17:I[462708,["/_next/static/chunks/3yo3kiro3bmlp.js","/_next/static/chunks/3vr2wvd8f2efb.js","/_next/static/chunks/2vtmb68_vu-9t.js","/_next/static/chunks/2s8mt6_8wrpfo.js","/_next/static/chunks/3vkulz2i3l61y.js","/_next/static/chunks/1cqw2i1silz0i.js","/_next/static/chunks/14dbm3lm_t629.js","/_next/static/chunks/335_v2mb569ld.js","/_next/static/chunks/1jvnwmb7jnkpz.js","/_next/static/chunks/3cmavum774kjt.js","/_next/static/chunks/3th-0-a2xf9qs.js","/_next/static/chunks/0p0xpwde6kzmv.js","/_next/static/chunks/401-sxxnzbtf_.js","/_next/static/chunks/0wywtv698a1v0.js","/_next/static/chunks/2botzqwpnrzyj.js"],"ArticleReader"] 18:T5487,## Summary Obstructive sleep apnea (OSA) is recurrent partial or complete upper-airway collapse during sleep, causing airflow limitation, intermittent hypoxemia, sleep fragmentation, swings in intrathoracic pressure, and sympathetic activation. Suspect it with habitual snoring, witnessed apneas, nocturnal choking or gasping, nonrestorative sleep, excessive daytime sleepiness, resistant hypertension, atrial fibrillation, obesity, or characteristic craniofacial/upper-airway anatomy. Screening questionnaires estimate probability but **do not establish the diagnosis**. [1] Diagnosis requires objective sleep testing. In an uncomplicated adult with a high pretest probability of moderate-to-severe OSA, either attended polysomnography (PSG) or a technically adequate home sleep apnea test (HSAT) is appropriate. A negative, inconclusive, or technically inadequate HSAT should be followed by PSG when clinical suspicion persists. PSG is preferred when significant cardiorespiratory disease, possible respiratory muscle weakness, awake or suspected sleep-related hypoventilation, chronic opioid use, prior stroke, or severe insomnia could make simplified testing misleading. [1] Severity is conventionally described by the apnea-hypopnea index (AHI): **mild 5 to <15, moderate 15 to <30, severe ≥30 events/hour**. Clinical burden is not captured by AHI alone; review oxygenation, event duration, sleep fragmentation, symptoms, cardiovascular and pulmonary comorbidity, occupation/driving risk, central events, and patient goals. Positive airway pressure (PAP) is the most consistently effective therapy for eliminating obstructive respiratory events. The American Academy of Sleep Medicine strongly recommends PAP for adults with OSA and excessive sleepiness and supports CPAP or auto-adjusting PAP for ongoing treatment in most adults. [2] Weight management is foundational when overweight or obesity contributes. A custom titratable mandibular advancement device is an evidence-based alternative when PAP is not tolerated or the patient prefers oral-appliance therapy. Selected PAP-intolerant patients should be referred for upper-airway or bariatric surgical assessment when appropriate. [3] In the United States, the FDA approved **tirzepatide on December 20, 2024 for moderate-to-severe OSA in adults with obesity**, in conjunction with reduced-calorie diet and increased physical activity. This is an obesity-directed adjunct; it does not remove the need to assess residual OSA, PAP requirements, driving safety, or other airway-directed treatment. [5] ## Pathophysiology Upper-airway patency during sleep reflects the balance between pharyngeal anatomy, dilator-muscle activity, ventilatory control, arousal threshold, and lung-volume effects. Sleep reduces compensatory neuromuscular tone. Collapse becomes more likely when anatomic load and collapsibility exceed the capacity of upper-airway dilator muscles to maintain patency. Common contributors include: - obesity and central adiposity; - increased tongue or pharyngeal soft tissue; - tonsillar hypertrophy; - retrognathia, micrognathia, or maxillary restriction; - nasal obstruction; - reduced lung volume; - alcohol or sedative exposure; - age-related changes in upper-airway neuromuscular control. Repetitive obstruction causes oxygen desaturation and reoxygenation, cortical and autonomic arousals, negative intrathoracic-pressure swings, blood-pressure surges, and fragmented sleep. These mechanisms help explain sleepiness and cardiometabolic associations, but treatment effects on long-term cardiovascular events depend on phenotype, adherence, and population studied. ## Risk factors and associated conditions Major risk factors include: - obesity, particularly central adiposity; - increasing age; - male sex before menopause, with risk increasing in women later in life; - craniofacial restriction or a crowded upper airway; - family history; - alcohol and sedating medications; - acromegaly and hypothyroidism; - resistant hypertension; - atrial fibrillation; - heart failure; - type 2 diabetes; - prior stroke. Normal body mass index does not exclude clinically important OSA, especially when craniofacial anatomy or ventilatory-control instability is prominent. ## Clinical presentation ### Nocturnal symptoms - loud habitual snoring; - witnessed pauses in breathing; - gasping, choking, or snorting arousals; - fragmented or unrefreshing sleep; - nocturia; - dry mouth on awakening; - morning headache; - sleep-maintenance insomnia. ### Daytime manifestations - excessive sleepiness or unintended dozing; - impaired attention, vigilance, memory, or work performance; - fatigue; - mood symptoms or irritability; - reduced libido; - drowsy driving, near misses, or crashes. Women and older adults may present with fatigue, insomnia, headache, cognitive complaints, or mood symptoms rather than classic overwhelming sleepiness. > **Caution:** Recurrent sleep episodes while driving or during safety-sensitive work require immediate risk counseling. The patient should avoid driving or hazardous duties until sleepiness is adequately controlled; licensing and reporting rules are jurisdiction-specific. ## Clinical assessment ### History Document: - frequency and intensity of snoring; - witnessed