Screening and Diagnosis of Obstructive Sleep Apnea April 15, 2015 Tina Waters, MD

Objectives 1. Identify clinical features that should prompt a suspicion for obstructive sleep apnea 2. Understand the importance of incorporating screening tools with testing to diagnose obstructive sleep apnea 3. To recognize the indications, technology & methodology of in-lab polysomnography & home sleep testing for the evaluation of obstructive sleep apnea

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Common Symptoms Daytime

Nighttime • • • • • • • • • •

Snoring Gasping/choking Witnessed apneas Insomnia Restless sleep Nocturia Night sweats Dry mouth Reflux Bed partner disruption

• • • • • • •

Excessive daytime sleepiness Fatigue Morning headaches Memory and concentration problems Irritability Decreased libido Drowsy driving

Risk Factors Modifiable • Obesity - BMI ≥ 30 kg/m2 • Medications - opiates - benzodiazepines - alcohol

• Smoking • Nasal congestion • Endocrine Disorders

Non-Modifiable • Gender • Genetic predisposition • Race/Ethnicity • Age • Menopause • Craniofacial anatomy Young et al. JAMA 2004;291:2013-2016

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AASM Adult OSA Task Force Physical examination findings that may suggest presence of OSA Neck circumference > 17” for Lateral peritonsillar narrowing men Neck circumference > 16” for women

Macroglossia

BMI ≥ 30 kg/m2

Tonsillar hypertrophy

Friedman Class 3 or greater

Elongated/enlarged uvula

Nasal abnormalities (turbinate hypertrophy, septal deviation)

High arched/narrow hard palate

Retrognathia

Overjet Epstein et al. JCSM 2009;5:263-276

Neck circumference • OSA patients have significantly increased neck circumference compared to nonapneic snorers • Measure at superior border of cricothyroid membrane • > 40 cm (15.7”) has been shown to be predictive of OSA with 61% sensitivity and 93% specificity, regardless of sex - > 17” in men and > 16” in women Katz et al. Am Rev Respir Dis 1990;141:1228-1231 Kushida et al. Ann Intern Med 1997;127:581-587 Friedman et al. Laryngoscope 1999;109:1901-7

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AASM Adult OSA Task Force Patients at High Risk who should be evaluated STANDARD

GUIDELINE

OPTION

CONSENSUS

Obese

CAD

Stroke

Tx refractory HTN

Systolic HF

Tachyarrhythmias

TIA

Type II DM

Diastolic HF

Bradyarrhythmias

Pulm HTN

CHF w/ sleep apnea symptoms despite optimal meds

Atrial fibrillation

HTN w/ sleep apnea symptoms

Pre-op upper airway surgery for snoring or OSA

High risk driving populations Pre-op bariatric surgery

Epstein et al. JCSM 2009;5(3)263-276; Chin Chest 1992;102;1663-1667

Screening questionnaires • • • • •

Epworth Sleepiness Scale Berlin Questionnaire Multivariate Apnea Prediction Index Pittsburgh Sleep Quality Index STOP-BANG Questionnaire

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Epworth Sleepiness Scale How likely are you to doze off or fall asleep in the following situations, in contrast to feeling just tired? - Usual way of life in recent times - Even if not applicable, try to work out how they would have affected you. Scale: 0 = would never doze or sleep 1 = slight chance of dozing or sleeping 2 = moderate chance of dozing or sleeping 3 = high chance of dozing or sleeping Johns Sleep 1991;14(6):540-545 Johns Sleep 1992;15:376-81

Epworth Sleepiness Scale - ESS 1. 2. 3. 4. 5. 6. 7. 8.

0 = never Sitting and reading 1 = slight chance 2 = moderate chance Watching TV 3 = high chance Sitting inactive in a public place Being a passenger in a motor vehicle for an hour or more Lying down in the afternoon Sitting and talking to someone Sitting quietly after lunch (no alcohol) Stopped for a few minutes in traffic while driving ≥ 10 is abnormal

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Excessive Daytime Sleepiness and OSA • Sleep Heart Health Study - Significant, progressive increase in ESS score with increasing AHI • ESS = 7.2 (AHI < 5) • ESS = 9.3 (AHI ≥ 30)

- % subjects with EDS increased from 21% in those with AHI < 5 to 35% in those with AHI > 30 • Wisconsin Sleep Cohort Study - Only 37% of severe OSA patients reported EDS - Mortality associated with long-term OSA was independent of subj sleepiness Gottlieb, et al. Am J Respir Crit Care Med 1999;159:502-507 Young T, et al. Sleep 2008;31:1071-1078

