Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bleeding Time”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed1995

Effects of temperature on bleeding time and clotting time in normal male and female volunteers.

OBJECTIVE: This study was done to assess the effects of temperature on bleeding time and clotting time in normal male and female volunteers. DESIGN: Open study utilizing normal volunteers. SETTING: University research laboratory. SUBJECTS: Fifty-four healthy male and female volunteers, ranging in age from 19 to 35 yrs, who were not receiving medications. The study was done and the samples of venous blood and shed blood collected at the template bleeding time site were obtained at a convenient time for each volunteer. INTERVENTIONS: Skin temperature was changed from +20 degrees to +38 degrees C and blood samples were obtained from the antecubital vein of each volunteer. MEASUREMENTS AND MAIN RESULTS: The effect of local skin temperature ranging from +20 degrees to +38 degrees C on bleeding time was evaluated in 38 normal volunteers (19 male and 19 female). Skin temperature was maintained at +20 degrees to +38 degrees C by cooling or warming the forearm. At each temperature, measurements were made of complete blood count, bleeding time, and thromboxane B2 concentrations in shed blood collected at the template bleeding time site and in serum and plasma isolated from blood collected from the antecubital vein. Clotting time studies were measured in 16 normal volunteers (eight male and eight female) at temperatures ranging from +22 degrees to +37 degrees C. At +32 degrees C, the bleeding time was longer and hematocrit was lower in female than in male volunteers. However, at local skin temperatures of < +32 degrees C, both the males and females exhibited significantly increased bleeding times, which were associated with a reduction in shed blood thromboxane B2. Each 1 degree C decrease in temperature was associated with a 15% decrease in the shed blood thromboxane B2 concentration. Clotting times were three times longer at +22 degrees C than at +37 degrees C. Each 1 degree C reduction in the temperature of the clotted blood was associated with a 15% reduction in the serum thromboxane B2 concentration. CONCLUSION: Our data indicate that during surgical procedures, it is important to maintain normothermia to ensure that platelets and clotting proteins function optimally.

Adult↗
PubMed1994

Bleeding time in preeclampsia.

The association of preeclampsia with thrombocytopenia and prolonged bleeding time is reported. The analysis of bleeding time (Simplate II) and the platelet count (Automatic Coulter Counter) in 41 patients with different grades of preeclampsia is presented. Our results suggest that the decrease in the bleeding time observed in moderate preeclampsia and the increase observed in severe preeclampsia are not mainly dependent on the platelet count.

Adult↗
PubMed1986

The preoperative bleeding time as a predictor of postoperative hemorrhage after cardiopulmonary bypass.

To determine whether the preoperative bleeding time, the most reliable indicator of in vivo platelet dysfunction, can prognosticate excessive postoperative hemorrhage and, hence, the need for infusion of platelet concentrations, we studied blood loss versus bleeding time in 43 patients undergoing coronary bypass grafting. There was no correlation between bleeding time and either fall in hemoglobin level (r = 0.04) or chest tube drainage (r = 0.004). In addition, bleeding time did not correlate with the number of units of platelet concentrate (r = 0.12) or packed red cells (r = 0.2) infused. The bleeding time, which has been recommended as an essential screening test before all cardiopulmonary bypass procedures, need not be performed as a preoperative screen in otherwise healthy patients with no history of bleeding abnormalities and a normal coagulation profile.

Bleeding Time↗
PubMed2001

The relationship between hematocrit and bleeding time in very low birth weight infants during the first week of life.

OBJECTIVES: The bleeding time is a measurement of platelet and capillary interaction following a small standardized cutaneous incision. In adults, anemia causes a prolongation of the bleeding time, and we hypothesized that the same would be true in very low birth weight (VLBW) infants during their first week of life. STUDY DESIGN: Template bleeding times, using the Surgicutt Newborn device, were performed on 20 VLBW weight infants 0.28 l/l had no significant reduction in bleeding time following transfusion. CONCLUSIONS: In VLBW infants, during their first week of life (the time when their risk of intraventricular hemorrhage is greatest), a low hematocrit is associated with a significant prolongation in the bleeding time.

Bleeding Time↗
PubMed1976

Studies on the prolonged bleeding time in von Willebrand's disease.

