Chapter 30 Disorders of Sleep. Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 2 Objectives Identify the estimated.

Chapter 30Chapter 30

Disorders of SleepDisorders of Sleep

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Objectives Objectives

Identify the estimated prevalence of obstructive sleep Identify the estimated prevalence of obstructive sleep apnea (OSA) in the general population.apnea (OSA) in the general population.

Define OSA, central sleep apnea, combined sleep Define OSA, central sleep apnea, combined sleep apnea, and overlap syndrome.apnea, and overlap syndrome.

Explain why airway closure occurs only during sleep.Explain why airway closure occurs only during sleep.

State the possible long-term consequences of State the possible long-term consequences of

uncontrolled OSAuncontrolled OSA..

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Objectives (cont.)Objectives (cont.)

List the clinical features associated with OSA.List the clinical features associated with OSA.

Describe how OSA is diagnosed.Describe how OSA is diagnosed.

Describe the treatments available for patients Describe the treatments available for patients with OSA.with OSA.

State how continuous positive airway State how continuous positive airway pressure (CPAP) works.pressure (CPAP) works.

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Objectives (cont.)Objectives (cont.)

Identify the problems associated with CPAP in the Identify the problems associated with CPAP in the treatment of OSA.treatment of OSA.

Describe when bilevel pressure is useful in the Describe when bilevel pressure is useful in the treatment of OSA.treatment of OSA.

Describe “auto-titrating” CPAP in the treatment of Describe “auto-titrating” CPAP in the treatment of OSA.OSA.

Describe the surgical alternatives for patients with Describe the surgical alternatives for patients with severe OSA.severe OSA.

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DefinitionsDefinitions Sleep apneaSleep apnea

Repeated episodes of no airflow for Repeated episodes of no airflow for 10 seconds10 seconds

Obstructive sleep apneaObstructive sleep apnea Effort but no airflow due to upper airway obstructionEffort but no airflow due to upper airway obstruction

Central sleep apneaCentral sleep apnea CNS fails to signal respiratory effortCNS fails to signal respiratory effort

Mixed apnea: elements of obstructive and central Mixed apnea: elements of obstructive and central apneaapnea

Hypopnea: decrease in breathing but still airflow Hypopnea: decrease in breathing but still airflow

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PathophysiologyPathophysiology

Obstructive sleep apnea (OSA)Obstructive sleep apnea (OSA) Primary cause is small or unstable pharyngeal airway.Primary cause is small or unstable pharyngeal airway.

Contributing: obesity, tonsillar hypertrophy, small chinContributing: obesity, tonsillar hypertrophy, small chin During sleep, upper airway dilator muscles relax, allowing During sleep, upper airway dilator muscles relax, allowing

narrowing or closure in one to many sites.narrowing or closure in one to many sites.

OSA increases risk of systemic and pulmonary HTN.OSA increases risk of systemic and pulmonary HTN. Related to increased sympathetic toneRelated to increased sympathetic tone Right ventricular failure may occur if not corrected.Right ventricular failure may occur if not corrected.

Suspect OSA in obese patients with excessive daytime Suspect OSA in obese patients with excessive daytime sleepiness (EDS).sleepiness (EDS).

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Pathophysiology (cont.)Pathophysiology (cont.)

Central sleep apnea (CSA)Central sleep apnea (CSA) Heterogeneous group of disordersHeterogeneous group of disorders

Characterized by periodic breathingCharacterized by periodic breathing Waxing and waning of respiratory driveWaxing and waning of respiratory drive Noted by an increase then a decrease in f and VNoted by an increase then a decrease in f and VTT

Cheyne-Stokes respirationsCheyne-Stokes respirations• Often occur in CHF or strokeOften occur in CHF or stroke• Severe type of periodic breathing Severe type of periodic breathing • Pattern of crescendo-decrescendo with hyperpnea alternating Pattern of crescendo-decrescendo with hyperpnea alternating

with apneawith apnea

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Pathophysiology (cont.)Pathophysiology (cont.)

