Transfusion science
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Over the last decade, the costs of blood procurement have increased as a result of regulatory pressure and scientific progress in understanding transfusion-transmitted disease. At the same time, hospitals are under tremendous pressure to reduce costs. ⋯ These decisions, however, should be made on assessments of the total cost of a safe and reliable blood supply: recruitment, collection, donor management, testing, manufacturing/processing, quality control, inventory management, quality assurance, regulatory, overhead and availability. If all of these costs are considered, it is unlikely that cost reduction can be achieved through hospital collections.
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According to our own experience and published reports the frequency of red cell transfusion in intensive care units is in the range of 0.2 to 0.4 units per patient per day and is dependent upon the local strategy, the patients involved and the kind of surgery performed. The rationale for red cell transfusion is to maintain or restore the oxygen carrying capacity of the blood to avoid tissue hypoxia which occurs when oxygen delivery drops below a certain critical value. Besides bleeding, phlebotomy is also a significant source of blood loss in critically ill patients. ⋯ However, individualised triggers for red blood cell transfusion are adequate for critically ill patients considering their co-morbidities and severity of disease. Finally, the decision to transfuse must also take into account the potential risks (infectious and non-infectious), as well as benefits for the individual patient. In the future, the level of transfusions may be reduced by using blood sparing techniques such as blood withdrawal in closed systems, bedside microchemistry, intravascular monitors, or autotransfusion of drainage blood in intensive care units.
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Transfusion science · Mar 1995
ReviewIntraoperative hemodilution and autologous platelet rich plasma collection: two techniques for collecting fresh autologous blood.
Intraoperative hemodilution (IH) and autologous platelet rich plasma (APRP) collection are two techniques used to obtain autologous blood in the operating room. They have been used to reduce allogeneic blood exposure in patients undergoing both cardiac and non-cardiac surgery. Both components have the advantage of providing fresh blood not subject to the storage lesion. ⋯ Although used commonly, the data supporting the use of either technique are controversial. Methodologic problems which have confounded studies evaluating their utility include: poorly defined transfusion criteria, concommitant use of other blood conservation techniques (i.e. cell salvage, pharmacologic agents, hypothermia, controlled hypotension) and changing transfusion practices with greater tolerance of normovolemic anemia. Randomized controlled studies with well defined up to date transfusion criteria are needed to identify patients likely to benefit from these techniques.
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Transfusion science · Dec 1994
ReviewExtracorporeal photochemotherapy: evaluation of two techniques and use in connective tissue disorders.
Extracorporeal photochemotherapy (ECP) consists of collection of mononuclear cells, their irradiation with UV-A light in the presence of a photoactivable molecule--8-methoxy-psoralen (8-MOP) being the most widely used--and their reinjection into a patient. Two technical approaches have been developed. The photopheresis procedure involves four steps: (i) 8-MOP is given to the patient orally, 2 h before collection of white blood cells; (ii) a discontinuous flow cell separator (UVAR, Therakos, West Chester, PA, U. ⋯ Hematocrit of the final product is always < 2%. (ii) Soluble 8-MOP is added to the mononuclear cell concentrate at a final concentration of 200 ng/mL. (iii) Mononuclear cell concentrate is transferred in an EVA plastic bag (Macopharma, Tourcoing, France) to ensure an efficient irradiation with a UV irradiator (Vilber Lourmat, Marne-la-Vallée, France). (iv) After irradiation at 2 J/cm2 (time < 20 min), the cells are reinfused into the patient. Experimental and clinical data suggest that ECP has potential applications in the treatment of connective tissue disorders, such as systemic sclerosis and rheumatoid arthritis. Although encouraging data have been obtained, further clinical trials are warranted to establish the role of this therapy in these indications.
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The pathophysiology and support of the massively transfused patient from the vantage of a blood banker is reviewed. Hypothermia, acidosis and shock must be reversed if blood component therapy is to be effective. Algorithms which employ ratios of various blood components have not proved themselves, nor are screening coagulation tests of value until they are remarkably abnormal. ⋯ A large part of the impaired hemostasis is due to a consumption coagulopathy rather than the anecdotal assumption that dilution of the hemostatic elements is to blame. Hypocalcemia, hypomagnesemia and hyperkalemia are rarely observed nor do they pose a problem for this group of individuals. The logistics of blood supply to the clinical areas are addressed by describing one system that has proved itself.