PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Platelet Count”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 235 records · Page 13Linked to original sources
PubMed2001

Prevalence of low automated platelet counts in cats: comparison with prevalence of thrombocytopenia based on blood smear estimation.

True thrombocytopenia is uncommon in cats; however, low platelet counts frequently are found using automated cell counters. Although this discrepancy is a well known problem, the prevalence of low automated platelet counts in feline blood samples has not been documented. We retrospectively compared the prevalence of low automated platelet counts with low blood smear-estimated platelet counts in feline blood samples. Results of blood sample analysis from 359 cats during a 1-year period at the University of Glasgow Veterinary Haematology Laboratory were examined. Smear estimates of platelet number were done in those cases in which records did not indicate adequate platelet numbers. Platelet counts obtained with an impedance counter (Minos Vet, Abx Hematologie) were <200X10(9) cells/L in 256 samples (71%) and <50X10(9) cells/L in 43 samples (12%). However, based on estimation of platelet numbers from blood smears, only 11 samples (3.1%) had platelet counts of <200X10(9) cells/L and 9 samples (2.5%) had counts of <50X10(9) cells/L. Four cats with thrombocytopenia estimated by blood smear evaluation had clinical signs of a bleeding disorder. Disorders associated with thrombocytopenia included neoplasia, cytotoxic chemotherapy, and infectious diseases. There was no evidence that delay due to mailing of samples was associated with lower automated platelet counts than would have been obtained on the day of sampling. The high prevalence of apparent thrombocytopenia in automated platelet counts was attributed to a combination of platelet aggregation and the impedance method of cell differentiation by size. Vigilance and careful examination of blood smears is required to identify the few cats with true thrombocytopenia.

Journal Article↗
PubMed2005

Decrease in platelet count as an independent risk factor for symptomatic vasospasm following aneurysmal subarachnoid hemorrhage.

OBJECT: Increased platelet consumption is expected in patients with cerebral vasospasm, according to data from clinical and experimental studies. The authors investigated sequential changes in platelet counts in patients with subarachnoid hemorrhage (SAH) and the difference in platelet consumption between patients with and those without symptomatic vasospasm (SV). Variables related to platelet count as well as other clinical and radiological variables were analyzed as independent predictors of SV. METHODS: One hundred consecutive patients who had undergone surgery within 48 hours after SAH onset were entered in the study. Clinical and radiological variables and blood cell counts, including red blood cells, white blood cells, and platelets, after SAH were retrospectively examined. Twenty of these variables were entered into univariatete and multivariate analyses to determine predictors for SV. After SAH, the platelet count decreased to a minimum and then increased rapidly to levels greater than those recorded on admission. This change was specific to SAH, and platelet consumption was more severe in patients with SV than in those without. There were three independent predictors of SV: a ratio of the lowest platelet count and the admission count greater than 0.7 (odds ratio [OR] 0.322, 95% confidence interval [CI] 0.124-0.834, p = 0.0196) and a history of hypertension (OR 0.338, 95% CI 0.126-0.906, p = 0.0311) were negatively significant (that is, decreases the occurrence of SV), and a Fisher Grade 3 (OR 4.42, 95% CI 1.48-13.2, p = 0.0077) was positively significant (that is, increases the occurrence of SV). CONCLUSIONS: The association between a decrease in platelet count and the occurrence of SV indicates the important role of platelets in the pathophysiology of vasospasm following SAH.

Adult↗
PubMed1986

The effect of lithium on platelet count.

The effect of lithium on platelet count was studied by examining 12 patients treated with lithium carbonate without any additional medication, 13 patients treated with lithium carbonate with additional psychotropic medication, 25 patients with major affective disorder prior to any treatment, 25 patients with panic disorder prior to any treatment and 25 healthy controls. The platelet counts were increased in the group of subjects treated with lithium carbonate without any additional psychotropic medication. The increase was not clinically significant.

Affective Disorders, Psychotic↗
PubMed1979

Potentiating effect of adrenaline on adenosine diphosphate-induced reduction in rabbit circulating platelet count: inhibition by dihydroergotoxine.