Case: 42 yo male truck driver with excessive daytime sleepiness (ESS = 12) recently involved in a MVA, sustaining a knee injury which requires surgical intervention. His wife has banished him from the bedroom because of loud disruptive snoring. He awakens often during the night because of an urge to urinate. • • • •

BP 135/80 Ht = 5’10” Wt = 210 lb BMI = 30 Neck circumference = 16.5” Deviated septum from a past football injury Friedman = 4

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STOP-BANG Questionnaire Answer - either yes or no: 1. Do you SNORE loudly (louder than talking or loud enough to be heard through closed doors)? 2. Do you often feel TIRED, fatigued or sleepy during the daytime? 3. Has anyone OBSERVED you stop breathing during your sleep? 4. Do you have or are you being treated for high blood PRESSURE? 5. BMI more than 35? 6. AGE over 50 years? 7. NECK circumference > 15.75 inches (40cm)? 8. Male GENDER? Chung, et al. Anesthesiology 2008;108:812-821

STOP • ≥ 2 yes answers: High risk of OSA • < 2 yes answers: Low risk of OSA

STOP Questionnaire AHI > 5

Sensitivity % 65.6

Specificity % 60.0

PPV % 78.4

NPV % 44.0

AHI > 15 AHI > 30

74.3 79.5

53.3 48.6

51.0 30.4

76.0 89.3

Adapted from Chung, et al. Anesthesiology 2008;108:812-821

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STOP-BANG • ≥ 3 yes answers: High-risk for OSA • < 3 yes answers: Low-risk for OSA

STOP‐BANG Questionnaire Sensitivity %

Specificity % PPV %

NPV %

AHI > 5

83.6

56.4

81.0

60.8

AHI > 15

92.9

43.0

51.6

90.2

AHI > 30

100.0

37.0

31.0

100.0

Sensitivity for moderate OSA increases from 74 to 93% using STOP-BANG and NPV increases from 76 to 90%. Adapted from Chung, et al. Anesthesiology 2008;108:812-821

STOP-BANG • Explore the predictive performance of the different combinations of items from “BANG” with the STOP component Moderate‐Severe OSA, AHI > 15 as cutoff  STOP‐BANG ≥ 3 STOP ≥ 2 + BMI>35 STOP ≥ 2 + Neck >40 STOP ≥ 2 + Male

N (%) 172 (33.3) 41 (7.9) 66 (12.8) 79 (15.3)

Sensitivity, % 87.3 20.8 33.5 40.1

Specificity, % 30.7 85.0 79.0 76.8

PPV, % 43.8 46.1 49.6 51.6

NPV, % 79.7 63.5 65.8 67.5

27.4 85.3 77.4 74.4

20.6 29.2 27.1 28.1

95.9 85.9 86.9 88.2

Severe OSA, AHI > 30 as cutoff STOP‐BANG ≥ 3 STOP ≥ 2 + BMI>35 STOP ≥ 2 + Neck >40 STOP ≥ 2 + Male

81 (15.7) 26 (5.0) 36 (7.0) 43 (8.3)

94.2 30.2 41.9 50.0

Adapted from Chung F et al. JCSM 2014;10:951-958

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2-Step Screening Strategy Total (n=516) AHI >15: 197 (38.2%) AHI >30: 86 (16.7%)

STEP 1 STOP-BANG = 0-2 (n=123) AHI >15: 25 (20.3%) AHI >30: 5 (4.1%) LOW risk

STOP-BANG = 3-4 (n=230) AHI >15: 88 (38.3%) AHI >30: 32 (13.9%) INTERMEDIATE risk

STOP-BANG ≥ 5 (n=163) AHI >15: 84 (51.5%) AHI >30: 49 (30.1%) HIGH risk

STEP 2

Other (n=180) AHI >15; 67 (37.2%) AHI >30; 22 (12.2%) INTERMEDIATE risk

STOP = 2 + Male or STOP = 2 + BMI >35 + Male (n=50) AHI >15: 21 (42%) AHI >30: 10 (20%) HIGH risk

Adapted from Chung F et al. JCSM 2014;10:951-958

Sleep Study Monitoring Devices • Type 1: In-lab, attended, overnight PSG • Type 2: Comprehensive portable, min 7 ch - EEG, EOG, chin EMG, ECG, airflow, effort, SPO2

• Type 3: Modified portable, min 4 ch - 2 effort channels or effort + airflow, ECG, SPO2

• Type 4: Single or dual parameter, 1-2 ch - SPO2 or airflow In March 2008, CMS approved CPAP coverage based on a diagnosis of OSA by HST Practice parameters for the use of portable monitoring devices in the investigation of suspected obstructive sleep apnea in adults. A joint project by the AASM, ATS, and ACCP SLEEP 2003;26(7):907-913; CMS. 2008; http://www.cms.hhs.gov/MLNMattersArticles/downloads/MM6048.pdf..

