Brazilian consensus of monitoring and hemodynamic support - part III: alternative methods for cardiac output monitoring and volemia estimation

Cardiac output and preload as absolute data do not offer helpful information about the hemodynamic of critically ill patients. However, monitoring the response of these variables to volume challenge or inotropic drugs is a very useful tool in the critical care setting, particularly for patients with signs of tissue hypoperfusion. Although PAC remains the " gold standard" to measure cardiac output and preload, new and alternative technologies were developed to evaluate these hemodynamic variables. Modified Delphi methodology was used to create and quantify the consensus between the participants. AMIB indicated a coordinator who invited more six experts in the area of monitoring and hemodynamic support to constitute the Consensus Advisory Board. Twenty three physician and two nurses selected from different regions of the country completed the expert panel, which reviewed the pertinent bibliography listed at the MEDLINE in the period from 1996 to 2004. Recommendations regarding the use of arterial pulse pressure variation during mechanical ventilation, continuous arterial pulse contour and lithium dilution cardiac output measurements, esophageal Doppler waveform, thoracic electrical bioimpedance, echocardiography and partial CO2 rebreathing for monitoring cardiac output and preload were created. The new and less invasive techniques for the measurement of cardiac output, preload or fluid responsiveness are accurate and may be an alternative to PAC in critically ill patients.