Internal Medicine

0521779407-15 CUNY1086/Karliner 0 521 77940 7 June 7, 2007 18:43

1076 Obstructive Sleep Apnea

Signs & Symptoms

■Snoring (often disturbs housemates)

■Excessive sleepiness or fatigue during daytime

■May manifest as frequent napping or dozing accidentally

■Morning headache

■Witnessed apnea

■Obesity

■Large neck size

■Overbite (retrognathia)

■Enlarged tonsils

■Narrowed airway noted in posterior pharynx

■Nasal obstruction

tests

Basic Blood Studies

■TSH (estimated prevalence of hypothyroidism 1–3% in apnea pts)

Screening Studies

■Oximetry during sleep often less helpful, because airflow not mea-

sured

■Home respiratory studies in selected pts

Specific Diagnostic Tests

■Formal polysomnography:

➣Gold standard

➣Measures airflow, chest movement, exhaled gases

➣Includes EEG staging of REM & non-REM sleep

➣Quantifies frequency of apneas & hypopneas

➣Index is # of events/h: usually referred to as

apnea-hypopnea index (AHI) or

respiratory disturbance index (RDI)

differential diagnosis

■Associated w/ abnormal breathing patterns:

➣Central sleep apnea

➣Upper airway resistance syndrome

➣Cheyne-Stokes respiration

➣Obesity hypoventilation (pickwickian syndrome)

■Other sleep disorders:

➣Narcolepsy

➣Idiopathic CNS hypersomnia

➣Periodic limb movements of sleep