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In-Lab PSG • Gold standard for evaluation of OSA • 6-8hr attended night study • Established scoring criteria • Tailored based on clinical history - PAP, OA Titration - Oxygen therapy - Expanded EEG/EMG

• Aim to record NREM/REM, supine/off-supine sleep Iber C et al, AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications, 2007.

Indications for In-Lab PSG • Sleep-related breathing disorders - OSA, CSA, Complex SA - Hypoventilation - Nocturnal desaturation

• Narcolepsy and other hypersomnias • Abnormal motor activity/behaviors in sleep - Seizures - Limb movements - Parasomnias International Classification of Sleep Disorders, 3rd ed. American Academy of Sleep Medicine. 2014.

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In-Lab PSG Parameters • • • • • • • • • •

EEG: bilateral frontal, central, occipital EOG: bilateral outer canthi EMG: submental and leg ECG Nasal-oral airflow Thoraco-abdominal effort Oxygen saturation Carbon dioxide Body position Snore Iber C et al, AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications, 2007.

Normal PSG

2 minutes displayed

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Normal Adult Hypnogram

Slow wave sleep (OSA protective) predominates in first 1/3

REM sleep (OSA exacerbating) increases in last 1/3

Staging Sleep on PSG

Eye blinks, alpha rhythm, high chin EMG

Slow eye movements, low amp mixed freq, vertex sharp waves

K complex, sleep spindle

Each 30 sec epoch is assigned a stage allowing for identification of state-dependency of respiratory events Slow wave activity

Rapid eye mvmt, sawtooth waves, low chin EMG, transient muscle activity

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Types of Apnea • Drop in thermal sensor excursion > 90% for > 10 sec - Obstructive: Continued effort during period of absent airflow - Central: Absent effort during period of absent airflow - Mixed: Absent effort initially followed by resumption of effort

Iber C et al, AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications, 2007.

Hypnogram

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Obstructive Apneas

2 minutes displayed

Obstructive Hypopneas

2 minutes displayed

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Sleep Apnea Severity Grading

Mild

AHI 5 -85

EKG Mild tachybradycardia

Moderate

15 -30

5 obstructive events/hr and at least 1 or more of the following: - Daytime sleepiness, sleep attacks, unrefreshing sleep, fatigue or insomnia - Waking with breath holding, gasping or choking - Observer reports loud snoring, breathing interruptions or both - Co-morbid HTN, mood disorder, cognitive dysfunction, CAD, stroke, CHF, afib, or DM-II OR • PSG or OCST reveals > 15 obstructive events/hr International Classification of Sleep Disorders, 3rd ed. American Academy of Sleep Medicine. 2014

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Recommended: 1A. Score a respiratory event as a hypopnea if ALL of the following criteria are met: a. The peak signal excursions drop by ≥ 30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative hypopnea sensor (diagnostic study). b. The duration of the ≥ 30% drop in signal excursion is ≥ 10 seconds. c. There is a ≥ 3% oxygen desaturation from pre-event baseline and/or the event is associated with an arousal.

Acceptable: 1B. Score a respiratory event as a hypopnea if ALL of the following criteria are met: a. The peak signal excursions drop by ≥ 30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative hypopnea sensor (diagnostic study). b. The duration of the ≥ 30% drop in signal excursion is ≥ 10 seconds. c. There is a ≥ 4% oxygen desaturation from pre-event baseline. Please note that the criterion involving arousals is included in 1A and excluded from 1B Reference: AASM Manual for the Scoring of Sleep and Associated Events, Version 2.0.2

Evolving Hypopnea Definition • Hypopnea = partial airway obstruction • 2007 Scoring Manual1 - Recommended: Drop in nasal pressure excursion by > 30% for > 10 sec w/ > 4% desaturation - Alternate: Drop in nasal pressure excursion by > 50% for > 10 sec w/ > 3% desaturation or arousal

• 2012 Revised Scoring2 - Recommended: Drop in nasal pressure excursion by > 30% for > 10 sec w/ > 3% desaturation and/or arousal 1Iber

C et al, AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications, 2007; Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications Version 2.0, 2012.

