Demand For Red Blood Cells Research Articles

Ectopic extramedullary hematopoiesis: evaluation and treatment of a rare and benign paraspinal/epidural tumor

Ectopic extramedullary hematopoiesis (EMH), defined as the formation of blood cells outside the bone marrow, usually occurs in a scenario of chronic anemia when, even after conversion of the bony yellow marrow to red marrow, the body is still unable to meet the demand for red blood cells. Ectopic extramedullary hematopoiesis most commonly occurs in the liver and spleen but may, in fact, occur almost anywhere in the body. Although previous reports have documented EMH presenting as paraspinal masses, such lesions have almost always been associated with a predisposing hematological disorder such as hemolytic anemia, myelofibrosis or myelodysplastic syndromes, thalassemia, polycythemia vera, leukemia, or lymphoma. The authors of this report describe the first reported instance of EMH in a patient presenting with a symptomatic epidural and paraspinal cervical lesion arising from the posterior spinal elements and no known predisposing hematological disease. Initial radiographs revealed a bony lesion arising posteriorly from the C2-3 laminae and spinous processes. Subsequent imaging suggested the diagnosis, which was confirmed by CT-guided biopsy, peripheral blood smears, and bone marrow aspirate. Despite epidural compression and slight displacement of the cervical cord and thecal sac, the patient's symptoms were limited to pain and diminished cervical range of motion. Therefore, surgery was deferred in favor of nonsurgical therapy. Several alternative modalities for the treatment of EMH have been suggested in the literature, including cytotoxic agents and radiotherapy. The authors opted for an approach utilizing directed low-dose radiotherapy of a total of 25 Gy divided in 2.5-Gy fractions. At the 3-month follow-up, the patient continued to be asymptomatic, and MRI demonstrated a significant reduction in the dimensions of the lesion. Extramedullary hematopoiesis with spinal cord compression in the absence of a preexisting hematological disorder has not been described in the context of clinical neurosurgical practice. Recognizing that EMH may present as an epidural or paraspinal lesion is important since chemotherapy and radiotherapy are effective therapeutic options in the majority of patients who suffer few if any symptoms. Extensive evaluation for underlying hematological disorders is necessary before undertaking directed therapy. Inadvertent resection of these highly vascularized masses may risk catastrophic intraoperative hemorrhage with no proven benefit as compared with medical treatment, which usually provides excellent long-term outcomes.

Hospital Demand for Blood Components in Ontario Correlates with Selected Diagnostic and Procedural Activities

AbstractAbstract 4272 Introduction:Demand for blood components in Canada is a significant and growing contributor to health care spending, but the drivers of this demand remain poorly characterized. While most institutions do not routinely monitor the transfusion requirements of individual diagnoses and procedures, an institution's overall demand for blood components and the types of clinical activities it provides are both well documented. Development of an institution-level inferential model may allow for more accurate demand forecasting for blood components. Methods:Hospital shipments of all blood components from Canadian Blood Services (red blood cells, platelets, plasma and cryoprecipitate) in the province of Ontario during the period 2006–2009 were merged with institution-level administrative data containing hospital characteristics and selected diagnostic and procedural codes as obtained from inpatient and ambulatory clinical databases maintained by the Canadian Institute for Health Information. Simple linear correlation and several nested multivariable linear regression models were fitted and compared. Results:From 2006–2009, our sample included 137 healthcare facilities, representing approximately 1.4 million units of RBCs, 400 000 units of plasma, 166 000 doses of platelets (defined as either one pool of whole blood-derived platelets or a single apheresis platelet), and 20 000 units of unpooled cryoprecipitate. Institutional demand for these blood components correlated with both hospital-level characteristics and diagnostic and procedural activity data. Institutional demand for red blood cells correlated most strongly with visits for cirrhosis and chemotherapy. Demand for plasma correlated most strongly with visits for cirrhosis and cardiac surgery procedures. Demand for platelets correlated most strongly with bone marrow and solid organ transplant procedures. Demand for cryoprecipitate correlated most strongly with visits for valvular heart disease and cardiac procedures. The strength of these correlations generally remained stable over the four years of analysis, during which time demand for red blood cells and platelets increased, demand for plasma decreased, and demand for cryoprecipitate remained stable. Conclusions:In the largest province of Canada, institutional demand for blood components correlate strongly with disease burden measured by diagnostic and procedural codes contained within administrative data. Disclosures:Pendergrast:Canadian Blood Services: Research Funding. Zagorski:Canadian Blood Services: Research Funding.

