During your Emergency Medicine rotation, you are asked to ev…
During your Emergency Medicine rotation, you are asked to evaluate a 5-year-old male child who presents after falling off a scooter. The patient reports that he fell sideways off the scooter as he rounded a curve in the road, and he describes dull, aching pain along his left side where he hit the ground. The patient’s parents report that he has never had any previous serious injury, but the mother recalls that he had increased bleeding following circumcision during infancy. There is no other history of surgery or trauma. On physical exam, the patient has extensive bruising of the lateral left thigh and tenderness to palpation. Initial CBC is performed and reveals normal WBC, Hgb, and HCT. Additional laboratory results are as follows: (Normal ranges in parentheses; abnormal results are in bold type) Initial Test Results PT 12.6 sec (11.0-13.5) PTT 50.0 sec (25.0-35.0) Plt 250,000 (150,000-400,000) Based on these findings, what clotting factor deficiency is most likely in this patient?