Hemostatic Profile Research Articles

Haemostatic Profile of Patients with Type 2 Diabetes Mellitus in Northern Nigeria

Diabetes Mellitus is a major health problem that results in significant morbidity and mortality from diverse complications. Thrombo-haemorrhagic complications are well recognized among diabetic populations. Many of the previous haemostatic studies in diabetic Nigerians focused on patients from the west and south eastern parts with scanty information from northern Nigeria. A total of 50 diabetic subjects aged between 30 – 80 years attending the diabetic clinic of the Jos University Teaching Hospital were selected for the study. 50 aged and sex matched non – diabetic persons in the family medicine outpatient clinic of the same hospital were recruited as controls. Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT), Thrombin Time (TT) and fibrinogen weight were estimated using standard methods. There was significant prolongation of PT, APTT, TT of diabetics when compared with the non – diabetic controls (P<0.005). Also the mean fibrinogen weight was significantly higher in the diabetic patients than the controls (P<0.05). These findings suggest that despite the popular notion of a prothrombotic tendency in diabetes, diabetics may also be prone to developing haemonhagic complications. It is helpful to bear this in mind, and to include incorporate PT, APTT, TT and fibrinogen assay as routine investigations for better management of these patients.

The hemostatic profile of recombinant activated factor VII. Can low concentrations stop bleeding in off-label indications?

BackgroundHigh concentrations of recombinant activated factor VII (rFVIIa) can stop bleeding in hemophilic patients. However the rFVIIa dose needed for stopping haemhorrage in off-label indications is unknown. Since thrombin is the main hemostatic agent, this study investigated the effect of rFVIIa and tissue factor (TF) on thrombin generation (TG) in vitro.MethodsLag time (LT), time to peak (TTP), peak TG (PTG), and area under the curve after 35 min (AUCo-35 min) with the calibrated automated thrombography was used to evaluate TG. TG was assayed in platelet-rich plasma (PRP) samples from 29 healthy volunteers under basal conditions and after platelet stimulation with 5.0 μg/ml, 2.6 μg/ml, 0.5 μg/ml, 0.25 μg/ml, and 0.125 μg/ml rFVIIa alone and in normal platelet-poor plasma (PPP) samples from 22 healthy volunteers, rFVIIa in combination with various concentrations of TF (5.0, 2.5, 1.25 and 0.5 pM).ResultsIn PRP activated by rFVIIa, there was a statistically significant increase in TG compared to basal values. A significant TF dose-dependent shortening of LT and increased PTG and AUCo→35 min were obtained in PPP. The addition of rFVIIa increased the effect of TF in shorting the LT and increasing the AUCo→35 min with no effect on PTG but were independent of rFVIIa concentration.ConclusionLow concentrations of rFVIIa were sufficient to form enough thrombin in normal PRP or in PPP when combined with TF, and suggest low concentrations for normalizing hemostasis in off-label indications.

Thromboelastometry to Guide Recombinant Activated Factor VII Therapy for Postoperative Refractory Intracranial Bleeding

Thromboelastometry to Guide Recombinant Activated Factor VII Therapy for Postoperative Refractory Intracranial Bleeding

Hemostatic profile, platelets, and blood constituents of the Arabian oryx (Oryx leucoryx)

Hemostatic, hematological, and chemical parameters were determined in 25 captive Arabian oryxes (Oryx leucoryx) of both sexes. Hemostatic parameters included prothrombin time, activated partial thromboplastin time, fibrinogen, and clotting factors activities. Serum concentrations of 26 biochemical and inorganic constituents were determined along with hematological data, namely platelet counts, platelet indices, and red and white blood cell variables. Hemostatic parameters, platelet indices, and many biochemical components are reported for the first time in the Arabian oryx. Relatively low mean platelet volume, plateletcrit and platelet distribution width, and relatively short prothrombin and activated partial thromboplastin times and high platelet counts, and F:VIII clotting activity were recorded in the oryx. Most of the basic hematological and biochemical parameters recorded in this species were consistent with other wild bovidae.

