Peritoneal lavage or flush is the "rapid" infusion and drainage of peritoneal dialysis solution with the purpose of removing blood, fibrin, debris or spent dialysate from the peritoneal cavity or catheter. The dwell time is minimal or non-existent.

Conventional hemodialysis machines generally employ a high dialysis flow rate, with urea clearance increasing as either blood low or dialysate flow rate increases. At high flow rates, clearance rate per unit of dialysate is lower and the dialysate is minimally saturated, resulting in inefficient dialysate use. By contrast, low-volume, high-efficiency platforms, such as the NxStage System One, provide effective dialysis with very low volumes of dialysate by maintaining a very low ratio of dialysate flow rate to blood flow rate (high blood flow rate relative to the dialysate flow rate). When dialysis is used at a lower flow ratio, the dialysis fluid becomes fully saturated with waste products and this saturation minimizes the amount of dialysis fluid that is needed to achieve a desired urea clearance. This allows for the efficient use of dialysate and minimizes the requirement for storage supply space and the use of water.

A type of tubing connector with threaded fittings for a secure connection and added leverage for a seal disconnect. The concept for these adapters was developed by Hermann Wulfing Luer, a German medical instrument maker whose name still defines this unique design.