According to recommended guidelines, what device should be used to monitor airflow and detect apnea during a diagnostic study?

The oronasal thermal sensor is the appropriate device for monitoring airflow and detecting apnea during a diagnostic study. This device works by measuring the temperature of the air entering and leaving the airway. When airflow ceases, such as during an apnea event, a change in temperature will indicate that no air is moving in or out, allowing for accurate detection of apneic events.

This method is particularly effective because it can quickly respond to even brief episodes of apnea and provides clear data on airflow cessation, which is crucial for evaluating sleep apnea conditions. The use of an oronasal thermal sensor is consistent with polysomnographic monitoring standards, as it helps to establish a complete diagnostic picture of the patient's breathing patterns throughout the study.

While other options may have specific uses in a sleep study, they do not directly provide the same level of accuracy or reliability in measuring airflow for apnea detection. An end-tidal CO2 monitor, for instance, measures the concentration of carbon dioxide in exhaled air and is not primarily designed for airway monitoring. A nasal cannula is used for airflow assessment as well, but it lacks the sensitivity of a thermal sensor for detecting very brief apneas. A pressure transducer can measure pressure changes in the respiratory tract but does not directly