Obstructive Sleep Apnea Flashcards
Common sites of Airway Collapse
- **Soft Palate **(MOST COMMON)
- Tongue base
- Lateral pharyngeal walls
- Epiglottis
LEST
OSA may be most severe during
Rapid Eye Movement (REM) sleep
When neuromuscular output to the skeletal muscles is particularly low and in supine position due to gravitational forces
Causes daytime sleepiness and impaired daily function
Obstructive sleep apnea
Causes Hypertension and is strongly associated with cardiovascular disease in adults and behavioral problems in children
Obstructive sleep apnea
Can occur as a primary condition (response to high altitude), or secondary to medical condition (e.g. heart failure) or medication (e.g. opioids)
Central sleep apnea
Report frequent awakenings and daytime fatigue
Central Sleep Apnea
Central Sleep Apnea is associated with increased risk for ______ (2)
Heart failure
Atrial fibrillation
OSA is defined on the basis of ______ and ______ and sleep study findings
-
Nocturnal Breathing disturbances
-snoring
-snorting
-gasping
-breathing pauses - Daytime Sleepiness or Fatigue DESPITE sufficient opportunity to sleep
SLEEP STUDY FINDINGS
Five or more episodes of Apnea or Hypopnea per hour of sleep during sleep study
OSA may be diagnosed in the absence of symptoms if the AHI is _____
≥15 episodes/hour
Definition of APNEA
Cessation of airflow for ≥10 seconds during sleep, accompanied by:
OBSTRUCTIVE: Persistent respiratory effort
CENTRAL: Absence of respiratory effort
Definition of HYPOPNEA
A ≥30% reduction in airflow for at least 10 s during sleep that is accompanied by either a ≥3% desaturation or an brain cortical arousal
Partial obstruction that does not meet the criteria for hypopnea but provides evidence of increasing inspiratory effort (usually through pleural pressure monitoring) punctuated by an arousal
Respiratory effort–related arousal (RERA)
A partially obstructed breath, typically within a hypopnea or RERA, identified by a flattened or scooped out inspiratory flow shape
Flow-limited breath
Airway patency is dependent on the stabilizing influence of the _______-
Pharyngeal dilator muscles
Airway lumen may be narrowed by enlargement of soft tissue structures (tongue, palate, uvula) due to ___ (3)
- fat deposition
- increased lymphoid tissue
- genetic variation
-mandibular retroposition
-micrognathia
___________ may trigger mouth opening during sleep, which breaks the seal between the tongue and the palate and allows the tongue to fall posteriorly and occlude the airway
High-level nasal resistance
__________ during sleep results in central nervous system arousal
Increasing CO2 level
This can preempt the CO2-mediated process of pharyngeal muscle compensation and prevent airway stabilization
A low arousal threshold
May prevent appropriate termination of apneas, prolonging apnea duration and exacerbating oxyhemoglobin desaturation.
. A high arousal threshold
Major risk factors for OSA
MOA
1. Obesity
2. Male sex
3. Older age
Additional risk factors:
-mandibular retrognathia
-micrognathia
-a positive family history of OSA
-sedentary lifestyle
-genetic syndromes that reduce upper airway patency (e.g., Down syndrome, Treacher-Collins syndrome)
-adenotonsillar hypertrophy (especially in children)
-menopause (in women)
-various endocrine syndromes (e.g., acromegaly, hypothyroidism)
Approximately 40-60% of cases of OSA are attritutable to ___
Excess weight
Obese individuals are at a ______ risk for OSA than their normal weight counterpart
fourfold or greater risk
A 10% weight gain is associated with _____ increase in AHI
> 30%
Prevalence of OSA is twofold higher among men than women. Factors that predispose men to OSA include ___ (2)
- Android pattern of obesity
- Relatively greater pharyngeal length, which increases collapsibility
TRUE OR FALSE
Premenopausal women are relatively protected from OSA by the influence of sex hormones on ventilatory drive.
TRUE
The contribution of skeletal features in OSA is most evident in _____
Non-obese patients
For a first-degree relative of a patient with OSA, the odds of having OSA is approximately ______ than that of someone without an affected relative.
twofold higher
OSA prevalence
Middle-aged adults: ______
Elderly: _______
Middle aged adults: 5-15%
Elderly: >20%
Peak of lymphoid hypertrophy among
children between 3-8 years old
Prevalence of OSA is high among the following patients (3)
HAD
- Diabetes mellitus
- Hypertension
- Atrial fibrillation
____ precipitates OSA symptoms
Weight gain
Most common complaint in OSA
Snoring
Note: absence does not exclude OSA
______ distinguishes OSA from Paroxysmal Nocturnal Dyspnea, Nocturnal Asthma and Acid reflux with laryngospasm
Absence of Dyspnea
Most common daytime symptom
Excessive daytime sleepiness
(however many women report fatigue instead of sleepiness)
TRUE OR FALSE
OSA alone is thought to cause right-sided heart failure.
