Short time dialysis with continuous blood volume control.

Continuous measurement of haemoglobin concentration is used to control changes of blood volume during haemodialysis. Ultrafiltration is either kept constant throughout the session or after starting with a rate (1.5 to 2 l/h), is manually controlled in order to limit blood volume reduction to a pre-set percentage. Ultrafiltration is step-wise decreased (a) or switched on and off (b) accordingly. Blood volume decrease with constant ultrafiltration is compared with method (a) and (b) in 4 stable haemodialysis patients. Constant ultrafiltration rate and the same total amount of ultrafiltrate causes a nearly 3% (mean) greater volume reduction as compared with method (a) and (b). No difference was observed in blood pressure and heart rate. We conclude that ultrafiltration in stable haemodialysis patients can be completed in short time without consequences for cardiovascular stability.