Problems of competition in charcoal hemoperfusion for the treatment of intoxications

Both toxic and physiological substances are adsorbed during an extracorporeal hemoperfusion for the treatment of exogenous and endogenous intoxications. Using a closed circuit in vitro, we perfused one liter saline or fresh human plasma with 4425 mumol creatinine, 4854 mumol and 97,086 mumol barbital-Na, 597 mumol bromthalein, 1942 mumol and 29,126 mumol raffinose, and 200 mumol inulin in different combinations over 70 gm of uncoated charcoal with the following results: 1. The adsorptive capacity of other substances is not influenced by preadsorption of the charcoal with a low or middle molecular weight substance; 2. In the low and middle molecular weight range, there is no competition between two substances in a solution; 3. The simultaneous usage of two substances of middle and high molecular weight, or preadsorption with a high molecular weight substance, reduces the rate of adsorption and the capacity of charcoal for middle molecular weight substances, but not for low molecular weight substances.