Which Sleep Test is Appropriate for my patient? Dr Malcolm Ogborne
Agenda Diagnostic Sleep studies Definitions of Diagnostic Polysomnograms (PSG) Advantages and disadvantages of various PSG Current recommendations Other sleep studies Multiple Sleep Latency Test Maintenance of Wakefulness Test Attended CPAP Titration Home Autoset-CPAP titration 2
Types of Diagnostic sleep studies Type of study Description Comments Level 1 Full in-lab Medicare 12203 (adult) Medicare 12210 (0-12yrs) Medicare 12213 (12-18yrs) Level 2 Full unattended Medicare 12250 (adult) Level 3 No EEG, unattended >=4 channels Airflow, oximetry, respiratory effort, body position Level 4 1-3 channels, unattended, No EEG For example, oximetry only
Type 1 Alice 6 Titanium Embla N7000 Compumedics E-series Compumedics Grael Grass Full Polysomnography
Type 2 Embletta Compumedics Somte Alice PDx Nox A1 Limited channels polysomnography
Type 4 Braebon MediByte WatchPAT ApneaLink Single / Dual channel devices WristOx
Consumer Products Zeo Personal Sleep Manager Fitbit Sleep Apps
Medicare requirements vs AASM scoring guidelines Medicare 12203 (in lab) Medicare 12250 (ambulatory) AASM scoring rules Minimum 8, usually >11 channels Minimum 7 channels 3(1) x EEG 1 x EEG 3 x EEG s 2(1) x EOG 1 x EOG* 2 x EOG s Chin EMG Chin EMG* Chin EMG ECG ECG ECG SpO2 SpO2 SpO2 (TcCO2, Video) Minimum 11 channels Thermister Airflow(Thermister/Pressure) Airflow Nasal Pressure Respiratory Movement Respiratory Movement Respiratory Movement Leg EMG Body Position Body Position* Leg EMG 8 hours No duration criteria No duration criteria *At least 2 of the 3 of these must be recorded 8
Advantages of Portable vs Attended PSG In a familiar environment Can do over weekends (when labs are closed) Fewer sensors - Easy to attach (for most people) - Patient comfort Possibility of multiple night recordings - Variability in the AHI and snoring Le Bon, J. Psychiatry Res 2000 35;165-192 Cathcart, Clin Otolaryngology 2010, 32; 228-229 9
Inability to fix loss of lead, poor signal Disadvantages Portable vs Attended PSG Failure rate 6-9%. Problem mitigated if set up at home with technitian, not often practical J Sleep Res 2011; 20(1):207-213 Sleep 2004; 27(3):536-540. Fewer leads therefore less information Central Sleep apnoea Respiratory effort related arousals REM- related hypoventilation Parasomnias, leg movement disorders Meta-analysis of Type 2 portable vs Type 1 attended studies showed underestimation by AHI of approximately 10% Anesthesiology 2009; 110: 928-39 10
Which is easier to interpret? 11
As of July 2015: NEW RULES AASM V2.2 New section in the AASM rules: Home Sleep Apnea Testing (HSAT) Berry R.B, et al., The AASM Manual for the Scoring of Sleep and Associated Events. Version 2.2, 2015, Westchester What is recorded: - Type of device, Type of airflow sensor, type of respiratory effort, Oxygen saturation, HR, body position, Sleep/wake or Monitoring time, Snoring What should be reported: - Recording time/ monitoring time / Total sleep time, - Number of Respiratory events (RE); Respiratory Event index (REI) based on monitoring time if no EEG (#RE x 60 / MT) or AHI (if EEG recorded); - Events in the supine/non-supine position; - Central apnoea Index (CAI), - Oxygen desaturation index (ODI), Min SpO2 - Occurrence of snoring 12
NEW RULES AASM V2.2 Definition of respiratory events on Home studies (ie without EEG) APNOEA: - At least 10 seconds of a reduction in airflow by >90% of baseline (in pressure transducer or thermister) - Classified as either obstructive / central / mixed depending of presence/ absence of respiratory effort. HYPOPNOEA: - If no EEG: Need >30% reduction in flow for >10sec & >=3% desaturation. (or, alternatively, >=4% desat) - If EEG: Need >30% reduction in flow for >10sec & >=3% desaturation or arousal (or alterntively >=4% desat) 13
Current ASA recommendations The investigation chosen is only one component of the diagnosis Clinical History Examination Diagnostic Sleep Study (PSG) not required for the routine assessment of Insomnia Restless Legs Syndrome/ Periodic Leg Movement disorder Uncomplicated Parasomnia Type 1 PSGs have the largest body of evidence regarding reliability and diagnostic accuracy (?gold standard) Type 2 PSGs have good diagnostic accuracy, both as a rule in and a rule out test. Are a reasonable alternative to Type 1 PSG Availability Patient factors Guidelines for the Diagnosis of Sleep Disorders in Adults, ASA July 2014 14
Current ASA Recommendations (cont.) Type 3 and Type 4 studies should only be arranged under the supervision of a Sleep Physician (direct or indirect) Not recommended for patient s with a low pre-test probability of OSA Type 1 ( in-lab ) PSG are the preferred investigation in cases of suspected Narcolepsy Primary (Idiopathic) Hypersomnia Central sleep apnoea REM- associated hypoventilation (Obesity hypoventilation syndrome, Severe COPD, Neuromuscular disease) Violent Parasomnia or parasomnia where the diagnosis is uncertain Sleep related seizure disorder (with expanded EEG) Guidelines for the Diagnosis of Sleep Disorders in Adults, ASA July 2014 15
?Central Sleep apnoea Congestive Cardiac Failure (?EF<40%) Recent AMI or unstable angina Chronic Narcotic use?rem-related hypoventilation (TcCO2 monitoring) Super -Morbid Obesity (BMI<40) Severe COPD (FEV1<50%) Resting hypoxia or hypercapnia Neuromuscular disease Kyphoscoliosis The young non-obese sleepy patient Where the result doesn t match the clinical situation Medicolegal issues Who might benefit from a Type 1 PSG? 16
Multiple Sleep Latency Test Other Sleep tests Formal measurement of sleepiness with defined normative values (?what is the gold standard) Used as an aid to diagnose narcolepsy and idiopathic hypersomnolence Sleepiness versus tiredness Maintenance of Wakefulness Test Daytime test of ability to maintain vigilence Useful for assessing response to treatment, occupational/ medicolegal puropses Attended CPAP titration study Ability to adjust mask and correct issues such as leak on the spot. Recognise supine and REM-sleep Recognise Central and complex sleep apnoea 17
Home Auto-CPAP titration v attended CPAP titration Difficult to make definitive statements about autosetting CPAP at home Home auto-cpap titration not indicated in COPD (FEV1 < 50% predicted) Regular use of supplemental oxygen Waking oxygen level less than 92% Awake hypercapnia or hypoventilation syndrome Heart failure Chronic narcotic use Neuromuscular / chest wall disease Alcohol abuse Significant other sleep disorders Guidelines for the Diagnosis of Sleep Disorders in Adults, ASA July 2014 Rosen, Sleep. 2012; 35: 757-67 18