormalities. In conclusion, Rab38 is expressed in platelets and megakaryocytes and may interact with other granule proteins during megakaryocyte development. Failure to express Rab38 is associated with platelet dysfunction. Further studies are needed to determine its function in megakaryocytes and platelets, and to determine whether defects in Rab38 are a cause of platelet SPD in humans.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4922-4922
Author(s):  
Kristina M. Haley ◽  
Susan Lattimore ◽  
Cara McDavitt ◽  
Ayesha Khader ◽  
Colin Boehnlein ◽  
...  

Abstract Introduction: Nearly 40% of adolescent women experience heavy menstrual bleeding (HMB), and identifiable bleeding disorders are diagnosed in only 20-60% of these patients. We suspect that qualitative platelet disorders contribute to HMB, but are under-diagnosed. A pilot study was conducted to evaluate platelet function in adolescent women with HMB employing four novel, small-volume, whole blood platelet function assays. In addition, primary and secondary hemostasis, bleeding phenotype, and quality of life were assessed. Methods: Patients referred to the Young Women's Hematology Clinic at Oregon Health & Science University for evaluation of HMB were offered participation in the study. Participants underwent standard review of their medical and family history and physical exam. Standard lab evaluation included CBC, PT, PTT, fibrinogen, thrombin time, Von Willebrand Panel, PFA-100, and iron studies with platelet aggregation or phenotyping performed if clinically indicated. Using less than 0.5 mL of whole blood, platelet function was assessed with four novel platelet function assays: assessment of platelet activation, secretion, and aggregation was assessed by flow cytometry analysis, while platelet adhesion and aggregation was assessed under shear in a capillary tube. Quality of life (QOL) was assessed using the PedsQL tool. Bleeding phenotype was assessed with the ISTH Bleeding Assessment Tool (ISTH BAT). Menorrhagia was assessed with the Pictorial Bleeding Assessment Chart (PBAC), the Philipp Tool and the clinical history. Results: Nine participants have enrolled on study to date, with 2 completing the 3-month visit. The median age of the cohort was 16 years (14-18 years). Eight out of nine categorized their period as heavy, 6 also had epistaxis, and 7 reported excessive bruising. The median ISTH BAT score was 4 (3-7). Of the 7 patients who had a Philipp Score obtained, 5 were positive. Median PBAC score was 161 (64-196). Median ferritin was 13 ng/mL (4-65 ng/mL). Median QOL psychosocial score was 70 (68.36-88.25), comparable to that of pediatric patients with cancer. Of the 9 participants, 6 had platelet aggregation and phenotyping. Four participants did not receive a bleeding disorder diagnosis, 1 was diagnosed with Type 1 VWD, 1 was diagnosed with bleeding disorder, NOS, and 1 was diagnosed with Ehlers Danlos Syndrome. Two participants were diagnosed with a qualitative platelet disorder (QPD): one based on platelet aggregation and one based on thromboelastography. The four novel platelet function assays confirmed platelet function abnormalities in the participants diagnosed with QPD's (Figure 1&2). Impaired platelet response to agonist stimulation was also observed in participants with non-platelet disorder bleeding disorder diagnoses and in participants without a bleeding disorder diagnosis. Conclusions: In this pilot study, the etiology of HMB in adolescent women was evaluated with four novel platelet assays in addition to standard assays of hemostasis. A bleeding disorder diagnosis was not made with standard evaluations in 4 out of 9 participants. The novel assays detected platelet abnormalities not observed using currently available clinical labs, and confirmed the presence of abnormal platelet function in participants with abnormal platelet function testing. These assays require significantly less blood volume than currently available assays and expand investigation of platelet function to platelet adhesion and platelet interactions in whole and flowing blood. Further work is needed to determine the sensitivity and specificity of the novel assays in detecting platelet dysfunction. Continued investigation into the impact of HMB on the adolescent female population is needed. Disclosures Haley: CSL Behring: Honoraria; Baxalta: Membership on an entity's Board of Directors or advisory committees. Recht:Biogen: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Biogen: Research Funding; Genentech: Research Funding; Novo Nordisk: Research Funding; Baxalta: Research Funding; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees.


