What is Sleep Apnea and why does it matter?

Noah S Siegel, MDDirector of Sleep Medicine and Sleep Surgery

Massachusetts Eye Ear InfirmaryHarvard Medical School

7/31/2021

Classes of sleep disordersSleep related breathing disorders

InsomniasParasomnias

Circadian Rhythm disordersHypersomnia

Movement disordersMiscellaneous

What is Sleep Medicine?

SLEEP MEDICINE

Otolaryngology

Pediatric pulm, neuro, etc

Pediatrics

Internal Medicine

Anesthesiology

Family medicine

Neurology

PsychiatryPulmonology/CCM

Classes of sleep disordersSleep related breathing disorders p g

InsomniasParasomnias

Circadian Rhythm disordersHypersomnia

Movement disordersMiscellaneous

Upper Airway Obstruction Upper Airway Obstruction

Upper Airway Obstruction Lower Airway Obstruction

Restrictive Airway Conditions Opioids

What is Obstructive Sleep Apnea?

• ↓airflow during sleep despite continued respiratory effort due to collapse of the pharyngeal airway• Hypoxemia, hypercapnia• Arousals with sympathetic surge

Prevalence of OSA in USA

Age (years)1988-1994

YoungNEJM, 1994

2007-2010Peppard

Am J Epidemiol, 2013

Men (%)AHI > 5/hr (30-70) 26 34

AHI > 15/hr (30-70) 9 13

Women (%)

AHI > 5/hr (30-70) 13 17

AHI > 15/hr (30-70) 4 6

What causes obstructive sleep apnea?

Anatomy:-PAP-Oral appliances-Surgery

Inadequate pharyngeal dilator response:-PAP-Upper airway stimulation-Medications

High loop gain:-PAP-O2-CO2 (increase dead space)-Acetazolamide

Low arousal threshold:-Hypnotics-PAP

Osman AM1,2, Carter SG1,2, Carberry JC1,2, Eckert DJ1,2. Obstructive sleep apnea: current perspectives. Nat Sci Sleep. 2018 Jan 23;10:21-34.

OSA Risk Factors

• Obesity, neck size >17 inches• Male gender• Snoring• Craniofacial abnormalities• Nasal obstruction/redundant soft palate• Hypothyroid• Family History

Impact of Untreated OSA

CardiovascularAccidents (MVA and work related)(Psychiatric and behavioralyQuality of life and productivityyEndocrineNeurocognitive

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Obstructive Events

Intermittent Hypoxia / hypercarbiaCortical Arousals / Adrenergic Pulses

Daytime SymptomsCardiovascular outcomes

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Punjabi et al, PLoS Medicine. 2009.

OSA and Mortality

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Consequences: Mortality

Marshall et al. Sleep 2008; 31:1079-1085Young et al. Sleep 2008; 31:1071-1078

Busselton, AustraliaWisconsin Cohort

RDI > 15

RDI < 5

RDI 5-15

YYears of follow-up

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Marin, Lancet 2005; 365: 1046-53

Non-fatal Cardiovascular Events

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AHI AHIQuartile

Coronary Coronary Heart Disease

Heart Heart Failure

StrokeQ

0Q

00-00-1.3 1.0 1.0 1.0

1.4.4-4-4.4 0.92 1.13 1.15

4.5.5-5-11.0 1.20 1.95 1.42

>11.0 1.27* 2.38* 1.58*

Shahar E et al. Am J Respir Crit Care Med 2001

Adjusted Relative Odds of Prevalent Coronary Heart Disease, Heart Failure, or Stroke, by Quartile of SDB

Sleep Heart Health Study:Cross-Sectional Analysis

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Wisconsin Sleep Cohort Study: Adjusted Odds Ratios for Hypertension at 4-year Follow-up Participants who were Normotensive at Baseline

0

0.5

1

1.5

2

2.5

3

3.5

0 0.1-4.9 5-14.9 >15

Odds Ratio

AHI

*OR adjusted for age, sex, ethnicity, BMI, neck & waist circumference, smoking and alcohol use

*

*

*

Peppard PE et al. N Eng J Med 2000 May 11; 342(19): 1378-84

Hypertension and OSA by AHI

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Sleep Apnea and Stroke

• Sleep apnea seen in 50%–80% of acute stroke and TIA patients.• OSA was the most common form• Central sleep apnea and Cheyne-stokes forms also reported • Sleep apnea improves in the subacute phase, primarily central and Cheyne-stokes

pattern, not OSA

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J Am Coll Cardiol. 2007.

