Despite recent controversies regarding its safety and efficacy, pulmonary artery catheterization
(PAC) remains a widely used tool for the management of patients with cardiovascular instability. In addition to providing measurements of cardiac out-put (CO), several other potentially useful pieces of data can be obtained, including estimates of preload,afterload, and oxygen utilization. However, many practitioners feel that CO is the most useful parameter obtained with PAC.The desire to measure CO without the risks of PAC has driven the search for other, less invasive measurement methods, such as esophageal Doppler measurements, lithium dilution, and carbon dioxide based techniques.
Factors Influencing Cardiac Output