Randomized controlled trials have shown a reduction in platelet alloimmunization and refractoriness in patients with acute leukemia (AL) with the use of poststorage leukoreduction of blood products. Universal prestorage leukoreduction (ULR) of red cell and platelet products has been performed in Canada since August 1999. We conducted a retrospective analysis of 13 902 platelet transfusions in 617 patients undergoing chemotherapy (CT) for AL or stem cell transplantation (SCT) before (n ‫؍‬ 315) and after (n ‫؍‬ 302) the introduction of ULR. Alloimmunization was significantly reduced (19% to 7%, P < .001) in the post-ULR group. Alloimmune platelet refractoriness was similarly reduced (14% to 4%, P < .001). Fewer patients in the post-ULR group received HLA-matched platelets (14% vs 5%, P < .001). Alloimmunization and alloimmune refractoriness in the 318 patients who were previously pregnant and/or transfused were also reduced after ULR (P ‫؍‬ .023 and P ‫؍‬ .005, respectively). In a Cox regression model, the 3 independent factors that predicted for alloimmune refractoriness were nonleukoreduced blood

The CHR includes the vast majority of factor concentrate users and is therefore ideal as the basis for a national monitoring system.

Previous studies have suggested that desmopressin may reduce the bleeding diathesis that often complicates open-heart surgery. To pursue this question further, we performed a double-blind, randomized, placebo-controlled trial to determine whether the previously reported beneficial effect of desmopressin on hemostasis during complex cardiac surgery was applicable to all elective cardiac surgical procedures involving cardiopulmonary bypass. In 150 consecutive patients, most of whom underwent primary coronary-artery bypass grafting, we compared the effects of intravenous desmopressin (0.3 microgram per kilogram of body weight) with those of saline placebo on postoperative blood loss and the need to replace blood products. The median amount of blood lost within the first 24 hours after operation was similar in the desmopressin and placebo groups (865 vs. 738 ml; P = 0.26). The postoperative use of blood replacement products did not differ significantly between the groups (1025 ml [95 percent confidence interval, 300 to 4140 ml] in the desmopressin group and 860 ml [247 to 5346 ml] in the placebo group). Desmopressin is believed to exert its hemostatic effect by releasing von Willebrand factor. The level of ristocetin cofactor, a functional index of the level of von Willebrand factor, was increased approximately twofold from base line in both treatment groups 90 minutes and 24 hours after the administration of medication. Similarly, the levels of von Willebrand factor multimers increased uniformly in both groups. These findings may be consistent with a normal stress response of von Willebrand factor to major surgery and could explain our failure to detect a therapeutic effect of desmopressin. We conclude that the majority of patients who undergo elective cardiac surgery receive no hemostatic benefit from the use of desmopressin.