Increasing the safety of volumetric ultrafiltration control.

Deviations in ultrafiltration volume can cause various problems for patients undergoing a haemodialysis treatment. With the introduction of high flux dialysers, closed systems with volumetric fluid balancing became the systems of choice, because control of transmembrane pressure used previously is too inaccurate and unsafe to be used with such filters. In this article, a reliable and cost effective test method is described to increase the safety of a closed system. The test is carried out by simply analysing the dialysate pressure while the dialyser is isolated from the system for typically 7.2 seconds. No additional sensors and components other then a valve combination used to isolate the dialyser are required.