Demographic changes and predicting blood supply and demand in the Netherlands

Concerns have been raised that aging of the general population will increase the demand for blood products. Modeling can be applied to assess trends in blood demand and supply and predict how these will develop over time. We developed mathematical models to describe and predict the national demand of red blood cell (RBC) products. The first demand model assumes that the mean numbers of transfusions per inhabitant per age and sex are constant. A second demand model incorporates observed changes in clinical blood use over time. Further, a donation model is developed to predict future RBC supply. To estimate the supply of whole blood donations, we used annual donor retention rates, donor recruitment rates, and mean numbers of donations per donor year. The model based on demography only predicts an increase of 23% in RBC demand over 2008 to 2015. The second model, incorporating both demographic changes and trends in clinical RBC use, predicts a decrease of RBC demand by 8% over the same period. The predicted RBC supply closely follows the demand as predicted by the second model. Despite an aging population, RBC demand may not increase as much as predicted in other studies. This depends on the extent to which other effects, like that of optimal blood use, will neutralize the effects of aging of the transfusion recipient population. Still, the observed downward trend in donor recruitment in the Netherlands must be stopped to maintain a sufficient RBC supply.

Management of blood supplies during an influenza pandemic

Blood supplies are delicate resources, particularly vulnerable to incidents affecting the health of donors. The critical impact of a pandemic on the availability of red blood cells (RBCs) has been demonstrated in previous research; however, a detailed estimate of the expected deficit is missing. This has become a priority issue in the face of the current influenza pandemic. Data from several major blood donation services were used to analyze management of blood supplies in Germany. Routine management of RBCs was extrapolated to epidemic and pandemic situations using computer simulations with a mathematical model that allows for analysis of deficits in blood supplies. Routine management and distribution of RBCs are driven by supply, which has marked fluctuations but does not appear to have seasonality. There seems to be a remarkable elasticity in the demand for RBCs that helps to mitigate minor crises in supply, but this is likely to be overstretched during a severe pandemic. The supply-driven management of RBCs in Germany implies that assessment of severity of shortages due to a pandemic depends on detailed knowledge about the fraction of transfusions that do not allow for postponement. Pandemic preparedness should include criteria for prioritization of transfusions.

Management of blood shortages in a tertiary care academic medical center: the Yale‐New Haven Hospital frozen blood reserve

Threats to national and local blood supplies in America mandate development of an effective blood management system for emergency preparedness and efficient blood inventory management. Seasonal or acute blood shortages could be compounded by the unavoidable distribution inefficiencies of the blood pipeline during an emergency. The Yale-New Haven Hospital (YNHH) Blood Bank has developed a comprehensive emergency blood management plan, which includes maintenance of a tactical, limited frozen blood supply. A computer spreadsheet-based disaster prediction model has been designed to guide the use of the frozen reserve by testing various emergency scenarios. The frozen blood reserve can likely support normal hospital red blood cell (RBC) demands during typical (3-4 days) seasonal shortages, provide a reduced supply for up to 10 days, or meet an unexpected transient increased RBC demand without requiring intensive support from the regional blood center. However, the frozen blood supply is not designed to meet the massive transfusion demand associated with extreme or sustained disasters. Rather, it serves as a short-term bridge-over supply until blood center support can be reestablished. We review the reasons for initiating a blood management plan and describe how YNHH has implemented and sustains a frozen blood reserve as part of a comprehensive disaster management plan. Despite the operational complexity, the benefits of self-sufficiency, the ability to support routine hospital requirements, and the security of having a backup supply justify the expense and difficulty of maintaining a frozen blood reserve.

Blood center and hospital relationships in England and North Wales: their impact on the declining demand for red blood cells?

Blood center and hospital relationships in England and North Wales: their impact on the declining demand for red blood cells?

Blood Substitutes

Blood Substitutes

Anemia of Chronic Renal Disease

The pathogenesis of the anemia of chronic renal disease is related (1) to the etiology of the renal disease, (2) to the failure of renal excretory function, and (3) to the failure of renal endocrine function. Failure of the renal excretory function leads to an increased demand for red blood cells because of shortening of the red blood cell life-span, impaired utilization of iron, decreased responsiveness to erythropoietin and increased blood loss. Failure of renal endocrine function leads to a decreased erythropoietic response to these demands because of impaired production of erythropoietin. A greater degree of anemic hypoxia is required to generate the necessary amount of erythropoietin, and an equilibrium between demand and supply is first established at anemic levels.