Abstract
As a centrifugal pump was widely used for eltracorporeal circulation in recent years, the clarification of the influences of nonpulsatile blood flow on physiological function has become more important, especially in pulmonary function. To analyze the influences, nonpulsatile pulmonary blood flow by a centrifugal pump was established in chronic animal models. A pulsatile RVAS was implanted to draw the blood from both the right atrium and ventricle and to send to the pulmonary artery in 4 goats. Two weeks after implanted, the pulsatile pump was quickly replaced by a centrifugal pump without anesthesia and a 100% nonpulsatile pulmonary blood flow was obtained. Cardiac output was kept at 80-120 ml/kg/min during the experiments and no changes were observed in hemodynamic parameters after the immediate depulsation of the pulmonary flow. Blood gas data and serum levels of angiotensin converting enzyme were maintained within normal range. There was no significant change in the ventral to dorsal blood perfusion ratio of the lower lobe of right lung which was calculated by the colored microsphere method, between pulsatile and nonpulsatile pulmonary flow. These results suggested that pulmonary functions including gas exchange and metabolism of vasoactive agent and lung tissue perfusion were not affected by nonpulsatile pulmonary circulation.
