Abstract: Abstract Objective To investigate maintained haemodynamic change during hemodialysis and analyze effects of cardiac index (CI) on hemodynamic parameters and associated influencing factors in maintenance hemodialysis(MHD) patients. Methods Seventy-five patients bearing an arteriovenous fistula (AVF) entered the study. Cardiac output (CO), cardiac index (CI), central blood volume (CBV) and peripheral vascular resistance (PR) were determined by ultrasound dilution technique at the end of 1 hour, 2 hours and 3 hours of dialysis. AVF blood flow (Qa) was also measured with the same device before maintained haemodynamic parameters investigation. Results Systolic arterial pressure, SV, CO, CI and CBV were significantly declined and no significant change for diastolic arterial pressure and heart rates at the end of 2 hour and 3 hour hemodialysis, whereas PR was increased gradually during hemodialysis. Patients were divided into there groups with CI less than 2.5 L/min?m2, 2.5-4.2 L/ min?m2 and more than 4.2 L L/ min?m2 at the end of 1 hour dialysis. Statistically significant decreasing SV, CO and increasing PR were detected in patients with CI4.2 L/min?m2 group (P4.2 L/min?m2 group. Some factors were found to be associated to CI values. Qa and systolic arterial pressure had positive relationship with CI, while age and diabetes had negative relationship with CI. Conclusions Systolic arterial pressure, CO, CI and CBV decrease and PR increases during hemodialysis. Obvious change occurs when CI is less than 2.5 L/min?m2. CI is associated with Qa, systolic arterial pressure, age and diabetes.

Key words: Hemodialysis, Hemodynamics, Cardiac index