1. Patients with end-stage renal disease and anephric patients underwent expansion and depletion of body fluids with salt and water. This resulted in four different sequential haemodynamic patterns: (i) no significant increase in blood pressure; (ii) increase in blood pressure associated with a rise in cardiac output and no effect on total peripheral resistance; (iii) increase in cardiac output followed by a rise in blood pressure and total peripheral resistance; (iv) increase in total peripheral resistance and blood pressure without significant changes in cardiac output.
2. It is concluded that an initial rise in cardiac output is not necessary to increase blood pressure in either anephric man or patients with end-stage renal disease.