Buzz Braydon had a heart attack 4 weeks ago and is taking the anticoagulant warfarin (Coumadin). He is at the office for a checkup and to have his prothrombin time testing. Blood is collected from a small vein in Buzz's left arm using the butterfly method. After collecting the specimen, Buzz wants to know why a red-stoppered tube was used to draw blood from him and then thrown away. Buzz says he is going on vacation in North Carolina for 2 weeks. He says that they explained to him at the hospital why he should have his blood tested every week, but he's unsure where to get his blood tested while he's on vacation. Buzz wants to know if, as long as he takes his medication exactly as he should, it would be all right to skip his weekly prothrombin test during that time.