N-acetylcysteine In Critically Ill Patients

Abstract

Oxidative stress defines an imbalance in production of oxidizing chemical species and their effective removal by protective antioxidants and scavenger enzymes. Evidence of massive oxidative stress is well established in critical illnesses characterized by tissue ischemia-reperfusion injury and by an intense systemic inflammatory response such as during sepsis, acute respiratory distress syndrome and acute lung injury. Several clinical trials have been performed in order to reduce oxidative stress by supplementation of antioxidants alone or in combination with standard therapies. N-acetyl cysteine (NAC) has been in clinical practice for several decades. Studies in the early 1960s demonstrated that thiol compounds had potent mucolytic properties. The biological activity of NAC is attributed to its sulfhydryl (thiol) group, while its acetyl-substituted amino group affords it protection against oxidative and metabolic processes. It exhibits direct, indirect antioxidant properties and anti-inflammatory properties demonstrated by various studies. NAC would be able to reduce acute exacerbations of COPD mainly through an antioxidant effect. NAC is currently the only FDA approved antidote for