Answer: Check AV graft for complications (good to check other vitals and utilise your nursing assessment skills, but this could be an emergent problem so act quickly as to not delay calling the Doctor!)
Step-by-step explanation:
An arteriovenous (AV) graft is a surgically constructed vascular access point inside the blood vessel structure of the patient's arm (think like adding a straw between a vein and and artery). It is used to exchange (in and out) blood during hemodialysis (when you use a machine to clean to blood such as when kidneys are failing). AV grafts however necessary have some risky possible complications including Ischemic Steal Syndrome and thrombosis. So check the AV graft, assess area surrounding it (already done to some extent with getting cap refill), and call the doctor!
Note: I think getting blood work would be a very bad idea before calling the doctor as blood work should be ordered by the Health Care Provider not the nurse (nurses don't write lab orders). Even if the nurse say had a prewritten lab which needed to be drawn, blood work can take a longtime, AV graft complications would likely not show in lab results (as blood flow not blood content is likely the problem), and the fact the the patient has a AV graft leads a nurse to worry about AV complications as a first culprit. Thus blood work should probably not be taken at this time!