apneas, choking, or gasping; - sleep duration and schedule; - insomnia and nocturnal awakenings; - daytime sleepiness and unintended dozing; - drowsy-driving events; - alcohol use and timing; - opioids, benzodiazepines, hypnotics, gabapentinoids, and other sedating drugs; - cardiovascular, cerebrovascular, pulmonary, endocrine, and neuromuscular disease; - prior sleep testing or OSA therapy; - PAP or oral-appliance use, barriers, and perceived benefit. When possible, obtain collateral sleep history from a bed partner. ### Physical assessment Relevant findings include: - body mass index and weight trajectory; - blood pressure; - central adiposity and neck habitus; - nasal obstruction; - tonsillar enlargement; - tongue size and tongue scalloping; - crowded soft palate/oropharynx; - mandibular or maxillary restriction; - dentition if an oral appliance is being considered; - signs of heart failure or pulmonary hypertension; - neuromuscular weakness; - features suggesting hypothyroidism or acromegaly. No single physical finding can rule OSA in or out. ## Diagnostic testing ### Polysomnography Attended PSG records sleep stage, airflow, respiratory effort, oxygenation, cardiac rhythm, and other physiologic signals. It allows event frequency to be indexed to actual sleep time and better characterizes central events, arousals, REM-related disease, positional effects, and other sleep disorders. Use PSG preferentially when there is: - significant cardiorespiratory disease; - possible respiratory muscle weakness from neuromuscular disease; - awake or suspected sleep-related hypoventilation; - chronic opioid use; - prior stroke; - severe insomnia; - an inconclusive or negative HSAT despite persistent clinical suspicion. [1] ### Home sleep apnea testing A technically adequate HSAT is appropriate for selected **uncomplicated adults with signs and symptoms indicating increased risk of moderate-to-severe OSA**. [1] Limitations include: - many devices use recording time rather than measured sleep time and may underestimate event frequency; - signal loss can make the study nondiagnostic; - central versus obstructive physiology may be incompletely characterized; - another sleep disorder can be missed. A negative HSAT does not reliably exclude OSA in a high-probability patient. Proceed to PSG when the result is negative, inconclusive, or technically inadequate and suspicion remains. [1] ## Interpreting a sleep study ### Key respiratory metrics | Metric | Interpretation | |---|---| | AHI | Apneas plus hypopneas per hour of measured sleep on PSG | | REI | Respiratory events per hour of recording/monitoring time on many HSAT systems; can underestimate sleep-based AHI | | ODI | Oxygen-desaturation events per hour using a specified threshold; physiologically useful but not a stand-alone OSA diagnosis | | Oxygen nadir | Lowest saturation reached; interpret with baseline oxygenation and event pattern | | Time below an oxygen threshold | Helps characterize cumulative hypoxemia, especially when disease severity seems disproportionate to AHI | ### Conventional AHI bands | AHI | Category | Clinical use | |---:|---|---| | <5/h | Below conventional OSA threshold | Does not exclude another sleep disorder or occasional clinically important respiratory events | | 5 to <15/h | Mild | Treat according to symptoms, comorbidity, safety risk, and preference | | 15 to <30/h | Moderate | Active treatment is usually appropriate | | ≥30/h | Severe | High event burden; pursue effective therapy and address adherence barriers promptly | ### Read beyond the AHI Review: - obstructive versus central event proportion; - REM and positional dependence; - oxygen nadir and cumulative hypoxemia; - arousal burden; - sleep efficiency and architecture on PSG; - whether adequate supine and REM sleep occurred; - cardiac-rhythm observations; - technical quality; - symptoms and comorbidity. Marked hypoxemia out of proportion to AHI should raise concern for obesity hypoventilation syndrome, chronic lung disease, neuromuscular weakness, heart failure, or another gas-exchange disorder. ## Differential diagnosis and overlap syndromes | Alternative/overlap | Clues | Next step | |---|---|---| | Chronic sleep restriction | Short habitual sleep time, improvement with adequate sleep opportunity | Correct sleep opportunity and reassess | | Insomnia disorder | Difficulty initiating/maintaining sleep without clear respiratory pattern | Treat insomnia; PSG if OSA probability remains significant | | Central sleep apnea | Central events, heart failure, opioids, high altitude, neurologic disease | PSG and cause-directed assessment | | Obesity hypoventilation syndrome | Obesity plus awake hypercapnia or strong suspicion of sleep-related hypoventilation | Blood gas/CO₂ assessment and PSG; ventilatory treatment pathway | | Narcolepsy/central hypersomnolence | Irresistible sleep attacks despite adequate sleep, cataplexy or other features | Sleep-specialist evaluation after sleep deprivation/OSA are addressed | | Restless legs/periodic limb movement disorder | Urge to move legs, discomfort at rest, repetitive limb movements | Iron status and sleep evaluation as appropriate | | Medication-related somnolence | Opioids, sedatives, antihistamines, dopamine agonists, other CNS drugs | Medication review and risk reduction | ## Management goals Treatment aims to: - eliminate or substantially reduce obstructive respiratory events; - improve sleepiness, alertness, sleep quality, and quality of life; - reduce driving and occupational risk; - control hypoxemia and related physiologic burden; - address obesity and other reversible contributors; - choose a treatment the patient can use consistently. ## Positive airway pressure ### Indications and modality PAP is the most reliably effective therapy for upper-airway obstruction. AASM guidance strongly recommends PAP in adults with