OSA vs Central sleep apnea
How to tell OSA and Central sleep apnea apart when a board question makes them look alike.
Step 2 CK pairs are in open beta while clinical review finishes. Spot an issue? Tell us.
Presence or absence of respiratory effort during apneic events is the primary discriminator.
Side by side
Obstructive sleep apnea shows continued respiratory effort during airflow cessation, often with loud snoring and obesity.
Central sleep apnea shows absent respiratory effort during apnea, often in heart failure, opioid use, or neurologic disease.
Recurrent upper airway collapse during sleep causes intermittent hypoxemia and arousals.
Reduced central respiratory drive causes transient cessation of both airflow and respiratory effort.
Polysomnography shows apnea-hypopnea index at or above 5 with obstructive events characterized by thoracoabdominal effort and airflow limitation.
Polysomnography shows central events with absent ventilatory effort; in Cheyne-Stokes respiration, periodic crescendo-decrescendo pattern is seen, often with reduced ejection fraction.
The trap
A common mistake is prescribing CPAP without identifying central events. The resolving clue is absent effort on sleep study, which should prompt evaluation of heart failure, opioid exposure, or neurologic drivers.
The repair move
Next best step: review polysomnography event type, then treat obstructive disease with CPAP and weight reduction strategies. For central sleep apnea, optimize the underlying disorder such as heart failure management and medication review, then consider PAP-based therapy tailored to central events.
Try a free question
CoreA sleep study shows frequent apneas with continued thoracic effort and oxygen desaturation in an obese patient who snores loudly. What is the next best step in management?
Show answer and explanation
Answer: A. Initiate CPAP therapy and weight-loss counseling. Obstructive event pattern is treated with CPAP and risk-factor modification.
Why the other choices are tempting
- B. Oxygen alone does not correct repetitive airway collapse.
- C. Infection treatment is unrelated to this sleep-disordered breathing pattern.
- D. Coronary angiography is not first-line sleep apnea management.
- E. Opioids can worsen sleep-disordered breathing.
Flashcards
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What effort pattern defines obstructive sleep apnea on polysomnography?
Airflow reduction with persistent thoracoabdominal respiratory effort.
What effort pattern defines central sleep apnea?
Absence of both airflow and respiratory effort during apneas.
Quick answers
What is the fastest way to tell OSA from Central sleep apnea?
Presence or absence of respiratory effort during apneic events is the primary discriminator.
What is the key clue for OSA?
Obstructive sleep apnea shows continued respiratory effort during airflow cessation, often with loud snoring and obesity.
What is the key clue for Central sleep apnea?
Central sleep apnea shows absent respiratory effort during apnea, often in heart failure, opioid use, or neurologic disease.
What is the common trap with OSA vs Central sleep apnea?
A common mistake is prescribing CPAP without identifying central events. The resolving clue is absent effort on sleep study, which should prompt evaluation of heart failure, opioid exposure, or neurologic drivers.