Newer methods of cardiac output monitoring

Table 1 Advantages and disadvantages of methods of cardiac output monitoring

No	Device	Type	Advantages	Disadvantages
1	PAC	Invasive	Gold standard	Catheter related complications
2	Continous CO by PAC	Invasive	Continous CO measurement	Catheter related complications Cost
3	LiDCO	Minimally invasive	Only one arterial line Continuous CO measurements Measure SV and SVV	Requires good arterial waveform Requires Calibration Contraindicated in Lithium therapy
4	PiCCO	Minimally invasive	Continuous CO measurement Effective during hemodynamic instability	Requires good arterial waveform Requires calibration
5	FloTrac	Minimally invasive	Continuous CO measurement No calibration	Requires good arterial waveform
6	PRAM	Minimally invasive	No calibration	Still not validated
7	ED	Minimally invasive	Simple to use Reliable Useful in GDT	Measure flow only in descending thoracic aorta Assumptions about aortic size may not be accurate
8	TEE	Minimally invasive	Evaluate cardiac anatomy preload and ventricular function	Cost Skilled personnel
9	Partial non-rebreathing systems	Non invasive	Ease of use Continuous CO measurement	Affected by changes in dead space or V/Q matching
10	Thoracic bioimpedance	Non invasive	Continuous CO measurement	Affected by electrical noise, movement, temperature and humidity Requires hemodynamic stability Not useful in dysrhythmias
11	ECOM	Non invasive	Continuous CO measurement	Coronary blood flow not recorded Electrocautery produces interference

CO: Cardiac output; LiDCO: Lithium dilution CO; PiCCO and FloTrac: Pulse contour analysis; PRAM: Pressure recording analytic method; ED: Esophgeal Doppler; TEE: Transesophgeal echocardiography; ECOM: Endotracheal cardiac output monitor; PAC: Pulmonary artery catheter; SV: Stroke volume; SVV: SV variation; GDT: Goal directed therapy.