Transfusion
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Mathematical models have been used to describe the factors that affect cell salvage (CS) and normovolemic hemodilution (ANH). Here, the CS and ANH models were used to compare these two techniques alone or in combination with each other. ⋯ When comparing ANH to CS, this mathematical model would suggest that CS has the potential to offer significantly greater red blood cell avoidance than does ANH; however, the combination of ANH with CS may offer allogeneic avoidance superior to either technique alone.
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Anemia commonly complicates critical illness. Restrictive transfusion triggers are appropriate in this setting, but no large studies have measured red cell (RBC) requirements for intensive care patients when evidence-based transfusion guidelines are followed consistently. ⋯ Despite evidence-based transfusion practice, 40 percent of ICU patients receive transfusions, which account for 7 to 8 percent of the national blood supply.
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Recombinant FVIIa (rFVIIa) has been approved for treatment of bleeding in hemophilia patients with inhibitors. It has also been successfully used in nonhemophilia patients with acquired antibodies against FVIII (acquired hemophilia). Pharmacological doses of rFVIIa have been found to enhance the thrombin generation on already activated platelets and, therefore, may also likely be of benefit in providing hemostasis in other situations characterized by profuse bleeding and impaired thrombin generation, such as patients with thrombocytopenia and in those with functional platelet defects. ⋯ Because of the recent trends in rFVIIa usage in non-approved settings among physicians from various disciplines, significant concerns about its safety, efficacy, and costs have arisen. Additionally, dosing of rFVIIa for these potentially broad clinical applications is not standardized. Currently, the decision on when and where to use rFVIIa for patients with uncontrolled bleeding continues to be one that must be made by individual physicians, assisted by their hospital pharmacotherapeutics and transfusion committees.
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Comparative Study
Lack of correlation between HBsAg and HBV DNA levels in blood donors who test positive for HBsAg and anti-HBc: implications for future HBV screening policy.
Studies showing a significant correlation between hepatitis B surface antigen (HBsAg) and hepatitis B virus (HBV) deoxyribonucleic acid (DNA) levels have focused on the HBV seroconversion window period. ⋯ HBV DNA levels in HBsAg-positive, anti-HBc-reactive blood donations can be extremely low. About 6 percent of donations would be negative by current minipool HBV NAT methods. About 3 percent of donations would remain undetected by sensitive single-donor NAT. These results indicate caution in any consideration of dropping HBsAg screening.