MKSAP 8: Sleep Medicine Flashcards
Define excessive daytime sleepiness
Also referred to as hypersomnia, refers to the struggle to remain awake and alert during daytime hours
What is fatigue?
lack of energy that prevents mental or physical activity at the intensity and/or pace desired and is rarely the result of a primary sleep disorder
What is the most common cause of EDS?
Overall lack of time devoted to the sleep period, insufficient sleep syndrome
What are extrinsic causes of excessive daytime sleepiness?
Insufficient sleep duration
Circadian rhythm disturbances
Drug, substance or medical condition related hypersomnia
Environmental sleep disorder
What are intrinsic causes of excessive daytime sleepiness?
Sleep disordered breathing syndromes such as OSA, central sleep apnea
Narcolepsy
Idiopathic hypersomnia
Restless legs syndrome and periodic limb movement disorder
CIrcadian rhythm sleep disorders
What are symptoms of jet lag? And what are management strategies?
Insomnia, daytime sleepiness, and neuropsychiatric impairment
Avoiding sleep deprivation prior to travel, a gradual shift in sleep period prior to travel over several days. Hypnotoic meds in flight may help promote sleep but pose a risk of sleepwalking
Exposure to sunlight at the destination during waking hours is most powerful environmental cue. Also OTC melatonin supplements can help synchronization
What is shift work sleep disorder and what is the first management strategy?
Characterized by insomnia during the daytime sleep period and resultant sleepiness during the nighttime work period. First step is to address sleep related behaviors and the sleep environment (sleep hygiene)
What drug is indicated for shift work sleep disorder if conservative strategies have not worked?
Modafinil
What are the stages of severity of OSA based on AHI?
AHI 5-15: mild OSA
AHI 16-30: moderate OSA
AHI > 30: severe OSA
What are risk factors for OSA?
Obesity is the most important risk factor
Tonsillar hypertrophy, macroglossia, retrognathia/micrognathia and upper airway mass lesions can cause upper airway narrowing. Cigarette smoking. Also can be worse with alcohol and sedative drugs. PCSO and advanced hypothyroidism can increase the risk of OSA
What are some of the initial presenting symptoms of OSA?
Loud snoring, gasping and breathing pauses observed by a bed partner.
Frequent awakenings, dry mouth, snorting and nonrestorative sleep. Nocturia in men and excessive daytime sleepiness. Mood alterations, difficulty concentrating and problems completing tasks at school or the workplace
How can OSA be unmasked following a surgical procedure?
Can be involved in repeated apneas, acute respiratory failure and even death unexpectedly
What pre-oeprative questionaire can help screen patients for post-operative complications?
STOP-BANG
How does out of center sleep testing compare to PSG in terms of diagnosing OSA?
OCST performs comparably to PSG in patients without comorbid cardiopulmonary disease who have a high pretest probability of moderate to severe OSA
How can overnight pulse oximetry alone be used for OSA evaluation?
Overnight pulse oximetry alone has a high rate of false positive and false negative results and has not been validated as a screening tool for OSA; its use should be limited to patients with low pretest probability, few symptoms or in patients who prefer to avoid treatment
What is the primary goal of OSA management and what should patients be counseled on?
Primary goal is to resolve attributable symptoms particularly EDS or daytime neurocognitive impairment. All patients should be counseled on bahavior modifications particularly weight loss
What is the preferred therapy for nearly all patients with symptomatic OSA?
PAP. The effectivness of PAP therapy is dependent on patient compliance which can be compromised by lack of motivation or side effects. 1st step is to check machine info for compliance. Also can check air leak for mask fit. Desensitization steps for claustrophobia. Also in line heated humidification or anticholinergic or glucocorticoid nasal sprays can help with comfort
What is an alternative OSA treatment for mild to moderate OSA?
Oral appliances aka oral mandibular advancement appliances
Define central sleep apnea
CAS is defined by the loss of neural output originating from the respiratory centers in the central nervous system to the respiratory pump machinery, resulting in pauses in breathing. CSA is manifested by the absence of respiratory effort associated with loss of airflow for at least 10 seconds
What comorbid heart condition and pattern of breathing can be associated with CSA?
Heart failure and Cheyne-Stokes breathing
How does CSA need to be tested and diagnosed?
In-lab PSG
What is the strongest indication for treatment of CSA and what should be the first target for therapy?
Presence of sleep related symptoms
Treatment should first target modifiable risk factors such as reducing use of opioids, medical optimization of heart failure.
CPAP may occasionally be useful
What are the most common sleep related hypoventilation syndromes?
Those associated with COPD, obesity and restrictive lung diseases related to kyphoscoliosis or neuromuscular disorders
What are neuromuscular diseases related to sleep related hypoventilation syndromes?
muscular dystrophy ALS Myesthenia gravis Guillain Barre syndrome Phrenic nerve injury Poliomyelitis, post-polio syndrome Cervical spine injury
How are hypoventilation syndromes diagnosed?
When there are sustained reductions in oxyhemoglobin saturations (<90%) for at least 5 minutes or more than 30% total sleep time by pulse ox or PSG in the context of a compatible medical condition
What differentiates OSA from hypoventilation syndromes?
Sustained reductions in oxyhemoglobin saturations that distinguish hypoventilation syndromes from the brief, repetitive deoxygenation-reoxygenation cycles typical of OSA
What is a cardinal sign of OHS?
Daytime hypercapnia (arterial PCO2 > 45mmHg) Reflects reduced ventilation during wakefulness and sleep that is not attributable to another cause
What therapies can help sleep related symptoms in patients with neuromuscular disorders?
Assisted breathing devices.
BPAP or volume cycled devices with or without supplemental oxygen
Trach and home mechanical ventilation
Supplemental oxygen should not be prescribed without adjunctive ventilatory support
