What is the primary purpose of a Swan-Ganz catheter?

• A. Measure and monitor cardiac pressures
• B. Obtain mixed venous O2 samples
• C. Monitor core body temperature
• D. Measure arterial blood gases

Answer: (A)

The main idea being tested is how invasive hemodynamic monitoring with a pulmonary artery (Swan-Ganz) catheter provides direct measurements of the heart’s pressures. This catheter is threaded from a central vein into the right atrium, right ventricle, and then into a branch of the pulmonary artery. By doing so, it allows continuous or repeated measurement of right atrial pressure, right ventricle pressure, pulmonary artery pressure, and the wedge (pulmonary capillary wedge) pressure, which estimates left atrial pressure and left-sided filling. These values are essential for assessing preload, right- and left-sided pressures, and overall cardiac function, guiding fluid management, inotropy, and other therapies in critically ill patients. While it can also sample mixed venous blood and help calculate cardiac output via thermodilution, its primary purpose is to measure and monitor cardiac pressures. It isn’t used primarily to monitor core body temperature or to obtain arterial blood gases, which require other methods.