A 66-year-old man presents with a complaint of bruising and severe pain in the right arm and forearm after painting a wall yesterday. His history is notable for osteoarthritis, hypertension, and non-insulin-dependent diabetes mellitus; he denies any prior history of bleeding. His medications include hydrochlorothiazide and glyburide (a sulfonylurea), and he took ibuprofen for the pain last night. Examination is notable for large ecchymoses over the right shoulder and triceps, with swelling and tenderness of the right forearm and wrist. The remainder of the examination is benign. CBC: Hemoglobin/hematocrit – 13 g/dU39% MCV – 94 fL MCH – 29 pg MCHC – 28 g/dl RDW-CV – I I% WBC count – 1 3,500/Jll Differential: Neutrophils – 45% Lymphocytes – 50% Monocytes – 5% Platelet count – 300,000/Jll Questions PT = 1 2.1 seconds (< 14=”” seconds)=”” inr=”1″ .0=””>< 1=”” .3)=”” ptt=”77″ seconds=”” (22-35=”” seconds)=””>

• Do the CBC and screening coagulation test results point to a specific cause for a bleeding tendency in this patient?

• Are additional studies warranted for diagnosis or determining therapy?