Pressure (BP) is easy to measure / Flow (CO) is tricky to measure!

Cardiac output more meaningful reflection of tissue perfusion and may be better predictor of mortality and morbidity.

Pulmonary artery catheter (Gold standard)

  • Useful in undifferentiated shock
  • High complication rate
  • Difficult to use
  • 10-20% error

LESS-invasive devices

Calibrated e.g. PiCCO
Uncalibrated e.g. FloTrac

  • Use pulse contour analysis
  • Require arterial line
  • Area under curve proportional to stroke volume
  • 40% error

NON-invasive devises

Numerous technologies in clinical use e.g. Finepress

  • Low risk of complications
  • >40% error



BJA 2015 Continuous Non-invasive CO Monitoring

CO overview Life in the Fast Lane