RPSGT Exam Oxygen Therapy & Alternative Sleep Treatments

Question 1

During a PAP titration study, at what SpO2 level is supplemental oxygen typically added when oxygen saturation remains persistently low despite adequate PAP therapy?

Accepted Answer

SpO2 < 88%

Answer

AASM titration guidelines recommend considering supplemental oxygen addition when SpO2 remains below 88% for more than 5 minutes despite optimized PAP pressure. This threshold aligns with CMS criteria for long-term oxygen therapy and reflects the point at which the hemoglobin-oxygen dissociation curve enters its steep portion.

Question 2

Adaptive servo-ventilation (ASV) is contraindicated in which specific patient population, based on the findings of the SERVE-HF clinical trial?

Accepted Answer

Patients with heart failure with reduced ejection fraction (EF < 45%) and predominant central sleep apnea

Answer

The SERVE-HF trial (2015) demonstrated significantly increased cardiovascular mortality with ASV in patients with heart failure with reduced ejection fraction (LVEF < 45%) who had predominant central sleep apnea. ASV is therefore contraindicated in this population. This is a critical safety contraindication that all sleep technologists must know.

Question 3

Mandibular advancement devices (MADs) treat obstructive sleep apnea through which primary mechanism?

Accepted Answer

Repositioning the mandible and tongue anteriorly to increase retropalatal and retroglossal airway dimensions

Answer

MADs hold the lower jaw (mandible) in a forward position during sleep, which secondarily advances the tongue base and tenses the pharyngeal walls, increasing the cross-sectional area of the upper airway. They are a guideline-recommended alternative to CPAP, particularly for patients with mild-to-moderate OSA or those intolerant of PAP.

Question 4

Positional obstructive sleep apnea is defined by AASM as an AHI that is at least how much higher in the supine position compared to non-supine sleep?

Accepted Answer

At least twice as high (≥2×) in the supine versus non-supine position

Answer

Positional OSA is defined as a supine AHI that is at least twice the non-supine AHI, with the non-supine AHI being ≤ 5 events/hour (some definitions require non-supine AHI < 5 to be truly positional). Patients with positional OSA may respond to positional therapy (devices that prevent supine sleep) as a primary or adjunct treatment.

Question 5

A patient with severe COPD and no co-existing OSA shows SpO2 < 88% for more than 30% of total sleep time on nocturnal oximetry. Which treatment is most appropriate?

Accepted Answer

Nocturnal supplemental oxygen therapy

Answer

In COPD patients without OSA, nocturnal desaturation results from hypoventilation and ventilation-perfusion mismatch rather than airway obstruction. CPAP would not correct this. Supplemental oxygen is the appropriate intervention, and criteria for nocturnal oxygen in COPD include SpO2 < 88% for ≥ 5 minutes during sleep, which this patient clearly meets.

RPSGT Exam Practice Test

RPSGT Exam Practice Test

RPSGT Exam Oxygen Therapy & Alternative Sleep Treatments