Hemodynamic function and volume of ultrafiltration (UF) during hemodialysis were studied in 8 patients with anuric acute renal failure (ARF) and severe sepsis. Patients were alternatively dialyzed with a saline priming (every 2 days) and with a 17.5% albumin priming. Hypovolemia, as indirectly reflected by reduced left ventricular filling pressure, decreased cardiac output (CO), and decline in mean systemic arterial pressure (MAP), was observed during the hemodialysis procedure using saline as the first prime. Hemodialysis was tolerated better after concentrated albumin priming; left ventricular filling pressure increased during the 1st h of dialysis, whereas CO and MAP remained close to that of control values. Furthermore, UF could be increased progressively without major hemodynamic consequences in the patients who received a concentrated albumin priming; moreover, larger volumes of fluid were removed.