OSA and excessive sleepiness and supports treatment in patients with impaired sleep-related quality of life or comorbid hypertension. [2] For most uncomplicated adults: - CPAP or auto-adjusting PAP can be used for ongoing therapy; - home initiation with auto-adjusting PAP is appropriate in selected patients without important comorbidities; - bilevel PAP is not routinely required for uncomplicated OSA but may be useful when high pressures, hypoventilation, or other ventilatory problems require a different strategy. ### Early troubleshooting Adherence improves when problems are addressed promptly. Review: - mask fit and leak; - nasal obstruction or dryness; - mouth leak; - pressure intolerance; - aerophagia; - claustrophobia; - insomnia; - persistent sleepiness despite apparently adequate use. Use device download data to assess nightly use, residual event index, pressure, and leak. Persistent residual events require review of mask leak, positional/REM disease, treatment-emergent central apnea, weight change, and whether repeat sleep testing is needed. > **Clinical pearl:** A device-reported residual event index is a monitoring signal, not a substitute for clinical interpretation. Large leak and proprietary event-detection algorithms can make the number misleading. ## Weight management Weight reduction can substantially improve OSA in patients with overweight or obesity and should be integrated with airway-directed treatment rather than deferred until PAP succeeds or fails. Components can include: - structured nutrition and physical-activity treatment; - behavioral obesity management; - anti-obesity pharmacotherapy when indicated; - bariatric-surgery referral for eligible patients. See [Obesity in Adults](../endocrinology/obesity-in-adults.md). ### Tirzepatide in OSA with obesity The U.S. FDA approved tirzepatide on **December 20, 2024** for adults with obesity and moderate-to-severe OSA, together with reduced-calorie diet and increased physical activity. The approval was based on randomized trials that enrolled adults both with and without ongoing PAP and showed clinically meaningful AHI reduction after 52 weeks. [5,6] This approval is jurisdiction-specific. Treatment selection should account for contraindications, gastrointestinal adverse effects, gallbladder/pancreatic risk, concomitant glucose-lowering therapy, pregnancy considerations, and local labeling. Reassess OSA after substantial weight loss rather than assuming that symptom improvement proves resolution. ## Oral-appliance therapy A custom, titratable mandibular advancement device is appropriate for selected adults who prefer it or cannot tolerate PAP. It is most effective when fitted and followed by a qualified dental professional working with the sleep clinician. After titration, confirm treatment effectiveness with objective sleep testing because improvement in snoring does not prove adequate control of OSA. Potential problems include jaw discomfort, temporomandibular symptoms, salivation/dry mouth, bite changes, and dental movement. ## Positional and adjunctive therapy Positional therapy may help patients whose OSA is substantially worse when supine. It can be used alone in carefully selected positional disease or as an adjunct. Confirm efficacy objectively if it is the principal treatment. Treat clinically important nasal obstruction to improve comfort and PAP tolerance, but nasal therapy alone rarely controls moderate-to-severe pharyngeal OSA. Avoid alcohol near bedtime and minimize unnecessary sedating drugs, particularly when they worsen respiratory events or daytime impairment. ## Surgical and device-based pathways Selected patients with persistent OSA who cannot use PAP should be considered for consultation about upper-airway surgery or other device-based therapy. The 2021 AASM guideline recommends discussing surgical referral with appropriate PAP-intolerant adults and recommends bariatric-surgical discussion for eligible patients with obesity. [3] Options depend on anatomy and include: - tonsil or palatal surgery in selected anatomy; - maxillomandibular advancement; - hypoglossal-nerve stimulation in appropriately selected patients meeting local criteria; - bariatric surgery when obesity is a major contributor and surgical criteria are met. Selection should be based on airway anatomy, OSA severity, body habitus, prior treatment response, patient preference, and procedure-specific risk. Objective follow-up testing is needed after definitive non-PAP therapy. ## Cardiovascular and metabolic comorbidity OSA is associated with hypertension, atrial fibrillation, stroke, coronary disease, insulin resistance, and heart failure, but the strength of treatment benefit differs by outcome and patient phenotype. - Treat symptomatic OSA and physiologic obstruction because PAP reliably improves respiratory events and sleepiness. - Continue guideline-directed management of hypertension, atrial fibrillation, heart failure, and vascular risk; OSA treatment does not replace it. - Do not promise prevention of myocardial infarction or stroke solely from PAP, particularly in minimally sleepy populations with limited adherence. Related library topics include [Primary Hypertension in Adults](../cardiology/primary-hypertension-in-adults.md), [Atrial Fibrillation](../cardiology/atrial-fibrillation.md), and [Heart Failure With Preserved Ejection Fraction](../cardiology/heart-failure-with-preserved-ejection-fraction.md). ## Special populations ### Chronic opioid use Opioids increase risk of central apnea and hypoventilation as well as obstruction. Prefer PSG to routine HSAT and characterize respiratory physiology before assuming uncomplicated OSA. [1] ### Neuromuscular disease or suspected hypoventilation Use PSG with appropriate gas-exchange assessment and evaluate awake CO₂ when indicated. PAP mode must match the ventilatory disorder; standard CPAP