1994 ◽  
Vol 72 (06) ◽  
pp. 912-918 ◽  
Author(s):  
M Gawaz ◽  
I Ott ◽  
A J Reininger ◽  
F-J Neumann

SummaryMagnesium deficiency and its association with platelet hyperreactivity has been well recognised in a variety of diseases including myocardial infarction, preeclampsia, and diabetes. In order to investigate potential effects of intravenous Mg2+ supplementation, platelet function was studied by measurements of in vitro bleeding time (BT) and of fibrinogen (Fg)-mediated aggregation of washed platelets. In addition, the effect of Mg2+ on platelet adhesion onto immobilised Fg, on Fg binding to activated platelets, and on surface expression of GMP-140 or GP53 was evaluated. Mg2+(4 mM) prolonged in vitro BT by 30% and inhibited Fg-mediated aggregation significantly, independent of the agonist used to initiate platelet aggregation (ADP, collagen, epinephrine, thrombin, phorbol ester). Adhesion of resting platelets to immobilised Fg was reduced by 50% in the presence of 2 mM Mg2+. Moreover, Mg2+ reduced Fg binding to ADP- or collagen-stimulated platelets as well as surface expression of GMP-140 with an IC50 of approximately 3 mM. Intravenous administration of Mg2+ to healthy volunteers inhibited both ADP-induced platelet aggregation (p <0.05) by 40% and binding of Fg or surface expression of GMP-140 by 30% (p <0.05). Thus, pharmacological concentrations of Mg2+ effectively inhibit platelet function in vitro and ex vivo.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4009-4009
Author(s):  
Diego Mezzano ◽  
Teresa Quiroga ◽  
Manuela Goycoolea ◽  
Blanca Muñoz ◽  
Eduardo Aranda ◽  
...  

Abstract Diagnosis of patients with IMCH is plagued with difficulties: 1. Type 1 VWD (VWD-1) and platelet function disorders (PFD), the best characterized disorders of primary hemostasis, present inherent diagnostic difficulties. 2. Bleeding may be present in healthy individuals and may be absent in patients with diagnosed diseases. 3. An unknown proportion of bleeders do not have an identifiable haemostatic disorder. We studied prospectively 280 consecutive patients (age = 14.5±9.5, range 4–48 years) with family bleeding history who had a high probability of being pathological bleeders, based on an objective bleeding score. Only one physician interviewed the patients and the non-bleeder matched controls, (n=299, age 12.2±6.5, range 4–44 years). Exclusion criteria: age <4 and >50 years; platelet count <100.000/μL; other concurrent diseases, drug intake and C-reactive protein >1mg/dL. VWD was diagnosed when at least two tests (VWF:Ag, VWF:RCo, VWF:CB) had values <percentil 2.5 of the controls, without considering ABO type. PFD were diagnosed by PRP aggregation and 14C-5-HT secretion using pre-established criteria and reference values obtained in the 299 controls. Only 66 (23.6%) of the patients had prolonged bleeding time (BT). Frequency of diseases: 38 (13.6%) patients had VWD-1; 1 (0.35%) had type 2A VWD; 52 (18.6%) had PFD; 8 (2.9%) had concomitant VWD-1 + PFD; 7 patients (2.5%) had mild coagulation factor deficiencies (CFD, 4 with ↓FVIII:C; 2 with ↓ FIX:C; 1 with ↓ FXI:C); and 3 (1.1%) had concomitant VWD-1 + CFD; 171 bleeders (61.1%) had an unknown disorder (UD); in this UD group, 29 (17%) patients had prolonged BT, but all the other hemostatic tests were within the normal range. No distinctive bleeding pattern/severity was found among the above diagnostic categories. One patient with type 2B VWD was excluded because of thrombocytopenia and no patients with type 2N VWD were found. Patients with PFD had a secretion defect, but only 2 of them had typical storage pool disease (↓platelet 5-HT and ADP and ↓ADP/ATP ratio). No phenotypic patterns of Glanzmann or Bernard-Soulier diseases, arachidonate metabolism, or of absent ADP, collagen and TxA2 receptors were observed among the patients with PFD. Interestingly, the 170 patients with UD and the controls had almost the same mean values and distribution of VWF and platelet function variables; so we expect that very few patients with UD would qualify as VWD or PFD in repeated studies. Conclusions: 1. Prevalence of platelet secretion defects is higher than that of type 1 VWD-1 in our population. 2. Types 2 and 3 VWD, as well as paradigmatic platelet disorders (i.e., Glanzmann′s thrombasthenia, Bernard Soulier syndrome) were not detected in this study; they are of very low frequency and they are likely diagnosed at earlier age. 3. Bleeding time lacks sensitivity as a global test of primary haemostasis defects and should be omitted as a diagnostic tool. 4. After a first complete lab workup, 60% of the population with IMCH remains undiagnosed. The overwhelming majority of patients with UD probably constitute a heterogeneous group, independent of VWD or PFD, with a bleeding pattern similar to that of other disorders of primary hemostasis. Hypothetically, structural vascular defects or substances derived from the vascular wall which interfere with the normal platelet-vessel wall interaction could be involved in the pathogenesis of the hemorrhages.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3962-3962 ◽  
Author(s):  
Shoshana Revel-Vilk ◽  
Esther Hyam ◽  
Tali Zelikowitz ◽  
Ela Shai ◽  
David Varon

