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Transcript of Chapter 30 Disorders of Sleep. Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of...
Chapter 30Chapter 30
Disorders of SleepDisorders of Sleep
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 2
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..
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 3
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.
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 4
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.
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 5
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 6
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).
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 7
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 8
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 9
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 10
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 11
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)
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 12
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 13
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 14
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 15
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 16
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 17
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).
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 18
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.
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 19
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
Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc. 20
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.