may be insufficient when hypoventilation is present. ### Heart failure Central sleep apnea may coexist with OSA. Review event type before escalating PAP. Continue evidence-based heart-failure therapy and avoid assuming all nocturnal respiratory events are obstructive. ### Pregnancy OSA can emerge or worsen with gestational weight gain and upper-airway edema. PAP is generally the preferred treatment when clinically important OSA is confirmed. Coordinate with obstetric care when hypertension, preeclampsia risk, or severe nocturnal hypoxemia is present. ### Older adults Symptoms may present as fatigue, cognitive impairment, falls, or insomnia rather than classic sleepiness. Balance treatment benefit against dexterity, cognition, caregiver support, mask handling, and comorbid sleep disorders. ## Perioperative and inpatient care Patients with known OSA should tell anesthesia and surgical teams and bring/use established PAP when feasible. Postoperative opioids and sedatives can worsen obstruction and hypoventilation; monitoring intensity should match OSA severity, procedure, opioid burden, and comorbidity. For hospitalized patients, continue established OSA treatment unless contraindicated. New severe nocturnal hypoxemia should not automatically be attributed to OSA; assess for atelectasis, pneumonia, pulmonary edema, pulmonary embolism, opioid effect, and hypoventilation as clinically appropriate. ## Monitoring and treatment response At follow-up, assess: - daytime sleepiness and alertness; - drowsy driving or occupational risk; - PAP adherence, leak, pressure, and residual events; - oral-appliance tolerance and dental effects; - weight trajectory; - blood pressure and relevant cardiometabolic disease; - persistent snoring or witnessed apneas; - new central events or hypoventilation concerns. Repeat objective sleep testing when: - symptoms persist despite apparently adequate therapy; - non-PAP treatment is used as the primary therapy; - major weight loss or gain may have changed disease severity; - device data and symptoms are discordant; - recurrent OSA is suspected after surgery or prior successful treatment. ## Disposition and referral Most OSA is managed outpatient. Urgent evaluation is appropriate for uncontrolled sleepiness creating immediate driving/occupational danger, severe unexplained hypoxemia, suspected awake hypercapnia, recurrent arrhythmia/syncope related to nocturnal events, or another acute cardiopulmonary disorder. Refer to sleep medicine when diagnosis is uncertain, HSAT is nondiagnostic, central apnea or hypoventilation is suspected, PAP remains intolerable despite troubleshooting, a non-PAP device/surgical pathway is being considered, or persistent sleepiness remains unexplained after adequate OSA control. ## References 1. Kapur VK, Auckley DH, Chowdhuri S, et al. Clinical practice guideline for diagnostic testing for adult obstructive sleep apnea: an American Academy of Sleep Medicine clinical practice guideline. *Journal of Clinical Sleep Medicine*. 2017;13(3):479-504. doi:10.5664/jcsm.6506. PMID: 28162150. https://pubmed.ncbi.nlm.nih.gov/28162150/ 2. Patil SP, Ayappa IA, Caples SM, Kimoff RJ, Patel SR, Harrod CG. Treatment of adult obstructive sleep apnea with positive airway pressure: an American Academy of Sleep Medicine clinical practice guideline. *Journal of Clinical Sleep Medicine*. 2019;15(2):335-343. doi:10.5664/jcsm.7640. PMID: 30736887. https://pubmed.ncbi.nlm.nih.gov/30736887/ 3. Kent D, Stanley J, Aurora RN, et al. Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine clinical practice guideline. *Journal of Clinical Sleep Medicine*. 2021;17(12):2499-2505. doi:10.5664/jcsm.9592. PMID: 34351848. https://pubmed.ncbi.nlm.nih.gov/34351848/ 4. National Institute for Health and Care Excellence. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s (NG202). 2021. https://www.nice.org.uk/guidance/ng202 5. U.S. Food and Drug Administration. FDA approves first medication for obstructive sleep apnea. December 20, 2024. https://www.fda.gov/news-events/press-announcements/fda-approves-first-medication-obstructive-sleep-apnea 6. Malhotra A, Grunstein RR, Fietze I, et al. Tirzepatide for the treatment of obstructive sleep apnea and obesity. *New England Journal of Medicine*. 2024;391:1193-1205. doi:10.1056/NEJMoa2404881. https://doi.org/10.1056/NEJMoa240488119:T54a7,## Summary Obstructive sleep apnea (OSA) is recurrent partial or complete upper-airway collapse during sleep, causing airflow limitation, intermittent hypoxemia, sleep fragmentation, swings in intrathoracic pressure, and sympathetic activation. Suspect it with habitual snoring, witnessed apneas, nocturnal choking or gasping, nonrestorative sleep, excessive daytime sleepiness, resistant hypertension, [atrial fibrillation](/library/atrial-fibrillation), obesity, or characteristic craniofacial/upper-airway anatomy. Screening questionnaires estimate probability but **do not establish the diagnosis**. [1] Diagnosis requires objective sleep testing. In an uncomplicated adult with a high pretest probability of moderate-to-severe OSA, either attended polysomnography (PSG) or a technically adequate home sleep apnea test (HSAT) is appropriate. A negative, inconclusive, or technically inadequate HSAT should be followed by PSG when clinical suspicion persists. PSG is preferred when significant cardiorespiratory disease, possible respiratory muscle weakness, awake or suspected sleep-related hypoventilation, chronic opioid use, prior stroke, or severe insomnia could make simplified testing misleading. [1] Severity is conventionally described by the apnea-hypopnea index (AHI): **mild 5 to <15, moderate 15 to <30, severe ≥30 events/hour**. Clinical burden is not captured by AHI alone; review oxygenation, event duration, sleep fragmentation, symptoms, cardiovascular and pulmonary comorbidity, occupation/driving risk, central