EFFECT OF PROSTACYCLIN ON MICROVASCULAR PRESSURES IN A PATIENT WITH PULMONARY VENOOCCLUSIVE DISEASE

Continuous-infusion prostacyclin improves symptom scores and decreases mortality in patients with primary pulmonary hypertension, but use of prostacyclin in patients with pulmonary veno-occlusive disease may precipitate pulmonary edema. A patient with pulmonary veno-occlusive disease received a graduated intravenous infusion of prostacyclin and pulmonary capillary pressures were calculated during prostacyclin dose ranging. Calculated capillary pressure increased with low-dose prostacyclin (less than or equal to 6 ng/kg/min) but decreased,vith higher doses. These data suggest that the post-capillary pulmonary venules in our patient had reversible vasomotor tone, but required a higher dose of prostacyclin to vasodilate than did the precapillary arterioles.