Cardiac output monitoring
modalities
oesophageal doppler
measures flow time for a red cell across a pre-determined distance
LiDCO, etc.
pulse contour analysis - calculates area under the curve then uses it to predict CO (?)
so naturally anything that changes the shape of the arterial waveform will make it less accurate: AF, damped line, swing in arterial line
normal parameters
- Stroke volume = 60-100ml/beat
- Cardiac index = CO/BSA (body surface area) = 2.5 - 4
- Stroke volume variation = quantifying the 'swing'
- Flow time, or FTc (corrected for HR) - 300
sources/links
source: Sachin?!