Tests
1st tests to order
attended polysomnography (PSG)
Test
Attended polysomnography at a sleep laboratory is the definitive test. PSG commonly includes electroencephalogram, electrooculographic recording, air flow assessment, electromyogram, capnography, esophageal manometry, ECG, and pulse oximetry.[68]
Can be a full night or split night study. Full night study: patient may return for continuous positive airway pressure (CPAP) titration, where the therapeutic CPAP level is determined and proper interface fitting and troubleshooting is performed.
Split study: diagnosis and CPAP titration performed on the same night.
Result
Apnea-Hypopnea Index (AHI) ≥15 episodes/hour or AHI ≥5 with symptoms or comorbidities (hypertension, ischemic cardiac disease, history of stroke, excessive daytime sleepiness, insomnia, mood disorder, or cognitive dysfunction)
unattended nonlaboratory PSG
Test
OSA is more commonly and efficiently diagnosed at home using unattended studies. Auto-titrating devices may be used in lieu of attended CPAP titration.
The absence of a sleep technician to exchange different interfaces, and troubleshoot problems during sleep may potentially be problematic.[69] Nonetheless, autoadjusting positive airway pressure expedites treatment initiation, may be better tolerated by some, may reduce aerophagia, and can adapt pressure to variable conditions such as weight changes and alcohol intake.[70]
Result
Apnea-Hypopnea Index (AHI) ≥15 episodes/hour or AHI ≥5 with symptoms or comorbidities (hypertension, ischemic cardiac disease, history of stroke, excessive daytime sleepiness, insomnia, mood disorder, or cognitive dysfunction)
portable multichannel home sleep tests
Test
Various home studies systems exist combining cardiorespiratory and other sensor channels. Portable tests typically include a smaller selection of channels than the polysomnogram (e.g., nasal pressure, oximetry, thoracoabdominal effort sensors, heart rate, mandibular movements, respiratory sounds, and position sensors), but most do not measure sleep.[72][73][74]
Portable tests may underestimate the Respiratory Event Index (REI) as obstructions are measured recording time, not sleep time.
The American Academy of Sleep Medicine recommends that portable studies be used for patients with high pretest probability of OSA when used as part of a comprehensive clinical sleep evaluation in patients without major comorbidities (e.g., cardiopulmonary disease, chronic opioid therapy, or neuromuscular disease).[39][76][Evidence B]
Result
REI of ≥15 episodes/hour or REI ≥5 with symptoms or comorbidities
awake fiberoptic endoscopy
Test
Routinely performed to exclude the presence of hypertrophic lingual tonsils or lesions, such as nasal polyps or tumors (pharyngeal, parapharyngeal, or laryngeal tumors), and to assess structures and sites mediating obstruction, especially in a continuous positive airway pressure-intolerant patient. Endoscopy may also be used for oral appliance therapy assessment.[86]
Result
may see nasal polyps or tumors, or hypertrophic lingual tonsils
Emerging tests
dynamic MRI
Test
Provides images of the exact sites and pattern of obstruction in OSA patients while asleep. A dynamic MRI modality. There is significant heterogeneity in the literature and standardization is needed.[87]
Result
location of airway obstruction may be detected
drug-induced sleep endoscopy (DISE)
Test
For evaluation of the OSA airway prior to surgery or or hypoglossal neurostimulation. Intravenous sedation in a monitored setting is used to induce sleep, and the airway is evaluated using fiberoptic endoscopy to assess the loci and pattern of dynamic collapse. Interobserver scoring and technique variability are problematic, however.
Result
variable
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