When airflow changes do not meet the criteria for obstructive apnea or hypopneas, respiratory effort event related arousals can be estimated by:

When airflow changes do not meet the criteria for obstructive apnea or hypopneas, respiratory effort event related arousals can be estimated by:

• A. Sawtooth patterns in the unfiltered airflow or mask pressure tracing
• B. Flattening of the inspiratory airflow profile associated with an arousal
• C. Detection of vibration by using piezoelectric transducers
• D. Measuring the pressure difference between the mask and the machine outlet

Answer: (B)

Focus on the evolving inspiratory effort that doesn’t reach apnea or hypopnea thresholds. A respiratory effort related arousal is identified by a sequence of breaths where the inspiratory flow becomes progressively flattened due to rising upper airway resistance, lasting at least about 10 seconds, and culminating in an arousal. That flattening of the inspiratory airflow is the clearest indicator of a RERA, which is why this option is the best choice. Other signals don’t specifically reflect the escalating inspiratory effort that defines a RERA: a sawtooth pattern in airflow or mask pressure traces can signal other breathing patterns or artifacts, and relying on vibration from a piezoelectric sensor or simply the pressure difference between the mask and machine outlet doesn’t reliably capture the hallmark flattening of inspiratory flow that marks a RERA.

Focus on the evolving inspiratory effort that doesn’t reach apnea or hypopnea thresholds. A respiratory effort related arousal is identified by a sequence of breaths where the inspiratory flow becomes progressively flattened due to rising upper airway resistance, lasting at least about 10 seconds, and culminating in an arousal. That flattening of the inspiratory airflow is the clearest indicator of a RERA, which is why this option is the best choice.

Other signals don’t specifically reflect the escalating inspiratory effort that defines a RERA: a sawtooth pattern in airflow or mask pressure traces can signal other breathing patterns or artifacts, and relying on vibration from a piezoelectric sensor or simply the pressure difference between the mask and machine outlet doesn’t reliably capture the hallmark flattening of inspiratory flow that marks a RERA.