Obstructive sleep apnea vs Central sleep apnea
How to tell Obstructive sleep apnea and Central sleep apnea apart when a board question makes them look alike.
Obstructive sleep apnea: apneas with continued respiratory effort; central sleep apnea: apneas with absent respiratory effort.
Side by side
Repeated sleep apneas with continued respiratory effort against a collapsed upper airway, often with loud snoring, obesity, witnessed apneas, and daytime sleepiness.
Repeated apneas from absent respiratory drive, with absent airflow and absent respiratory effort, often associated with heart failure, stroke, opioids, high altitude, or Cheyne-Stokes breathing.
Upper airway collapses during sleep while the brainstem continues to send breathing signals.
Ventilatory control instability or impaired central drive fails to generate respiratory effort during apnea events.
Polysomnography showing airflow cessation with ongoing thoracoabdominal effort points obstructive sleep apnea.
Polysomnography showing airflow cessation with no thoracoabdominal effort points central sleep apnea.
The trap
Snoring and sleepiness are not enough; the sleep-study separator is respiratory effort.
Watch it explained
The repair move
For sleep apnea, classify the event by effort: blocked airway with effort, or absent central drive without effort.
Try a free question
CoreA patient with obesity and loud snoring has repeated sleep apneas with continued chest and abdominal effort against an obstructed upper airway. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Obstructive sleep apnea. Obstructive sleep apnea has absent airflow despite continued respiratory effort because the upper airway collapses.
Why the other choices are tempting
- B. Central sleep apnea has absent airflow because respiratory effort stops.
- C. Narcolepsy causes daytime sleep attacks/cataplexy rather than obstructive apneas.
- D. COPD exacerbation is awake obstructive respiratory worsening.
- E. PE causes acute vascular obstruction, not recurrent sleep apneas.
Flashcards
Tap a card to flip it.
What polysomnography variable separates OSA from CSA?
Respiratory effort: present effort means obstruction; absent effort means central drive failure.
What symptom cluster supports obstructive sleep apnea?
Loud snoring, witnessed apneas, obesity, and daytime sleepiness fit upper-airway collapse.
Quick answers
What is the fastest way to tell Obstructive sleep apnea from Central sleep apnea?
Obstructive sleep apnea: apneas with continued respiratory effort; central sleep apnea: apneas with absent respiratory effort.
What is the key clue for Obstructive sleep apnea?
Repeated sleep apneas with continued respiratory effort against a collapsed upper airway, often with loud snoring, obesity, witnessed apneas, and daytime sleepiness.
What is the key clue for Central sleep apnea?
Repeated apneas from absent respiratory drive, with absent airflow and absent respiratory effort, often associated with heart failure, stroke, opioids, high altitude, or Cheyne-Stokes breathing.
What is the common trap with Obstructive sleep apnea vs Central sleep apnea?
Snoring and sleepiness are not enough; the sleep-study separator is respiratory effort.