The volume of blood shed during the bleeding time correlates with the peripheral venous hematocrit.

The relation among the bleeding time, the peripheral venous hematocrit, and the amount of blood shed at the template bleeding time site has not been previously defined. We studied this relation in 227 persons: 26 were patients with idiopathic thrombocytopenic purpura (ITP), 137 were patients with a variety of other bleeding disorders, and 64 were healthy subjects. The bleeding time (mean +/- SD) for the healthy group was 7.1 +/- 1.2 minutes, and the amount of shed blood was 136.4 +/- 47.2 microL; in patients with ITP the bleeding time was 14.0 +/- 4.1 minutes and the shed blood was 508.1 +/- 387 microL; and in the group with other bleeding disorders, the mean bleeding time was 9.0 +/- 3.5 minutes, and the amount of shed blood was 224.7 +/- 184 microL. Bleeding times for all persons studied showed a significant correlation of 0.75 for the amount of shed blood on the filter paper and a significant correlation of 0.28 for the peripheral venous hematocrit. There was also a significant correlation between the bleeding time and the platelet count in patients with ITP. This study demonstrates that the volume of blood shed at the bleeding time site correlates with the peripheral venous hematocrit and emphasizes the contribution of the hematocrit to primary hemostasis in healthy subjects and patients with bleeding disorders.

Blood rheology and 2,3-diphosphoglycerate levels after erythropoietin treatment.

Twenty-seven transfusion dependent patients with end-stage renal disease on long-term dialysis had blood cell counts, serum chemistries, blood pressure, and whole blood viscosity measured, as well as having transfusion requirements assessed. Three months after the institution of recombinant human erythropoietin (rHU-EPO) (75 u per kg per wk), there was an 88 percent fall in transfusion requirement. After four months, the hematocrit increased from 24 +/- 3.8 to 25.6 +/- 4.2 percent, mean corpuscular volume from 93 +/- 4.9 to 97 +/- 6.6 fl, 2-3-diphosphoglycerate (2,3-DPG) from 13.2 +/- 3.2 to 15.6 +/- 4.3 microM per g of Hb. Whole blood viscosity fell from 14.1 +/- 2.1 to 12.7 +/- 2.3 seconds, and ferritin levels fell from 3282 +/- 3889 to 2131 +/- 2441 ng per ml. In eight patients in whom the dose of rHU-EPO was further increased by up to 50 units per kg three times weekly for three months, the hematocrit rose further to 29.3 +/- 3.0 percent and the rise in hematocrit was accompanied by a further increase in 2,3-DPG to 17.9 +/- 2.8 microM per g of Hb (p < 0.03). There were no major side effects or vascular complications.

Whole blood viscosity in beta thalassemia minor.

Patients with heterozygous beta-thalassemia minor have a decreased hematocrit (HCT). Since the HCT is a primary determinant of whole blood viscosity, the known reduction in HCT in beta-thalassemia minor should lead to a measurable reduction of whole blood viscosity. The influence of the relatively lower mean corpuscular volume and consequent higher red blood cell count and beta-thalassemia minor on whole blood viscosity using a microporous viscometer has not previously been the subject of investigation. Accordingly, the blood of a group of normal and beta-thalassemia minor subjects was examined with a microporous viscometer to elucidate further the relations between whole blood viscosity, HCT, and red blood cell count. The data show that for normal and beta-thalassemia minor subjects a significant positive correlation (r = 0.65, p less than 0.01) exists between HCT and whole blood viscosity. However, the slope of the regression of whole blood viscosity and HCT of beta-thalassemia minor subjects was significantly higher z = 3.14, p less than 0.001) than that of normals. Thus, for any given HCT their whole blood viscosity was higher than that of normals. Studies of the relation of red blood cell counts to whole blood viscosity indicate the higher whole blood viscosity at a given HCT was related to the increased red blood cell counts in beta-thalassemia minor subjects. Because of the opposing interactions of HCT and red blood cell counts, the mean whole blood viscosity of the group of beta-thalassemia minor subjects examined was not significantly lower than the normal whole blood viscosity.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemoglobin and 2,3-diphosphoglycerate levels in transfused dialysis patients with myocardial infarction.