Coagulation and fibrinolysis in thyroid dysfunction

Various abnormalities of hemostasis, ranging from subclinical laboratory abnormalities to clinically significant disorders of hemostasis, and rarely major hemorrhage or thromboembolism, may occur in patients with thyroid diseases. The objective of this review is to discuss the relationships between thyroid dysfunction and hemostasis (primary hemostasis and coagulation/fibrinolytic system). According to the recent literature, most of the hemostatic abnormalities associated with thyroid dysfunction are the consequences of direct effects of thyroid hormones on the synthesis of various hemostatic parameters. Thyroid autoimmunity may also modify the processes of primary and secondary hemostasis. We have concluded that hyperthyroidism is generally associated with hypercoagulability and hypofibrinolysis, whereas the hemostatic profile in hypothyroidism depends on the severity of the disease. As few data are available on hemostasis in subclinical thyroid disease, further studies on this subject are needed.

Evidence of maternal platelet activation, excessive thrombin generation, and high amniotic fluid tissue factor immunoreactivity and functional activity in patients with fetal death

Objective. Fetal death can lead to disseminated intravascular coagulation or fetal death syndrome. However, currently it is not clear what are the changes in the coagulation system in patients with a fetal death without the fetal death syndrome. This study was undertaken to determine: (1) whether fetal death in the absence of fetal death syndrome is associated with changes in hemostatic markers in maternal plasma and amniotic fluid; and (2) whether maternal hypertension or placental abruption are associated with further changes in the hemostatic profile of these patients.Methods. A cross-sectional study included the following: (1) determination of changes in markers of coagulation and platelet activation in patients with a normal pregnancy (n = 71) and patients with fetal demise (FD) without disseminated intravascular coagulation (n = 65); (2) determination of the amniotic fluid (AF)–tissue factor concentration and activity, as well as the concentrations of thrombin–antithrombin III (TAT) complexes in patients with a normal pregnancy (n = 25) and those with a FD (n = 36) who underwent amniocentesis. Plasma and AF concentrations of TAT complexes and TF (an index of thrombin generation), as well as maternal plasma concentrations of sCD40L (a marker of platelet activation), tissue factor pathway inhibitor (TFPI) and prothrombin fragments (PF) 1 + 2 (also an indicator of in vivo thrombin generation) were measured by ELISA. TF and TFPI activity were measured using chromogenic assays.Results. (1) patients with FD without hypertension had a higher median maternal plasma sCD40L concentration than normal pregnant women (P < 0.001); (2) patients with FD had a higher median maternal plasma TAT III complexes than women with a normal pregnancy (P < 0.001); (3) the median AF–TF concentration and activity were higher in the FD group than in the normal pregnancy group (P < 0.001 for both); (4) patients with preeclampsia and FD had a higher median maternal plasma immunoreactive TF concentration than both normotensive patients with FD and women with normal pregnancies (P < 0.001 and P = 0.001, respectively); (5) the median plasma TF activity was higher in patients with preeclampsia and FD than that of women with normal pregnancies (P = 0.003); (6) among patients with a FD, those with placental abruption had a higher median AF–TAT complexes concentration than those without abruption (P = 0.0004).Conclusions. Our findings indicate that: (1) mothers with a FD have evidence of increased in vivo thrombin generation and platelet activation than women with normal pregnancies; (2) patients with a FD and hypertension had a higher degree of TF activation than those with fetal death but without hypertension; (3) the AF of women with a FD had a higher median TF concentration and activity than that of normal pregnant women. AF can be a potential source for tissue factor and it participates in the development of fetal death syndrome in patients with a retained dead fetus.

