Renal anemia and its hemodynamic response--findings invasively determined over a period of 20 years

Abstract

Among the uremia-associated risk factor, which can be influenced today, anemia is considered most relevant because it induces functional and organic alterations of cardiac/circulatory function. Research concerning influence of the anemia on the pulmonary hemodynamic and cardiac output (CO) in pre-uremic patients are not available up to now. Cardiac and circulatory function of 52 patients were examined before initiation of dialysis therapy using a Swan-Ganz thermodilution catheter. After excluding patients with impaired cardiac pump function the results of 31 of the 52 patients could be analyzed. They were divided into two groups (Hb > resp. < 7.0 g/dl): in patients with severe anemia (Hb 5.7 +/- 0.6 g/dl; n = 7) cardiac index was higher (4.8 +/- 0.4 1/min/m2 < 0.01) compared with the other group (Hb 9.8 +/- 1.7 g/dl; n = 24; CI 3.9 +/- 1.1 1min/m2). The increase of cardiac index caused by anemia correlated with increased stroke volume and heart rate and lowered pulmonary and peripheral resistance. Patients with severe anemia showed a tendency to an impaired cardiac index below Hb < 5-6 g/dl. The hypercirculation did not cause an increase of the pulmonary arterial and pulmonary wedge pressure. Particularly in the case of already existing myocardial damage and coronary arteriosclerosis the presence of anemia and renal insufficiency leads to a highly increased morbidity and mortality. This "cardio-renal anemia-syndrom" is responsible for frequent refractory heart failure. Disturbances of cardiac/circulatory function are observed in pre-uremic patients three times more frequently than in patients after myocardial infarction. Early correction of anemia seems to reduce the risk of fatal cardial complications and to improve the quality of life and the prognosis of pre-uremic patients.