Polysomnogram interpretation by dr md abdullah saleem

sleep study

1. Interpretation of Polysomnography Presented By Dr. MD ABDULLAH SALEEM MBBS, MD(Pulmonary Medicine)

2. Signs and Symptoms The signs and symptoms(EDS associated with fatigue or impaired concentration , unrefreshing sleep,choking or gasping during sleep,recurrent awakenings from sleep) helps in determining the patient’s overall need for the polysomnogram as well as their chief complaint.

3. Recording Protocol This is the devices and recording instrumentation used on the patient during there nocturnal polysomnogram.

4. Sleep Architecture The NREM/REM stage and cycle infrastructure of sleep understood from the vantage point of the quantitative relationship of these components to each other.

5. Time in bed Time in bed is the total number of minutes that a patient spends in bed. This amount varies for different age groups and can also vary on an individual patient basis. This is important because it gives a basic idea as to whether or not the patient is spending enough time attempting to sleep.

6. Total Sleep Time Total sleep time is the actual amount of sleep time in a sleep period ; equal to total sleep period less movement and awake time. Total sleep time is the total of all REMS and NREMS in a sleep period. This is important because it gives a basic idea as to whether or not the patient is achieving enough sleep for the time they are in bed.

7. Sleep Efficiency Sleep efficiency is the proportion of sleep in the period potentially filled by sleep, that is, the ratio of total sleep time to time in bed. Normal is >80%This is important because it displays the patients overall quality of sleep as it pertains to any sleep disorder they exhibit.

8. Sleep Latency Sleep latency is the period of time measured from “lights out”, or bedtime, to the commencement of sleep. This is important because it can show the level of sleepiness by how fast the patient gets to sleep or their sleep latency (<30 minutes) It can also help to determine insomnia in patients that displays signs of excessive daytime sleepiness but do not achieve sleep in a timely manner.

9. REM Latency Is the period of time measured from “lights out”, or bedtime, to the commencement of REM sleep (70-120 minutes)

10. Wake Percentage Wake percentage is the percentage of wake scored from lights out to the final wake-up. This is important because it will help determine how much any sleep disorder is affecting the patient’s sleep architecture.

11. Stage 1 Stage 1 is a stage of NREM sleep that ensues directly from the awake state. It’s criteria consists of a low-voltage EEG with slowing to theta frequencies, alpha activity less than 50%,EEG vertex spikes, and slow rolling eye movements. Stage 1 percentage is the total time spent in stage1 sleep from lights out to the final wake-up. Stage 1 generally constitutes about 4-5% of sleep.

12. Stage 2 Stage 2 is a stage of NREM sleep characterized by the advent of sleep spindles and K complexes against a relatively low-voltage, mixed-frequency EEG background, high-voltage delta waves may compromise up to 20% of stage 2 epochs. Stage 2 percentage is the total time spent in stage 2 from lights out to the final wake-up. Stage 2 generally constitutes 45-55% of sleep.

13. Stage 3 Stage 3 is a stage of NREM sleep defined by at least 20% of the epoch consisting of EEG waves less than 2 Hz and more than 75 Micro V , it constitutes deep NREM sleep. Stage 3 percentage is the total time spent in stage 3 from lights out to final wake-up. Stage 3 sleep is usually constitutes 12-18% of sleep.

14. REM Sleep REM sleep consists of low-voltage, mixed frequency EEG which may be accompanied by both saw-tooth waves and rapid eye movements. REM percentage is the total time spent in REM sleep from lights out to the final wake-up. REM sleep usually constitutes 20-25% of sleep in 4 to 6 episodes.

15. REM latency REM latency is the period of time from sleep onset to the first appearance of REM sleep. This is important in showing a short onset of REM sleep, which is a sign of Narcolepsy.

16. Respiratory Events Respiratory events is the breakdown of the respiratory changes recorded during the entire polysomnogram.

17. Obstructive Apneas Obstructive apneas are respiratory episodes where there is a complete cessation of airflow lasting greater than 10 seconds associated with thoracic and abdominal efforts

18. Hypopneas Hypopneas are a respiratory episode where there is partial obstruction of the airway lasting greater than 10 seconds (30% fall in nasal flow)and accompanied by a 4% desaturation

19. Central Apneas Central Apneas are respiratory episodes where there is no airflow and no effort to breathe lasting greater than 10 seconds. Atleast >5 events per hour

20. Mixed Apneas Mixed Apneas are respiratory episodes where there are features of both obstructive and central apneas in the same event.