Overlap syndromeOverlap syndrome COPD patients with coexisting OSACOPD patients with coexisting OSA Patients are typically obese smokers with moderate Patients are typically obese smokers with moderate

to severe nocturnal oxyhemoglobin desaturations.to severe nocturnal oxyhemoglobin desaturations. Worst events occur during REMWorst events occur during REM

Worse prognosis and ABGs, then OSA without COPDWorse prognosis and ABGs, then OSA without COPD Undiagnosed OSA complicates COPD patients with Undiagnosed OSA complicates COPD patients with

nightly arousals, dyspnea, desaturations resistant to nightly arousals, dyspnea, desaturations resistant to OO22

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Clinical FeaturesClinical Features Tend to be men (3:1 ratio men to women), >40 years of Tend to be men (3:1 ratio men to women), >40 years of

age with HTNage with HTN

Report snoring that has become progressively worse, tied Report snoring that has become progressively worse, tied to sensation of choking, gasping, or snortingto sensation of choking, gasping, or snorting

Disturbed sleep leads to fatigue, EDS, irritability, Disturbed sleep leads to fatigue, EDS, irritability, depression, possible neuropsychological deficitsdepression, possible neuropsychological deficits

May have right heart failure secondary to pulmonary HTNMay have right heart failure secondary to pulmonary HTN More common in overlap syndrome or severe obesityMore common in overlap syndrome or severe obesity

Increased risk of cardiac arrhythmia associated with Increased risk of cardiac arrhythmia associated with moderate to severe desaturationsmoderate to severe desaturations

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Laboratory TestingLaboratory Testing

Polysomnogram (PSG)Polysomnogram (PSG) Overnight study required for definitive diagnosisOvernight study required for definitive diagnosis Record several physiological parameters:Record several physiological parameters:

• EEG, EOG, chin EMG, and ECGEEG, EOG, chin EMG, and ECG

• Airflow at nose and mouthAirflow at nose and mouth

• Ventilatory effort by inductive plethysmographyVentilatory effort by inductive plethysmography

• Oxygen saturation by pulse oximetryOxygen saturation by pulse oximetry

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Laboratory Testing (cont.)Laboratory Testing (cont.)

Interpretation of PSGInterpretation of PSG Effort detected but no airflow, with or without desaturation, Effort detected but no airflow, with or without desaturation,

defines OSAdefines OSA Effort detected with minimal airflow, with or without Effort detected with minimal airflow, with or without

desaturations, defines hypopneadesaturations, defines hypopnea No effort and no airflow, with or without desaturations, No effort and no airflow, with or without desaturations,

defines CSAdefines CSA

Scoring of PSGScoring of PSG Number of apneas and hypopneas per hour reported as an Number of apneas and hypopneas per hour reported as an

apnea-hypopnea index (AHI)apnea-hypopnea index (AHI)

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Laboratory Testing (cont.)Laboratory Testing (cont.)

Severity of OSA definedSeverity of OSA defined Normal: Normal: AHI < 5 AHI < 5 Mild: Mild: AHI 5–15 AHI 5–15 Moderate: AHI 15–30Moderate: AHI 15–30 Severe: Severe: AHI > 30 AHI > 30

Additional information reportedAdditional information reported Number of arousals/hour (arousal index)Number of arousals/hour (arousal index) Percentage of each sleep stagePercentage of each sleep stage Frequency of oxygen desaturation, mean SpOFrequency of oxygen desaturation, mean SpO22, lowest SpO, lowest SpO22

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TreatmentTreatment

Behavioral interventions and risk counselingBehavioral interventions and risk counseling Counsel on risks of uncontrolled sleep apneaCounsel on risks of uncontrolled sleep apnea Behavioral interventions that may be usefulBehavioral interventions that may be useful

• Weight loss if obeseWeight loss if obese

• Avoidance of alcohol, sedatives, and hypnoticsAvoidance of alcohol, sedatives, and hypnotics

• Avoid sleep deprivationAvoid sleep deprivation

Positional therapy (avoid supine position)Positional therapy (avoid supine position) If sleep study notes OSA occurs only supine—avoidIf sleep study notes OSA occurs only supine—avoid Tennis ball at nape of neck will discourage position Tennis ball at nape of neck will discourage position Typically only useful in mild OSATypically only useful in mild OSA

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Treatment (cont.)Treatment (cont.)

Medical interventionsMedical interventions• Positive pressure therapy (first-line therapy for OSA)Positive pressure therapy (first-line therapy for OSA)• CPAP of 7.5–12.5 cm HCPAP of 7.5–12.5 cm H22O alleviates upper airway O alleviates upper airway

obstruction in most patientsobstruction in most patients Best titrated during sleep studyBest titrated during sleep study Shown to:Shown to:

• Decrease EDS and improve neurocognitive testingDecrease EDS and improve neurocognitive testing• Decrease incidence of pulmonary hypertension and right-Decrease incidence of pulmonary hypertension and right-

sided heart failuresided heart failure• Decrease ventilation-related arousals and nocturnal cardiac Decrease ventilation-related arousals and nocturnal cardiac

eventsevents• Improved daytime oxygenation and ventilationImproved daytime oxygenation and ventilation

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Treatment (cont.)Treatment (cont.)