Three experimental models have been employed to investigate the mechanism of the prolonged bleeding time in patients with von Willebrand's disease (vWd). 1-deamino-8-D-arginine vasopressin (DDAVP), a synthetic analogue of the antidiuretic hormone, was administered to normal volunteers and patients with vWd in order to induce a short-term, endogenous increase of factor VIII procoagulant activity (VIIIAHF), factor VIII-related antigen (VIIIAGN), and Willebrand factor (VIIIVWF); and to investigate the relationship between bleeding time and plasma variations of factor VIII-associated properties. In normal subjects DDAVP administration was followed by a marked increase of VIIIAHF, VIIIAGN, and VIIIVWF; yet the bleeding time remained unchanged. The same parameters were also raised in two groups of patients with vWd. In a third group of patients with severe recessive vWd, factor VIII-associated properties, which were not measurable before the infusion, were unmodified. The bleeding time remained unchanged in all vWd patients. To investigate the effect of the exogenous increase of factor VIII-associated properties, cryoprecipitate was given to ten vWd patients before dental surgery. Despite the marked increase of VIIAHF, VIIAGN, and VIIVWF observed after the infusion, bleeding time was not shortened. Finally, in order to evaluate the hypothesis that factor VIII may exert its effect on primary hemostasis locally in the vessel wall, VIIIAGN and its relationship with the bleeding time were studied by direct immunofluorescence in gum-biopsy specimens obtained in vWd patients before cryoprecipitate infusion. No reaction could be elicited in five patients with severe, recessive vWd, whereas venules and arterioles stained positively in five patients with a moderate form of the disease. Immunofluorescence microscopy was also carried out in specimens obtained after cryoprecipitate at a time when the plasma defects were corrected but the long bleeding time was not modified; no reaction was detectable on the vessel wall of the three patients who were negative before the infusion.

Adult↗
PubMed1992

Sustained correction of the bleeding time in an afibrinogenaemic patient after infusion of fresh frozen plasma.

We have evaluated the duration of the effect of replacement therapy with two different doses of fibrinogen on the prolonged bleeding time of an afibrinogenaemic patient and the relationship between changes in bleeding time and plasma and platelet fibrinogen concentrations. The infusion of 40 mg/kg fibrinogen, as fresh frozen plasma (FFP), corrected the prolonged bleeding time of the patient from longer that 30 min to 8 min. The bleeding time was still normal 9 d after infusion, at a time when the plasma and platelet fibrinogen levels were low (0.13 g/l and 27 micrograms/10(9) platelets; normal ranges 1.6-4.0 and 60-190). Two months later, the infusion of a smaller dose of fibrinogen (4 mg/kg) also corrected the bleeding time, which remained normal until the second day after infusion, despite the fact that plasma and platelet fibrinogen were very low (0.02 g/l and 3.4 micrograms/10(9) platelets). The bleeding time returned to the prolonged baseline values only by day 6 post-infusion, when plasma and platelet fibrinogen levels were 4 x 10(-4) g/l and 1.4 micrograms/10(9) platelets. Therefore, sustained correction of the prolonged bleeding time may be obtained in afibrinogenaemic patients with a single infusion of fibrinogen at lower doses than usually recommended.

Adult↗
PubMed1998

Development and practical use of the new quantitative bleeding time test apparatus.

We have developed a new computerized system for measurement of quantitative bleeding time (QBT) to detect subtle abnormalities of primary hemostasis that are difficult to detect with the standard bleeding time determination. This new apparatus can simultaneously measure the bleeding time (BT; sec), amount of total blood loss (Tv; microl), maximum bleeding rate (Rmax; microl/sec) and bleeding pattern from the bleeding time incision. We have also developed a new holder for the Simplate that enables more consistent incisions and thus improves the reproducibility of the BT test. In this study, the newly developed QBT test was performed in 137 normal healthy volunteers and 10 patients having defined abnormalities of either primary or secondary hemostasis. Comparisons of the standard BT test and our QBT were made in 5 normal subjects and 7 thrombocytopenic patients. Additionally, 6 normal subjects were examined with both tests before and after administration of aspirin. Those results show that our QBT appears to be a more sensitive indicator of primary hemostasis than the standard BT method.

Adolescent↗
PubMed1982

Bleeding time and scoliosis.

Collagen abnormalities in idiopathic scoliosis are on record. Since there is a correlation between the platelet aggregating power of the collagen and the bleeding time in patients with scoliosis, the bleeding time was studied in 195 cases with scoliosis and in 318 controls. The bleeding time was longer in the females, especially in those with idiopathic scoliosis (n = 149). Patients with paralytic scoliosis (n = 5) also had a significantly longer bleeding time than non-scoliotic controls. The patients with congenital scoliosis (n = 13) did not differ significantly from the controls or from patients with idiopathic scoliosis. The bleeding time in idiopathic scoliosis did not vary with age or magnitude of the scoliosis. Our data support the view that collagen abnormalities play a role not only in the aetiology of idiopathic scoliosis, but also in other forms of scoliosis.