21. Total events Total events is the total number of Obstructive apneas, Hypopneas, Central apneas, and mixed apneas from lights out to the final wake-up.

22. RERA characterized by marked decreased in airflow for at least 10 secs with increased respiratory effort, no significant desaturation and which leads to an arousal from sleep.

23. CENTRAL SLEEP APNOEA SYNDROME If > 50% of events are purely central = CSAS

24. Cheyne Stokes breathing

25. Cyclical crescendo and decrescendo breathing pattern for 3 consecutive cycles associated with A.5 or more Central sleep apnoea or hypopnoea per hour or B.Cyclical crescendo and decrescendo breathing pattern has duration of atleast 10 minutes

26. RDI RDI is an abbreviation for Respiratory Disturbance Index. This number is the average number of respiratory events per hour of sleep. APNOEA+HYPOPNOEA+CENTRAL APNOEA+ RERA Any RDI lower than 5/hr is considered to be within normal limits.

27. REM RDI REM RDI is the total number of respiratory episodes per hour of REM sleep.

28. Supine RDI Supine RDI is the number of respiratory episodes per hour of supine sleep. This is important because the patient may have only positional apnea and therefore can be treated with positional therapy.

29. Oxygen (SaO 2 ) Baseline = the baseline oxygen level for the entire polysomnogram. Low = the lowest oxygen level recorded during the polysomnogram.

30. UARS: > 5 RERA’s per hour of sleep

31. Arousals Abrupt change of EEG from a deeper stage of NREM sleep to a lighter stage, or from REM sleep toward wakefulness, with the possibility of awakening as the final outcome An arousal may be accompanied by increased chin (EMG) activity and heart rate, as well as by an increased number of body movement

32. Minimum duration is 3 secs Types: respiratory, PLMs, spontaneous Increased arousals are associated with increased daytime sleepiness and decreased performance, similar to that seen in sleep deprivation

33. EKG abnormalities during sleep Heart rate too fast (tachycardia) or too slow ( bradycardia ) Heart rhythm irregular Pauses

34. Miscellaneous The miscellaneous category is for other important information regarding the patient’s polysomnogram.

35. Blood pressure Blood pressures are taken both before and after the polysomnogram. The blood pressure before the study is to determine a baseline for this patient. The blood pressure after the polysomnogram is to help determine any hypertensive response to sleep apnea or any other sleep disorder that may be present during the polysomnogram.

36. Periodic Limb Movements No of PLMS = the total number of periodic limb movements during the polysomnogram . Limb movement should be of atleast 0.5 to 10 seconds and > 75 MicroVolts 4 successive limb movements separated by duration of least 5 to 90 seconds between each movement PLMS Index = the average number of PLMS per hour of sleep.

37. Arousals # of arousals = the total number of arousals recorded during the polysomnogram . Arousal index = the average number of arousals per hour of sleep. <20 years is 10-20/hour 50-60 years 20-22/hr

38. Technical impression The technical impression is the overall breakdown and comments for the entire polysomnogram.

39. Review of Sleep Study Times, formulas and calculations: Sleep statistics – Lights Out – Light On – Total Recording Time – Total Sleep Time – Sleep Latency – Sleep Efficiency – Rem Latency – WASO (wake after sleep onset) – Time and percentage in each sleep stage

40. Respiratory Events Number of obstructive apneas – Number of mixed apneas – Number of central apneas – Number of hypopneas – Respiratory effort related arousals (RERAs)

41. Oxygen saturation Baseline oxygen saturation (at the start of the study) Lowest oxygen saturation during sleep

42. Diagnosis The diagnosis portion is where the diagnosis for this polysomnogram are listed. The diagnosis of Obstructive sleep apnea is based upon the RDI. Mild RDI 5/hr. to 15/hr. Moderate RDI 15/hr. to 30/hr. Severe RDI >30/hr. -Split Night Study:in patients with moderate to high probabity of OSA at least 3 hours of Diagnostic portion followed by atleast 4 hours for titration

43. Recommendations This can include positional therapy, nasal CPAP, dental appliance, and surgery for treatment of OSAS. This can also include medications for treatment of Periodic Limb Movement Syndrome, as well as Insomnia or any other sleep disorder .

44. THANK YOU