RPSGT Best Practices & Methodologies 3 — Questions and Answers
Question 1: According to the AASM recommended (1B) hypopnea scoring rule, what percentage reduction in airflow signal amplitude is required?
- 10%
- 20%
- 30% (Correct answer)
- 50%
Correct answer: 30%
The AASM recommended rule scores a hypopnea when the airflow signal drops ≥30% from baseline, associated with ≥3% oxygen desaturation or an arousal.
Question 2: A central apnea is characterized by cessation of airflow for ≥10 seconds with what respiratory pattern?
- Increasing respiratory effort throughout the event
- Absent respiratory effort throughout the event (Correct answer)
- Paradoxical thoracoabdominal movement
- Obstructive snoring preceding the event
Correct answer: Absent respiratory effort throughout the event
Central apneas show absent respiratory effort (both thoracic and abdominal excursion cease) throughout the event, distinguishing them from obstructive apneas.
Question 3: During CPAP titration, a patient continues to have obstructive apneas at 8 cmH₂O. What is the typical next pressure adjustment step?
- Increase pressure by 0.5 cmH₂O
- Increase pressure by 1 cmH₂O (Correct answer)
- Increase pressure by 2 cmH₂O
- Switch to BiPAP therapy
Correct answer: Increase pressure by 1 cmH₂O
CPAP titration protocols typically increase pressure in 1 cmH₂O increments when obstructive apneas persist, allowing adequate time to assess response.
Question 4: What criteria must be met on a diagnostic split-night study before transitioning to PAP titration according to AASM protocols?
- AHI ≥5 after at least 90 minutes of diagnostic recording
- AHI ≥10 after at least 120 minutes of diagnostic recording
- AHI ≥15 after at least 120 minutes with ≥90 minutes of PAP titration remaining (Correct answer)
- AHI ≥40 during the first 2 hours of the study
Correct answer: AHI ≥15 after at least 120 minutes with ≥90 minutes of PAP titration remaining
AASM criteria for split-night studies require AHI ≥40 (or 20–40 with extenuating events) after ≥2 hours diagnostic, ensuring ≥3 hours remain for adequate PAP titration.
Question 5: A respiratory effort-related arousal (RERA) is characterized by which of the following?
- A sequence of breaths lasting ≥10 seconds with flattened inspiratory airflow leading to arousal (Correct answer)
- Cessation of airflow for ≥10 seconds without respiratory effort
- A ≥3% oxygen desaturation following an apnea
- Paradoxical breathing during NREM sleep
Correct answer: A sequence of breaths lasting ≥10 seconds with flattened inspiratory airflow leading to arousal
A RERA is a sequence of breaths ≥10 seconds showing flattened inspiratory airflow or increasing respiratory effort culminating in an arousal, not meeting apnea or hypopnea criteria.
Question 6: During CPAP titration, persistent flow limitation without discrete apneas or hypopneas is best addressed by:
- Decreasing pressure by 1 cmH₂O
- Increasing pressure in 1 cmH₂O increments (Correct answer)
- Switching to a chinstrap
- Adding supplemental oxygen at 2 L/min
Correct answer: Increasing pressure in 1 cmH₂O increments
Flow limitation (flattened inspiratory flow curve) indicates partial upper airway obstruction; increasing CPAP pressure in 1 cmH₂O steps reduces airway resistance.
Question 7: What distinguishes a mixed apnea from other apnea types?
- It occurs only during REM sleep
- It begins with absent respiratory effort and ends with resumed but obstructed effort (Correct answer)
- It has a duration of less than 10 seconds
- It is associated with central nervous system pathology exclusively
Correct answer: It begins with absent respiratory effort and ends with resumed but obstructed effort
A mixed apnea begins with the absent effort of a central apnea and transitions to obstructive respiratory effort before airflow resumes.
RPSGT Best Practices & Methodologies 3
According to the AASM recommended (1B) hypopnea scoring rule, what percentage reduction in airflow signal amplitude is required?