Unstable angina

Disease Description (Causes and Symptoms)

Disease name: Sleep apnea (Sleep apnea) — This is a medically valid term.

• Definition and types
  • A condition in which breathing repeatedly stops for 10 seconds or longer during sleep because the upper airway repeatedly narrows (obstructive), respiratory effort decreases due to reduced output from the respiratory center (central), or these two mechanisms are combined.
• Major pathophysiology
  • Obstructive: anatomical narrowing (fat accumulation around the neck due to obesity, enlarged tonsils/adenoids, a large tongue, a short jaw, nasal narrowing, etc.) + reduced function of the pharyngeal dilator muscles → airway collapse → intermittent hypoxia and arousal → increased sympathetic nervous system activity and sleep fragmentation.
  • Central: respiratory effort during sleep disappears due to reduced output from the brain’s respiratory center, resulting in hypoventilation/apnea.
• Major symptoms
  • Snoring (especially loud), witnessed pauses in breathing during sleep, dry mouth and headache upon waking, excessive daytime sleepiness (reduced concentration and increased risk of accidents), insomnia or fragmented sleep, sleepwalking (rare), sexual dysfunction (e.g., erectile dysfunction), fatigue and lack of energy, reduced skin tone, etc.
• Diagnostic indicators (clinical summary)
  • Medical history (reported by the patient/sleep partner), physical examination (weight, neck circumference, oral, nasal, and pharyngeal structures), and polysomnography to measure breathing, oxygen saturation, brain waves, movement, and other parameters during sleep.
  • Apnea-hypopnea index (AHI): Generally, treatment is considered indicated when AHI ≥5/hr with daytime symptoms or AHI ≥15/hr. (Some clinical reports also consider 5 or more apnea episodes per hour, each lasting 10 seconds or longer, to be clinically significant.)

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Treatment Methods (Including Standard Treatment · Medication · Procedures/Surgery · Lifestyle Management) and Precautions

• First-line nonsurgical treatment
  • Continuous positive airway pressure (CPAP): First-line standard treatment for obstructive and mixed types. It prevents airway collapse by maintaining pressure in the airway. Highly effective (reduces symptoms and the risk of complications).
    • Precautions: Mask fit, nasal congestion, dry mouth, skin pressure, and adherence (usage rate) are important for treatment success.
  • BiPAP/ASV/automatic positive airway pressure (APAP): Used as alternatives to CPAP or according to the breathing pattern (central components and changes in the required pressure). ASV may be contraindicated in some patients with heart failure (HFrEF)—specialist judgment is required.
  • Oral appliances (mandibular advancement devices, MAD): Recommended for mild to moderate cases or patients who cannot tolerate CPAP. The condition of the teeth and temporomandibular joints should be evaluated.
  • Weight loss, improved sleep habits, abstinence from alcohol, avoidance of sleeping pills and sedatives, and sleeping on one’s side (positional therapy): Primary supportive treatments.
  • Medication: For residual daytime sleepiness (when fatigue persists even after treatment), modafinil/armodafinil and similar medications may be considered, but indications, adverse effects, and interactions must be checked.
• Surgical treatment
  • Uvulopalatopharyngoplasty (UPPP): Expands the airway by removing and reshaping the soft palate, uvula, tonsils, and other structures. Selective treatment (the effect varies by patient; partial improvement occurs in approximately 50%). Complications include bleeding, pain, and airway edema.
  • Laser-assisted uvulopalatoplasty (LAUP): May be useful for snoring, but its effectiveness in treating sleep apnea itself is limited. Objective sleep evaluation is recommended before surgery.
  • Nasal surgery (such as correction of a deviated nasal septum): Improves CPAP tolerance or assists breathing improvement by improving the nasal passage.
  • Tonsillectomy and adenoidectomy (children): Highly effective when these are major causes in children.
  • Highly selective surgeries such as maxillomandibular advancement (MMA) and tongue-base reduction procedures, as well as newer non-drug treatments (e.g., an implantable hypoglossal nerve stimulator (IHNS)), should be applied after careful evaluation of the indications.
• Complications and precautions (treatment-related)
  • If untreated: Increased risk of hypertension, coronary artery disease, heart failure, arrhythmia, stroke, and metabolic syndrome; increased risk of daytime accidents (including traffic accidents); and reduced cognitive function.
  • Adaptation to and maintenance during CPAP use (cleaning the mask, adjusting pressure, and managing skin and nasal problems) are important. The benefits and adverse effects of surgery should be discussed thoroughly with a specialist.
  • In central sleep apnea, treating the cause (heart failure, neurological disease, medications, etc.) takes priority, and the choice of respiratory support device requires specialist judgment.

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Checklist Before an Outpatient Visit (Items to Prepare and Example Questions)

• Items to prepare (recommended to bring)
  • A list of all medications and supplements currently being taken (including sleeping pills, antidepressants, opioids, etc.)
  • Previous test and surgical records (results of any previously performed polysomnography are essential)
  • A record of sleep symptoms (sleep duration, frequency and intensity of snoring, number and timing of witnessed apneas, degree of daytime sleepiness)—if possible, include the Epworth Sleepiness Scale score
  • Physical information: weight, BMI, neck circumference, and information about alcohol use, smoking, and work (including whether the patient works night shifts)
  • Observations from the sleep partner (whether apnea is present, breathing sounds, tossing and turning, etc.)
• Items likely to be checked and measured during the outpatient visit
  • Vital signs (blood pressure), oral, nasal, and pharyngeal examination, basic cardiovascular and neurological examinations, and, if necessary, guidance on scheduling an immediate polysomnography
• Example questions (information the patient may explain to or receive from the doctor during the visit)
  • "How should the results of my recent polysomnography (including AHI) be interpreted?"
  • "Could the medications I am taking (or my medical conditions) affect sleep apnea?"

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Examples of General Questions to Ask the Doctor

• What are the expected effects and adverse effects of this medication (or device)?
• How severe is my apnea (mild, moderate, or severe)? Which treatment is recommended as first-line therapy?
• If CPAP is recommended but I have difficulty adjusting to it, what are the next alternatives?
• What kind of prognosis can be expected after treatment (improvement in sleepiness, reduction in cardiovascular risk, etc.)?
• What are the expected benefits and risks if surgery is considered?

Examples of condition-specific questions

• If obstructive sleep apnea is confirmed: "Where are the main sites of obstruction in my upper airway, and what is the optimal treatment for that location (device versus surgery)?"
• If there is a central component or a history of heart failure: "If there is a central component, which device (e.g., ASV) or medication treatment would be appropriate, and what points require attention because of the relationship with heart failure?"