The number of circulating platelets was monitored in anaesthetized rabbits by a continuous flow technique, using a Technicon Autocounter. Transient reductions in circulating platelet count induced by a submaximal dose of adenosine diphosphate (ADP) were potentiated by concomitant infusion of adrenaline at doses (1-25 microgram/kg) i.v.) which did not influence platelet count when infused alone. The adrenaline effect was dose-dependent. Repeated infusions of adrenaline at 15 min intervals resulted in reproducible reductions in circulating platelet count during an observation period of at least 105 min. Dihydroergotoxine (DHET), administered either i.v. (2.5-10 microgram/kg) or intraduodenally (i.d.; 25-100 microgram/kg), inhibited adrenaline-induced potentiation dose-dependently; ADP-induced effects were not influenced. Duration of action was relatively long, and significant inhibitory activity was still apparent 50 (i.v.) and 115 (i.d.) min after drug administration. DHET doses inhibiting adrenaline-induced potentiation of platelet aggregation in the rabbit are similar to doses used in the treatment of impaired human cerebral function. It is conceivable that DHET could prevent activation of human platelets by catecholamines released into the blood stream in clinical stress situations.

Adenosine Diphosphate↗
PubMed2006

Usefulness of clopidogrel in abolishing the increased risk of reinfarction associated with higher platelet counts in patients with ST-elevation myocardial infarction (results from CLARITY-TIMI 28).

Previous studies have demonstrated an association between increased baseline platelet counts and poorer clinical and angiographic outcomes in patients with ST-elevation myocardial infarction (STEMI). We hypothesized that antiplatelet therapy would mitigate the effect of high baseline platelet counts on clinical outcomes. Data were obtained from 3,491 patients with STEMI in the CLARITY-TIMI 28 trial. Patients were categorized into 3 groups based on their baseline platelet counts: <200 x 10(3)/microl (group 1), 200 to 300 x 10(3)/microl (group 2), and >300 x 10(3)/microl (group 3). Among placebo-treated patients, reinfarction rates increased in a stepwise fashion as platelet counts increased (3.6%, 5.4%, and 9.0%, respectively, p for trend = 0.0025). When confounders of high platelet counts and correlates of reinfarction were adjusted for in a multivariate model, high platelet counts remained independently associated with increased rates of reinfarction at 30 days in placebo-treated patients; using group 1 as a reference group, multivariate odds ratios were 1.45 (95% confidence interval 0.91 to 2.31, p = 0.119) for patients in group 2 and 1.78 (95% confidence interval 1.03 to 3.08, p = 0.038) for patients in group 3. In contrast, among clopidogrel-treated patients, there was no increase in the risk of reinfarction as the platelet count increased (3.2%, 4.1%, and 3.3%, respectively; p for trend = 0.9073, p for interaction=0.064). In conclusion, among patients with STEMI who are treated with aspirin and a fibrinolytic agent, high platelet counts on presentation are independently associated with increased rates of reinfarction. Clopidogrel therapy abolishes this increase in the risk of reinfarction as platelet counts increase. These data are consistent with a putative role of platelets in reinfarction.

Aged↗
PubMed1994

The significant relationship between platelet count and haemorrhagic complications on ECMO.

Haemorrhagic complications, which occur in up to 35% of infants during extracorporeal membrane oxygenation (ECMO), often produce devastating sequelae. Although many complex factors interact to control haemostasis, platelet number and function has significant impact on the development of primary haemostasis. The optimum platelet count on ECMO, however, has not been defined. At our institution prior to August 1987, platelet counts were maintained at greater than 100,000/mm3. After August 1987, however, platelet counts of greater than 200,000/m3 were maintained. In a retrospective study, patients were randomly chosen from these two treatment periods: group 1--March 1986 to July 1987; and group 2--June 1988 to June 1989. The average platelet count, platelets administered, hours on ECMO, and bleeding complications were compared to each other and to the July 1992 ELSO Registry. There was a significant difference in average platelet counts between group 1 and group 2. However, the amount of platelets administered per kg per day was similar. There was a significant difference in overall bleeding complications between Group 2 (12%) and the ELSO Registry (35%) (p < 0.01). There was a trend towards decreased complications in all subgroups, although sample size precluded significance. We conclude that increasing platelet counts to greater than 200,000/mm3 decreases the overall bleeding complication rate. This advantage is achieved without a continuous need for increased platelet administration once the desired level is reached and without an increase in perfusion time, mechanical complications, or mortality.

Extracorporeal Membrane Oxygenation↗
PubMed1995

Bacterial infection-associated improvement of platelet counts in two patients with chronic and unresponsive idiopathic thrombocytopenic purpura with normal platelet survival studies.

