Transfusion science
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Transfusion science · Dec 2000
ReviewTransfusional iron overload and chelation therapy with deferoxamine and deferiprone (L1).
Iron is essential for all living organisms. Under normal conditions there is no regulatory and rapid iron excretion in humans and body iron levels are mainly regulated from the absorption of iron from the gut. Regular blood transfusions in thalassaemia and other chronic refractory anaemias can result in excessive iron deposition in tissues and organs. ⋯ Combination therapy could also benefit patients experiencing toxicity with DF and those not responding to either chelator alone. The overall efficacy and toxicity of L1 is comparable to that of DF in both animals and humans. Despite the steady progress in iron chelation therapy with DF and L1, further investigations are required for optimising their use in patients by selecting improved dose protocols, by minimising their toxicity and by identifying new applications in other diseases of iron imbalance.
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Transfusion science · Oct 1999
ReviewAutoapheresis and intraoperative blood salvage in oncologic surgery.
Transfusion of predeposit or salvaged autologous blood has continued to grow since the 1980s. Issues such as the indications for use and cost effectiveness as well as the safety of autologous blood salvaged during cancer surgery have emerged and should be addressed. The concern for possible contamination of autologous RBC with cancer cells responsible for metastasis has limited the use of autologous salvaged blood in cancer patients. ⋯ However, a number of limitations have hampered the widespread use of IOBS in these patients and the technique is not well established. Increasing knowledge of the deleterious effects of allogeneic blood transfusion both in terms of the increased number of viral or bacterial infections and the down-regulation of the patient's immune system have recalled attention to IOBS and to the techniques such as filtration, which might reduce the risk of reinfusion of cancer cells, or totally eliminate the risks such as irradiation has been proposed by Hansen's group. This paper reviews the topic with some emphasis on our personal experience with gamma and X-ray irradiation of salvaged blood in a large reference hospital, where IOBS and filtration of salvaged blood were established for use in cancer patients in 1993 and 1996.
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Transfusion science · Mar 1998
ReviewFuture directions in utilization review: the role of transfusion algorithms.
Transfusion practice guidelines and retrospective utilization review have been ineffective in curtailing the inappropriate use of blood and blood products, particularly in cardiac surgical patients. Patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) are at increased risk for excessive perioperative blood loss requiring transfusion of blood products. Recent evaluations have focused on the use of point-of-care coagulation assays for patient-specific therapy. ⋯ Methods are now available for rapid, on-site assessment of coagulation assays to allow appropriate, targeted therapy for acquired hemostatic abnormalities. Recent studies indicate that a rapid evaluation of thrombocytopenia and coagulation factor deficiencies, coupled with transfusion algorithms, can facilitate the optimal administration of transfusion-based therapy in patients who exhibit excessive bleeding after CPB. The use of point-of-care assays and transfusion algorithms may provide an effective concurrent method of utilization review of blood products in the surgical setting.
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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.