Cardiopulmonary effects of ketanserin infusion in human pulmonary embolism.

The release of platelet-derived vasoactive substances, particularly serotonin (5-HT), have been implicated in the pulmonary vasoconstrictor response following acute pulmonary embolism. Therefore, we studied the effects of infusing ketanserin, a 5-HT blocking agent, upon pulmonary and systemic hemodynamics and gas exchange in 10 patients with severe acute pulmonary embolism. These patients evidenced 45 ± 17% mean angiographic pulmonary vascular obstruction. Ketanserin significantly decreased the mean pulmonary arterial pressure from 26 ± 6 to 23 ± 5 mm Hg (p < 0.001). The total pulmonary vascular resistance decreased from 9.1 ± 3.2 to 8.3 ± 2.5 mm Hg/L · min · m2 (p < 0.001). However, the mean cardiac index was unchanged. The systemic arterial and right atrial pressures were significantly decreased after ketanserin. The PaO2 increased in all patients from 60.5 ± 12.6 to 66.5 ± 13.6 mm Hg (p < 0.05), whereas the venous admixture was unchanged. This was attributed to an increased PvO2 (27 ± 7 to 30 ± 5 mmHg,...