PSG tracings for sleep disordered breathing


  • Polysomnogram (PSG): includes EEG, ECG, EMG, electooculogram (EOG)
    • can diagnose variety of disorders including central sleep apnea
    • split night: 1/2 diagnose, 1/2 treatment for OSA
      • First 2 hours AHI must be > 15 to continue

  • M1 and M2: EEG signals
  • PTAF (pressure transducer): nasal pressure flow signal. Measures pressure difference between inhale and exhale to determine airflow. Better for hypopneas
  • Therm or Tflow2: thermositor. Gives similar information as PTAF but uses temperature difference. Better for apnea.1
  • Chest/Abdomen: movement of muscle
  • snore: snoring2
  • This PSG shows example of RERA with airflow obstruction but no desat followed by microarousal

  • A: normal breathing
  • B: simple snoring
  • C: hypopnea: no nasal flow but has thermistor signal
  • D: obstructive apnea: both Tflow and nasal flow signal absent. There is muscle movement so obstructive
  • E: central apnea: lack of muscle movement shows central apnea

Example of apnea:

2

Footnotes

  1. http://www.cliniquesomnomed.com/blog/en/sleep-apnea-polysomnography/

  2. Murray and Nadel Ch 120 Obstructive Sleep Apnea 2