Abstract Background: von Willebrand’s disease (VWD) is the most common bleeding disorder, affecting between 1–10% of the general population. There is a need for a simple test to screen patients with bleeding symptoms before more labor-intensive diagnostic steps are taken. The Impact-R [Cone and Plate(let) Analyzer (CPA)] (DiaMed Switzerland), was designed in an attempt to test platelet function under close to physiological conditions. Citrated whole blood is applied on polystyrene surface, under controlled shear conditions using a cone and plate device, followed by a quantitative analysis of platelet deposition to immobilized plasma von Willebrand’s factor (VWF) and fibrinogen. Results of the test are presented for adhesion as % surface coverage (SC) and for aggregation as average size (μm2, AS). In this study we report the use of CPA test in evaluation of children with suspected bleeding disorder. Methods: Fifty-four consecutive children with bleeding symptoms and normal platelet count and coagulation tests were evaluated between August 1st, 2006 and July 31, 2007. In addition to the CPA test, all children were tested for VWF: antigen plasma level, VWF: ristocetin activity, factor VIII: C plasma level, platelet aggregation test using turbidometric aggregometer (Helena, USA) and blood type. The study was approved by the local Helsinki committee. Statistical analysis was done by SPSS. Results: Of 54 children, 10 (18.9%) were diagnosed with VWD and 6 (11.1%) children were diagnosed with platelet function defect according to bleeding history, family history, aggregation and factor VIII/VWF tests. To test the validity of the CPA as a screening test for diagnosis of VWD and platelet function defects a ROC curve was formulated for both SC and AS measurements. The best cutting point for a positive test was equal or less then 6.5% for SC measurement (sensitivity 60%, specificity 65%), and equal or lest then 26.5μm2 for AS measurement (sensitivity 67%, specificity 81.6%). The predictive value of a normal CPA test (negative predictive value), i.e. SC &gt; 6.5% and AS &gt; 26.5μm2, was 92%. Of the 26 normal CPA tests, one child was diagnosed with mild type I VWD and one child was diagnosed with mild platelet defect in response to epinephrine (40%). The predictive value of an abnormal CPA test (positive predictive value) was 50%. Of the 28 abnormal CPA test, 9 children were diagnosed with VWD, 4 children with platelet defect in response to epinephrine (&lt;30%) and one child with platelet defect in response to collagen (10%). Significant bleeding symptoms (bleeding score 3 or more) were reported in 4 of 14 children with abnormal CPA test but with normal VWF, normal factor VIII and normal platelet aggregation. Conclusions: The CPA test was found to be a useful tool for excluding VWD and platelet function defect in children suspected for bleeding disorder. Yet, in case of an abnormal CPA test, further testing are needed. Interestingly, abnormal CPA test was the only finding in some children with a significant bleeding history, suggesting other underlying adhesion defects yet to be described.


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