Haemostatic profile of full-term, healthy, small for gestational age neonates

Background Small for Gestational Age (SGA) neonates often appear with haemostatic alterations, principally due to hepatic dysfunction that results from chronic intrauterine hypoxia. Polycythaemia and thrombocytopenia are common findings in this neonatal population. Study design We performed a comparison of coagulation, natural inhibitors and fibrinolysis between SGA and Appropriate for Gestational Age (AGA) infants born full term [gestational age (G.A.) > 37 weeks]. Study population consisted of 188 healthy newborns, 90 of whom were SGA (62 females and 28 males), while the rest were the control group (44 females and 54 males). Blood samples were obtained within 30 minutes following birth and before the administration of vitamin K. Investigation included: PT, INR, APTT, fibrinogen, coagulation factors II, V, VII, VIII, IX, X, XI, XII, vWillebrand factor, protein C and free protein S, antithrombin (AT), APCR, tPA and PAI-1. The independent t-test was used to compare the differences between the values of haemostatic parameters. Results Statistical analysis revealed a significant prolongation in PT, INR, elevated levels of tPA ( p < 0.015, 0.01 and 0.002 respectively) and a decrease in the values of XII and free protein S ( p < 0.045 and 0.007 respectively) in SGA full term neonates. The two groups had similar demographic characteristics (except birth weight), without significant differences in the values of other haemostatic parameters. Conclusions Despite of statistically significant differences in PT, INR, values of tPA, XII and free protein S, levels of haemostatic factors range within laboratory references for healthy full term newborns. These findings were not accompanied with clinical manifestations of altered haemostasis.

Overfatness, stunting and physical inactivity are determinants of plasminogen activator inhibitor-1activity, fibrinogen and thrombin–antithrombin complex in African adolescents

We examined fibrinogen, thrombin-antithrombin complex, factor VIIIc and plasminogen activator inhibitor-1 activity in African children in order to determine haemostatic profile patterning and to identify possible subdivisions at high risk for cardiovascular disease. In a cross-sectional analysis, a convenience sample of 117 girls and 78 boys (15.6 +/- 1.35 years) in a South African township was investigated within the Physical Activity in Youth study. Haemostatic variables were investigated in the total group and subdivisions for physical activity levels, maturity (Tanner staging), sex, fat percentage and height for age. Overfatness (53.6%) coexisted with stunting (17.5%). Plasminogen activator inhibitor-1 activity differed significantly between the sexes after adjustments for fat percentage and physical activity levels. Sex explained 10% and muscle mass 1% of the variance in plasminogen activator inhibitor-1 activity. Fibrinogen was significantly higher in girls than in boys (before adjustment for fat percentage), in overfat than in lean children and in stunted than in the nonstunted children (even after adjustment for fat percentage). C-reactive protein, sex and height for age were predictors of fibrinogen. Thrombin-antithrombin complex was significantly higher in girls than in boys, but after separate adjustment for physical activity and fat percentage there were no significant differences. Fitness and muscle mass explained the variance in thrombin-antithrombin complex the best. No significant differences were seen between the groups for C-reactive protein and factor VIIIc. Overfatness, stunting and inactivity negatively influenced plasminogen activator inhibitor-1 activity, fibrinogen and thrombin-antithrombin complex possibly increased the risk for cardiovascular disease. These factors are modifiable through behavioural changes and optimal nutritional status throughout the early life.

Blood coagulation and fibrinolysis in patients with acromegaly: increased plasminogen activator inhibitor-1 (PAI-1), decreased tissue factor pathway inhibitor (TFPI), and an inverse correlation between growth hormone and TFPI

