Antioxidant treatment with N-acetylcysteine during adult respiratory distress syndrome: a prospective, randomized, placebo-controlled study

Crit Care Med. 1992 Jul;20(7):918-23. doi: 10.1097/00003246-199207000-00004.


Objective: To examine whether the antioxidant N-acetylcysteine could ameliorate the course of the adult respiratory distress syndrome (ARDS) in man.

Design: Randomized, double-blind, placebo-controlled study.

Setting: Medical and surgical ICU in a regional hospital.

Patients: Sixty-six ICU patients with ARDS.

Interventions: 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.

Measurements and main results: 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.

Conclusions: 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.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcysteine / therapeutic use*
  • Adult
  • Aged
  • Antithrombin III / analysis
  • Double-Blind Method
  • Female
  • Fibrinogen / analysis
  • Humans
  • Lung Compliance / drug effects
  • Male
  • Middle Aged
  • Oxygen / metabolism
  • Partial Pressure
  • Platelet Count / drug effects
  • Prospective Studies
  • Respiratory Distress Syndrome / drug therapy*


  • Antithrombin III
  • Fibrinogen
  • Oxygen
  • Acetylcysteine