THE RULE OF 6 (Ball, Lynda et. al.)
A fistula is mature when it is already a minimum of 6 mm in diameter with discernible margins when a torniquet is in place, be less than 6 mm deep, have a blood flow greater than 600 ml/ min, and be evaluated for non maturation 4- 6 weeks after surgical creation if it does not meet the above criteria.
During the maturation process, it is most necessary to feel, look, and listen and feel the AVF at every dialysis treatment. You can begin assessing the AVF by placing a torniquet gently placed just below the axilla area. Instruct patient to start exercising their access provided it is cleared by the surgeon. It is very important for you to document patient education and including the condition and maturation ofthe fistula.
According to Robinn, ML., et. al., experienced dialysis nurses have an 80 % success rate for identifying a mature fistula.
Furthermore, a mature fistula has a vessel diameter of 4-6 mm, the wall should be firm to the touch, there should be no prominent collateral veins, there is a strong thrill at the arterial anastomosis, and the presence of bruit.