Transcript Slide 1

Chapter 30
Disorders of Sleep
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Learning Objectives
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Define Obstructive Sleep Apnea (OSA)
Explain why airway closure occurs only
during sleep.
State the long-term consequences of
uncontrolled OSA.
Determine which group of people are at
particular risk of OSA.
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Learning Objectives (cont.)
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List the clinical features associated with OSA.
Describe how OSA is diagnosed.
Describe the treatments available for patients
with OSA.
State how continuous positive airway
pressure (CPAP) works.
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Learning Objectives (cont.)
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Identify the problems associated with CPAP
Describe when bilevel pressure is useful
Define “auto-titrating” CPAP
Describe the surgical alternatives
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Definitions
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Sleep apnea
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Obstructive sleep apnea
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Effort but no airflow due to upper airway
obstruction
Central sleep apnea
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Repeated episodes of no airflow for 10 seconds
CNS fails to signal respiratory effort
Overlap syndrome
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Chronic obstructive pulmonary disease (COPD)
with coexisting OSA
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Definitions (cont.)
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Mixed apnea
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Elements of obstructive & central apnea
Hypopnea
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Decrease in breathing but still airflow
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Definitions (cont.)
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Definitions (cont.)
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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All of the following are types of sleep disorders,
except:
A.
B.
C.
D.
Obstructive sleep apnea
Central sleep apnea
Mixed apnea
Hyperpnea
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Pathophysiology
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Obstructive sleep apnea (OSA)
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Primary cause is small or unstable pharyngeal
airway
• Contributing: obesity, tonsillar hypertrophy, small chin
• During sleep, upper airway dilator muscles relax,
allowing narrowing or closure in one to many sites
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OSA increases risk of systemic & pulmonary HTN
• Related to increased sympathetic tone
• Right ventricular failure may occur if not corrected
Suspect OSA in obese patients with excessive
daytime sleepiness (EDS)
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Pathophysiology (cont.)
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Central sleep apnea (CSA)
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Heterogeneous group of disorders
Characterized by periodic breathing
• Waxing & waning of respiratory drive
• Noted by increase then decrease in f & VT
• Cheyne-Stokes respiration
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Often occur in CHF or stroke
Severe type of periodic breathing
Pattern of crescendo-decrescendo with hyperpnea
alternating with apnea
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Pathophysiology (cont.)
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Overlap syndrome
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COPD patients with coexisting OSA
Patients are typically obese smokers with
moderate to severe nocturnal oxyhemoglobin
desaturations
• Worst events occur during REM
Worse prognosis & ABGs, then OSA without
COPD
Undiagnosed OSA complicates COPD patients
with nightly arousals, dyspnea, desaturations
resistant to O2
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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All of the following are clinical presentations of
CSA except:
A. increase and respiratory rate and Vt after
apnea occurs
B. periodic breathing
C. Cheyne–Stokes respirations
D. COPD patient with OSA
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Clinical Features
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Tend to be men (3:1 ratio men to women),
>40 years of age with HTN
Report snoring that has become
progressively worse, tied to sensation of
choking, gasping, or snorting
Disturbed sleep leads to fatigue, EDS,
irritability, depression, possible
neuropsychologic deficits
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Clinical Features (cont.)
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May have right heart failure secondary to
pulmonary HTN
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More common in overlap syndrome or severe
obesity
Increased risk of cardiac arrhythmia
associated with moderate to severe
desaturations
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Laboratory Testing
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Polysomnogram
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Overnight study required for definitive diagnosis
Record several physiological parameters:
• EEG, EOG, chin EMG, & ECG
• Airflow at nose & mouth
• Ventilatory effort by inductive plethysmography
• Oxygen saturation by pulse oximetry
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Laboratory Testing (cont.)
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Interpretation of PSG
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Effort detected but no airflow, with or without
desaturation, defines OSA
Effort detected with minimal airflow, with or without
desaturations, defines hypopnea
No effort & no airflow, with or without
desaturations, defines CSA
Scoring of PSG
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Number of apneas & hypopneas per hour reported
as apnea-hypopnea index (AHI)
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Laboratory Testing (cont.)
