SYSTEMIC LIPID-PEROXIDATION AND INFLAMMATION INDUCED BY THERMAL-INJURY PERSISTS INTO THE POST-RESUSCITATION PERIOD

We determined the time course of the oxidant-induced systemic lipid peroxidation seen after burn injury. Twelve sheep were given a 15% of total body surface third-degree burn and monitored for 3 or 5 days. Circulating lipid peroxides were monitored by both malondialdehyde (MDA) and conjugated dienes (CD). Lung and liver tissue MDA was also measured and compared to controls. A significant but transient increase in circulating MDA and CD was noted several hours after burn. Venous plasma levels increased again 3–5 days postburn with onset of wound inflammation. Oxygen consumption, (Formula presented), also increased by 35 ± 12% at this time. Lung MDA, which increased to 64 ± 5 from a control of 45 ± 4 nMol/gm, at 12 hours after burn was still increased 3 days after injury. Marked lung inflammation was present early after injury and persisted for the 5-day study period. Liver MDA also increased from control value of 110 ± 20 to 252 ± 25 at 12 hours and remained increased over the 5-day period. Serum alkaline phosphatase was also increased. Burn biopsies revealed no infection to explain the ongoing lipid peroxidation process, i.e., bacterial content was less than 105 organisms/gram burn tissue. We conclude that an initial system lipid peroxidation occurs immediately after burn injury, and that this process continues well into the post-resuscitation period, corresponding in time with increased (Formula presented), lung inflammation, and evidence of liver dysfunction. The ongoing oxidant changes with the presence of a burn may explain the accentuated organ dysfunction seen with an additional septic insult in burned patients. © 1990 by The Williams and Wilkins Co.