Background
Measurement of cardiac output
How does TPTD measure cardiac output?
Is TPTD accurate for measuring cardiac output?
What are the limitations of TPTD for measuring cardiac output?
Variable | Main advantages | Main drawbacks |
---|---|---|
Cardiac output measured by TPTD | As reliable as pulmonary thermodilution | Does not provide a continuous measurement |
Cardiac output measured by pulse contour analysis | Continuous measurement Precise measurement Assesses short-term and small changes | Requires regular recalibration |
Global end-diastolic volume | Better reflects cardiac preload than pressure markers of preload | Does not distinguish between the right and left ventricles Less directly reflects the risk of pulmonary oedema than PAOP |
Stroke volume variation | Continuous automated assessment of fluid responsiveness | Cannot be used in case of spontaneous breathing, cardiac arrhythmias and ARDS |
Cardiac function index, global ejection fraction | Can be used as an alarm for decreased LV systolic function | Overestimate LV systolic function in case of right ventricular dilation Indirect markers of cardiac systolic function Do not precisely assess cardiac structure and function |
Extravascular lung water | Directly estimates the volume of lung oedema | Unreliable in case of pulmonary embolism, lung resection, large pleural effusions |
Pulmonary vascular permeability index | Directly estimates lung permeability Distinguishes hydrostatic from permeability pulmonary oedema | Same as for extravascular lung water |