Comparison Between Hydroperoxides and Malondialdehyde as Markers of Acute Oxidative Injury During Hemodialysis

: An increased free‐radical production has been documented during hemodialysis (HD) particularly when bio‐incompatible membranes are utilized. These highly reactive free radicals can cause damage through several pathways, one of the best known being lipid peroxidation. Malondialdehyde (MDA) is a product of lipid peroxidation, which can partly be removed by HD due to its low molecular weight and water solubility. Hydroperoxides are predominantly found in lipid substances, and therefore their removal by HD could be difficult. We evaluated the behavior of these two by‐products of lipid peroxidation during HD, comparing their behavior in three different membranes, in order to study their reliability as markers of acute oxidative injury. Fifteen stable HD patients were dialyzed with each of the following membranes: cuprophan, polyamide, and polysulfone, three sessions for every membrane. MDA and hydroperoxides were measured pre‐HD and then both from the arterial and venous line at 8, 15, 30, and 240 min. During HD with cuprophan membrane MDA decreased significantly in the venous line compared with the arterial line at 8, 15, and 30 min (P