Problem
78 y/o male was admitted to the ICU for severe sepsis from a UTI. After the nurse drew blood, the venipuncture site was oozing. Labs revealed: CBC with markedly decreased platelet count, peripheral blood smear showed decreased number of platelets and presence of large platelets and fragmented red cells (schistocytes), prothrombin time prolonged as was the partial thromboplastin time. The d-dimer was markedly elevated, and fibrinogen level was low. Based on the clinical presentation and laboratory data provided, what is your working diagnosis?