Transfusion
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The risks of transfusion-associated infectious disease have led to a reassessment of transfusion practice, which in turn has resulted in a trend toward the reduction of homologous transfusion. This reduction is primarily due to the initiation of hemotherapy at more severe levels of anemia. The optimum threshold for the initiation of transfusion therapy, or the transfusion trigger (TT), is unknown. ⋯ Oxygen delivery fell after ET (18.9 vs. 11.1 cc/kg/min, p less than 0.001), but there was no significant change in oxygen consumption after ET. The unanesthetized animals adapted well to severe anemia and experienced no adverse effects on their long-term survival in this setting, which suggests that the reduction of the TT to a Hct of 15 percent in normal animals is safe. Adoption of this TT could result in a significant reduction in the requirements for homologous transfusion with its attendant risks.
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Most commercial blood warmers are unable to warm blood components to greater than 35 degrees C at rapid flow rates (greater than 100 mL/min) because of problems with inefficient heat transfer and resistance to the flow of blood through the instrument's tubing. A new blood warmer, using a closed-flow 40 degrees C counter-current water bath and large-bore tubing, is able to warm cold (10 degrees C) packed red cells to temperatures greater than 35 degrees C even at flow rates of 500 mL per minute. ⋯ In vivo survivals of chromium-51-labeled warmed autologous red cells were greater than 75 percent in four volunteers and 49.5 percent in the fifth volunteer, whose abnormally low unwarmed red cell ATP level suggested a storage problem. Thus, this blood warmer, which warms blood efficiently at high flow rates, causes no red cell damage, even with prolonged exposure of old red cells to the 40 degrees C heat exchanger.
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The use of 1930 units of blood or blood products during 765 transfusion episodes in 560 patients was reviewed. This represented one-half of all transfusions in a large medical center over a 2-month period. By clearly defined, present criteria, 42.3 percent of the episodes were found not to be appropriate. ⋯ Three groups of patients were especially prone to inappropriate transfusions: those with end-stage renal disease or terminal cancer and cancer patients on chemotherapy. Age, sex, and specific hospital wards were not associated with inappropriate use. Most unjustified episodes occurred as a result of the overestimation of the immediate risk incurred by withholding transfusion.
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Randomized Controlled Trial Clinical Trial
ABO compatibility can influence the results of platelet transfusion. Results of a randomized trial.
Sixty consecutive patients with untreated acute leukemia alternately received either ABO-matched or ABO-mismatched random-donor platelet transfusions prepared from pooled platelet concentrate stored for 1 to 3 days. Patients were assigned randomly to receive matched or mismatched platelets as their first transfusion, and the first four transfusions were analyzed. In 40 evaluable patients, there was no significant difference (paired t test) between the 10-minute posttransfusion corrected count increments (CCI) of the initial transfusions of matched and mismatched platelets. ⋯ Conversely, in five patients in whom there was no apparent effect of ABO mismatching, only one had an increase in isoagglutinin titer. Platelet survival was not altered as the ratio of 18-hour to 10-minute posttransfusion CCl was 0.6 for both matched and mismatched platelet transfusions. These data demonstrate that ABO compatibility can affect the results of random-donor platelet transfusions and that patients who experience poor increments from ABO-mismatched platelets may benefit from a trial of ABO-compatible platelets before the initiation of HLA-matched platelet transfusion.
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To compare changes in platelets stored in the new di-n-decyl phthalate (DnDP)-plasticized polyvinyl chloride (PVC) bag with those in a di-(2-ethylhexyl) phthalate (DEHP)-plasticized PVC bag, single-donor apheresis platelet concentrates (PCs), 133 +/- 11 x 10(7) platelets per ml (n = 7), were stored with 94 +/- 3 ml of plasma in a new 1-liter bag with a surface area of 44 +/- 7.1 cm2 per 10(10) platelets. Oxygen and carbon dioxide gas diffusion properties of PVC-DnDP films were respectively, 1.6 and 2 times those of standard PVC-DEHP films. The amounts of DnDP leaked into the plasma of PCs were low at 0.58 +/- 0.06 mg per bag after 5-day storage, which is about one-eightieth the amount of DEHP leaked. ⋯ Platelet aggregation and responses to hypotonic shock were significantly better in the new bags at the end of storage. Shape changes of platelets into spherical forms with dendrites were more frequently observed in PVC-DnDP bags than in PVC-DEHP bags. The study indicated that platelets stored in the new DnDP-plasticized PVC bags have retained aggregation and responses to hypotonic shock more than platelets in the PVC-DEHP bags, but spherical forms and anaerobic metabolism increased in the new bags.