P = 0.002

AF, n = 114

AF, n = 19

OSA and Atrial Fibrillation

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Gami et al, N Engl J Med. 2005 Mar 24;352(12):1206-14..

Sudden death during night more likely in those with OSA

OSA and Sudden Cardiac Death

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Consequences: Diabetes • Severe OSA patients with sleepiness are at ↑ risk for diabetes (83% of

patients diabetes have unrecognized OSA)*

• Insulin sensitivity improves after CPAP therapy

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*Pamidi et al, Front Neurology 2012; 3, 126

Consequences: Gastroesophageal Reflux Disease

• 54-76% of OSA patients have (GERD) • Risk factors: obesity, male sex, and alcohol use• OSA may trigger GERD due to decreased intrathoracic pressure

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sleepiness and cognition• Reduced alertness & vigilance

• Increased motor vehicle crashes

• Increased work-related accidents

• Poor job/school performance

• Difficulty concentrating & reduced productivity

• Falling asleep inappropriate social circumstances

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Daytime Symptoms

• Lower quality of life• Depression• Fatigue/malaise• Worse perceived pain• Irritability• Morning headaches• Decreased Libido

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DIAGNOSING SLEEP APNEA

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Patient Symptoms• Nocturnal symptoms:

• Snoring• Witnessed Apneas, gasping or choking• Insomnia, frequent awakenings, limb movements• Nocturia• Bruxism/clenching

• Daytime symptoms:• Somnolence, fatigue, nonrefreshing sleep regardless of TST• Poor concentration, morning HA, diff driving

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BMI and OSA• ~60-70% of OSA is attributable to obesity• 10% weight gain = 6x increase risk of mod-sev

OSA, 32% increase in AHI• 10% weight loss = 26% reduction in AHI

• Bottom line: higher BMI, higher likelihood of OSA

Young T, Peppard PE, Taheri S. Excess weight and sleep-disordered breathing. Journal of applied physiology (Bethesda, Md : 1985) 2005; 99:1592-1599.Peppard PE, Young T, Palta M, Dempsey J, Skatrud J. Longitudinal study of moderate weight change and sleep-disordered breathing. JAMA 2000; 284:3015-3021.

Nasal exam: external• Nasal bones, upper and lower lateral

cartilages

• Straight• Slant• C-shape (or reverse C-shape)• Width• Dorsal hump• Dynamic exam

Airway resistance during sleep

• 12 healthy volunteers, no nasal complaints• Randomized, single blinded, cross-over• Airflow resistance measured by SG pressure• No difference during wakefulness• UAR during sleep: oral 12.4 cmH2O (4.5-40.2) vs nasal 5.2 cmH2O (1.7-10.8),

p=0.012• AHI: oral 43/h +/- 6 vs nasal 1.5/h +/-0.5, P<0.01

• All obstructive

Fitzpatrick MF, McLean H, Urton AM, Tan A, O'Donnell D, Driver HS. Effect of nasal or oral breathing route on upper airway resistance during sleep. Eur Respir J 2003; 22:827-832.

Friedman tongue position (modified Mallampati)

Friedman M et al. Staging of Obstructive Sleep Apnea/Hypopnea Syndrome: A Guide to Appropriate Treatment. Laryngoscope. 114:454-459, 2004.

Brodsky and Friedman tonsil size

Friedman M et al. Staging of Obstructive Sleep Apnea/Hypopnea Syndrome: A Guide to Appropriate Treatment. Laryngoscope. 114:454-459, 2004.

