Restoration of pulmonary perfusion by a serotonin antagonist

R 41 468, a selective serotonin receptor blocking agent, was found to improve pulmonary perfusion in patients with venous air embolism, in patients with adult respiratory distress syndrome (ARDS), and in certain cases of impairment of the pulmonary circulation during prolonged major surgery accompanied by blood transfusion. Continuous monitoring of end-tidal (CO2 (FETCO2) by means of infra-red capnography combined with blood gas estimations were the principle methods of assessment used.