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 (?)
anything that changes the shape of the arterial waveform will make it less accurate:
- AF
- damped trace
normal parameters
| Parameter | What it means | Normal values | Abnormal values |
|---|---|---|---|
| Stroke volume | 60-100ml/beat | ||
| Cardiac index | CO/BSA (body surface area) | 2.5 - 4 | |
| Stroke volume variation | quantifying the 'swing' with respiration = fluid status | <10% | |
| Flow time | 300? |