Are antioxidant levels measured immediately postoperatively an indicator of magnitude of injury?

BACKGROUND: Little is known about the changes that occur in antioxidant lev els in response to surgical trauma. The antioxidant system may influence re covery and healing after operation. Miller et al described a reliable assay for total antioxidant capacity of serum. We studied changes in antioxidant levels secondary to operation using this assay. METHODS: Twenty-seven patients were studied: 14 abdominal and 13 breast can cer operations. Initial blood samples were obtained when starting the preop erative intravenous line, the second in the recovery room, and every 6 hour s thereafter. RESULTS: Levels did not correlate with diagnosis, extent of operation, age, body mass index, or complications. Differences between preoperative and po stoperative values in the down and up groups were significant at P = 0.002 and P = 0.023, respectively. Differences in initial levels between the down and up groups were significant at P = 0.005, Levels 12 hours after operati on were stable. CONCLUSIONS: Rapid return to a baseline of approximately 1 mu mole/L, regar dless of the direction of initial response, supports the concept of a set p oint for regulation of serum's antioxidant capacity. Am J Surg. 2000;180:21 2-216. (C) 2000 by Excerpta Medica, Inc.