The adult respiratory distress syndrome (ARDS) is a multifactorial disorder most commonly occurring secondary to sepsis syndrome. Sepsis syndrome occurs in 250,000 to 500,000 patients per year with approximately one-third of these developing ARDS and other organ failures. Extensive studies utilizing the sheep endotoxin model of ARDS as well as data from human pilot studies suggest that cyclooxygenase inhibitors (in particular, ibuprofen) would be useful in the prevention and reversal of many of the pathophysiological abnormalities related to sepsis. Animal studies where ibuprofen treatment was given prior to endotoxin have shown that ibuprofen can improve oxygenation, pulmonary and systematic hemodynamics, airway mechanics, and lung lymph flow. Importantly, animal studies have also shown that established airways mechanics abnormalities and pulmonary hypertension can be reversed by ibuprofen even when given 2.5 hours post endotoxin. Pilot studies of ibuprofen in patients with sepsis syndrome showed that temperature and heart rate were significantly reduced and suggested that airway mechanics and oxygenation were improved, shock was reversed and that these changes were temporally related to prostaglandin levels in urine and plasma.