Beitrage zur Infusionstherapie = Contributions to infusion therapy最新文献

The washing of cells in blood components for transfusion is necessary (1) in cases of severe incompatibility to constituents of plasma in these components and (2) in cases of maternal antibodies to blood cells of the child when the child needs maternal blood components, e.g. in many cases of neonatal alloimmune thrombocytopenia. A single washing step is recommended in certain cases: paroxysmal nocturnal hemoglobinuria and T activation of red blood cells. There is no indication that components should be washed in cases of autoimmune hemolytic anemia. There are well-documented data which propound the necessity of filtering blood components in order to reduce the leukocyte content aiming at the prevention of a primary immune response to HLA antigens, of repeated febrile transfusion reactions caused by leukocyte antibodies and of the transmission of cytomegalovirus via blood components. Some observations suggest that the same type of filtration also should be carried out on blood components given to patients with paroxysmal nocturnal hemoglobinuria.

When no specific factor concentrate is available fresh-frozen plasma (FFP) is indicated in the treatment of clinically relevant hemorrhagic diathesis. These disorders include congenital factor V and XI deficiencies, multiple factor defects, as disseminated intravascular coagulation and severe liver disease, and patients receiving massive transfusions, when bleeding occurs and severe abnormalities on coagulation testing are evident. FFP is beneficial when used with plasma exchange in thrombotic thrombocytopenic purpura and related disorders. Various virucidal treatments including solvent-detergent (SD), photoactivated dyes (methylene blue) or pasteurization have been evolved to improve virus safety of human plasma. More extensive studies to demonstrate efficient virus inactivation in plasma have been performed with SD compared to other methods. On the other hand, the use of single-donor FFP in methylene blue treatment is possibly superior to pooled plasma which is processed according to the SD procedure. Pasteurization enables the inactivation not only of lipid-enveloped but also of non-lipid-enveloped viruses. Virucidal treatment of plasma may cause alterations in clotting factors, fibrinolysis and protease inhibitors; however, the currently achieved recovery of procoagulant activities is approximately comparable with that found in untreated FFP. The toxicity of virucidal additives is reported to be negligible since manufacturing includes a removal procedure (SD) or comparably low amounts (methylene blue) are used in inactivation treatment.

Quality controls of autologous blood collections in critically ill patients comprise the control of blood products, blood collection, and of the patients themselves. The control of products is defined in European guidelines, the AMG (law governing the manufacture and prescription of medicine) and GMP regulations. The products are described in the monograph of the Federal Health Office. The quality control of blood collection in patients with a critical vascular disease is important since vagotonic or hypertensive crises may occur frequently (in 10-15% of cardiosurgical patients). The quality control of the critically ill patients themselves is important in order to be able to balance benefits against risks. A phlebotomy of 500 ml may lead to a considerable deterioration of the clinical condition. The clinical condition can be controlled by simple exercise tests prior to and after the blood collection (bicycle ergometer, treadmill or climbing stairs). In our own investigations only about 25% of cardiosurgical patients (40% of patients with aortocoronary venous bypass) received autohemotherapy, and 20% of them showed a clinical deterioration during the phase of blood collection. Other problematic patients are those suffering from a tumor. A clear clinical benefit of autohemotherapy in these patients has not been demonstrated up to now; nevertheless, when a curative therapy is possible, they should be treated with autohemotherapy.

We report on the adaptation of a 'Walkaway' instrument (ES 600, Boehringer Mannheim) to be used in a blood transfusion service for donor screening of HBsAG and anti-HIV 1 + 2. Anti-CMV is obtainable, and anti-HCV will be available in the near future. Sample processing is done by a Tecan 8051 ID from barcoded primary tubes into ES 600 carousels. The capacity of this instrument is limited to 150 specimens and 600 tests per run. After mounting of reagents and control specimens, the tests are performed fully automatically without a technician. Regarding our experiences, the instrument is unanimously suited for use of blood donor testing in transfusion services with less than 145 samples to be tested daily.

We compared the reactivity of a new 3rd-generation anti-HCV enzyme immunoassay (EIA) using an additional, nonstructural antigen from the NS5 region, with a currently used 2nd-generation anti-HCV EIA, by investigating 419 serum specimens from healthy blood donors with normal liver function and 256 samples from patients at risk for hepatitis C infection; 2 of 419 blood donors and 1 of 256 patients were reactive to the NS5 region antigens only (later confirmed by Western blot and RP-2 RIBA), whereas 1 patient was reactive with the 2nd-generation EIA only (antibodies against c33c). We further evaluated the recently developed anti-HCV RP-2 RIBA by testing samples, that were indeterminate by the 2nd-generation RIBA. Nine of 15 patients were identified as reactive by RP-2 RIBA, 6 remained indeterminate. Of the 6 blood donor samples tested, 2 were found reactive, 1 remained indeterminate, and 3 were negative. These test results suggest a higher sensitivity and specificity of the RP-2 RIBA, whereas the relevance of an isolated NS5 EIA reactivity remains to be established.

The evaluation of a new Walkaway instrument (Behring Elisa Processor III) for testing HBsAG, anti-HCV and anti-HIV 1/2 in three blood transfusion services with different sample volumes (from 60,000 to 450,000/year) gave the following results: the instrument fulfills the promises of being a real Walkaway system under routine conditions, saving labor and gaining security. The instrument must work in agreement with GLP rules, and all test steps are documented. The organization of the laboratory becomes more transparent and less flexible.