Continuous measurement of pressure in internal arteriovenous fistulae and prevention of symptomatic hypotension during hemodialysis.

To continuously monitor the blood pressure (BP) in an internal arteriovenous fistula, the blood tubing wall was punctured with a long, fine needle (25 gauge), and the needle tip was advanced into the fistula vein through the lumen of the outflow blood access puncture needle. It was found that the intrafistula BP thus measured varied in parallel with the systemic arterial BP during hemodialysis (HD). When the intrafistula BP fell to 60% of the level at the start of HD, 50 ml of saline was administered. As a result, hypotension was prevented completely in 60 HD in five patients who often showed symptomatic hypotension during HD.