Adolescent↗
PubMed2001

Effects of agents, used to treat bleeding disorders, on bleeding time prolonged by a very high dose of a direct thrombin inhibitor in anesthesized rats and rabbits.

Melagatran is the active form of the oral, direct thrombin inhibitor, H 376/95, that is under evaluation in clinical trials for the prevention and treatment of thromboembolism. In this study, a single dose, calculated on body weight basis, of antifibrinolytic treatment, factor VIIa, factor VIII with and without von Willebrand factor (vWF), factor IX, activated (APCC) or nonactivated (PCC) prothrombin complex concentrates was given intravenously to rats and rabbits, in an attempt to reverse the prolonged bleeding time during intensive anticoagulation with melagatran (2 micromol/kg/h). The doses used were at or above human therapeutic doses. The cutaneous tail bleeding time in the rat, as well as the ear incision bleeding time and cuticle bleeding time, and the blood loss in the rabbit were used for evaluation of the hemostatic effects of these agents. In vivo Feiba (APCC) and Prothromplex-T (PCC) shortened the prolonged cutaneous bleeding times in rats (P<.05); Feiba and Autoplex (APCC) shortened the cutaneous bleeding times in rabbits (P<.05). In contrast, Prothromplex-T prolonged bleeding times and blood loss in the rabbits (P<.05). Ex vivo Feiba, Autoplex and NovoSeven (rF VIIa) significantly (P<.05) shortened the prolonged whole blood clotting time (WBCT). Prothromplex-T significantly prolonged WBCT, activated clotting time (ACT) and activated partial thromboplastin time (APTT). Feiba, Autoplex, and Prothromplex-T increased thrombin generation measured as increased thrombin-antithrombin complex (TAT) formation. In conclusion, APCCs were found to be the most effective agents for reversing bleeding time induced by a very high plasma concentration of melagatran. APCC and recombinant activated factor FVII (rF VIIa) effectively shortened the prolonged WBCT. Thus, stimulating thrombin generation with the use of APCC may counteract the anticoagulant effect observed with a very high dose of a thrombin inhibitor.

Animals↗
PubMed1999

Can the Platelet Function Analyzer (PFA)-100 test substitute for the template bleeding time in routine clinical practice?

The bleeding time (BT) is widely used in clinical medicine as a screening test of platelet function, although its deficiencies in such a role are well recognized. The Platelet Function Analyzer (PFA)-100 measures the ability of platelets activated in a high-shear environment to occlude an aperture in a membrane treated with collagen and epinephrine (CEPI) or collagen and ADP (CADP). The time taken for flow across the membrane to stop (closure time) is recorded. This study compared the PFA-100 with the BT as a screening test of platelet dysfunction in 113 hospital inpatients. The PFA-100 test was performed initially using the CEPI cartridge; CADP tests were performed on those with abnormal (> 163 s) CEPI closure times. Whole blood platelet aggregation studies and chart review were performed on patients in whom the BT and PFA-100 results did not agree.Abnormal bleeding times and PFA-100 results were obtained in 20.4% and 35.4% of patients, respectively. The results of BT and PFA-100 agreed in 74.3% of patients. Of the 29 patients in whom the BT and PFA-100 results were discordant, whole blood platelet aggregation studies supported the PFA-100 result in 25 (86.2%). The PFA-100 was more sensitive to aspirin-induced platelet dysfunction and was more rapidly and cheaply performed than the BT. Since the PFA-100 test reflects platelet function better than the BT, we conclude that this test could replace the BT as a first-line screening test for platelet dysfunction in clinical practice.

Journal Article↗
PubMed1992

Prolonged bleeding time of Chediak-Higashi cats corrected by platelet transfusion.

Cats with the Chediak-Higashi syndrome (CHS) have a platelet storage pool deficiency (SPD). Ten CHS cats were transfused with a concentrate of 51Cr-labeled platelets prepared from normal donor cats. One hour after transfusion, the donor platelet count in CHS recipient cats was 40,000-60,000/microliters. Bleeding time before transfusion was 9.1 +/- 3.0 min. When donor platelet count in CHS cats was 50,000/microliters, bleeding time was 1.7 +/- 0.2 min. Bleeding time of normal cats was 1.4 +/- 0.3 min. Bleeding time increased to 3.3 +/- 0.2 min and to 5.3 +/- 0.2 min when the platelet count was 30,000/microliters, and 15,000/microliters, respectively. The close inverse relationship between bleeding time and number of donor platelets in CHS cats (r = -0.92), suggests that prolonged bleeding time is due to a platelet abnormality, that platelet transfusion can effectively correct prolonged bleeding time in an animal model of platelet SPD and that CHS cats may be an appropriate animal model to evaluate hemostatic capabilities of transfused platelets.