Approximately 20% of adult patients with idiopathic thrombocytopenic purpura (ITP) do not respond to splenectomy and require alternative therapies to achieve a clinically safe platelet count. A small percentage of these patients have very refractory disease and are either unresponsive or poorly responsive to almost any therapy. In this report we describe two patients with chronic and unresponsive ITP with normal platelet survivals. Neither patient had responded to a large variety of treatments including corticosteroids, splenectomy, IVIgG, anti-D, chemotherapy, and ascorbic acid. However, both had a rapid, but short-lived, rise in their platelet count following a bacterial infection. One patient had a rise in platelet count for 6 months following the acute episode of bacteraemia. The second patient had a shorter response of 1 week. It is possible that these two patients represent a subset of patients with ITP who may benefit from cytokine therapy.

Aged↗
PubMed2006

Platelet counts are persistently increased following simultaneous pancreas and kidney transplantation.

BACKGROUND: Increased platelet counts has been reported to be a sequela of pancreas transplantation and even incriminated in the increased rate of thrombosis of pancreas grafts. The aim of the study was to measure the platelet counts after simultaneous kidney-pancreas transplantations compared to kidney transplants alone in diabetic patients. METHODS: This retrospective case-control study included 57 patients who received simultaneous pancreas and kidney transplants (SPK), from 1985 to 2000 and had functioning grafts for more than 1 month. The control patients were 38 type I diabetic recipients of kidney transplants alone (KTA), matched for sex, era, and immunosuppression. The platelet counts, white cell counts, and hemoglobin were analyzed on the preoperative day, weeks 1 to 6, 3 months, 6 months and 1 year. RESULTS: The mean age of the SPK group was significantly lower than that of the KTA group (39.8+/-8.3 versus 48.2+/-11.7, P<.01). Significantly higher platelet counts were demonstrated during weeks 2 to 6, which persisted at 3 months and at 1 year among the SPK compared to the KTA group. Although significantly higher white cell counts and lower hemoglobin levels were seen among the SPK versus KTA group during weeks 3 to 6, it did not persist after 3 months. CONCLUSION: The mean platelet counts of patients with simultaneous pancreas and kidney transplantation was significantly higher than that of diabetic patients with kidney transplants alone. This thrombocytosis persisted up to the first year and cannot be explained by an increased amount of blood loss or higher infectious complications in the SPK group. Routine antiplatelet prophylaxis is recommended in this group of patients.

Case-Control Studies↗
PubMed1987

Platelet counts in three racial groups.

Documented differences exist in red blood cell (RBC) and granulocyte counts between black and white people. However, little comparative information is available on differences in platelet counts in the two racial groups. Therefore, this study was performed to compare platelet counts in healthy white (94), black (92), and Latin-American (63) persons. Black women had significantly higher platelet counts than did white women (P less than 0.025). Latin-American women were between the other two groups. No differences were noted among men. Black women also had a significantly higher prevalence of iron deficiency and microcytosis of RBCs than did white women. After exclusion of women with either microcytosis or iron deficiency, racial differences in platelet counts were no longer evident. The authors conclude that the differences in the platelet counts between black and white women were secondary to common RBC differences (such as iron deficiency and other causes of microcytic anemia) and were not intrinsic to the platelets. These and other factors that can affect platelet counts should be excluded before determining the reference ranges for proper interpretation of the platelet counts.

Black or African American↗
PubMed2003

Correlation of platelet count changes with liver cell destruction in HELLP syndrome.

OBJECTIVE: HELLP syndrome is defined as a subset of preeclampsia involving a combination of hemolysis, low platelets affecting the circulatory system, and elevated liver enzymes, reflecting liver cell destruction. Our objective was to assess the correlation between the platelet count changes and liver cell destruction as indicated by aspartate aminotransferase (AST) levels. METHOD: We reviewed the records of 15 preeclamptic patients who developed HELLP syndrome as defined by 1) hemolysis, 2) elevated liver enzymes with an AST greater than 70 U/L (>2 SD above mean), and 3) low platelets (<100x10(9)/L). In these patients, both platelet counts and AST were assessed every 4-6 hr before and after delivery until recovery. At least eight laboratory assessments were done on each patient and were available for review. In each patient, the correlation between platelet count and AST levels was done using the Spearman rank order correlation coefficient. RESULTS: A negative correlation was found between platelet count and AST levels. A correlation coefficient of greater than 0.8 occurred in 53% of cases. The correlation coefficient ranged from 0.1 to 0.93. In all cases, improvement of liver cell dysfunction occurred within 4 hr of recovery of platelet count. At 72 hr postpartum, 73% of the platelet counts had not recovered to >150x10(9)/L, and 66% of patients with abnormally elevated AST levels had not returned to <35 U/L. CONCLUSIONS: Liver dysfunction and platelet count are poorly correlated in individual cases. This lack of correlation is evident both during decline and recovery of the platelet counts. Changes in platelet count cannot be used as a proxy for liver dysfunction in severe preeclampsia with HELLP syndrome.