events, and patient goals. Positive airway pressure (PAP) is the most consistently effective therapy for eliminating obstructive respiratory events. The American Academy of Sleep Medicine strongly recommends PAP for adults with OSA and excessive sleepiness and supports CPAP or auto-adjusting PAP for ongoing treatment in most adults. [2] Weight management is foundational when overweight or obesity contributes. A custom titratable mandibular advancement device is an evidence-based alternative when PAP is not tolerated or the patient prefers oral-appliance therapy. Selected PAP-intolerant patients should be referred for upper-airway or bariatric surgical assessment when appropriate. [3] In the United States, the FDA approved **tirzepatide on December 20, 2024 for moderate-to-severe OSA in adults with obesity**, in conjunction with reduced-calorie diet and increased physical activity. This is an obesity-directed adjunct; it does not remove the need to assess residual OSA, PAP requirements, driving safety, or other airway-directed treatment. [5] ## Pathophysiology Upper-airway patency during sleep reflects the balance between pharyngeal anatomy, dilator-muscle activity, ventilatory control, arousal threshold, and lung-volume effects. Sleep reduces compensatory neuromuscular tone. Collapse becomes more likely when anatomic load and collapsibility exceed the capacity of upper-airway dilator muscles to maintain patency. Common contributors include: - obesity and central adiposity; - increased tongue or pharyngeal soft tissue; - tonsillar hypertrophy; - retrognathia, micrognathia, or maxillary restriction; - nasal obstruction; - reduced lung volume; - alcohol or sedative exposure; - age-related changes in upper-airway neuromuscular control. Repetitive obstruction causes oxygen desaturation and reoxygenation, cortical and autonomic arousals, negative intrathoracic-pressure swings, blood-pressure surges, and fragmented sleep. These mechanisms help explain sleepiness and cardiometabolic associations, but treatment effects on long-term cardiovascular events depend on phenotype, adherence, and population studied. ## Risk factors and associated conditions Major risk factors include: - obesity, particularly central adiposity; - increasing age; - male sex before menopause, with risk increasing in women later in life; - craniofacial restriction or a crowded upper airway; - family history; - alcohol and sedating medications; - acromegaly and hypothyroidism; - resistant hypertension; - atrial fibrillation; - heart failure; - type 2 diabetes; - prior stroke. Normal body mass index does not exclude clinically important OSA, especially when craniofacial anatomy or ventilatory-control instability is prominent. ## Clinical presentation ### Nocturnal symptoms - loud habitual snoring; - witnessed pauses in breathing; - gasping, choking, or snorting arousals; - fragmented or unrefreshing sleep; - nocturia; - dry mouth on awakening; - morning headache; - sleep-maintenance insomnia. ### Daytime manifestations - excessive sleepiness or unintended dozing; - impaired attention, vigilance, memory, or work performance; - fatigue; - mood symptoms or irritability; - reduced libido; - drowsy driving, near misses, or crashes. Women and older adults may present with fatigue, insomnia, headache, cognitive complaints, or mood symptoms rather than classic overwhelming sleepiness. > **Caution:** Recurrent sleep episodes while driving or during safety-sensitive work require immediate risk counseling. The patient should avoid driving or hazardous duties until sleepiness is adequately controlled; licensing and reporting rules are jurisdiction-specific. ## Clinical assessment ### History Document: - frequency and intensity of snoring; - witnessed apneas, choking, or gasping; - sleep duration and schedule; - insomnia and nocturnal awakenings; - daytime sleepiness and unintended dozing; - drowsy-driving events; - alcohol use and timing; - opioids, benzodiazepines, hypnotics, gabapentinoids, and other sedating drugs; - cardiovascular, cerebrovascular, pulmonary, endocrine, and neuromuscular disease; - prior sleep testing or OSA therapy; - PAP or oral-appliance use, barriers, and perceived benefit. When possible, obtain collateral sleep history from a bed partner. ### Physical assessment Relevant findings include: - body mass index and weight trajectory; - blood pressure; - central adiposity and neck habitus; - nasal obstruction; - tonsillar enlargement; - tongue size and tongue scalloping; - crowded soft palate/oropharynx; - mandibular or maxillary restriction; - dentition if an oral appliance is being considered; - signs of heart failure or pulmonary hypertension; - neuromuscular weakness; - features suggesting hypothyroidism or acromegaly. No single physical finding can rule OSA in or out. ## Diagnostic testing ### Polysomnography Attended PSG records sleep stage, airflow, respiratory effort, oxygenation, cardiac rhythm, and other physiologic signals. It allows event frequency to be indexed to actual sleep time and better characterizes central events, arousals, REM-related disease, positional effects, and other sleep disorders. Use PSG preferentially when there is: - significant cardiorespiratory disease; - possible respiratory muscle weakness from neuromuscular disease; - awake or suspected sleep-related hypoventilation; - chronic opioid use; - prior stroke; - severe insomnia; - an inconclusive or negative HSAT despite persistent clinical suspicion. [1] ### Home sleep apnea testing A technically adequate HSAT is appropriate for selected **uncomplicated adults with signs and symptoms indicating increased risk of moderate-to-severe OSA**. [1] Limitations include: - many devices use recording time rather than measured sleep time and may underestimate event frequency; - signal loss can make the study nondiagnostic; - central versus obstructive