Sleep Medicine, NMS

Question 1

How is delayed sleep-phase syndrome managed?

Answer 1

Morning light exposure, melatonin at night

Question 2

Who can be considered for hypoglossal nerve stimulator for sleep apnea?

Answer 2

At least 18yo, AHI between 15-65, BMI <35. If a candidate, undergo drug-induced sleep endoscopy to see if there is soft-palate collapse. Not for patients with complete concentric collapse of pharyngeal airway (as opposed to anterior collapse)

Complications include tongue weakness, hematoma, site infection, and post-op pain. AE are rare. Inspire brand is MRI compatible. Battery lasts 10 years but needs to be replaced surgically.

Question 3

How is persistent excessive daytime sleepiness managed in patients on CPAP therapy?

Answer 3

First make sure patient is compliant with therapy. If compliant, use modafinil

Question 4

What must be considered before starting modafinil/armodafinil therapy?

Answer 4

Renders OCPs ineffective. No major affect on BP/HR like stimulants do (ie methylphenidate)

Question 5

How are central sleep apneas treated?

Answer 5

Treat underlying cause (ie heart failure). Don’t do ASV in HF patients with central sleep apnea (increased mortality)

Question 6

What are the benefits of a nasal CPAP mask over a oronasal CPAP mask?

Answer 6

Though oronasal masks have been shown to worsen disease and have higher effective pressure requirements, there have not been a difference in diurnal function, objective/subjective measures including ESS in side to side comparisons

Question 7

What are the features of Guillain-Barre syndrome?

Answer 7

Features- bilateral flaccid paralysis and hyporeflexia, dysautonomia in 70%
Dx- elevated CSF protein and normal WBC, EMG
Tx- IVIG or plasma exchange

Question 8

How can CPAP affect blood pressure?

Answer 8

Reduces BP, even in patients without HTN

Question 9

What disorders are REM sleep disorders associated with?

Answer 9

neurodegenerative disease such as Lewy Body dementia/PD. Screen for anosmia. Tx with low dose clonazepam (contraindicated in narrow-angle glaucoma) and/or melatonin

Question 10

When should NIPPV be initiated in ALS patients?

Answer 10

MIP less than -60, pCO2 >45, FVC <50, reduced SpO2 on nocturnal oximetry for >5min. FVC has been shown to correlate with disease progression and mortality. If patients cannot get a good seal for MIP/VC, can substitute maximal sniff inspiratory pressure (SNIP)- less than 40 then recommends NIV

Question 11

What does expiratory pressure relief on CPAP achieve?

Answer 11

Comfort feature on hoe CPAP devices to decrease CPAP pressure by 1-3cm during the early phase of exhalation but then gradually increases back to baseline

Question 12

What are the recommendations regarding newly diagnosed OSA for pre-op clearance?

Answer 12

Untreated mild OSA doesn’t worsen post-op outcomes, so proceed with surgery. Unrecognized severe OSA with high risk comorbidities (CAD, HF, CVA/TIA, DM on treatment, CKD) is associated with worse pulmonary AND cardiovascular post-op complications, but there are no clear guidelines for pre-op clearance. OHS patients should be stabilized on PAP therapy before elective surgeries.

Question 13

What parameters in myasthenia gravis suggest ICU monitoring?

Answer 13

VC lower than 15-20mL/kg, MIP less than -30

Question 14

What situations can precipitate a myasthenia crisis?

Answer 14

Infection, injury, dose reduction of immunosuppression, start of macrolides/fluorooquinolones/aminoglycosides/Mg/BBers

Question 15

What are ways to improve compliance with CPAP?

Answer 15

Frequent contact with health-care team, CBT, education about benefits of therapy, mitigation of common side effects, short term use of eszopiclone (benefit not seen with zolpidem). Heated humidification may help patients with nasal congestion/rhinitis

Question 16

How does high altitude affect sleep-disordered breathing?