Adult↗
PubMedDate not supplied

Platelets counts closely correlate with the disease-free survival interval of pancreatic cancer patients.

BACKGROUND/AIMS: We investigated the relationship between preoperative platelets count and the outcome of pancreatic cancer patients. METHODOLOGY: We retrospectively reviewed the clinical records of 105 patients with invasive ductal carcinoma of the pancreas who underwent radical resection at our institution over a 20-year period. The patients were divided into two groups based on their preoperative platelets counts: a group with thrombocytosis (> or = 40x10(4)/mL) and a group with non-elevated platelets counts (< 40x10(4)/mL). Histopathological findings, survival rates, recurrence patterns, and disease-free survival intervals were compared between the two groups. RESULTS: The outcome of the group with thrombocytosis was significantly poorer than that of the group with non-elevated platelets counts (p=0.043). The mean disease-free interval of patients with thrombocytosis was 4.9 months as opposed to 46.5 months for those with non-elevated platelets counts (p=0.006). Patients were classified into four groups according to changes in platelets counts after surgery. Consistently, the outcome of the group with both pre- and postoperative non-elevated platelets counts was the best compared to groups with post- and/or postoperative thrombocytosis. CONCLUSIONS: Our clinical data suggest that high platelets counts in the preoperative and postoperative period may be associated with a poor outcome and shortening of postoperative disease-free survival interval.

Adult↗
PubMed1989

Effect of dopamine and dopamine-antagonist infusion on blood platelet count, size and release reaction in hypertensive and normotensive subjects.

To examine the effect of dopamine on in vivo platelet function and a possible platelet contribution to the clearance of dopamine we measured platelet count, platelet size and plasma concentration of the platelet specific protein beta-thromboglobulin (BTG) in groups of 40 year old untreated hypertensive and normotensive men. One hypertensive (n = 10) and one normotensive (n = 10) group received dopamine infusion at doses from 0.5 to 2.0 micrograms/kg/min which increased plasma dopamine 100-fold from baseline. Two other groups of hypertensive (n = 10) and normotensive (n = 11) subjects received 10 mg of the dopamine antagonist metoclopramide intravenously, upon which serum prolactin concentration increased 10-fold. No significant effect on platelet function in any group was observed during these interventions. Platelet phenol-sulphotransferase may contribute to dopamine conjugation. However, the selected platelet parameters correlated only weakly with dopamine kinetics during the infusion. Neither dopamine nor a dopamine antagonist altered the selected platelet parameters, nor did these parameters influence the clearance of dopamine during a short-lasting pharmacological infusion.

Blood Platelets↗
PubMedDate not supplied

Preeclampsia effect on platelet count.

Thrombocytopenia is well recognized when preeclampsia is complicated by the hemolysis, elevated liver tests, low platelet count (HELLP) syndrome. We studied the effect of preeclampsia on the platelets of women whose platelet count and liver function were within normal range. We prospectively evaluated 67 preeclamptic women, gestational age 30 to 42 weeks, with disease of variable severity. The platelet counts of these patients, obtained within 24 hours preceding delivery, were significantly lower than the platelet counts of 71 control subjects. The platelet counts did not differ significantly between patients with mild and severe preeclampsia. Our findings suggest the existence of subclinical thrombocytopenia in preeclamptic women whose platelet values are within normal range.

Adult↗
PubMed1992

Thrombocytopenia post liver transplantation. Correlations with pre-operative platelet count, blood transfusion requirements, allograft function and outcome.