Growth hormone/insulin-like growth factor-1(GH/IGF-1) hypersecretion may influence risk factors contributing to the increased cardiovascular morbidity and mortality associated with acromegaly However, so far little is known about the impact of GH/IGF-1 on coagulation and fibrinolysis in acromegalic patients as possible risk factors for cardiovascular disease (CVD). To our knowledge, plasma tissue factor pathway inhibitor (TFPI) and thrombin-activatable fibrinolysis inhibitor (TAFI) levels in these patients have not been investigated. Therefore, the main purpose of this study was to evaluate the markers of endogenous coagulation/fibrinolysis, including TFPI and TAFI, and to investigate the relationships between GH/IGF-1 and these hemostatic parameters and serum lipid profile in patients with acromegaly. A total of 22 patients with active acromegaly and 22 age-matched healthy controls were included in the study. Fibrinogen, factors V, VII, VIII, IX, and X activities, von-Willebrand factor (vWF), antithrombin III (AT III), protein C, protein S, tissue plasminogen activator (t-PA), tissue plasminogen activator inhibitor-I (PAI-1), TFPI and TAFI, as well as common lipid variables, were measured. The relationships between serum GH/IGF-1 and these hemostatic parameters were evaluated. Compared with the control subjects, fibrinogen, AT III, t-PA, and PAI-1 were increased significantly in patients with acromegaly (P < 0.0001, P < 0.05, P < 0.01, and P < 0.0001, respectively), whereas protein S activity and TFPI levels were decreased significantly (P < 0.05 and P < 0.01, respectively). Plasma TAFI Ag levels did not significantly change in patients with acromegaly compared with the controls. In patients with acromegaly, serum GH levels were inversely correlated with TFPI and apo AI levels (r: -0.514, P: 0.029 and r: -0.602, P: 0.014, respectively). There was also a negative correlation between insulin-like growth factor-1 (IGF-1) and PAI-1 (r: -0.455, P: 0.045). We found some important differences in the hemostatic parameters between the patients with acromegaly and healthy controls. Increased fibrinogen, t-PA, PAI-1 and decreased protein S and TFPI in acromegalic patients may represent a potential hypercoagulable and hypofibrinolytic state, which might augment the risk for atherosclerotic and atherothrombotic complications. Thus, disturbances of the hemostatic system and dyslipidemia may contribute to the excess mortality due to CVD seen in patients with acromegaly.

Blood coagulation and fibrinolysis in male patients with hypogonadotropic hypogonadism: Plasma factor V and factor X activities increase in hypogonadotropic hypogonadism

In men, androgens have both pro- and anti-thrombotic effects. Androgen deficiency in men is associated with an increased incidence of cardiovascular disease (CVD). However, the influence of hypogonadism on hemostasis is controversial. Little is known about hemostatic features of male patients with idiopathic hypogonadotropic hypogonadism (IHH). Thus, the aim of the present study was to evaluate the markers of endogenous coagulation and fibrinolysis, and to investigate the relationships between endogenous sex hormones and hemostatic parameters and serum lipid profile in men with IHH. Seventeen patients with IHH and 20 age-matched healthy controls were included in the study. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, factors (F) V, VII, VIII, IX, and X activities, von Willebrand factor (vWF), antithrombin III (AT III), protein C, protein S, tissue plasminogen activator (t-PA), and tissue plasminogen activator inhibitor (PAI-1), as well as common lipid variables, were measured. The relationships between serum sex hormones and these hemostatic parameters were examined. Compared with the control subjects, platelet count, FV, FX, and protein C activities were significantly increased in patients with IHH (p<0.01, p<0.05, p<0.01, and p<0.05, respectively), whereas AT III was decreased (p<0.05). Fibrinogen, FVIII, vWF, t-PA, PAI-1, and the other coagulation/fibrinolysis parameters and lipid profile in patients with IHH were not different from the controls. In patients with IHH, we showed that serum LH level was negatively correlated with fibrinogen (r: -0.78, p<0.01) and protein C (r: -0.55, p<0.05) and positively correlated with t-PA (r: 0.53, p<0.05). Serum FSH levels inversely correlated with fibrinogen (r: -0.75, p<0.01). We found some differences in the hemostatic parameters between the patients with IHH and healthy controls. Increased platelet count, FV and FX activities and decreased AT III levels in patients with IHH represent a potential hypercoagulable state, which might augment the risk for atherosclerotic and atherothrombotic complications. Therefore, IHH may be associated with an increased risk of CVD. However, sex hormones may play a role at different levels of the complex hemostatic system in patients with IHH.

