Problem:
Mr. James Hobson is a 69-year-old male with a history of hypertension that is fairly well controlled on medication. He has been a smoker for 52 years and has a body mass index of 37.3. He awoke yesterday morning complaining of blurry vision and some weakness on the left side of his body. He thought he had just slept wrong, so he was not concerned. Later in the morning, he was having trouble walking and his wife convinced him to call his physician. The physician's office called 9-1-1, and Mr. Hobson was transported to the nearest hospital. Upon arrival to the emergency department, the physical exam findings were as follows: heart rate, 112 beats/min; blood pressure, 172/90 mm Hg; respiratory rate, 24 breaths/min; O2 saturation, 90%; arm and leg weakness (3/5); and decreased sensation. He was awake and responding to questions appropriately, although slowly. The following diagnostics tests were ordered: noncontrast CT of the head; electrocardiogram; complete blood count with platelets, cardiac enzymes, and troponin; electrolytes; blood urea nitrogen; creatinine; glucose; prothrombin time/international normalized ratio; and partial thromboplastin time. A noncontrast CT can exclude or confirm the presence of hemorrhage. The sensitivity of a noncontrast CT to show ischemia increases