Effects of Anti-inflammatory Agents on Hydrochloric Acid-Induced Pulmonary Injury

Abstract

To determine the effects of anti-inflammatory agents on hydrochloric acid lung injury, the heart and lungs were harvested from rats, placed in a lung chamber, constant flow perfused with whole blood, and ventilated. The following experiments were conducted: observation alone; intratracheal infection of normal saline; intratracheal hydrochloric acid; and intravenous meclofenamate or indomethacin before intratracheal hydrochloric acid. Wet-to-dry lung weights were measured. Peak airway pressures increased immediately (p <,001 vs. baseline; ANOVA) in all intratracheal groups, hydrochloric acid producing even greater (p <. 05) increases than saline—effects unaltered by meclofenarnare or indomethacin. The increased (p <. 001 vs. baseline) 2-h pulmonary artery pressures in hydrochloric acid-treated groups were unaltered by meclofenamate or indomethacin. All hydrochloric acid-treated groups demonstrated increases (p <. 05) in weight that were unchanged by meclofenamate or indomethacin. These data suggest that the beneficial effects of these medications described elsewhere, using a variety of in vivo lung injury experimental models, may be attributed to their experimental design, or to contributions from organshystems outside the pulmonary circuit.

Key Words:

• hydrochloric acid aspiration
• indomethacin
• isolated-perfused lungs
• meclofenamate