Hemostatic Profile in Sedentary African American Woman

Hemostatic Profile in Sedentary African American Woman

Ischemic Stroke Related to Anabolic Abuse

Anabolic-androgenic steroid (AAS) abuse increased in recent years, and it is associated with numerous adverse effects. Few reports on ischemic stroke related to anabolic steroid abuse have been published. We report a case of a 26-year-old male amateur athlete who suffered a posterior territory ischemic stroke. No abnormalities were found in angiography and echocardiography studies, neither in hemostatic profile. His only significant risk factor was nonmedical use of stanozolol, an anabolic steroid. Anabolic steroids are capable of increasing vascular tone, arterial tension, and platelet aggregation; therefore, they are prone to produce atherothrombotic phenomena. Because of young people's widespread use of anabolic steroids, physicians should be aware of this kind of complication.

Biologic response to subcutaneous and intranasal therapy with desmopressin in a large Amish kindred with Type 2M von Willebrand disease

The aim of this study was to characterize the adequacy and longevity of biological response to desmopressin (DDAVP) in a large Amish kindred of Type 2M von Willebrand disease (VWD) possessing C-to-T transition at nucleotide 4120 in exon 28 of A1 domain of von Willebrand factor (VWF) gene. Response to both intranasal (Stimate) and subcutaneous DDAVP administration was assessed. Rise in ristocetin cofactor activity (VWF:RCo) > or = 40% at 90-min post-Stimate and 1-2 h after subcutaneous DDAVP was defined as initial response; response longevity was assessed only after subcutaneous dosing by measuring VWF:RCo levels at time-points 1, 2, 4 and 6 h. Eleven patients (five males, six females; age range: 20-56 years) participated in intranasal and 9/11 (four males, five females) in subcutaneous testing. Baseline haemostatic profiles included: VWF:RCo < 15%, VWF:Ag < 40% and normal VWF multimers. Initial response was comparable by both intranasal (6/11; 54.5%) and subcutaneous (4/9; 44%) routes; sustained response (VWF:RCo > 40% for 2 h) was observed in only one in nine (11%) patients tested. Median VWF:RCo peak levels after intranasal (40%) and subcutaneous (39%) routes were equivalent. Peak VWF:Ag levels were significantly higher after subcutaneous than intranasal DDAVP (94% vs. 54%; P = 0.03). Area under the curve for VWF:RCo was significantly decreased (170 microg h mL(-1)) compared with VWF:Ag (471 microg h mL(-1)) and FVIII:C (624.60 microg h mL(-1)). This study suggests that in this population: (i) intra-individual DDAVP response is consistent with subcutaneous and intranasal administration; and (ii) extending DDAVP challenge test up to at least 6 h is required to characterize adequacy and longevity of biologic response prior to using DDAVP as a sole haemostatic intervention.

Nutrition and hemostasis: A focus on urbanization in South Africa

South Africa is experiencing a rapid urbanization of its African population characterized by a demographic, nutrition, lifestyle, and health transition. The resultant high prevalence of high cardiovascular disease, in particular of stroke, is of concern. In this narrative review it is suggested that, together with hypertension, changes in the hemostatic system may be one of the major contributors to stroke in this population. It is further suggested that these changes are related to increased fat and animal protein intakes, decreased intakes of total carbohydrate and dietary fiber, as well as persistent suboptimal micronutrient intakes of Africans in transition. The effects of this nutrition transition on plasma fibrinogen, fibrin network structures, plasminogen activator inhibitor 1 activity levels and some other clotting and fibrinolytic factors are discussed. It is concluded that despite indications of present protective mechanisms against the development of coronary heart disease (CHD) in this population the observed changes in diet and hemostatic profiles may eventually lead to a high prevalence of both stroke and CHD in urban black South Africans. It is further suggested that timely nutritional interventions and research of effects thereof on the hemostatic system are urgently needed.

