33_34_ Sleep related breathing disorders Flashcards
What are the signs and symptoms of sleep-related breathing disorders?
- Nighttime symptoms include snoring, observed apneas, poor sleep quality, night sweating, and enuresis.
- Daytime symptoms include sleepiness, morning headache, dry mouth, poor short-term memory, depression, poor mood, GERD symptoms, and decreased libido.
What is the importance of sleep history in diagnosing sleep-related breathing disorders?
Sleep history, including third-party reports, is important in diagnosing sleep-related breathing disorders as it helps in identifying symptoms that may not be apparent to the patient.
What are the laboratory tests used in diagnosing sleep-related breathing disorders?
Complete blood count may show polycythemia (↑Hb + Hct) and ABG may show ↑serum HCO3-.
What is polysomnography (PSG)?
Polysomnography (PSG) is a sleep study that is performed in a sleep lab to assess physiologic variables including O2 saturation, nasal airflow, respiratory effort (thoracic/abdominal movements), sleep stages, and arousal events.
What are the recording methods used in polysomnography (PSG)?
The recordings are done via EEG (electroencephalography), EMG (electromyography), EOG (electrooculography), and ECG (electrocardiography).
What is the gold standard for diagnosing sleep-related breathing disorders?
Polysomnography (PSG) is the gold standard for diagnosing sleep-related breathing disorders.
What is hypopnea?
- Reduction of oronasal airflow, peak signal drop >30%,
- lasts more than 10 seconds
- reduction of O2 saturation >4%
What is apnea?
Cessation of oronasal flow, peak signal drop >90%, lasts more than 10 seconds.
What is obstructive apnea?
- Ineffective thoracic/abdominal movements can be observed during apnea,
- airflow cessation is caused by airway obstruction.
What is central apnea?
No thoracic/abdominal movements can be observed during apnea.
What is the apnea-hypopnea index (AHI)?
Number of apnea/hypopnea events per hour of sleep.
What is the most common sleep-related breathing disorder?
Obstructive sleep apnea syndrome (OSAS), where airflow reduces due to upper airway obstruction.
What is the main sign of central sleep apnea?
Cheyne-Stokes breathing
What is sleep-related hypoventilation?
A condition where there is reduced breathing during sleep, including obesity hypoventilation syndrome (OHS), simultaneously with other diseases, drug-induced, congenital, primary/idiopathic (Ondine’s curse).
What is sleep-related hypoxemia?
A condition where there is low oxygen levels in the blood during sleep.
What is Obstructive Sleep Apnea Syndrome (OSAS)?
A sleep-related breathing disorder in which airflow decreases or ceases due to obstruction of the upper airways (oropharynx).
What are the main features of OSAS?
- Lack of ventilation is associated with a decrease in PaO2 (intermittent hypoxia) +/- increase in PaCO2.
- Episodes are terminated by different levels of arousal (sleep fragmentation) and a sudden increase in SYM activity.
What are the morphological factors that can cause OSAS?
- Obesity (especially around the neck),
- short neck,
- retrognathia (mandible set back from maxilla),
- micrognathia (mandible is undersized),
- macroglossia,
- large uvula,
- tonsil hypertrophy,
- nasal septum deviation.
What are the functional factors that can cause OSAS?
- Chronic upper airway inflammation,
- alcohol consumption,
- smoking,
- sedatives with muscle relaxing effect,
- CNS diseases,
- pharyngeal neuropathy/myopathy.
What are the clinical features of OSAS during nighttime?
Snoring, sweating, palpitations, enuresis, observed apneas, bad sleep quality.
enuresis: involutary peeing during sleep
What are the clinical features of OSAS during daytime?
Sleepiness, fatigue, memory impairment, morning headache, depression, GERD symptoms, decreased libido.
What are the immediate consequences of apnea?
- Hypoxia, hypercapnia, vagotonia, bradycardia, decreased blood pressure, decreased cardiac output during apnea.
- Increased sympathetic tone, arousal, increased blood pressure, tachycardia, and stress reaction upon apnea termination.
