No Effect of Melatonin to Modify Surgical-Stress Response after Major Vascular Surgery: A Randomised Placebo-controlled trial

Abstract

Background A possible mechanism underlying cardiovascular morbidity after major vascular surgery may be the perioperative ischaemia–reperfusion with excessive oxygen-derived free-radical production and increased levels of circulating inflammatory mediators. We examined the effect of melatonin infusion during surgery and oral melatonin treatment for 3 days after surgery on biochemical markers of oxidative and inflammatory stress. Methods Patients received an intra-operative intravenous infusion of 50 mg melatonin or placebo. In addition, all patients received 10 mg melatonin or placebo orally the first 3 nights after surgery. Blood samples for analysis of malondialdehyde (MDA), ascorbic acid (AA), dehydroascorbic acid (DHA) and C-reactive protein (CRP) were collected preoperatively, and at 5 min, 6 h and 24 h after clamp removal (recirculation of the first leg). Results Twenty-six patients received melatonin and 24 patients received placebo. No significant differences were observed in any of the oxidative and inflammatory stress parameters. There were significantly more side effects in the melatonin group than in the placebo group. Conclusions Melatonin treatment in the perioperative period did not reduce the oxidative and inflammatory parameters measured in this study.