In vitro adsorption of possible aetiological factors of hepatic encephalopathy.

Four different adsorbents (activated charcoal, XAD-4, a strong base anion and a strong acid cation-exchange resin) were tested in vitro for their capacity to remove substances that may be important in the development of hepatic encephalopathy. Separate columns packed with one of these adsorbents were perfused for three hours with a reconstituted plasma solution containing simultaneously high concentrations of amino-acids, ammoniumchloride, short-chain fatty acids, octopamine and bile salts. Effective removal of all these substances was only obtained when either activated charcoal, or XAD-4, were combined with the cation-exchange resin. Possible implications for the treatment of hepatic coma are discussed.