Animals↗
PubMed2000

The effects of chloroquine on bleeding time and disappearance of platelet 5-hydroxytryptamine in rabbits.

BACKGROUND: Chloroquine inhibits platelet aggregation in vitro and in vivo. Because inhibition of platelet aggregation may prolong bleeding time, the effect of chloroquine administration on bleeding time and disappearance of platelet serotonin, which may affect bleeding time, were studied. METHODS AND RESULTS: Platelets were harvested from 12 rabbits. They were labelled with (111)In to tag individual platelets and (14)C-labelled 5-hydroxytryptamine (5HT) or serotonin. Doubly labelled platelets from the rabbits were returned to their donors. At timed intervals, from 2 to 66 hours, blood samples were drawn and platelets collected. (111)In and (14)C were separately counted. In 6 experiments, the animals served as control and received normal saline intraperitoneally (IP) daily for 4 days; the other 6 rabbits served as test and were given a therapeutic dose of chloroquine phosphate (10 mg/kg, IP) daily for 4 days. Indium disappeared in an exponential fashion in both control and test groups. The fraction of indium disappearing per hour was significantly less in chloroquine-treated rabbits than in control rabbits (P <.001). Ninety-nine percent of the indium-labelled platelets disappeared in 7.0 days in chloroquine-treated rabbits and 5.8 days in control rabbits (P <.001). Bleeding times in chloroquine-treated and control rabbits were not significantly different (64.8 +/- 2.2 vs. 62.3 +/- 4.0 sec, respectively). However, the labelled platelet serotonin disappeared more slowly in chloroquine-treated rabbits than in control rabbits. (K for chloroquine-treated and control rabbits was 0.0096 +/- 0.0064 and 0. 0254 +/- 0.0016; respectively, P <.001). CONCLUSION: Chloroquine prolongs platelet survival but does not affect bleeding time in rabbits. Chloroquine also slows down the disappearance of labelled platelet serotonin. We propose that chloroquine increases the recycling of platelet 5HT, passing it on from platelet to platelet in rabbits and this may have a role in the maintenance of hemostasis.

Animals↗
PubMed1988

Patients with prolonged bleeding time of undefined etiology, and their response to desmopressin.

Between 1981 and 1986, we evaluated 59 patients who presented with isolated prolongation of bleeding time with normal platelet counts, platelet aggregation and coagulation parameters (including von Willebrand's factor), and without evidence of liver or kidney disease, or exposure to anti-platelet agents. These patients, termed as vascular fragility syndrome (VFS), were analyzed to further characterize their bleeding patterns. The pattern of bleeding manifestations was similar to that of patients with platelet dysfunction, such as mucocutaneous bleeding or excessive post-operative bleeding. In 16 patients, desmopressin (1-desamino-8-d-arginine vasopressin, DDAVP) was infused to control active bleeding or as a part of pre-surgical evaluation. Bleeding time improved (pre-DDAVP bleeding time 15.3 +/- 3.4 min, mean +/- S.D.; post-DDAVP bleeding time 10.7 +/- 3.9 min; p less than 0.01) within 30 minutes following the DDAVP infusion with either satisfactory arrest of acute bleeding or good control of subsequent hemostasis with surgery. Side effects with DDAVP were transient and minor, i.e. facial flushing, or conjunctival erythema. These findings indicate that VFS with isolated prolongation of bleeding time is a frequently encountered bleeding disorder and that DDAVP is effective in achieving hemostasis for the management of acute bleeding and may be useful prior to surgical procedures.

Bleeding Time↗
PubMed1976

Effect of aspirin on bleeding time during elective abortion.

The template bleeding time, indicative of a predictable measure of potential blood loss due to altered platelet function, is unaffected by pregnancy or by the first stage of labor. Two tablets of aspirin (650 mg), but not sodium salicylate or acetaminophen, significantly prolongs the template bleeding time for at least 26 hours after consumption in patients undergoing first or second trimester induced abortion. Patients anticipating induced pregnancy interruption should refrain from any aspirin consumption for at least 26 hours prior to abortion.

Abortion, Induced↗
PubMed1983

Deamino-8-D-arginine vasopressin shortens the bleeding time in uremia.

