Your patient is a 56 y/o male who fell from a ladder and struck his head on a concrete driveway.  According to his wife he immediately picked himself up after the fall and there was no obvious change in mantal status. When you arrive he is alert, oriented and refusing transport.  A physical exam is completed and the only abnormal finding is a large hematoma to the occipital region of his skull.  His vital signs are normal with the exception of an irregular pulse.  The ECG reveals controlled atrial fibrillation.  A review of his medications reveals that he takes a fish oil capsule daily, Zocor daily, and 7 mg of warfarin daily.

What is your primary concern regarding this patient?