physiology may be incompletely characterized; - another sleep disorder can be missed. A negative HSAT does not reliably exclude OSA in a high-probability patient. Proceed to PSG when the result is negative, inconclusive, or technically inadequate and suspicion remains. [1] ## Interpreting a sleep study ### Key respiratory metrics | Metric | Interpretation | |---|---| | AHI | Apneas plus hypopneas per hour of measured sleep on PSG | | REI | Respiratory events per hour of recording/monitoring time on many HSAT systems; can underestimate sleep-based AHI | | ODI | Oxygen-desaturation events per hour using a specified threshold; physiologically useful but not a stand-alone OSA diagnosis | | Oxygen nadir | Lowest saturation reached; interpret with baseline oxygenation and event pattern | | Time below an oxygen threshold | Helps characterize cumulative hypoxemia, especially when disease severity seems disproportionate to AHI | ### Conventional AHI bands | AHI | Category | Clinical use | |---:|---|---| | <5/h | Below conventional OSA threshold | Does not exclude another sleep disorder or occasional clinically important respiratory events | | 5 to <15/h | Mild | Treat according to symptoms, comorbidity, safety risk, and preference | | 15 to <30/h | Moderate | Active treatment is usually appropriate | | ≥30/h | Severe | High event burden; pursue effective therapy and address adherence barriers promptly | ### Read beyond the AHI Review: - obstructive versus central event proportion; - REM and positional dependence; - oxygen nadir and cumulative hypoxemia; - arousal burden; - sleep efficiency and architecture on PSG; - whether adequate supine and REM sleep occurred; - cardiac-rhythm observations; - technical quality; - symptoms and comorbidity. Marked hypoxemia out of proportion to AHI should raise concern for obesity hypoventilation syndrome, chronic lung disease, neuromuscular weakness, heart failure, or another gas-exchange disorder. ## Differential diagnosis and overlap syndromes | Alternative/overlap | Clues | Next step | |---|---|---| | Chronic sleep restriction | Short habitual sleep time, improvement with adequate sleep opportunity | Correct sleep opportunity and reassess | | Insomnia disorder | Difficulty initiating/maintaining sleep without clear respiratory pattern | Treat insomnia; PSG if OSA probability remains significant | | Central sleep apnea | Central events, heart failure, opioids, high altitude, neurologic disease | PSG and cause-directed assessment | | Obesity hypoventilation syndrome | Obesity plus awake hypercapnia or strong suspicion of sleep-related hypoventilation | Blood gas/CO₂ assessment and PSG; ventilatory treatment pathway | | Narcolepsy/central hypersomnolence | Irresistible sleep attacks despite adequate sleep, cataplexy or other features | Sleep-specialist evaluation after sleep deprivation/OSA are addressed | | Restless legs/periodic limb movement disorder | Urge to move legs, discomfort at rest, repetitive limb movements | Iron status and sleep evaluation as appropriate | | Medication-related somnolence | Opioids, sedatives, antihistamines, dopamine agonists, other CNS drugs | Medication review and risk reduction | ## Management goals Treatment aims to: - eliminate or substantially reduce obstructive respiratory events; - improve sleepiness, alertness, sleep quality, and quality of life; - reduce driving and occupational risk; - control hypoxemia and related physiologic burden; - address obesity and other reversible contributors; - choose a treatment the patient can use consistently. ## Positive airway pressure ### Indications and modality PAP is the most reliably effective therapy for upper-airway obstruction. AASM guidance strongly recommends PAP in adults with OSA and excessive sleepiness and supports treatment in patients with impaired sleep-related quality of life or comorbid hypertension. [2] For most uncomplicated adults: - CPAP or auto-adjusting PAP can be used for ongoing therapy; - home initiation with auto-adjusting PAP is appropriate in selected patients without important comorbidities; - bilevel PAP is not routinely required for uncomplicated OSA but may be useful when high pressures, hypoventilation, or other ventilatory problems require a different strategy. ### Early troubleshooting Adherence improves when problems are addressed promptly. Review: - mask fit and leak; - nasal obstruction or dryness; - mouth leak; - pressure intolerance; - aerophagia; - claustrophobia; - insomnia; - persistent sleepiness despite apparently adequate use. Use device download data to assess nightly use, residual event index, pressure, and leak. Persistent residual events require review of mask leak, positional/REM disease, treatment-emergent central apnea, weight change, and whether repeat sleep testing is needed. > **Clinical pearl:** A device-reported residual event index is a monitoring signal, not a substitute for clinical interpretation. Large leak and proprietary event-detection algorithms can make the number misleading. ## Weight management Weight reduction can substantially improve OSA in patients with overweight or obesity and should be integrated with airway-directed treatment rather than deferred until PAP succeeds or fails. Components can include: - structured nutrition and physical-activity treatment; - behavioral obesity management; - anti-obesity pharmacotherapy when indicated; - bariatric-surgery referral for eligible patients. See [Obesity in Adults](../endocrinology/obesity-in-adults.md). ### Tirzepatide in OSA with obesity The U.S. FDA approved tirzepatide on **December 20, 2024** for adults with obesity and moderate-to-severe OSA, together with reduced-calorie diet and increased physical activity. The approval was based on randomized trials that enrolled adults both with and without ongoing PAP and showed clinically meaningful AHI reduction after 52 