In a randomized double-blind cross-over trial we gave either 1-deamino-8-D-arginine vasopressin or placebo to 12 patients with uremia, hemorrhagic tendencies, and prolonged bleeding times. After vasopressin infusion, all patients had shortened bleeding times, with the effect lasting for at least four hours in most cases. Platelet count, platelet cyclic AMP levels, platelet retention on glass beads, plasma fibronectin, serum thromboxane B2 and residual prothrombin, hematocrit, and plasma osmolarity were unchanged after vasopressin. A consistent post-infusion increase in factor VIII coagulant activity and, to a lesser extent, in factor VIII-related antigen and ristocetin cofactor accompanied the shortening of bleeding time. In addition, vasopressin induced the appearance in plasma of larger von Willebrand-factor multimers than those present in the resting state. The compound was given to nine additional patients with acute or chronic renal failure and prolonged bleeding times, before major surgery or renal biopsy. In these patients, shortening of the bleeding time was associated with normal hemostasis. Our findings indicate that 1-deamino-8-D-arginine vasopressin can be used for temporary correction of bleeding time and may prevent surgical bleeding in patients with uremia.

Adult↗
PubMed1994

Bleeding time in patients with cirrhosis: relation with degree of liver failure and clotting abnormalities. C.A.L.C. Group. Coagulation Abnormalities in Cirrhosis Study Group.

Patients with cirrhosis suffer from a complex haemostatic disturbance, due to abnormalities in clotting and fibrinolytic system activation and in primary haemostasis. The latter is indicated by a prolongation of bleeding time, which is a reliable indicator of platelet function in vivo. To further assess the relationship between bleeding time, degree of liver failure and clotting abnormalities in patients with cirrhosis, bleeding time was investigated in a prospective study of 70 consecutive patients with cirrhosis diagnosed by liver-needle biopsy, of whom 19 belonged to Child-Pugh class A, 29 to B and 22 to C. Among patients with cirrhosis, 40% had an abnormal bleeding time (> 10 min), and 42% had a platelet count < 100,000/microliters. Patients with severe liver failure (class C) had a lower platelet count and a more prolonged bleeding time than patients in classes A and B. Bleeding time was significantly inversely correlated to platelet count, fibrinogen, prothrombin activity and packed cell volume, and directly correlated to serum bilirubin and D-dimer. However, in class C patients, only a significant inverse correlation between bleeding time and fibrinogen was observed. These findings indicate that in cirrhosis worsening of platelet function is closely related to the degree of liver failure. The inverse correlation between bleeding time and fibrinogen indicates that a low value of this clotting parameter may account in part for platelet dysfunction.

Bleeding Time↗
PubMed1978

Factor VIII--related protein on vascular intima of patients with chronic renal failure and prolonged bleeding times.

To determine whether the prolonged bleeding time so common to chronic renal failure (CRF) was due to defective factor VIII-related activities, as in von Willebrand's disease, vascular-factor VIII-related protein was measured in patients with CRF. Factor VIII-related protein was detected by immunofluorescence on the vascular intima of all 13 patients with CRF and greatly prolonged bleeding times. This protein was also present on the vascular intima of a patient with CRF and moderate von Willebrand's disease. These findings support a previous suggestion that the disturbed haemostasis in patients with CRF is not linked to defective factor VIII-related activities.

Adult↗
PubMed1998

Effects of skin mast cells on bleeding time and coagulation activation at the site of platelet plug formation.

We studied the effects of stimulated skin mast cells on bleeding time and thrombin generation which was measured using prothrombin fragment F 1+2 (F 1+2) and thrombin-antithrombin-III-complex (TAT). In 10 patients with urticaria pigmentosa (chronic cutaneous mast cell accumulation) the mean bleeding time was significantly prolonged in wounds made on urticaria pigmentosa lesions vs. normal skin (460 +/- 34 vs. 342 +/- 27 s, p = 0.005). In 10 atopic subjects skin incisions were made on prick-tested sites 30, 60, 120 and 240 min after administration of an allergen (acute mast cell stimulation), histamine or vehicle. The mean bleeding time was significantly prolonged at all time points, being maximal at 120 min (60% prolonged) in wounds made on allergen-stimulated skin areas (p < 0.01) compared with histamine or vehicle sites. Administration of allergen or histamine lowered the TAT concentration in the bleeding-time blood. Furthermore, TAT and F 1+2 levels in the bleeding-time blood were lower at 60, 120 and 240 min after allergen or histamine application in comparison with samples collected at 30 min. We conclude that skin mast cells can regulate primary hemostasis by prolonging bleeding time and by inhibiting thrombin generation.

Adult↗