Answer 16

Worsens it due to development of central sleep apneas, not worsening of OSA. Treat with acetazolemide to reduce apenic threshold.

Question 17

What are the discharge treatments for a patient hospitalized with newly diagnosed OHS?

Answer 17

Empiric NIPPV at discharge and get outpatient sleep study as only 70% of OHS patients have concomitant OSA. Trach without nocturnal ventilation is unlikely to help those without severe OSA

Question 18

How is a hypopnea defined?

Answer 18

30+% decrease in flow for more than 10 seconds with 3-4% desaturation

Question 19

How is an apnea defined?

Answer 19

90+% decrease in flow. Obstructive if there’s physical effort, central if there’s no physical effort.

Question 20

How does APAP compare to CPAP?

Answer 20

APAP has lower mean airway pressure but with slightly higher residual AHI. Same functional status and subjective sleepiness. About 15 more minutes a night of compliance

Question 21

When is ASV indicated?

Answer 21

Treatment emergent periodic breathing that persists after 3 months of CPAP for central sleep apneas/Cheynes Stokes. Not used in patients with hypoventilation as it target’s the patient’s baseline (not OHS/NM disease, use BiPAP instead)

Question 22

During OSA sleep titration studies, how do you determine correct settings?

Answer 22

When AHI for obstructive apneas fall below 5, ignore central apneas due to treatment emergent CSA which will likely resolve in a few months

Question 23

What are the narcolepsy/hypersomnias diagnosis criterion?

Answer 23

Narcolepsy I- hypocretin below 100 OR cataplexy plus MSLT <8min with 2 SOREMs (can include one on PSG)
Narcolepsy II- no hypocretin/cataplexy, MSLT <8min with 2 SOREMs
Idiopathic hypersomnia- Routine sleep 11+hr/day OR normal hypocretin/cataplexy, MSLT <8min with 0-1 SOREMs

Question 24

What is the first NIV mode for OHS?

Answer 24

CPAP. BiPAP for patients who don’t tolerate high CPAP levels on PAP titration. Backup rate for patients who do not have concommitant OSA

Question 25

When you have a patient with high suspicion of having OSA but has a negative HSAT, what is the next best step?

Answer 25

In-lab PSG

Question 26

How do opioids affect sleep-disordered breathing?

Answer 26

Risk factor in low-normal BMI, more CSAs
Acute use- promotes N2 and wake time after sleep onset, decreases N3
Chronic- sleep distributions may normalize
Withdrawal- rebound increase in N3/REM

Question 27

For insomnia, what measures should be attempted first?

Answer 27

Behavioral/sleep hygiene changes

Question 28

What are causes of secondary central sleep apneas

Answer 28

Cheynes-Stokes (from HF or CVA), high altitude, sedative-hypnotic use. Use CPAP, but if CPAP fails consider supplemental oxygen to decrease CO2 chemosensitivity to improve AHI and desaturations

Question 29

How are limb movement disorders classified?

Answer 29

RLS- symptomatic, associated with insomnia, may warrant ferritin and pharmacologic therapy, PSG not needed (dopamine agonists pramipexole/rotigotine and gabapentin)
PLMS- PSG finding, often asymptomatic
PLMD- PLMS + symptoms. Treat like RLS (data less robust)

Question 30

Who are candidates for HSAT?

Answer 30

High pre-test probability of OSA- symptomatic, frequent witnessed apneas, obese, neck circumference >17inches without comorbidities that would require monitoring (COPD/HF, NM disorders, awake hypoxemia/hypercapneia, CSA risk factors, significant insomnia)

Question 31

For patients with restrictive lung disease due to kyphoscoliosis, when should NIPPV be considered?

Answer 31

RA SpO2 <95%, pCO2 >45, awake dyspnea, MIP/MEP <60

Question 32

When diagnosing narcolepsy, why do we perform PSG prior to MSLT?

Answer 32

To ensure patient is starting MSLT with adequate sleep