This study reports that thrombocytopenia is a universal phenomenon post hepatic transplantation. In 53 consecutive adult patients undergoing liver transplantation the platelet count fell by a mean of 63% (157 x 10(9)/l to 50 x 10(9)/l). The platelet count reached a nadir at Day 5 post-transplant but returned to pre-operative levels by Day 14. Non-parametric regression analysis found that pre-operative platelet count, blood transfusion requirements and maximum post-operative ALT values were independent predictors of the percentage fall in platelet count. No correlation was seen with length of graft cold ischaemic time or the use of University of Wisconsin (UW) solution. The nadir day correlated with maximum post-operative bilirubin and ALT, graft ischaemic time and use of UW solution. Maximum post-operative ALT was also an independent predictor of nadir platelet count. It was observed that patients who did not survive the hospital admission had lower post-operative platelet counts and these did not return to pre-operative levels by Day 14. The percentage fall in platelet count was an independent predictor of survival. Severe thrombocytopenia was associated with cerebral haemorrhage in 3 patients. This report provides evidence that allograft dysfunction (maximum post-operative bilirubin and/or AST/ALT) was the most consistent independent predictor of the nadir platelet count, nadir day and percentage fall in platelet count post liver transplantation although the exact mechanism(s) of the platelet changes remain uncertain.

Blood Transfusion↗
PubMed2005

[Correlation between platelet count and CA-125 in ovarian cancer].

OBJECTIVE: To determine whether a correlation between platelet count and CA-125 exists, and to compare the mean levels of CA-125 in groups with normal and elevated platelet counts. DESIGN: A retrospective analysis of the medical records concerning to 31 ovarian cancer inpatients, treated 1998-2002 with primary surgery and subsequent platinum-based chemotherapy at the Division of Gynecology, Department of Perinatology and Gynecology, University Medical School Poznań. MATERIALS AND METHODS: 137 serum and whole blood samples collected from 31 ovarian cancer patients during their consecutive hospital stays. RESULTS: There was a positive, moderate (r = 0.49) and highly significant (p < 0.0000001) correlation between platelet count and CA-125 levels. Thrombocytosis occurred in 45% patients before treatment, and in none when the 6th course of chemotherapy was given. In the thrombocytosis group, an average CA-125 level (913.5 U/ml) was significantly higher (p < 0.00001) then in the group with normal platelet count (103.7 U/ml). CONCLUSIONS: Platelet count and CA-125 levels do correlate in blood samples taken from ovarian cancer patients at the same time.

Adult↗
PubMed1998

Serum thrombopoietin levels in patients correlate inversely with platelet counts during chemotherapy-induced thrombocytopenia.

We studied serum thrombopoietin (TPO) levels and circulating numbers of platelet during five courses of myelosuppressive post-remission chemotherapy in three patients with acute leukemia in complete remission. Serum TPO levels were measured by a newly developed and sensitive sandwich enzyme-linked immunosorbent assay. In all courses, serum TPO levels changed reciprocally with the platelet counts. When platelets were transfused into patients near the time of platelet nadir, the TPO levels dropped temporarily, while platelet counts temporarily increased. In addition, platelets obtained after transfusion in a thrombocytopenic patient showed lower binding to biotinylated TPO than donor platelets prior to the transfusion. The finding indicated that the TPO receptors were saturated with endogenous TPO of the patient with a high serum TPO level. These results suggest that the platelet mass directly regulates serum TPO levels by receptor-mediated absorption and is one of the major regulators of serum TPO levels in humans.

Adolescent↗
PubMed1992

Phosphodiesterase-inhibitors enoximone and piroximone in cardiac surgery: influence on platelet count and function.

OBJECTIVE: Some phosphodiesterase (PDE)-inhibitors are believed to alter platelet count and function due to changes in intracellular cAMP. Whether newly developed (specific) PDE-inhibitors negatively influence platelet function in cardiac surgery should be investigated in a randomized study. METHODS: Eighty patients undergoing aorto-coronary bypass grafting were divided into 4 groups and received either the new PDE-III-inhibitor piroximone (group 1), the PDE-III-inhibitor enoximone (group 2), epinephrine (group 3) or no inotropic support (control). PDE-III-inhibitors were given as a bolus followed by infusion until starting of cardiopulmonary bypass (CPB). In addition to platelet count and a thrombelastogram, platelet function was assessed by aggregometry (ADP, epinephrine, collagen). Measurements were done before, during and after CPB until the 1st postoperative day. RESULTS: Platelet count and postoperative blood loss did not differ between the groups within the entire investigation period. Maximum aggregation and maximum gradient of platelet aggregation to all stimuli were not changed by either PDE-inhibitor enoximone or piroximone. CPB resulted in a significant decrease of all aggregation variables which was without differences due to treatment. Platelet aggregation recovered in the post-bypass period and exceeded baseline values on the 1st postoperative day. CONCLUSION: It is concluded that enoximone and the new PDE-III-inhibitor piroximone do not affect platelet function and can be used before CPB without risking platelet-related bleeding in cardiosurgical patients in the perioperative period.

Adenosine Triphosphate↗