To examine the hemodynamic and metabolic characteristics and ICU outcome of septic shock in patients with cirrhosis. Prospective, comparative study. Measurements performed in the first 24 hrs of septic shock. A general hospital ICU. Twelve patients with cirrhosis and 23 patients without cirrhosis admitted for septic shock. Arterial pressure was measured using an arterial catheter. Pulmonary arterial and right atrial pressures were measured by using a pulmonary artery catheter. Cardiac output was determined by using the thermodilution method. Pulmonary arterial L-lactate plasma concentrations were measured using an automated spectrophotometer, and blood temperature was measured using a cardiac output computer. Arterial and mixed venous PO2, PCO2, and pH values were measured by using specific electrodes. Oxygen saturations and hemoglobin concentrations were measured using a hemoximeter. Patients with cirrhosis had decompensated liver disease (grade C of the Child-Pugh classification). The number of Gram-negative infections and therapeutic interventions were similar in both groups. Patients with cirrhosis had higher cardiac indices (5.14 +/- 0.52 [SE] vs. 3.91 +/- 0.30 L/min/m2, p less than .05), plasma lactate concentrations (9.0 +/- 2.0 vs. 5.2 +/- 0.7 mmol/L, p less than .05) and ICU mortality rates (100% vs. 43%, p less than .05), and lower blood temperatures (35.5 +/- 0.6 vs. 37.6 +/- 0.2 degrees C, p less than .05) than patients without cirrhosis. Systemic vascular resistance, arterial pressure, pulmonary arterial pressure, oxygen delivery and consumption, and arterial and mixed venous acid-base status were not significantly different between the two groups. In patients with cirrhosis, septic shock was characterized by severe liver dysfunction, low blood temperature, marked increases in cardiac index and lactic acidemia, and a 100% ICU mortality rate. These findings should be taken into account if patients with cirrhosis are to be included in controlled studies on septic shock.