Same as Brodsky

Tongue findings

• Tongue scalloping• Macroglossia (DS, BWS)• Midline tongue groove

Other palate findings

• Tonsil depth• Palatal webbing,

length• Thickness,

erythema• Uvular length• Bulky lateral walls

Neck circumference

• 17cm for men• 16cm for women

• 17 is used in STOP-BANG

Hyoid position• Low anterior hyoid

position implies a longer (and therefore more collapsible tongue base)• Airway rotates anteriorly

(note epiglottis)

Dental findings

Maxillomandibular insufficiency/hypoplasiaPHYSICAL EXAMThere were no vitals filed for this visit.

BMI 30.4 kg/m2General: no distress, awake, no central obesity, not overtly sleepy todayPsych: responds appropriate to questioningNeuro: A&Ox3, CN II-XII grossly intactMusculoskeletal: normal movement of all four extremitiesPulmonary: breathing comfortably on room air, no stridor/stertorCardiovascular: good peripheral perfusionEars: external ears normal bilaterallyNormal EAC, TM and MES bilaterallyNose: no external nasal deformityCaudal septum midline, nasal mucosa healthyInferior turbinates normalCraniofacial structure: good maxillary projectionClass 1 occlusion, good dentition, no overjetNo mandibular insufficiencyHard palate good width and not high archedIntermolar distance 5cmOral cavity: + tongue scalloping, large for oral cavityOropharynx: tonsils 1+Modified Mallampati 3Good retropalatal space, soft palate and uvula not thick or elongated, no posterior pillar webbingNeck: thick/muscular, supple, hyoid in good positionNo lymphadenopathyTrachea midline thyroid normal to palpation

Sleep medicine PE:

“Crowded pharynx”

STOP-BANG

• Validated screening tool for obstructive sleep apnea• Score of ≥ 3 has >90% sensitivity to

detect moderate to severe OSA• High positive predictive value (85%)

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Chung; Anesthesiology; 2008Chung; Br. J Anaesth; 2012

45 46

SSTOP-BANG (Give 1 point for each “Yes”)

STOP-BANG Sleep Apnea Screening Tool

Snoring louder than talking, heard through doors

Tired tired, fatigued, sleepy during the day

Observed stop breathing, choking, gasping

Pressure hypertension

BMI > 35

Age > 50

Neck > 17 in (male) or >16 in (female)

Gender male≥ 3 points indicates significant risk for OSA

*There are multiple versions and scoring systems for STOP-BANG

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Diagnostic Approach

• Clinical suspicion and evaluation

• Sleep testing• Home sleep apnea test• Polysomnography

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Types of Sleep testing devices

• Type I - Attended with full sleep staging • EEG, EOG, ECG, Limb EMG, Chin EMG, respiratory effort at chest and abdomen, airflow monitors, pulse oximetry

• Type II – Unattended with at least 7 channels• EEG, EOG, ECG, EMG, Airflow, Respiratory effort, Oxygen saturation

• Type III – Unattended with at least 4 channels• 2 respiratory /airflow,1 Cardiac (ECG), oxygen saturation

• Type IV – Unattended with at least 3 channels• Channels to calculate AHI or RDI by airflow or thoraco-abdominal movement

• Other – Peripheral arterial tonometry

Polysomnography channels

• EOG – Electrooculogram• EEG - Electroencephalogram• EMG - Electromyogram• EKG - Electrocardiogram• Nasal and oral airflow• Thoracic and abdominal respiratory effort• Pulse oximetry• Body Position

16 channel PSG – 1 epochSleep onset Home Sleep (Apnea)Testing - HST

• Designed to evaluate breathing conditions• Flow, effort (chest and abdomen), SaO2, HR• Some have position and snore channel

• A breathing test

Type 3 HST and Watchpat Home Sleep Testing

Advantages

In-lab

• Gold standard• More info/assess multiple sleep

disorders (architecture, limb, EKG)• Technologist monitored

HST

• Cost• Patient comfort• Accessibility• ‘real life’

