In our unit we have a high occurance of clots being aspirated out of the access immediately after cannulation. The circumstances vary. It happens to various nurses, some are fistula, some are graft, some are on coumadin, some are not. We use 3cc needles on the access needle. We clamp site with hemoband after dialysis. I have monitored accessing technique. I worked in another unit and never had this occur except in a severely stenosed access. Any ideas???