Assessment of hypercoagulability markers and lipid levels in postmenopausal women undergoing either oral or transdermal hormone replacement therapy

This study investigated the effect of either oral or transdermal hormone replacement therapy (HRT) on haemostatic, fibrinolytic and lipid profiles in a group of Brazilian women 3 months after beginning treatment by comparing these results with those obtained immediately before HRT. Plasma levels of TAT, DDi, F1+2, PC, PS, AT, PAI-1 and serum lipids were determined in blood samples collected from 24 women undergoing oral HRT and from 11 women undergoing transdermal HRT. Significant increases in DDi and F1+2 plasma levels were observed after 3 months of oral HRT, while PS levels decreased. After transdermal HRT, a significant decrease was observed only for AT levels. After 3 months of oral HRT and in the absence of major genetic and acquired risk factors, women displayed a predisposition for activation of blood coagulation, and an increased activity of the fibrinolytic system. Oral HRT seemed to be more effective in predisposing haemostatic changes as compared to transdermal.

Effect of oral anticoagulant therapy on thrombospondin-1 and von Willebrand factor in patients with stable heart failure

IntroductionHeart failure (HF) is associated with coagulation activation, abnormal inflammation and endothelial dysfunction. High levels of von Willebrand factor (VWF) may manifest endothelial dysfunction and hypercoagulable state. The haemostatic activity of VWF is a function of multimers size; only large multimers of VWF are haemostatically active. Thrombospondin-1 (TSP-1) reduces the average multimer size of VWF. Patients with HF are in risk of thromboembolic events and oral anticoagulation therapy (OAT) has been shown to prevent it. This study was designed to evaluate whether VWF and TSP-1 levels are modified by OAT in stable HF patients. The effect of OAT on markers of inflammation and coagulation was also investigated. Materials and methodsFifty-nine patients with stable HF were studied and 33 of them received OAT. VWF, TSP-1, fibrinogen, prothrombin fragment 1+2 (F1+2), tissue factor (TF), D-dimer, endogenous thrombin generation (ETG), C reactive protein (CRP), tumour necrosis factor α (TNFα) and interleukin 6 (IL-6) were measured. ResultsStable HF patients receiving OAT had higher VWF (p=0.02) and lower TSP-1 (p=0.02), ETG and F1+2 (p=0.003) than patients without OAT. However, there were no significant differences in the levels of fibrinogen, TF, D-dimer, CRP, IL6 and TNFα. The TSP-1/VWF ratio in patients receiving AOT was significantly lower than in patients without OAT (p=0.005). ConclusionOAT may have a dual effect on the haemostatic profile in stable HF by reducing thrombin generation and increasing the VWF. The decrease of TSP-1 induced by OAT may be clinically effective in neoangiogenesis. The increase of VWF in patients receiving anticoagulant treatment may also reflect an effect of OAT on endothelial dysfunction.

Intake of phenol-rich virgin olive oil improves the postprandial prothrombotic profile in hypercholesterolemic patients

