Endogenous and exogenous protection from surgically induced reactive oxygen and nitrogen species

Surgical intervention creates reactive oxygen species through diverse molecular mechanisms, including direct stimulation of immune-mediated inflammation necessary for wound healing. However, dysregulation of redox homeostasis in surgical patients overwhelms the endogenous defense system, slowing the healing process and damaging organs. We broadly surveyed reactive oxygen species that result from surgical interventions and the endogenous and/or exogenous antioxidants that control them. This study assimilates current reports on surgical sources of reactive oxygen and nitrogen species along with literature reports on the effects of endogenous and exogenous antioxidants in human, animal, and clinical settings. Although exogenous antioxidants are generally beneficial, endogenous antioxidant systems account for over 80% of total activity, varying based on patient age, sex, and health or co-morbidity status, especially in smokers, the diabetic, and the obese. Supplementation of exogenous compounds for support in surgical patients is thus theoretically beneficial, but a lack of persuasive clinical evidence has left this potential patient support strategy without clear guidelines. A more thorough understanding of the mechanisms of exogenous antioxidants in patients with compromised health statuses and pharmacokinetic profiling may increase the utility of such support in both the operating and recovery rooms.