Flow monitoring devices that may be used on patients during a sleep study include all of the following EXCEPT:

Flow monitoring devices that may be used on patients during a sleep study include all of the following EXCEPT:

• A. Nasal/oral thermistor or thermocouple
• B. A pressure transducer airflow
• C. A transcutaneous carbon dioxide (CO2) monitor
• D. An end-tidal CO2 monitor

Answer: (C)

Flow sensing in a sleep study relies on sensors that detect air movement or directly infer flow from how air moves. A nasal/oral thermistor or thermocouple watches the temperature changes of inspired and expired air to indicate airflow. A pressure transducer in the breathing circuit detects pressure variations caused by airflow, which is used to calculate flow. An end-tidal CO2 monitor measures CO2 in the exhaled gas (capnography) to assess ventilation; this reflects respiratory activity but is not a direct measure of airflow itself. A transcutaneous CO2 monitor, on the other hand, measures CO2 through the skin and does not provide airflow information. Therefore, the transcutaneous CO2 monitor is not a flow-monitoring device.

Flow sensing in a sleep study relies on sensors that detect air movement or directly infer flow from how air moves. A nasal/oral thermistor or thermocouple watches the temperature changes of inspired and expired air to indicate airflow. A pressure transducer in the breathing circuit detects pressure variations caused by airflow, which is used to calculate flow. An end-tidal CO2 monitor measures CO2 in the exhaled gas (capnography) to assess ventilation; this reflects respiratory activity but is not a direct measure of airflow itself. A transcutaneous CO2 monitor, on the other hand, measures CO2 through the skin and does not provide airflow information. Therefore, the transcutaneous CO2 monitor is not a flow-monitoring device.