What are the clinical consequences of apnea?
(aka what we notice in everyday life)
Hypertension, arrhythmias, heart failure, pulmonary hypertension, atherosclerosis, diabetes, GERD, and nocturnal enuresis.
What are the diagnostic methods for sleep apnea?
Sleep history, evaluation of comorbidities, screening for OSA using standardized screening questionnaires such as STOP-BANG, and sleep studies (PG, PSG).
What is central sleep apnea (CSA)?
It is a sleep-related breathing disorder in which the drive to breathe periodically decreases or ceases due to impaired function of the respiratory center, caused by either hyperventilation (non-hypercapnic CSA) or hypoventilation (hypercapnic CSA).
What are the predisposing factors for CSA?
- Congestive heart failure,
- atrial fibrillation,
- neurological (mainly vascular) diseases with midline, brainstem involvement,
- older age (>80y/o),
- renal failure,
- increased intracranial pressure.
What are the clinical features of CSA?
Daytime sleepiness, repeated waking at night, morning headaches, snoring, and in some cases, Cheyne-Stokes breathing pattern (in HF patients).
What is Cheyne-Stokes breathing?
Cyclic episodes of central apnea and hyperventilation with a crescendo-decrescendo breathing pattern.
How many consecutive central apneas are required for Cheyne-Stokes breathing?
At least 3.
What is the duration of an episode of Cheyne-Stokes breathing?
45-90 seconds.
What is the gold standard test for diagnosing CSA
Polysomnography, ideally with esophageal pressure manometry.
What is obesity hypoventilation syndrome (OHS)?
A type of sleep-related hypoventilation disorder defined by a BMI of >30kg/m2, diurnal hypercapnia and disordered breathing during sleep.
What is Pickwickian syndrome?
Coexistence of OHS and OSA.
What are the risk factors for OHS?
Same as those for obesity (lifestyle factors, genetic, metabolic).
What is the pathophysiology of OHS?
Increased work of breathing due to obesity -> increased respiratory drive -> inability to maintain during REM sleep -> hypoventilation (increased PaCO2, decreased PaO2) during sleep -> repetitive hypoventilation causes depression of central respiratory centers -> diurnal hypercapnia.
What is the treatment for OHS?
Weight loss.
What is the significance of obesity in OSA?
Increases the collapsibility of the pharynx → obstruction, Impairs breathing during sleep → hypoventilation.
What type of obesity is the most dangerous form in OSA?
Pharyngeal (neck) and abdominal adipose tissue accumulation.
What is PAP therapy?
Positive airway pressure therapy is a treatment for respiratory events that uses pressure to keep airways open.
What are the types of PAP therapy?
Bilevel PAP (BPAP) and Continuous PAP (CPAP).
What are the benefits of CPAP therapy?
Improves quality of life, daytime sleepiness, hypertension, mood, anxiety, and depressive symptoms.
What is position therapy?
A therapy recommended for position-dependent breathing problems that involves using a position pad to prevent sleeping in the supine position.
What is the compliance rate for long-term position therapy?
Poor.
What are intraoral devices?
Devices that prevent the jaw and tongue from sliding backwards, recommended for snorers and mild to moderate OSA.
What are the common complaints during prolonged use of intraoral devices?
Hypersalivation, dry mouth, jaw pain, tooth sensitivity, permanent tooth retention, and occlusion abnormalities.
What are some ENT surgical procedures for sleep apnea?
Septo-rhinoplasty, septum resection, FESS, adenectomy, tonsillectomy, uvulo-palato-pharyngoplasty (UPPP), mandibular osteotomy (MMA), epiglottopexy, and tracheotomy.
What is the purpose of ENT surgical procedures for sleep apnea?
To address specific areas of the airway that may be causing obstruction during sleep.
What is the success rate of surgery for sleep apnea?
Varies depending on the individual case and type of surgery, and should be discussed with a medical professional.
Are there any other treatments for sleep apnea?
Yes, there are other treatments such as weight loss, avoiding alcohol and sedatives, and positional therapy.