2AASM

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Impact of Hypopnea Scoring on AHI 3 recognized hypopnea definitions produce markedly different AHIs Apnea Hypopnea Indices and Hypopnea Indices using different hypopnea scoring criteria Hypopnea Definition

AHI (events/hr)

HI (events/hr)

Chicago

25.1 (11.1, 48.5)

16.3 (7.8, 26.4)

Recommended

8.3 (2.1, 26.4)

2.2 (0.5, 6.6)

Alternative

14.9 (5.5, 37.4)

7.2 (2.4, 15.0)

Values are median (interquartile range). p 45 Collop NA et al. For AASM Task Force on PM. JCSM 2007;3(7):737-747.

HST Methodology • 4-7 channel devices including airflow (thermal & nasal pressure), effort (inductive plethysmography) & oximetry • Tech applies sensors/directly educates patient • Raw data display w/editing & manual scoring Raw data review by sleep specialist • AHI based on recording time -> underestimates AHI • Follow-up to review results Collop NA et al. For AASM Task Force on PM. JCSM 2007;3(7):737-747; CMS. 2008; http://www.cms.hhs.gov/MLNMattersArticles/downloads/MM6048.pdf..

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Type 3 Home Sleep Test

5 minutes displayed

American College of Physicians Clinical Practice Guideline Adapted from Qaseem A., et al. Ann Intern Med. 2014;161:210-220 Tool

Quality of Evidence

AHI cut-off (events/hr)

Sensitivity, %

Specificity, %

Type II monitor

Moderate

5 15 30

88-94 79-100 61-77

36-77 71-100 96-98

Type III monitor

Moderate

5 15 30

83-97 64-100 70-96

48-100 41-100 79-100

Type IV monitor ≥ 2 channels

Moderate

1 channel/oximetry

Moderate

5 15 30 5 15 30

75-100 67-98 80-100 27-100 39-100 18-100

43-100 50-100 74-98 67-100 32-100 29-100

ESS

Low

5 15 30

24-96 21-50 36-50

29-89 43-83 70-79

STOP-BANG

Low

5 15 30

36-97 44-99 56-100

18-89 11-77 11-74

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American College of Physicians Clinical Practice Guideline • ACP recommends a sleep study for patients with unexplained daytime sleepiness (weak rec, low quality evidence) • ACP recommends PSG for diagnostic testing in patients suspected of OSA. ACP recommends PM in those lacking serious comorbidities as an alternative to PSG when PSG is not available (weak rec, moderate quality evidence) Qaseem A, et al. Ann Intern Med. 2014;161:210-220

What about Split Night Studies? • Diagnostic PSG (2 hr) followed by PAP titration if criteria met • AASM recommends split for AHI > 40 • Position & state dependency of events often precludes splitting • Providers may request split at lower cutoff (i.e. AHI > 15)

Chesson AL et al. SLEEP 1997;20:406-422

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Emerging technology

Nakano H et al. JCSM 2014;10:73-78 Sands S, Owens R. JCSM 2014;10:79-80

In-lab PSG vs. HST Which Procedure is Right? • In newly presenting patients w/ OSA symptoms, two main questions should be considered: - How severe is the patient’s OSA likely to be? - Does the patient have a medical condition or co-morbid sleep disorder that would make HST unsafe, misleading or substantially incomplete?

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Decision Tree for Mod-Severe OSA Does pt have high pre-test prob of mod-severe OSA?

Evaluate for other sleep disorders; and consider in-lab PSG

N

Y Does pt have signs/symptoms of co-morbid medical disorders?

Y

N

N Does pt have signs/symptoms of co-morbid sleep disorders? N

Y

OSA diagnosed?

In-lab PSG

Y

N

Sleep study: PM or in-lab PSG

PM PM: Portable monitoring

OSA diagnosed?

Y

Treatment

Adapted from Collop NA et al. For AASM Task Force on PM. JCSM 2007;3(7):737-747.

Limitations of Testing for OSA • First night effect – sleep architecture changes induced by artificial environment - Prolonged sleep & REM latency - Increased light sleep, arousals & awakenings - Reduced REM & deep NREM (stage N3) sleep

• Night-to-night variability esp. for milder cases • Stage & position dependent OSA - Reduced detection on in-lab PSG - May miss entirely on HST

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Conclusion • OSA is characterized by repeated episodes of complete or partial obstruction of the upper airway during sleep • A simple upper airway exam and quick validated screening tools can be used to aid in the diagnosis of OSA

Conclusion • In-lab PSG is recommended for most sleep disorders including OSA in presence of co-morbid sleep/medical disorders • HST is a confirmatory test for adults 18-65 yr w/ high pre-test probability of mod-tosevere OSA without co-morbidities • HST is not recommended for screening asymptomatic populations

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