To evaluate the effects of short-term, high-volume hemofiltration (STHVH) on hemodynamic and metabolic status and 28-day survival in patients with refractory septic shock. Prospective, interventional. Intensive care unit (ICU), tertiary institution. Twenty patients with intractable cardiocirculatory failure complicating septic shock, who had failed to respond to conventional therapy. STHVH, followed by conventional continuous venovenous hemofiltration. STHVH consisted of a 4-hr period during which 35 L of ultrafiltrate is removed and neutral fluid balance is maintained. Subsequent conventional continuous venovenous hemofiltration continued for at least 4 days. Cardiac index, systemic vascular resistance, pulmonary vascular resistance, oxygen delivery, mixed venous oxygen saturation, arterial pH, and lactate were measured serially. Fluid and inotropic support were managed by protocol. Therapeutic endpoints were as follows during STHVH: a) by 2 hrs, a > or =50% increase in cardiac index; b) by 2 hrs, a > or =25% increase in mixed venous saturation; c) by 4 hrs, an increase in arterial pH to >7.3; d) by 4 hrs, a > or =50% reduction in epinephrine dose. Patients who attained all four goals (11 of 20) were considered hemodynamic "responders"; patients who did not (9 of 20) were considered hemodynamic "nonresponders." There were no differences in baseline hemodynamic, metabolic, and Acute Physiology and Chronic Health Evaluation and Simplified Acute Physiology Scores between responders and nonresponders. Survival to 28 days was better among responders (9 of 11 patients) than among nonresponders (0 of 9). Factors associated with survival were hemodynamic-metabolic response status, time interval from ICU admission to initiation of STHVH, and body weight. These data suggest that STHVH may be of major therapeutic value in the treatment of intractable cardiocirculatory failure complicating septic shock. Early initiation of therapy and adequate dose may improve hemodynamic and metabolic responses and 28-day survival.