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Severity of OSA defined:
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Normal:
Mild:
Moderate:
Severe:
AHI <5
AHI 5–15
AHI 15–30
AHI >30
Additional information reported
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Number of arousals/hour (arousal index)
Percentage of each sleep stage
Frequency of oxygen desaturation, mean SpO2,
lowest SpO2
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Treatment
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Behavioral interventions & risk counseling
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Counsel on risks of uncontrolled sleep apnea
Behavioral interventions that may be useful:
• Weight loss if obese
• Avoidance of alcohol, sedatives, & hypnotics
• Avoid sleep deprivation
Positional therapy (avoid supine position)
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If sleep study notes OSA occurs only supine—avoid
Tennis ball at nape of neck will discourage position
Typically only useful in mild OSA
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Which of the following is a common feature of OSA
patients?
A. approximately 75% of population with OSA are
males
B. report snoring which progressively diminishes
over time
C. will present with left heart failure secondary to
pulmonary HTN
D. will always present with overlap syndrome
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Treatment (cont.)
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Oral appliances (second-line therapy)
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Devices that enlarge airway by:
• Moving mandible forward
• Keeping tongue forward
May be useful with mild OSA if cannot tolerate CPAP
• Regarded as second-line intervention, particularly for severe
OSA
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Fitted by dentists, fairly well tolerated
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Treatment (cont.)
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Treatment (cont.)
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Medications
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Ineffective for most patients with sleep apnea
Antidepressants may be useful for mild cases
(rare)
Oxygen helps avoid desaturations
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Medical Interventions
● Positive pressure therapy (first-line therapy
for OSA)
 CPAP of 7.5–12.5 cm H2O alleviates upper airway
obstruction in most patients
 Best titrated during sleep study
 Shown to:
• Decrease EDS & improve neurocognitive testing
• Decrease incidence of pulmonary hypertension & right
heart failure
• Decrease ventilation-related arousals & nocturnal cardiac
events
• Improved daytime oxygenation & ventilation
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Medical Interventions (cont.)
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CPAP therapy (cont.)
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CPAP primarily works by pressure splinting airway
open
CPAP titration should stop all apneic episodes &
reduce number of hypopneas
Improved sleep occurs with obliteration of
breathing related EEG arousals microarousals
Patient compliance is key to CPAP success (80%)
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Medical Interventions (cont.)
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Medical Interventions (cont.)
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Bilevel pressure therapy (BiPAP)
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Better tolerated by patients with high CPAP levels
Assists in ventilation & airway splinting
Autotitrating devices (smart CPAP)
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Adjust to varying patient needs
Use computer algorithm to adjust CPAP to
changes in airflow and/or vibration (snoring)
Average pressures may decrease
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Medical Interventions (cont.)
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Side effects & troubleshooting strategies (PPT)
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Claustrophobia & skin irritation: change interface
Nasal congestion, rhinorrhea, nasal dryness, irritation
• Topical steroids, antihistamines, nasal saline sprays, lotions
Sensation of too much pressure
• Ramp-up of pressure over number of minutes MAY be
useful (no evidence)
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Pressure leaks
• Mouth breathers have problems with nasal masks
• Add chin strap to close mouth or change to full mask
(oronasal)
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Which of the following are characteristics of autotitrating devices (smart CPAP)?
A. Adjust to varying patient needs
B. Use computer algorithm to adjust CPAP to
changes in airflow
C. Use computer algorithm to adjust CPAP to
changes in vibration (snoring)
D. Average pressures may be increased to 50 cm
H2O
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Surgical Interventions
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Uvulopalatopharyngoplasty (UPPP)
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Reconstructs portions of uvula, soft palate, soft
tissue of pharynx
 Success is less than 50%
 Not currently recommended for management of
OSA
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Maxillofacial surgery (more promising)
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Phase I: UPPP, genioglossal advancement, hyoid
bone resuspension
Phase II: Only if phase I is unsuccessful, then
advance maxilla & mandible
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Surgical Interventions (cont.)
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
31
Surgical Interventions (cont.)
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In worst cases (nonresponsive to all other
management techniques), tracheostomy may
be performed that bypasses obstruction in
OSA
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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Role of Respiratory Therapist
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Management of patients with sleep disorders
Observe evidence of abnormal breathing
during sleep
Recommend testing of patients
Team member of sleep laboratory
Assist in titration of CPAP, interface fitting &
management
Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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