PUSH-PULL SORBENT BASED PHERESIS FOR TREATMENT OF ACUTE HEPATIC-FAILURE - THE BIOLOGIC-DETOXIFIER PLASMA FILTER SYSTEM

The BioLogic-DT(R) (detoxifier) System is an extracorporeal blood trea tment device that uses the membranes of a cellulosic plate dialyzer to propel blood in and out through a single lumen access (on a 12 sec cy cle) and circulates a suspension of powdered charcoal and cation excha nger through the dialysate spaces to absorb many soluble toxins in the treatment of hepatic failure. The BioLogic-DTPF (detoxifier/plasma fi lter) System adds two Gambro plasma filters downstream from the plate dialyzer, which allows most of the blood plasma to pass out of the blo od, contact powdered charcoal in a suspension, and then return to the blood during each 12 sec cycle (creating push-pull sorbent based phere sis). A roller pump exchanges charcoal suspension between the plasma f ilter case and a 700 mi bag of powdered charcoal suspension. At a bloo d flow rate of 150-200 ml/min, 100 ml/min of plasma moves bidirectiona lly through the plasma filter membranes. Direct contact of plasma with charcoal outside the plasma filter membranes removes creatinine with a clearance rate equal to plasma flow (100 ml/min); clearance of stron gly protein bound toxins, such as unconjugated bilirubin, is lower (10 -40 ml/min). In this article, the authors explain the mechanisms of op eration of this system and present in vitro tests that define its chem ical efficiency. Also described are potential problems, tests that ind icate the severity of these problems, and monitors and algorithms to d etect or avoid these problems in clinical use of the system. The resul ts of the treatment of two patients with acute hepatic failure and com a using the BioLogic-DTPF System are reviewed.