CPAP therapy (cont.)CPAP therapy (cont.) CPAP works by pressure splinting the airway open.CPAP works by pressure splinting the airway open. CPAP titration should stop all apneic episodes and reduce CPAP titration should stop all apneic episodes and reduce

number of hypopneas.number of hypopneas. Improved sleep occurs with obliteration of breathing related Improved sleep occurs with obliteration of breathing related

EEG arousals and microarousals. EEG arousals and microarousals. Patient compliance is key to CPAP success (80%).Patient compliance is key to CPAP success (80%).

Bilevel pressure therapy (BiPAP)Bilevel pressure therapy (BiPAP) Better tolerated by patients with high CPAP levelsBetter tolerated by patients with high CPAP levels Assists in ventilation as well as airway splintingAssists in ventilation as well as airway splinting

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Treatment (cont.)Treatment (cont.)

Autotitrating devices (smart CPAP)Autotitrating devices (smart CPAP) Adjust to varying patient needsAdjust to varying patient needs Use computer algorithm to adjust CPAP to changes in Use computer algorithm to adjust CPAP to changes in

airflow and/or vibration (snoring) airflow and/or vibration (snoring) Average pressures may decreaseAverage pressures may decrease

Side effects and troubleshooting strategies (PPT)Side effects and troubleshooting strategies (PPT) Claustrophobia and skin irritation: change interfaceClaustrophobia and skin irritation: change interface Nasal congestion, rhinorrhea, nasal dryness, irritationNasal congestion, rhinorrhea, nasal dryness, irritation

• Topical steroids, antihistamines, nasal saline sprays, Topical steroids, antihistamines, nasal saline sprays, lotionslotions

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Treatment (cont.)Treatment (cont.)

Side effects and troubleshooting strategies Side effects and troubleshooting strategies (cont.)(cont.) Sensation of too much pressureSensation of too much pressure

• Ramp-up of pressure over a number of minutes MAY be Ramp-up of pressure over a number of minutes MAY be useful (no evidence)useful (no evidence)

Pressure leaksPressure leaks• Mouth breathers have problems with nasal masks.Mouth breathers have problems with nasal masks.

• Add a chin strap to close mouth or change to full mask Add a chin strap to close mouth or change to full mask (oronasal).(oronasal).

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Treatment (cont.)Treatment (cont.)

Oral appliances (second-line therapy)Oral appliances (second-line therapy) Devices that enlarge airway by:Devices that enlarge airway by:

• Moving mandible forwardMoving mandible forward

• Keeping the tongue forwardKeeping the tongue forward

May be useful with mild OSA if cannot tolerate CPAPMay be useful with mild OSA if cannot tolerate CPAP Fitted by dentists, fairly well toleratedFitted by dentists, fairly well tolerated

MedicationsMedications Ineffective for most patients with sleep apneaIneffective for most patients with sleep apnea Antidepressants may be useful for mild cases (rare)Antidepressants may be useful for mild cases (rare) Oxygen helps avoid desaturations.Oxygen helps avoid desaturations.

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Treatment (cont.)Treatment (cont.)

Surgical interventionsSurgical interventions Uvulopalatopharyngoplasty (UPPP)Uvulopalatopharyngoplasty (UPPP)

Reconstructs portions of uvula, soft palate, and soft tissue of Reconstructs portions of uvula, soft palate, and soft tissue of pharynx pharynx

Success is less than 50%.Success is less than 50%. Not currently recommended for management of OSANot currently recommended for management of OSA

Maxillofacial surgery (more promising)Maxillofacial surgery (more promising) Phase I: UPPP, genioglossal advancement, and hyoid bone Phase I: UPPP, genioglossal advancement, and hyoid bone

resuspensionresuspension Phase II: Only if phase I is unsuccessful, then advance Phase II: Only if phase I is unsuccessful, then advance

maxilla and mandiblemaxilla and mandible

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Treatment (cont.)Treatment (cont.)

Surgical interventions (cont.)Surgical interventions (cont.) In worst cases (nonresponsive to all other In worst cases (nonresponsive to all other

management techniques), a tracheostomy management techniques), a tracheostomy may be performed that bypasses the may be performed that bypasses the obstruction in OSA.obstruction in OSA.