RCIS Practice Test 2026 – All-in-One Exam Prep

The blue proximal port on the Swan catheter is primarily used to inject saline for a cardiac output measurement. This port allows healthcare providers to deliver a precise amount of saline into the bloodstream, which is crucial for performing thermodilution to calculate cardiac output. During this process, the temperature change of the blood is measured as the saline passes through the heart, providing valuable information about the heart's function and efficiency.

Other functions associated with Swan catheters, such as measuring cardiac output or pulmonary capillary wedge pressure, are typically performed through different ports or mechanisms. The proximal port's specific design and purpose focus on facilitating the injection of saline, showing its integral role in accurate cardiac assessments. Additionally, while there are medication delivery capabilities within the system, the blue proximal port is not designated for this purpose, further supporting its function as primarily for saline injection in cardiac output calculations.