Background: Oxidative stress associated with postprandial lipemia contributes to endothelial dysfunction, which shifts hemostasis to a more thrombogenic state.Objective: We investigated whether a high concentration of phenols in olive oil can partly reverse this phenomenon.Design: Twenty-one hypercholesterolemic volunteers received 2 breakfasts rich in olive oils with different phenolic contents (80 or 400 ppm) according to a randomized, sequential crossover design. Plasma concentrations of lipid fractions, factor VII antigen (FVIIag), activated factor VII (FVIIa), and plasminogen activator inhibitor-1 (PAI-1) activity were measured at baseline and postprandially.Results: Concentrations of FVIIa increased less (P = 0.018) and plasma PAI-1 activity decreased more (P = 0.021) 2 h after the high-phenol meal than after the low-phenol meal. FVIIa concentrations 120 min after intake of the olive oil with a high phenol content correlated positively with fasting plasma triacylglycerols (P = 0.001), area under the curve (AUC) of triacylglycerols (P = 0.001), and AUC of nonesterified fatty acids (P = 0.024) and negatively with hydroxytyrosol plasma concentrations at 60 min (P = 0.039) and fasting HDL-cholesterol concentrations (P = 0.005). PAI-1 positively correlated with homeostasis model assessment of insulin resistance (P = 0.005) and fasting triacylglycerols (P = 0.025) and inversely with adiponectin (P = 0.026). In a multivariate analysis, the AUCs of nonesterified fatty acids (R2 = 0.467; β: 0.787; SE: 0.02; P < 0.001) and adiponectin (R2 = 0.232; β: −1.594; SE: 0.629; P < 0.05) were the strongest predictors of plasma FVIIa and PAI-1, respectively.Conclusions: A virgin olive oil with a high content of phenolic compounds changes the postprandial hemostatic profile to a less thrombogenic state.

The Hemostatic Profiles of Patients with Type O and Non-O Blood After Acute Normovolemic Hemodilution with 6% Hydroxyethyl Starch (130/0.4)

Individuals with Type O blood have been reported to have a tendency toward reduced Factor VIII and von Willebrand Factor (vWF) levels. If this is true, patients with Type O blood might be vulnerable to coagulopathy during acute normovolemic hemodilution using hydroxyethyl starch (HES), both from hemodilution as well as HES-related coagulopathy. Thirty non-O and 15 type O ASA 1 or 2 patients scheduled for spinal surgery involving more than two spinal levels were enrolled for the study. After anesthesia induction, 30% of the estimated blood volume was removed, and the volume was simultaneously replaced with 6% HES (130/0.4). Coagulation profiles were measured before (T0) and 30 min after acute normovolemic hemodilution (T30). Factor VIII activity, vWF antigen levels (vWF:ag), and vWF ristocetin cofactor activity (vWF:RCof) were lower in the O group than in the non-O group before and after acute normovolemic hemodilution, and decreased below the normal range in the O group after acute normovolemic hemodilution. The decrease was beyond that expected from hemodilution alone. Maximum amplitude and coagulation index of the thromboelastogram decreased below the normal range in the O group after acute normovolemic hemodilution. The decrease in vWF:ag was related to the degree of blood loss, and was greater in patients in the O group. Patients with Type O blood may have increased coagulation compromise, and greater dilution of Factor VIII activity, vWF:ag, and vWF:RCof after acute normovolemic hemodilution with HES.

The Hemostatic profile of blood type O and non O patients after acute normovolemic hemodilution with hydroxyethyl starch

Shin, Y. H.; Kang, J. G.; Kim, G. S.; Lee, S. M.; Kim, C. S.; Hahm, T. S.; Choi, S. J.; Ahn, H. J. Author Information

Duration of effects of aspirin on platelet function in healthy volunteers: an analysis using the PFA-100

Study Objective The aim of the study was to determine the duration and effects of aspirin on platelet function. Study Design Prospective investigation. Setting Blood samples from volunteers. Patients and Monitoring Ten healthy male volunteers took part in this investigation. After having measured baseline hemostatic parameters, 2000-mg aspirin was taken orally. Subsequently, the hemostatic profile had been compiled daily for a duration of 4 days after ingestion. Measurements and Main Results Platelet function was analyzed (1) after 3 hours and (2) daily for 4 days by the platelet function analyzer (PFA-100, Dade Co, Miami, Fla), which represents a sensitive investigation method for measuring platelet function and dysfunction. Routine hemostatic parameters were investigated. Three hours after ingestion of aspirin, abnormal PFA-100 values could be detected. Further detectable elevated values were found during the following 3 days. Conclusion Effects of single-dose aspirin 2000 mg on platelet function were detected after 3 hours and had been lasting for the following 3 days. This result shows that PFA-100 may help by evaluating hemostasis during the preoperative period.