Obstructive sleep apnea involves episodes where nasal and/or oral airflow is absent for 10 or more seconds. Severe obstructive sleep apnea can be associated with increased mortality. If patients at high risk can be identified, then they can receive appropriate therapy.


Clinical features of obstructive sleep apnea:

(1) usually occurs in obese males

(2) repetitive apneic episodes occur during sleep

(3) apneic episodes are associated with bradycardia, hypoxemia, and arousals with fragmented sleep


Classification of apneic episodes:

(1) central: cessation of nasal and oral airflow with cessation of respiratory effort

(2) obstructive: absence of nasal and oral airflow despite continuing respiratory effort

(3) mixed: both central and obstructive patterns, usually with the central apnea being followed by the obstructive component


apnea index =

= (sum of all apneic episodes during study period) / (number of hours in study period)



• Patients with apnea index >=20 associated with higher mortality rate than patients with apnea index < 20

• 8-year survival in patients with apnea index >=20 is 63 +/- 17%

• 8-year survival in patients with apnea index <20 is 96 +/- 2%


If patients with a high apnea index do not respond to surgical therapy (uvulopalatopharyngoplasty), then they should be treated with either nasal CPAP or tracheostomy.


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