Disadvantages

In-lab

• Cost• Labor intensive• Patient comfort• Access• ‘artificial environment’

HST

• False negatives• Limited to respiratory disorders• No sleep architecture• Bad data • No CPAP titration studies• Not approved for diagnosis of

central sleep apnea

Definitions

1. Apneaa. > 90% drop airflow excursion from baseline lasting >10

seconds2. Hypopnea

a. 30% drop in airflow from baseline lasting > 10 seconds and:

b. Associated with > 3% oxygen desaturation or arousal3. RERA:

a. ≥ 10 seconds increased respiratory effort or flattening of inspiratory waveform leading to an arousal. Does not meet criteria for apnea or hypopnea.

The AASM Manual for the Scoring of Sleep and Associated Events, Version 2.5

Obstructive Hypopnea

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The AASM Manual for the Scoring of Sleep and Associated Events, Version 2.5

Obstructive Apnea Respiratory Effort Related Arousal (RERA)

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Measures of Sleep Apnea Frequency

• Apnea / Hypopnea Index (AHI)• # apneas + hypopneas per hour of sleep

• Respiratory Disturbance Index (RDI)• # apneas + hypopneas + RERAs per hour of sleep

• Respiratory Event Index (REI)• # respiratory events per hour of monitoring time on Home

Sleep Apnea Testing (HSAT)

The AASM Manual for the Scoring of Sleep and Associated Events, Version 2.5

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IICSD-3 Diagnostic Criteria for OSA

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≥ 15 obstructive respiratory events/hour

≥ 5 obstructive respiratory events/hour

and:

Snoring, witnessed apneas, fatigue, somnolence, mood/cognitive disorder, hypertension, type 2 diabetes, stroke or cardiac disease

- or -

How to Treat OSA – Open the airway

CPAPOral appliance therapySurgical therapyPositional therapyWeight lossImplantable devices

HHow do we treat OSA?Open the upper airway

• Positive pressure therapy•Oral appliance therapy• Surgical procedures•Weight loss• Positional therapy•Nasal expiratory resistor (Provent®)• Hypoglossal nerve stimulation

Positive Pressure therapy

Positive Pressure therapy

• Most commonly recommended Rx for OSA• Extensive long term data• Approx. 50% compliance @ 1 year

PPositive Pressure Devices

•CPAP•BiPAP•APAP (auto-adjusting or auto-titrating)•Adaptive Servoventilation (ASV)

OSA – CPAP Decreases CV Events

AHI Number of Patients

Treatment Non-fatal CV events/100 person years

Fatal CV Events/100 person years

Healthy N/A 264 None 0.45 0.30

Simple Snorers <5/hour 377 None 0.58 0.34

Mild to Moderate OSA

5-30/hour 403 None 0.89 0.55

Severe OSA >30/hour 235 None 2.13 1.06

Long-Term CV Outcomes in Men with OSA-Hypopnea with or without Treatment with CPAP: an observational Study. Marin JM, Carrizo SJ, et al. Lancet 2005; 365: 1046-53.

OSA – CPAP Decreases CV Events

AHI Number of Patients

Treatment Non-fatal CV events/100 person years

Fatal CV Events/100 person years

Healthy N/A 264 None 0.45 0.30

Simple Snorers <5/hour 377 None 0.58 0.34

Severe OSA >30/hour 373 CPAP 0.64 0.35

Mild to Moderate OSA

5-30/hour 403 None 0.89 0.55

Severe OSA >30/hour 235 None 2.13 1.06

Long-Term CV Outcomes in Men with OSA-Hypopnea with or without Treatment with CPAP: an observational Study. Marin JM, Carrizo SJ, et al. Lancet 2005; 365: 1046-53.

