Pulm - Obstructive Sleep Apnea Syndrome

Front 1

What is obstructive sleep apnea syndrome?

Back 1

Repetitive airway collapse that happens during sleep.

Front 2

Hypopnea

Back 2

A 30% decrement in flow with an associated 4% oxyhemoglobin desaturation or a 50% decrement in flow associated with arousal.

Front 3

Apnea

Back 3

A complete cessation in airflow with respect to baseline airflow.

Front 4

Apnea-Hypopnea Index (AHI)

Back 4

(apneas + hypopneas) / (time asleep in hours)

< 5 = normal
6-15 = mild
16-29 = moderate
> 30 = severe

Front 5

What are the 3 main risk factors for the development of OSAS?

Back 5

Airway anatomy and collapsibility, age, and obesity

Front 6

What is the strongest risk factor for the development of OSAS?

Back 6

Obesity

Front 7

What are the physiologic changes associated with the pharynx seen in sleep?

Back 7

Reduced tonic input to upper airway muscles, diminished reflexes that protect the pharynx from collapse, and reduced load compensation

Front 8

What are the manifestations paramount to obstructive sleep apnea syndrome?

Back 8

Snoring and excessive daytime sleepiness (measured by Epworth Sleepiness Scale)

Front 9

What is the association between OSAS and systemic hypertension?

Back 9

Large clinical studies have confirmed the association and have demonstrated a causal relationship of OSAS and systemic hypertension. Subjects have significantly higher blood pressure than subjects who snored but did not have apnea, and subjects who neither snored nor had apnea. The elevated blood pressure is present during both wakefulness and sleep and existed even after controlling for weight and gender. Acute therapy either with tracheostomy or CPAP results in decreased systemic blood pressure.

Front 10

What is the association between OSAS and pulmonary arterial hypertension?

Back 10

OSAS alone may cause mild pulmonary hypertension, but a coexisting source of daytime hypoxia is necessary to produce sustained, severe pulmonary hypertension and cor pulmonale.

Front 11

What is the association between OSAS and MI?

Back 11

There is little direct evidence to support the hypothesis that untreated OSAS contributes to vascular morbidity. There is, however, increasing epidemiologic evidence that makes this possibility a concern.

Front 12

What is the association between OSAS and cardiac arrhythmias?

Back 12

The most common arrhythmias seen in OSAS is sinus arrhythmia, sinus bradycardia, and sinus tachycardia. Sinus bradycardia is observed during the obstructive event and sinus tachycardia is seen at the termination of the obstructive event.

Front 13

Continuous Positive Airway Pressure (CPAP)

Back 13

This therapy has been proven to be the most effective therapy for sleep apnea. CPAP is administered through a nasal or nasal/oral interface that administers air pressure at a set level to provide a pneumatic stent to prevent airway collapse. The amount of pressure is titrated in the sleep laboratory to eliminate apneas, hypopneas, and snoring.

Front 14

Oral appliances in OSAS treatment

Back 14

Usually reserved for mild to moderate disease. These are fitted by a dentist and pushes the lower jaw forward. This helps open the pharyngeal space and overcome the anatomical obstruction.

Front 15

What is the most effective surgical option for OSAS?

Back 15

Tracheostomy

It is used to bypass the pharyngeal airway obstruction.