Antioxidant treatment with N-acetylcysteine during adult respiratory distress syndrome

Abstract

To examine whether the antioxidant N-acetylcysteine could ameliorate the course of the adult respiratory distress syndrome (ARDS) in man. Randomized, double-blind, placebo-controlled study. Medical and surgical ICU in a regional hospital. Sixty-six ICU patients with ARDS. Patients with ARDS (PaO2/FiO2 ratio less than 250 torr) were treated with either the antioxidant N-acetylcysteine 150 mg/kg as a loading dose and then 20 mg/kg/hr, or with placebo for 6 days. No improvement could be demonstrated in the PaO2/FiO2 ratio in the study group as compared with the control group on any day. Pulmonary compliance was higher in the N-acetylcysteine group than in the placebo group on all days, but this difference did not reach the chosen 5% level of significance. No difference between the two groups could be demonstrated on chest radiograph or on survival rate. We documented that N-acetylcysteine acts as an anticoagulant and perhaps decreases pulmonary fibrin uptake during ARDS. N-acetylcysteine might be of benefit in ARDS. Before further clinical studies are started, problems with N-acetylcysteine and coagulation have to be elucidated in order to find out whether N-acetylcysteine could have a beneficial effect in the treatment of ARDS.