Oral appliance therapy

Surgery for OSA

• General comments• Nasal surgery• Soft Tissue Surgery• Oropharynx (UPPP)• Base of tongue/hypopharynx

• Skeletal Surgery• Upper Airway Stimulation Surgery• Bariatric surgery

Surgical Considerations• CPAP Compliance• Severity of apnea• Anatomy/level of obstruction

(DISE)• Comorbidities• Patient expectations• Anesthetic considerations• Recovery/complications

Velopharyngeal Pattern (AP)

3:20

Velopharyngeal patterns

CCC

LCAP

Kezirian EJ, Hohenhorst W, de Vries N (2011) Drug-induced sleep endoscopy: the VOTE classification. Eur Arch Otorhinolaryngol 268:1233–1236. doi:10.1007/s00405-011-1633-8

Oropharyngeal Collapse ccc

Tongue base collapse

Tongue Base Collapse1:30 Epiglottis Patterns

Anterior Posterior

Lateral collapse

1:30

• Meta-analysis of papers on surgical modifications of the upper aerodigestive tract in patients with obstructive sleep apnea

Efficacy of Surgery

• “Analysis of the uvulopalatopharyngoplasty papers revealed that this procedure is, at best, effective in treating less than 50% of patients with obstructive sleep apnea syndrome.”

Efficacy of Surgery

UPPP Response Rates Based on Level of Obstructionn=168 patients (9 papers)

Level of obstruction

50% decrease

in AI

50% decrease

in RDI

50% decrease in RDI or

AI

50% decrease in RDI & RDI <20 or 50%

in AI & AI<20

Oropharyngeal83% 67% 76% 52.3%

Hypopharyngeal19% 24% 21% 5.3%

Classic UPPP

Oropharyngeal Procedures(aka – Retropalatal)

Pharyngoplasty (eg. UPPP)Tonsillectomy +/ adenoidPalatal implants?

Hypopharyngeal procedures

• Lingual tonsillectomy

• Tongue reduction/partial glossectomy

• Radiofrequency reduction of BOT

Skeletal Surgery• Maxillomandibular Advancement (MMA)• Genioglossus Advancement• Hyoid suspension• Transpalatal advancement

MMA – Meta AnalysisZaghi JAMA Otolaryngol Head Neck Surg. 2016 Jan;142(1):58-66

• 518 patients in 45 studies• Mean BMI=34, 83% male

• Success – 86% (50% ↓AHI and AHI<20)• Cure – 39% (AHI<5)

Pre-Op Post - Op

AHI 57.2 9.5ESS 13.5 3.2Oxygen Nadir 70.1% 87.0%

Hypoglossal Nerve Stimulation Pre-op Anatomical Assessment Drug Induced Sleep Endoscopy (DISE)

Examples

Complete AP collapse at palate Complete concentric collapse at palateGood candidate Not a good candidate

Hypoglossal Nerve Stimulation EffectNo Stimulation Mild Stimulation

Base of TongueBase of Tongue

Palate Palate

Stimulation Therapy for Apnea Reduction (STAR)Strollo, NEJM 2014

• 129 patients, 83% male, mean BMI -28.3, mean age 54 year• Outcomes at 1 year:

Baseline Post-Op 12 months

AHI 29.3 9.0 (p<0.0001)

ODI 25.4 7.4 (p<0.0001)

ESS 11.0 6.0 (p<0.0001)

FOSQ 14.6 18.2 (p<0.0001)

STAR STUDYUpper Airway Stimulation for Obstructive Sleep ApneaStrollo et al.,NEJM 370;2, 2014

• Adverse events• 2 patients needed repositioning and fixation• 18% with temporary tongue weakness• 40% ‘some discomfort’ associated with stimulation• 21% tongue soreness /abrasion from stimulation

Hypoglossal Nerve Stimulator – Inclusion Criteria

• AHI 15-65• Can’t/won’t use CPAP• <25% central or mixed apneas• BMI <32• Age >22• DISE (no complete concentric collapse)

Upper Airway Stimulation for Obstructive Sleep Apnea: 5-Year OutcomesWoodson et al. Otolaryngol Head Neck Surg 2018 Jul;159(1):194-202

• At 5 years, improvements persisted:• Sleepiness• quality of life• respiratory outcomes

• Serious adverse were are uncommon

Questions?