MKSAP 8: Sleep Medicine

Question 1

Define excessive daytime sleepiness

Answer 1

Also referred to as hypersomnia, refers to the struggle to remain awake and alert during daytime hours

Question 2

What is fatigue?

Answer 2

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

Question 3

What is the most common cause of EDS?

Answer 3

Overall lack of time devoted to the sleep period, insufficient sleep syndrome

Question 4

What are extrinsic causes of excessive daytime sleepiness?

Answer 4

Insufficient sleep duration
Circadian rhythm disturbances
Drug, substance or medical condition related hypersomnia
Environmental sleep disorder

Question 5

What are intrinsic causes of excessive daytime sleepiness?

Answer 5

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

Question 6

What are symptoms of jet lag? And what are management strategies?

Answer 6

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

Question 7

What is shift work sleep disorder and what is the first management strategy?

Answer 7

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)

Question 8

What drug is indicated for shift work sleep disorder if conservative strategies have not worked?

Answer 8

Modafinil

Question 9

What are the stages of severity of OSA based on AHI?

Answer 9

AHI 5-15: mild OSA
AHI 16-30: moderate OSA
AHI > 30: severe OSA

Question 10

What are risk factors for OSA?

Answer 10

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

Question 11

What are some of the initial presenting symptoms of OSA?

Answer 11

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

Question 12

How can OSA be unmasked following a surgical procedure?

Answer 12

Can be involved in repeated apneas, acute respiratory failure and even death unexpectedly

Question 13

What pre-oeprative questionaire can help screen patients for post-operative complications?

Answer 13

STOP-BANG

Question 14

How does out of center sleep testing compare to PSG in terms of diagnosing OSA?

Answer 14

OCST performs comparably to PSG in patients without comorbid cardiopulmonary disease who have a high pretest probability of moderate to severe OSA

Question 15

How can overnight pulse oximetry alone be used for OSA evaluation?

Answer 15

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

Question 16

What is the primary goal of OSA management and what should patients be counseled on?

Answer 16

Primary goal is to resolve attributable symptoms particularly EDS or daytime neurocognitive impairment. All patients should be counseled on bahavior modifications particularly weight loss

Question 17

What is the preferred therapy for nearly all patients with symptomatic OSA?

Answer 17

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

Question 18

What is an alternative OSA treatment for mild to moderate OSA?

Answer 18

Oral appliances aka oral mandibular advancement appliances

Question 19

Define central sleep apnea

Answer 19

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

Question 20

What comorbid heart condition and pattern of breathing can be associated with CSA?

Answer 20

Heart failure and Cheyne-Stokes breathing

Question 21

How does CSA need to be tested and diagnosed?

Answer 21

In-lab PSG

Question 22

What is the strongest indication for treatment of CSA and what should be the first target for therapy?

Answer 22

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

Question 23

What are the most common sleep related hypoventilation syndromes?

Answer 23

Those associated with COPD, obesity and restrictive lung diseases related to kyphoscoliosis or neuromuscular disorders

Question 24

What are neuromuscular diseases related to sleep related hypoventilation syndromes?

Answer 24

muscular dystrophy
ALS
Myesthenia gravis
Guillain Barre syndrome
Phrenic nerve injury
Poliomyelitis, post-polio syndrome
Cervical spine injury

Question 25

How are hypoventilation syndromes diagnosed?

Answer 25

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

Question 26

What differentiates OSA from hypoventilation syndromes?

Answer 26

Sustained reductions in oxyhemoglobin saturations that distinguish hypoventilation syndromes from the brief, repetitive deoxygenation-reoxygenation cycles typical of OSA

Question 27

What is a cardinal sign of OHS?

Answer 27

Daytime hypercapnia (arterial PCO2 > 45mmHg)
Reflects reduced ventilation during wakefulness and sleep that is not attributable to another cause

Question 28

What therapies can help sleep related symptoms in patients with neuromuscular disorders?

Answer 28

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