A 42 year old man sustained severe injuries in an automobile accident and is admitted to the intensive care unit. Examination of a peripheral blood smear on the 3rd day of admission reveals helmet cells, schistocytes, and decreased platelets. Which of the following is most strongly suggested by these findings?

The findings suggest disseminated intravascular coagulation (DIC), which is a feared complication of many other disorders, such as obstetrical catastrophes, metastatic cancer, massive trauma, and bacterial sepsis. The basic defect in DIC is a coagulopathy characterized by bleeding from mucosal surfaces, thrombocytopenia, prolonged PT and PTT, decreased fibrinogen level, and elevated fibrin split products. Helmet cells and schistocytes (fragmented red blood cells) are seen on peripheral blood smear. Autoimmune hemolysis and hereditary spherocytosis would be characterized by spherocytes in the peripheral smear. Macro-ovalocytes and hypersegmented neutrophils can be seen in megaloblastic anemia. Ref: Mims M.P., Prchal J.T. (2010). Chapter 7. Hematology during Pregnancy. In J.T. Prchal, K. Kaushansky, M.A. Lichtman, T.J. Kipps, U. Seligsohn (Eds), Williams Hematology, 8e.