Figure 60-14 Dilutional thrombocytopenia occurs whenever massive blood loss takes place. The need for platelet transfusion, however, depends on the starting platelet count. In patients who started with low platelet counts, dilutional thrombocytopenia developed after blood loss of one or two blood volumes, whereas patients who started with very high platelet counts did not require transfusions of platelets. The bottom three sets of points represent patients with initial low platelet counts, and the top two sets of points represent children with initial high platelet counts. (Data from Coté CJ, Liu LM, Szyfelbein SK, et al: Changes in serial platelet counts following massive blood transfusion in pediatric patients. Anesthesiology 62:197–201, 1985.)