Intermittent haemodialysis-induced oxidative stress and the effect on inflammatory parameters in critically ill patients

In this study, we evaluated the impact of intermittent haemodialysis (IHD) on different indices of inflammation [elastase, procalcitonin (PCT) and neopterin]_and on oxidative stress biomarkers [total peroxides (TOC), autoantibodies against oxidized LDL (oLAb), malondialdehyde (MDA)]_in eight mechanically ventilated, critically ill patients with acute oliguric renal failure. IHD decreased the neopterin levels (113 ± 74 vs. 81 ± 46 nmol/L, p = 0.003) in contrast to elastase concentrations, which increased in plasma during this procedure (100 ± 45 vs. 184 ± 73 μg/L, p = 0.002). The membrane passage increased the generation of total peroxides (247 ± 232 vs. 342 ± 253 μmol/L, p = 0.028), whereas PCT, MDA and oLAb were not affected. These results indicate that inflammatory parameters are significantly affected by renal replacement therapy and that membrane passage causes peroxide generation. Therefore, these markers should be interpreted with caution to avoid misinterpretation if used as clinical prognostic markers in critically ill patients undergoing renal replacement therapy.