The relative benefits and hazards of bronchial lavage with 10% acetylcysteine (Mucomyst) compared to sodium chloride solution was studied in 14 patients with cystic fibrosis who were treated on 16 occasions. Lavage with acetylcysteine produced a significant increase in arterial carbon dioxide tension (Paco2) and a decrease in arterial oxygen tension (Pao2) immediately after lavage. Lavage with sodium chloride solution produced a decrease in Paco and an increase in `Pao2. Regardless of lavage agent, pulmonary function was impaired for 48 to 72 hours after lavage, and three patients developed pneumonia within three days after lavage. When bronchial lavage was used as one part of a complete therapeutic program, some improvement in pulmonary function could be demonstrated two to six weeks after therapy.
Cezeaux G, Telford J, Harrison G, Keats AS. Bronchial Lavage in Cystic FibrosisA Comparison of Agents. JAMA. 1967;199(1):15–18. doi:10.1001/jama.1967.03120010059010