Sleep apnea syndrome Flashcards
_____: Pauses in breathing. From the greek roots “a,” which means not
and “pnea,” which means breathing
Apnea:
_____: Some breathing still occurs, but decreased effectiveness
Hypopnea
_____: ineffective respiratory effort due to “blocking”
or obstruction of airflow
Obstructive Sleep Apnea
______: a lack of respiratory effort, originating from the
central nervous system
Central Sleep Apnea
Complications of sleep apnea
● Neuropsychiatric Dysfunction
● Learning and behavioral problems in children
● Nonalcoholic fatty liver disease (NAFLD)
● Higher risk for certain cancers
● Metabolic syndrome and type 2 diabetes
● Cardiovascular and cerebrovascular morbidity
● Pulmonary hypertension and right heart failure
Diagnostic Testing for sleep apnea
Polysomnography (PSG)
● Attended, in-laboratory polysomnography (PSG) is the
gold standard diagnostic test for sleep apnea
Home Sleep Apnea Testing (HSAT) - (Sample Report)
● Can be used for diagnosis if high pretest probability of moderate to severe
uncomplicated OSA and no suspicion for nonrespiratory sleep disorders
Polysomnography Recorded Measures
● Respiratory Airflow: Measures passage of air in/out of nose and mouth
● Respiratory Effort: Measurement of abdominal and thoracic effort. Used
to distinguishes between Obstructive and Central apnea
● Pulse Oximetry: Evaluating for periods of poor oxygenation
● EEG Brain Readings
● Cardiac Rhythm
● Body Movements (including eye movements)
● Body Position
● Snoring
Polysomnography Calculated Measures:
● Sleep Staging and Arousals
● Apneas: cessation, or near cessation, of airflow for more than 10 seconds
○ Obstructive Apnea: evidence of continued respiratory effort
○ Central Apnea: Absence of respiratory effort
○ Mixed Apnea: low effort initially, then evidence effort (even though still
no airflow)
● Hypopneas: At least 30% decreased airflow, for at least 10 seconds, and
O2 desaturation or arousal.
● Cheyne-Stokes Respirations: Cyclic pattern of - 1. Apnea, 2. Increasing
respiratory rate/volume, 3. Gradually shrinking respiratory effort, 4. Apnea
● Hypoventilation Statistics
Calculated Measures of Severity of disordered breathing:
● Apnea-Hypopnea Index (AHI)
= [apneas + hypopneas] / total sleep time
● Respiratory Disturbance Index (RDI)
= [apneas + hypopneas + RERAs)] / total sleep time in hours
● Respiratory Event Index (REI) used during home sleep studies
= total respiratory events / total recording time in hours
Sleep Apnea - Summary of the 3 types
Obstructive: (Most common) Intermittent relaxation of the throat muscles that allows
the airway to become obstructed.
Central: The brain does not tell the
diaphragm muscles to breathe
Mixed: Combination of obstructive and central sleep apnea
Obstructive sleep apnea is linked to:
Obesity, Down
Syndrome, Pregnancy,
CHF, Renal Disease, Lung
Disease, Hypothyroidism,
PCOS Acromegaly
Central sleep apnea is linked to:
CHF, Thyroid disease, kidney failure,
neurologic disease, damage to brainstem
(stroke, trauma, etc). Idiopathic in some cases
Most common sleep-related breathing disorder
Obstructive Sleep Apnea (OSA)
Prevalence in US is increasing due to rising rates of obesity
OSA
Risk Factors/Etiology for OSA
● Obesity - The strongest risk factor
● Advancing age - increases through 6th - 7th decade
● Male gender - 2-3 x greater in males than premenopausal females
● Peri and Postmenopausal Women
● Craniofacial or upper airway abnormalities
● Smoking - up to 3x more likely to have OSA
● Pregnancy
● Heart Disease: Hypertension (especially if resistant), CVD, Congestive
heart failure, Atrial fibrillation, pulmonary hypertension
● Chronic Lung Disease: asthma, COPD, idiopathic pulmonary fibrosis
● Endocrine Conditions: Acromegaly, Hypothyroidism,
Polycystic ovary syndrome
● Parkinson’s disease
● Down syndrome
● GERD
Pathogenesis of OSA
Interaction between
unfavorable anatomic upper airway
structure and sleep-related changes in
airway function
● Recurrent, functional collapse/obstruction during sleep, of the
velopharyngeal (soft palate and pharynx) and/or oropharyngeal airway
● Substantial or complete cessation of airflow despite vigorous breathing
efforts
● Leads to intermittent disturbance in gas
exchange (hypercapnia/ hypoxemia)
● Results in hypoxia and fragmented sleep (ie,
poor sleep quality)
Common History Findings of OSA
● Daytime sleepiness and non-restorative sleep
● Awakening with sensation of choking, gasping, or smothering
● Morning headaches (10-30%)
● Sleep Maintenance Insomnia (repetitive awakenings) and Nocturia
● Associated Complications: Weight Gain, depression, poor concentration
● Loud snoring, gasping, choking, interruptions in breathing while sleeping
(commonly leads to restless sleep)
Common Physical Exam Findings in OSA
● Large neck circumference and waist circumference. Neck/collar greater
than 17 inches in men, 16 inches in women.
● Increased BMI/Obesity is the most common clinical finding in OSA
● Crowded oropharyngeal airway
Diagnosis is made using Polysomnography based on either:
● >5 obstructive respiratory events per hour and the patient has at
least 1 of the following symptoms or comorbidities:
● Sleepiness, nonrestorative sleep, fatigue, insomnia
● Waking up with breath holding, gasping, or choking
● Observed habitual snoring, breathing interruptions, or both
Or
● >15 obstructive respiratory events per hour
of sleep, even if no associated symptoms or
comorbiditie
Classification of severity of OSA
Mild: 5 to 14 events per hour
● These patients are relatively asymptomatic in general.
Moderate: 15 to 30 events per hour
● These patients typically have noticeable symptoms, like daytime sleepiness
Severe: >30 events per hour
● These patients typically have symptoms that interfere with daily activities
Patient Education for OSA
● Weight Loss and Exercise - Long term goal of losing and keeping off
● Sleep position changes - Use sleep study results, usually involves
avoiding supine sleeping position
● ETOH Avoidance - (Depresses the CNS response to apnea)
● Counselled against cigarette and cannabis smoking
● Concomitant Medications - Avoid medications that potentially inhibit the
CNS: benzodiazepines, barbiturates, antiepileptics, sedating
antidepressants (mirtazapine, trazodone), antihistamines, opiates
Goals of Treatment for OSA
reduce frequency of hypoxemia (improve
oxygenation), eliminate apneas, reduce symptoms
Management of OSA
Continuous Positive Airway Pressure (CPAP)
The mainstay of therapy for OSA
Trials indicate CPAP is more effective than
oral appliances in reducing frequency and
severity of both respiratory and desaturation
events
Oral Appliances for OSA
● For patients with mild to moderate OSA
● These either protrude the mandible
forward or hold the tongue anteriorly
