Hemodynamic Studies in Chronic Uremia

Hemodynamic functions and blood volume were observed in patients with chronic uremia. Thirty-one patients had clinical features of circulatory congestion and 37 did not. The degree of anemia and acidosis was comparable in both groups. However, creatinine clearance was significantly lower in patients with circulatory congestion. Both groups of patients had greater blood pressure, heart rate, plasma volume, and total peripheral resistance than normal. Resting cardiac output was abnormally decreased in 19% of the patients with circulatory congestion and in 14% of patients without features of circulatory congestion. There was no correlation between blood volume and blood pressure. Intravenous digitalization of seven of the patients with circulatory congestion produced clinical and hemodynamic improvement in only two. Hemodialysis effected an increase in cardiac output and a decrease in total peripheral resistance in six patients with congestion. In seven patients without circulatory congestion after dialysis there was a fall in plasma and blood volume, associated with a slight decrease in cardiac output. It is suggested that congestion of the circulation in chronic uremia results from a variety of hemodynamic, myocardial, and metabolic alterations, rather than from any single abnormality.