Comparative studies of hemoperfusion devices. I. In vitro clearance characteristics.
Drug adsorption studies were carried out using three charcoal-based and one resin-based hemoperfusion devices. They were the Sandev Hemocol unit, the Gambro Adsorba 300C unit unit, the Becton-Dickinson Hemodetoxifier, and the Extracorporeal Medical Specialties XR-010 Hemoperfusion column, respectively. Clearance versus time tests of up to six hours duration were performed using solutions of sodium salicylate, sodium barbital, and creatinine in a pH 7.4 buffer which were pumped through the columns at flow rates of either 100 or 200 ml/minute. Short term clearance tests were performed at various other flow rates to determine overall mass transfer resistances for the devices. Further analysis yielded values for the individual fluid-phase and solid-phase resistances. Studies were also done using sodium salicylate in bovine blood. The results provide information on typical adsorption capacities and drug removal rates for the four devices, and indicate the relative extents to which the solid and fluid phases control the drug uptake rates.