During blood transfusion, clotting of transfused blood is associated with

Most transfusion reactions are hemolytic and are due to clerical errors that result in administration of blood with major (ABO) and minor antigen incompatibility. Interestingly, Rh incompatibility is not associated with intravascular hemolysis. Administration of blood through hypotonic solutions such as 5% dextrose and water results in swelling of the erythrocytes and hemolysis. Calcium-containing solutions such as Ringer's lactate cause clotting within the intravenous line rather than hemolysis and may lead to pulmonary embolism. Delayed transfusion reactions, caused by a presumed anamnestic immune response that occurs 3-21 days after blood is infused, result in a hemolytic anemia.