Estimated Fick vs. Thermodilution: Which One Do You Trust? 🤔 When measuring cardiac output (CO), we often rely on either the Estimated Fick method (which uses assumed VO2 and calculated variables) or Thermodilution (which directly measures CO using injectate and temperature changes). Key differences: -Estimated Fick: Can be less accurate in critically ill patients due to reliance on assumed values. -Thermodilution: More reliable but affected by arrhythmias, tricuspid regurg, and injectate techn