FALSE
Evidence of cor pulmonale suggests a comorbid cardiopulmonary condition
Gold standard for diagnosing OSA
Overnight Polysomnogram
Causes of False-negative Sleep Study (3)
LIN
- Night-to-night variation in OSA
- Insufficient REM sleep
- Less supine sleep during testing
If there is a high prior probability of OSA, a negative home study should be followed by ___
Polysomnogram
The key physiologic information collected during a sleep study for OSA assessment includes : (4)
BB CO
- measurement of breathing (changes in airflow, respiratory excursion)
- oxygenation (hemoglobin oxygen saturation)
- body position
- cardiac rhythm.
Mild OSA
AHI 5-14 events/hour
Moderate OSA
15-29 events/hour
Severe OSA
≥30 events/hour
Expected result of Overnight BP monitoring in OSA
“nondipping” pattern (absence of the typical 10% fall of blood pressure during sleep compared to wakefulness)
ABG finding suggesting coexisting cardiopulmonary disease or hypoventilation syndromes.
Waking hypoxemia or hypercarbia
Seen in patients with severe nocturnal hypoxemia
Elevated hemoglobin
Useful test in quantifying sleepiness and helping to distinguish OSA from narcolepsy.
A multiple sleep latency test or a maintenance of wakefulness test
OSA-related respiratory events stimulate sympathetic overactivity, leading to _____
- Acute blood pressure surges during sleep and nocturnal
- Daytime hypertension
OSA-related hypoxemia also stimulates release of acute- phase proteins and reactive oxygen species that exacerbates ______
- Insulin resistance and lipolysis a
- Augmented prothrombotic and proinflammatory state
Inspiratory effort against an occluded airway causes large intrathoracic negative pressure swings, altering ______
Cardiac preload and afterload and resulting in cardiac remodeling and reduced cardiac function
Hypoxemia and sympathetic-parasympathetic imbalance also may ____
Cause electrical remodeling of the heart and myocyte injury
Treatment of OSA with nocturnal continuous positive airway pressure (CPAP) has been shown to reduce 24-h ambulatory blood pressure by ____
2–4 mmHg
TRUE OR FALSE
OSA treatment with CPAP reduces cardiac event rates or prolongs survival.
FALSE
TRUE OR FALSE
Treatment of OSA has been shown to reduce several markers of cardiovascular risk and improve insulin resistance and, in uncontrolled studies, is associated with a decreased recurrence rate of atrial fibrillation.
TRUE
Patients with OSA has ____ increase in occupational accidents
twofold increase
Management of OSA
- Reduce weight
- Optimize sleep duration (7–9 h)
- Regulate sleep schedules (with similar bedtimes and wake times across the week)
- Encourage the patient to avoid sleeping in the supine position
- Treat nasal allergies
- Increase physical activity
- Eliminate alcohol ingestion (which impairs pharyngeal muscle activity) within 3 h of bedtime
- Minimize use of opiate medications
OSA: standard medical therapy with the highest level of evidence for efficacy.
Continuous Positive Airway Pressure (CPAP)
CPAP works as a mechanical splint to hold the airway open, thus maintaining airway patency during sleep.
Specific treatment for nasal congestion
Provide heated humidification, administer saline/steroid nasal sprays
Specific treatment for Claustrophobia
Change mask interface (e.g., to nasal prongs), promote habituation (i.e., practice breathing on CPAP while awake)
Specific treatment for Difficulty exhaling
Temporarily reduce pressure, provide bilevel positive airway pressure
Specific treatment for Bruised nasal ridge
Change mask interface, provide protective padding
Specific treatment for Aerophagia
Administer antacids
Oral appliances are most often used for treating patients with ______
- Mild/moderate OSA
- Do not tolerate CPAP
Upper airway surgery for OSA is less efficacious than CPAP and is mostly reserved for the treatment of patients ___
- Snoring
- Mild OSA
- Cannot tolerate CPAP
Most commonly performed surgery for OSA
Uvulopalatopharyngoplasty
Indications of Upper Airway Neurostimulation (alternative treatment for OSA)
- Moderate to Severe OSA (AHI 15–65)
- BMI <32 kg/m2
- Absence of complete concentric collapse at the level of the velum documented by awake and drug-induced endoscopy (a predictor of response to surgery).
Predictor of response of Upper airway neurostimulation
Absence of complete concentric collapse at the level of the velum documented by awake and drug-induced endoscopy
TRUE OR FALSE
In OSA, Supplemental oxygen can improve oxygen saturation, but there is little evidence that it improves OSA symptoms or the AHI in unselected patients.
TRUE
Caused by an increased sensitivity to pCO2, which leads to an unstable breathing pattern that manifests as hyperventilation alternating with apnea.
Central sleep apnea
With prolonged circulation delay, there is a crescendo-decrescendo breathing pattern known as
Cheyne-Stokes breathing
Risk factors for Central Sleep Apnea
- Congestive Heart failure
- Opioid (Dose-dependent)
- Hypoxia
CPAP—particularly at high pressures—seems to
induce central apnea; this condition is referred to as
Complex sleep
apnea or treatment-emergent central sleep apnea
An independent risk factor for the development of both heart failure and atrial fibrillation
Central Sleep Apnea
Early marker of subclinical myocardial infarction
Central Sleep Apnea
TRUE OR FALSE
Supplemental oxygen can reduce the frequency of central apneas, particularly in patients with hypoxemia.
TRUE
