What does the Thermistor Lumen Port connect to?

• A. Cable that displays temp and/or thermodilution curve on monitor
• B. Connects to saline injectate line
• C. Used for balloon inflation
• D. Provides arterial line pressure

Answer: (A)

The thermistor lumen port is the connection for the temperature sensor at the catheter tip. It links to the monitor with a temperature/thermodilution cable so the monitor can display the blood temperature and the thermodilution curve, which are used to calculate cardiac output. The other ports have different roles: the saline injectate line has its own port for injecting the cold bolus; the balloon inflation lumen inflates the balloon; and arterial pressure comes from the catheter’s pressure-transducer lumen. So this port’s purpose is to transmit temperature data to the monitor, enabling the temperature readout and thermodilution curve.