weeks. [5,6] This approval is jurisdiction-specific. Treatment selection should account for contraindications, gastrointestinal adverse effects, gallbladder/pancreatic risk, concomitant glucose-lowering therapy, pregnancy considerations, and local labeling. Reassess OSA after substantial weight loss rather than assuming that symptom improvement proves resolution. ## Oral-appliance therapy A custom, titratable mandibular advancement device is appropriate for selected adults who prefer it or cannot tolerate PAP. It is most effective when fitted and followed by a qualified dental professional working with the sleep clinician. After titration, confirm treatment effectiveness with objective sleep testing because improvement in snoring does not prove adequate control of OSA. Potential problems include jaw discomfort, temporomandibular symptoms, salivation/dry mouth, bite changes, and dental movement. ## Positional and adjunctive therapy Positional therapy may help patients whose OSA is substantially worse when supine. It can be used alone in carefully selected positional disease or as an adjunct. Confirm efficacy objectively if it is the principal treatment. Treat clinically important nasal obstruction to improve comfort and PAP tolerance, but nasal therapy alone rarely controls moderate-to-severe pharyngeal OSA. Avoid alcohol near bedtime and minimize unnecessary sedating drugs, particularly when they worsen respiratory events or daytime impairment. ## Surgical and device-based pathways Selected patients with persistent OSA who cannot use PAP should be considered for consultation about upper-airway surgery or other device-based therapy. The 2021 AASM guideline recommends discussing surgical referral with appropriate PAP-intolerant adults and recommends bariatric-surgical discussion for eligible patients with obesity. [3] Options depend on anatomy and include: - tonsil or palatal surgery in selected anatomy; - maxillomandibular advancement; - hypoglossal-nerve stimulation in appropriately selected patients meeting local criteria; - bariatric surgery when obesity is a major contributor and surgical criteria are met. Selection should be based on airway anatomy, OSA severity, body habitus, prior treatment response, patient preference, and procedure-specific risk. Objective follow-up testing is needed after definitive non-PAP therapy. ## Cardiovascular and metabolic comorbidity OSA is associated with hypertension, atrial fibrillation, stroke, coronary disease, insulin resistance, and heart failure, but the strength of treatment benefit differs by outcome and patient phenotype. - Treat symptomatic OSA and physiologic obstruction because PAP reliably improves respiratory events and sleepiness. - Continue guideline-directed management of hypertension, atrial fibrillation, heart failure, and vascular risk; OSA treatment does not replace it. - Do not promise prevention of myocardial infarction or stroke solely from PAP, particularly in minimally sleepy populations with limited adherence. Related library topics include [Primary Hypertension in Adults](../cardiology/primary-hypertension-in-adults.md), [Atrial Fibrillation](../cardiology/atrial-fibrillation.md), and [Heart Failure With Preserved Ejection Fraction](../cardiology/heart-failure-with-preserved-ejection-fraction.md). ## Special populations ### Chronic opioid use Opioids increase risk of central apnea and hypoventilation as well as obstruction. Prefer PSG to routine HSAT and characterize respiratory physiology before assuming uncomplicated OSA. [1] ### Neuromuscular disease or suspected hypoventilation Use PSG with appropriate gas-exchange assessment and evaluate awake CO₂ when indicated. PAP mode must match the ventilatory disorder; standard CPAP may be insufficient when hypoventilation is present. ### Heart failure Central sleep apnea may coexist with OSA. Review event type before escalating PAP. Continue evidence-based heart-failure therapy and avoid assuming all nocturnal respiratory events are obstructive. ### Pregnancy OSA can emerge or worsen with gestational weight gain and upper-airway edema. PAP is generally the preferred treatment when clinically important OSA is confirmed. Coordinate with obstetric care when hypertension, preeclampsia risk, or severe nocturnal hypoxemia is present. ### Older adults Symptoms may present as fatigue, cognitive impairment, falls, or insomnia rather than classic sleepiness. Balance treatment benefit against dexterity, cognition, caregiver support, mask handling, and comorbid sleep disorders. ## Perioperative and inpatient care Patients with known OSA should tell anesthesia and surgical teams and bring/use established PAP when feasible. Postoperative opioids and sedatives can worsen obstruction and hypoventilation; monitoring intensity should match OSA severity, procedure, opioid burden, and comorbidity. For hospitalized patients, continue established OSA treatment unless contraindicated. New severe nocturnal hypoxemia should not automatically be attributed to OSA; assess for atelectasis, pneumonia, pulmonary edema, pulmonary embolism, opioid effect, and hypoventilation as clinically appropriate. ## Monitoring and treatment response At follow-up, assess: - daytime sleepiness and alertness; - drowsy driving or occupational risk; - PAP adherence, leak, pressure, and residual events; - oral-appliance tolerance and dental effects; - weight trajectory; - blood pressure and relevant cardiometabolic disease; - persistent snoring or witnessed apneas; - new central events or hypoventilation concerns. Repeat objective sleep testing when: - symptoms persist despite apparently adequate therapy; - non-PAP treatment is used as the primary therapy; - major weight loss or gain may have changed disease severity; - device data and symptoms are discordant; - recurrent OSA is suspected after surgery or prior successful treatment. ## Disposition and referral Most OSA is managed outpatient. Urgent evaluation is appropriate for uncontrolled sleepiness creating immediate driving/occupational danger, severe unexplained hypoxemia, suspected awake hypercapnia, recurrent arrhythmia/syncope related to nocturnal events, or another acute cardiopulmonary disorder. Refer to sleep medicine when diagnosis is uncertain, HSAT is nondiagnostic, central apnea or hypoventilation is suspected, PAP remains intolerable despite troubleshooting, a non-PAP device/surgical pathway is being considered, or persistent sleepiness remains unexplained after adequate OSA control. ## References 1. Kapur VK, Auckley DH, Chowdhuri S, et al. Clinical practice guideline for diagnostic testing for adult obstructive sleep apnea: an American Academy of Sleep Medicine clinical practice guideline. *Journal of Clinical Sleep Medicine*. 