Effects of long-term hemofiltration on circulating mediators and superoxide production during continuous endotoxin administration

Background: The purpose of this study was to test whether continuous hemofi ltration eliminates cytokines and eicosanoids, or stimulates granulocyte fu nction, Methods: Nineteen pigs were divided into a control group (n = 7), a hemofil tration group (n = 7), and an extracorporeal circuit only group (n = 5), Al l animals received the same amount of intravenous endotoxin and resuscitati on fluid. Zero-balanced hemofiltration was started 30 minutes after initiat ion of endotoxemia and continued throughout the experiment, Plasma endotoxi n, tumor necrosis factor-alpha, eicosanoids, superoxide production. and oth er physiologic parameters were measured before challenge and at scheduled i ntervals thereafter. Results: Eicosanoids were filtered but plasma concentrations were not reduc ed. Tumor necrosis factor-alpha was not filtered or adsorbed, There were no significant differences between groups in any measured parameters. Conclusion: Continuous hemofiltration could not efficiently remove tumor ne crosis factor-alpha or eicosanoids, Also, continuous hemofiltration did not stimulate production of the proinflammatory mediators measured, nor improv e respiratory distress.