The effects of indomethacin, a prostaglandin synthesis blocker, were tested in a porcine model of spetic acute respiratory failure (ARF) produced by continuous infusion of livePs. aeruginosa.Control groups received either indomethacin boluses (2 mg/kg) intravenously at 20 and 210 minutes or Ps.aeruginosainfusion (2 x 108CFU/20 kg/min). The treatment group received both continuousPs. aeruginosainfusion and indomethacin. Indomethacin alone transiently but significantly decreased cardiac indices, heart rate, and PaCO2. WithPs. aeruginosainfusion, significant pulmonary hypertension, hypoxemia, increased intrapulmonary shunt fraction, and systemic hypotension occurred. In this porcine model of septic ARF, indomethacin doubled the survival period and improved cardiopulmonary parameters.