Metabolic Cluster Analysis in Septic Shock Patients

Inclusion Criteria: \- Septic shock patients within the first 24 hours of ICU admission, and selected by the attending physician for performing a fluid challenge (FC) due to suspected tissue hypoperfusion (elevated lactate and/or ScvO2 \< 70%). Exclusion Criteria: * Age under 18 years old * Uncontrolled hemodynamic instability, defined as the need for significant changes in vasopressor support (\> 10% from baseline dose) within the 15-minute period prior to, and/or during the administration of fluids. * Patients receiving continuous renal replacement therapies, since the CO values obtained from the thermodilution techniques might be potentially affected.