Cardiopulmonary bypass as a cause of free radical-induced oxidative stress and enhanced blood-borne isoprostanes in humans

Free radicals are believed to be involved in postsurgery-related complications. We studied whether cardiopulmonary bypass (CPB) operation has any immediate impact on the initiation of oxidative stress and inflammatory response by measuring isoprostanes and prostaglandin F-2alpha during and 24 h following CPB. The levels of 8-iso-PGF(2alpha) (a major F-2-isoprostane and biomarker of oxidative stress) and 15-keto-dihydro-PGF(2alpha) (a major metabolite of PGF(2alpha) and biomarker of inflammatory response) were measured in frequently collected plasma samples before, during, and up to 24 h postsurgery in 21 patients. 8-Iso-PGF(2alpha) levels significantly increased within 3 min (p <.0001) and continued until 50 min (p <.0001) during CPB. On the contrary, no significant increase of inflammatory response indicator, 15-keto-dihydro-PGF(2alpha) was found during and up to 24 h postoperatively. These findings establish an increased free radical-induced oxidative stress activity rather than inflammatory response after CPB. (C) 2003 Elsevier Science Inc.