Effects of Long-Term Hemofiltration on Circulating Mediators and Superoxide Production during Continuous Endotoxin Administration

BACKGROUNDThe purpose of this study was to test whether continuous hemofiltration eliminates cytokines and eicosanoids, or stimulates granulocyte function. METHODSNineteen pigs were divided into a control group (n = 7), a hemofiltration group (n = 7), and an extracorporeal circuit only group (n = 5). All animals received the same amount of intravenous endotoxin and resuscitation fluid. Zero-balanced hemofiltration was started 30 minutes after initiation of endotoxemia and continued throughout the experiment. Plasma endotoxin, tumor necrosis factor-alpha, eicosanoids, superoxide production, and other physiologic parameters were measured before challenge and at scheduled intervals thereafter. RESULTSEicosanoids were filtered but plasma concentrations were not reduced. Tumor necrosis factor-alpha was not filtered or adsorbed. There were no significant differences between groups in any measured parameters. CONCLUSIONContinuous hemofiltration could not efficiently remove tumor necrosis factor-alpha or eicosanoids. Also, continuous hemofiltration did not stimulate production of the proinflammatory mediators measured, nor improve respiratory distress.