2017;13(3):479-504. doi:10.5664/jcsm.6506. PMID: 28162150. https://pubmed.ncbi.nlm.nih.gov/28162150/ 2. Patil SP, Ayappa IA, Caples SM, Kimoff RJ, Patel SR, Harrod CG. Treatment of adult obstructive sleep apnea with positive airway pressure: an American Academy of Sleep Medicine clinical practice guideline. *Journal of Clinical Sleep Medicine*. 2019;15(2):335-343. doi:10.5664/jcsm.7640. PMID: 30736887. https://pubmed.ncbi.nlm.nih.gov/30736887/ 3. Kent D, Stanley J, Aurora RN, et al. Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine clinical practice guideline. *Journal of Clinical Sleep Medicine*. 2021;17(12):2499-2505. doi:10.5664/jcsm.9592. PMID: 34351848. https://pubmed.ncbi.nlm.nih.gov/34351848/ 4. National Institute for Health and Care Excellence. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s (NG202). 2021. https://www.nice.org.uk/guidance/ng202 5. U.S. Food and Drug Administration. FDA approves first medication for obstructive sleep apnea. December 20, 2024. https://www.fda.gov/news-events/press-announcements/fda-approves-first-medication-obstructive-sleep-apnea 6. Malhotra A, Grunstein RR, Fietze I, et al. Tirzepatide for the treatment of obstructive sleep apnea and obesity. *New England Journal of Medicine*. 2024;391:1193-1205. doi:10.1056/NEJMoa2404881. https://doi.org/10.1056/NEJMoa24048817:["$","$L17",null,{"article":{"id":"medical-obstructive-sleep-apnea-in-adults","title":"Obstructive Sleep Apnea in Adults","slug":"obstructive-sleep-apnea-in-adults","description":"Obstructive sleep apnea (OSA) is recurrent partial or complete upper-airway collapse during sleep, causing airflow limitation, intermittent hypoxemia, sleep fragmentation, swings in intrathoracic pressure, and sympath…","aliases":[],"category":"Sleep Medicine","tags":["Sleep Medicine"],"updatedAt":"$undefined","body":"$18","headings":[{"id":"summary","text":"Summary","level":2},{"id":"pathophysiology","text":"Pathophysiology","level":2},{"id":"risk-factors-and-associated-conditions","text":"Risk factors and associated conditions","level":2},{"id":"clinical-presentation","text":"Clinical presentation","level":2},{"id":"nocturnal-symptoms","text":"Nocturnal symptoms","level":3},{"id":"daytime-manifestations","text":"Daytime manifestations","level":3},{"id":"clinical-assessment","text":"Clinical assessment","level":2},{"id":"history","text":"History","level":3},{"id":"physical-assessment","text":"Physical assessment","level":3},{"id":"diagnostic-testing","text":"Diagnostic testing","level":2},{"id":"polysomnography","text":"Polysomnography","level":3},{"id":"home-sleep-apnea-testing","text":"Home sleep apnea testing","level":3},{"id":"interpreting-a-sleep-study","text":"Interpreting a sleep study","level":2},{"id":"key-respiratory-metrics","text":"Key respiratory metrics","level":3},{"id":"conventional-ahi-bands","text":"Conventional AHI bands","level":3},{"id":"read-beyond-the-ahi","text":"Read beyond the AHI","level":3},{"id":"differential-diagnosis-and-overlap-syndromes","text":"Differential diagnosis and overlap syndromes","level":2},{"id":"management-goals","text":"Management goals","level":2},{"id":"positive-airway-pressure","text":"Positive airway pressure","level":2},{"id":"indications-and-modality","text":"Indications and modality","level":3},{"id":"early-troubleshooting","text":"Early troubleshooting","level":3},{"id":"weight-management","text":"Weight management","level":2},{"id":"tirzepatide-in-osa-with-obesity","text":"Tirzepatide in OSA with obesity","level":3},{"id":"oral-appliance-therapy","text":"Oral-appliance therapy","level":2},{"id":"positional-and-adjunctive-therapy","text":"Positional and adjunctive therapy","level":2},{"id":"surgical-and-device-based-pathways","text":"Surgical and device-based pathways","level":2},{"id":"cardiovascular-and-metabolic-comorbidity","text":"Cardiovascular and metabolic comorbidity","level":2},{"id":"special-populations","text":"Special populations","level":2},{"id":"chronic-opioid-use","text":"Chronic opioid use","level":3},{"id":"neuromuscular-disease-or-suspected-hypoventilation","text":"Neuromuscular disease or suspected hypoventilation","level":3},{"id":"heart-failure","text":"Heart failure","level":3},{"id":"pregnancy","text":"Pregnancy","level":3},{"id":"older-adults","text":"Older adults","level":3},{"id":"perioperative-and-inpatient-care","text":"Perioperative and inpatient care","level":2},{"id":"monitoring-and-treatment-response","text":"Monitoring and treatment response","level":2},{"id":"disposition-and-referral","text":"Disposition and referral","level":2},{"id":"references","text":"References","level":2}],"readingMinutes":13},"linkedMarkdown":"$19","backlinks":[],"related":[],"previewBySlug":{"abcde-approach":{"title":"ABCDE Approach","description":"The ABCDE approach is a structured method for the immediate assessment and treatment of a deteriorating or critically ill patient: Airway, Breathing, Circulation, Disability, Exposure. 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