Thirty frequently transfused patients on long term hemodialysis were studied and a similar number of age and sex-matched patients who were infrequently transfused were used as a control group to ascertain the influence of a previous myocardial infarction (MI) on transfusion requirements. The frequency of previous MI on electrocardiogram (ECG) in the transfused and control groups was similar (40 percent and 37 percent, respectively). In frequently transfused dialysis patients with MI, the hemoglobin level (transfusion trigger) at which these patients were transfused was higher than that of frequently transfused patients without MI (8.3 +/- 1.5 g per dl vs. 6.9 +/- 1 g per dl, p less than 0.01) which indicated that patients without MI tolerated a greater degree of anemia than those with MI. The 2,3-diphosphoglycerate (2,3-DPG) levels were significantly elevated in all transfused patients when compared to matched controls. However, levels of 2,3-DPG were significantly higher in MI patients receiving frequent transfusions than in other transfused patients, suggesting oxygen demands may not have been fully met despite the frequent transfusions. The results suggest levels of 2,3-DPG deserve further study in relation to the adequacy of tissue oxygenation in anemic dialysis patients.

Lymphocyte subpopulations in long-term dialysis patients: a case-controlled study of the effects of blood transfusion.

Lymphocyte subsets in a group of intensely transfused (greater than 10 units/year) patients on long-term hemodialysis were compared with those in a carefully controlled population of lightly transfused (1-10 units/year, no units during study period) long-term dialysis patients. The data confirm previous reports of lymphopenia and a symmetrical reduction of both T- and B-cell subpopulations in patients on long-term dialysis. Eleven (36.7%) of 30 intensely transfused dialysis (ITD) patients had a low T8 population when expressed as a percentage value, while 0 of 25 lightly transfused dialysis (LTD) control patients exhibited a low percentage of T8 cells. There were no significant absolute differences between the lymphocyte subsets in the ITD and LTD patients. These data contrast with previous reports of other groups of ITD patients in whom there was an observed increase in T8 cytotoxic suppressor cells. Our findings suggest that the immunologic effects of renal failure and long-term dialysis largely override the increase in T8 lymphocyte subsets observed in other groups of transfused patients. There is little difference between ITD and LTD patients, but both groups are significantly different from nontransfused controls. Further longitudinal studies are needed in completely untransfused patients to resolve the contribution of minimal transfusion therapy to the immunologic deficits observed in long-term dialysis patients.

A model for capacity planning of a comprehensive integrated information system for hospitals and clinics.

Appropriate system sizing is essential to ensuring a reasonable computer response time for end users. A model is discussed that describes the type and number of interactions between user terminals and printers and the central processor for a comprehensive, integrated medical information system. The system modeled includes support to inpatient and outpatient order entry and results reporting for clinical services; registration; admission, disposition, and transfer; patient appointing; pharmacy, clinical laboratory, and radiology; medical record management; and electronic messages. Originally developed for use in benchmark testing of comprehensive systems designed for military hospitals and clinics, the model has been generalized to be applicable to other systems and settings. Results are presented for a routine busy day in a 200-bed teaching hospital providing extensive outpatient services, and a large free-standing clinic. The model results can be applied to several facets of system planning, including sizing of the central processor and communications network, determining the optimal number of storage devices and user devices, and fine tuning the user interface.

Pulmonary oxalosis caused by Aspergillus niger.

A case report involving a pleuropulmonary mixed bacterial infection in association with Aspergillus niger is described. The patient responded to a combination of antibiotics, aerosolized and intravenously administered amphotericin B, and surgery. Aspergillus niger appeared to be a secondary invader and caused lung damage by the production of oxalic acid.

The blood counts and lactate dehydrogenase levels in thrombotic thrombocytopenic purpura (TTP).

The blood counts and lactic dehydrogenase values of eight patients with thrombotic thrombocytopenic purpura (TTP) were reviewed in relation to the clinical course. Three of the eight patients died. In these patients, the hemoglobin was significantly lower and the LDH higher at the time of presentation than that of the patients responding to treatment. The height of the absolute reticulocyte count and platelet count did not correlate as well with outcome as did the degree of anemia and LDH elevation. Microangiopathic changes were noted in all eight patients. A differential count showed that the total microangiopathic changes varied from 0.8 to 54%. The more severe microangiopathic changes occurred in the fatal cases. The observations indicate that the degree of anemia, elevation of LDH, and severity of microangiopathic changes at the time of presentation correlate with the outcome in TTP and provide useful parameters in the assessment of response to therapy.