IGP 4 Sleep apnea

Define apnea.

≥10 seconds of airflow cessation

Define hypopnea.

≥30% reduction in airflow for ≥10 seconds with 4% drop in oxygen saturation

What does AHI stand for in sleep apnea?

Apnea-Hypopnea Index

How is AHI calculated?

Number of apnea + hypopnea events per hour of sleep

AHI threshold for OSA diagnosis without symptoms or comorbidities.

AHI > 15 events per hour

AHI threshold for OSA diagnosis with symptoms or comorbidities.

AHI > 5 events per hour

AHI range for mild OSA.

5-14 events per hour

AHI range for moderate OSA.

15-29 events per hour

AHI for severe OSA.

≥30 events per hour

Most common type of sleep apnea.

Obstructive sleep apnea

Physiologic mechanism of obstructive sleep apnea.

Upper airway collapse with continued respiratory effort

Physiologic mechanism of central sleep apnea.

Cessation of airflow due to absent or reduced respiratory effort

Typical snoring pattern in OSA vs CSA.

OSA: snoring common; CSA: typically no snoring

Gold standard diagnostic test for OSA.

Overnight polysomnography

When is home sleep apnea testing appropriate?

Uncomplicated suspected OSA without major comorbidities

Name 3 key nocturnal symptoms of OSA.

Snoring, nocturnal gasping or choking, witnessed apneas

Name 3 key daytime symptoms of OSA.

Excessive daytime sleepiness, fatigue, impaired memory or concentration

Neck circumference associated with increased OSA risk in men.

>17 inches

Neck circumference associated with increased OSA risk in women.

>15 inches

Most important modifiable risk factor for OSA.

Obesity

Effect of 10% weight gain on OSA risk.

Approximately 6-fold increase in OSA risk

Effect of current smoking on OSA risk compared to past/never smokers.

Approximately 3-fold increase in OSA risk

Name 3 medication classes that can worsen OSA.

Alcohol, benzodiazepines, opioids (other sedatives)

What respiratory condition can increase risk of OSA via nasal obstruction?

Allergic rhinitis or chronic nasal congestion

Two broad categories of clinical consequences of untreated OSA.

Cardiovascular/metabolic complications and neurocognitive/quality-of-life impairment

Relationship between OSA and hypertension.

Mild-moderate OSA doubles HTN risk; severe OSA triples HTN risk

Association between OSA and diabetes.

30-50% of patients with OSA have type 2 diabetes; OSA increases insulin resistance

How does intermittent hypoxia in OSA affect inflammation?

Promotes inflammatory cytokine release and atherosclerosis

How does OSA contribute to metabolic syndrome?

Promotes insulin resistance, dyslipidemia, and weight gain (via leptin resistance)

Impact of OSA on accident risk.

Increases risk of motor vehicle and work-related accidents

First-line nonpharmacologic strategy for most patients with OSA.

Weight loss and lifestyle modification

Key sleep hygiene recommendation related to caffeine.

Avoid caffeine after noon

Recommended sleep position in OSA.

Avoid supine (back) position; favor side-sleeping

Role of tobacco cessation in OSA.

Reduces upper airway inflammation and may improve OSA severity

Can medications alone treat OSA?

No; no medication cures OSA—mechanical and behavioral therapies are primary

Primary first-line device therapy for moderate to severe OSA.

Continuous positive airway pressure (CPAP)

Main mechanism of CPAP in OSA.

Provides continuous positive airway pressure that splints the upper airway open

Common local adverse effects of CPAP.

Nasal congestion, nasal dryness, skin irritation or abrasions at mask site

Common general adverse effects of CPAP.

Mask discomfort, claustrophobia, device noise, partner intolerance

Typical adherence definition for CPAP use.

Use ≥4 hours per night on ≥70% of nights

How does BiPAP differ from CPAP?

BiPAP uses higher inspiratory pressure and lower expiratory pressure

Clinical situations where BiPAP is preferred over CPAP.

Patients with COPD, restrictive lung disease, or CHF needing ventilatory support

Typical OSA severity where oral appliances are most useful.

Mild to moderate OSA, or patients intolerant to CPAP

Mechanism of mandibular advancement oral appliances.

Advance mandible and tongue forward to increase upper airway patency

Indication for Inspire hypoglossal nerve stimulation.

Moderate to severe OSA with CPAP intolerance and BMI <40

General effect of Inspire on AHI.

Reduces AHI by about 50%

Main role of modafinil or armodafinil in OSA.

Treatment of residual excessive daytime sleepiness despite adequately treated OSA with CPAP

Are modafinil and armodafinil treatments for the airway obstruction of OSA?

No; they treat only daytime sleepiness, not the obstruction

Role of solriamfetol in OSA.

Treats residual excessive daytime sleepiness associated with OSA

Role of theophylline in sleep apnea.

Respiratory stimulant mainly used in certain cases of central sleep apnea, especially in heart failure

Role of levothyroxine in OSA.

Used when OSA is associated with hypothyroidism; treats the thyroid disorder, not primary OSA

Two key treatment components for central sleep apnea.

Treat underlying cause and consider CPAP with or without supplemental oxygen

Definition of snoring.

Inspiratory sound from vibration of soft tissues in the upper airway during sleep

Can snoring occur without OSA?

Yes; snoring alone is not necessarily OSA if there is no sleep fragmentation or apneas

First-line non-device treatments for primary snoring.

Weight loss, avoidance of alcohol, positional therapy, management of nasal congestion