Chapter 30 Disorders of Sleep Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973,...
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Transcript of Chapter 30 Disorders of Sleep Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973,...
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
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.
2Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Learning Objectives (cont.)
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.
3Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Learning Objectives (cont.)
Identify the problems associated with CPAP Describe when bilevel pressure is useful Define “auto-titrating” CPAP Describe the surgical alternatives
4Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Definitions
Sleep apnea Repeated episodes of no airflow for 10 seconds
Obstructive sleep apnea Effort but no airflow due to upper airway
obstruction Central sleep apnea
CNS fails to signal respiratory effort Overlap syndrome
Chronic obstructive pulmonary disease (COPD) with coexisting OSA
5Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Definitions (cont.)
Mixed apnea Elements of obstructive & central apnea
Hypopnea Decrease in breathing but still airflow
6Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Definitions (cont.)
7Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Definitions (cont.)
8Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
9Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
All of the following are types of sleep disorders, except:
A. Obstructive sleep apnea
B. Central sleep apnea
C. Mixed apnea
D. Hyperpnea
Pathophysiology
Obstructive sleep apnea (OSA) 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 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)
10Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Pathophysiology (cont.)
Central sleep apnea (CSA) Heterogeneous group of disorders Characterized by periodic breathing
• Waxing & waning of respiratory drive
• Noted by increase then decrease in f & VT
• Cheyne-Stokes respiration Often occur in CHF or stroke Severe type of periodic breathing Pattern of crescendo-decrescendo with hyperpnea
alternating with apnea
11Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Pathophysiology (cont.)
Overlap syndrome 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
12Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
13Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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
Clinical Features
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
14Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Clinical Features (cont.)
May have right heart failure secondary to pulmonary HTN More common in overlap syndrome or severe
obesity Increased risk of cardiac arrhythmia
associated with moderate to severe desaturations
15Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Laboratory Testing
Polysomnogram 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
16Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Laboratory Testing (cont.)
Interpretation of PSG 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
Number of apneas & hypopneas per hour reported as apnea-hypopnea index (AHI)
17Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Laboratory Testing (cont.)
Severity of OSA defined: Normal: AHI <5 Mild: AHI 5–15 Moderate: AHI 15–30 Severe: AHI >30
Additional information reported Number of arousals/hour (arousal index) Percentage of each sleep stage Frequency of oxygen desaturation, mean SpO2,
lowest SpO2
18Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Treatment
Behavioral interventions & risk counseling 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) If sleep study notes OSA occurs only supine—avoid Tennis ball at nape of neck will discourage position Typically only useful in mild OSA
19Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
20Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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
Treatment (cont.)
Oral appliances (second-line therapy) 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
Fitted by dentists, fairly well tolerated
21Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Treatment (cont.)
22Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Treatment (cont.)
Medications Ineffective for most patients with sleep apnea Antidepressants may be useful for mild cases
(rare) Oxygen helps avoid desaturations
23Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
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
24Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Medical Interventions (cont.)
CPAP therapy (cont.) 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%)
25Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Medical Interventions (cont.)
26Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Medical Interventions (cont.)
Bilevel pressure therapy (BiPAP) Better tolerated by patients with high CPAP levels Assists in ventilation & airway splinting
Autotitrating devices (smart CPAP) Adjust to varying patient needs Use computer algorithm to adjust CPAP to
changes in airflow and/or vibration (snoring) Average pressures may decrease
27Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Medical Interventions (cont.)
Side effects & troubleshooting strategies (PPT) 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)
Pressure leaks• Mouth breathers have problems with nasal masks
• Add chin strap to close mouth or change to full mask (oronasal)
28Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
29Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Which of the following are characteristics of auto-titrating 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
Surgical Interventions
Uvulopalatopharyngoplasty (UPPP) Reconstructs portions of uvula, soft palate, soft
tissue of pharynx Success is less than 50% Not currently recommended for management of
OSA Maxillofacial surgery (more promising)
Phase I: UPPP, genioglossal advancement, hyoid bone resuspension
Phase II: Only if phase I is unsuccessful, then advance maxilla & mandible
30Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Surgical Interventions (cont.)
31Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Surgical Interventions (cont.)
In worst cases (nonresponsive to all other management techniques), tracheostomy may be performed that bypasses obstruction in OSA
32Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.
Role of Respiratory Therapist
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
33Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc.