Apnea

Obstructive Sleep Apnea

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Obstructive Sleep Apnea

  • Epidemiology
  1. More common in men (by 3 fold)
    1. However women are likely underdiagnosed (esp. postmenopausal, not on HRT)
  2. Prevalence increases with age (esp. over age 60 years old)
  3. Incidence: Apneas and Hypopneas (AHI) >5/hour in ages 30 to 60 years of age
    1. Without daytime Somnolence: 24% of men and 9% of women
    2. With daytime Somnolence: 4% of men and 2% of women
  • Causes
  1. Adults
    1. Narrow airway (key factor)
      1. Narrows most in the hypopharynx (below Tongue)
      2. Can narrow to pencil diameter in some patients
    2. Obesity and short neck
    3. Hypognathia
    4. Jaw deformities
    5. Large Tongue and uvula
    6. Neurologic deficits (central or peripheral)
  2. Children (occurs in 1-3% of children)
    1. See Obstructive Sleep Apnea in Children
  • Risk Factors
  1. Sleep deprivation or excessive Daytime Sleepiness
  2. CNS Depressant medications
  3. Chronic nasal congestion
  4. Obesity (especially morbid Obesity qualifying for Bariatric Surgery, BMI >35 kg/m2)
  5. Middle age or older (ages 40-70 years old)
  6. Male gender (or post-menopausal women not on HRT)
  7. Alcohol Abuse
  8. Tobacco Abuse
  9. Family History of Obstructive Sleep Apnea
  • Associated Conditions
  1. Atrial Fibrillation (OR 4.0)
  2. Major Depression (OR 2.6)
  3. Congestive Heart Failure (OR 2.4)
  4. Cerebrovascular Accident (OR 1.6 to 4.3)
  5. Hypertension, especially Refractory Hypertension (OR 1.4 to 2.9)
  6. Coronary Artery Disease (OR 1.3)
  7. Type 2 Diabetes Mellitus (OR 1.2 to 2.6)
  8. Nocturnal cardiac arrhythmia
  9. Pulmonary Hypertension
  • Symptoms
  • Adults
  1. Excessive Daytime Sleepiness (daytime Somnolence)
    1. Falling asleep at wheel or in conversation
    2. May also present with alternative terminology
      1. Fatigue
      2. Tiredness
      3. Lack of energy
  2. Loud snoring
  3. Gasping or Choking during sleep
  4. Nocturnal Hypertension and arrhythmias
  5. Morning Headache
  6. Nocturia
  7. Nocturnal confusion
  8. Intellectual deterioration or cognitive Impairment
  • Symptoms
  • Children
  1. Minimal Hypersomnolence if any
  2. Nocturnal Enuresis
  3. Excessing nighttime sweating
  4. Developmental Delay
  5. Learning difficulties (e.g. ADHD)
  • Signs
  1. General appearance
    1. Short neck
    2. Overweight (Obesity in 70% of cases)
  2. Nasopharynx
    1. Nasal Polyps
    2. Severe septal deviation
    3. Large residual adenoid tissue
  3. Oropharynx
    1. Macroglossia
    2. Large Tonsils
    3. High arched Palate and narrow oropharyngeal opening
    4. Micrognathia (small jaw) and Retrognathia (posterior chin position)
    5. Mallampati Score 3 or 4
      1. Disproven: Does not predict Obstructive Sleep Apnea risk
  4. Larynx and trachea
    1. Large obstructive lesions
  5. Neck circumference (best predictor of Sleep Apnea)
    1. Men: >17 inch (42.5 cm) neck circumference
    2. Women: >16 inch (40.6 cm) neck circumference
  • Differential Diagnosis
  • Complications
  1. See Sleep Apnea
  2. Increased mortality risk and stroke risk
    1. Yaggi (2005) N Engl J Med [PubMed]
  3. Hypertension is closely associated with Sleep Apnea
    1. Risk of developing Hypertension with mild to moderate OSA: Odds Ratio 2-3
    2. Peppard (2000) N Engl J Med [PubMed]
  4. Public health concern
    1. Higher health care utilization (more frequent hospitalizations, for longer durations, and higher costs)
    2. Associated with more MVAs and workplace injuries
  • Diagnostics
  1. Screening Tools (USPTF does not recommend general screening)
    1. STOP-Bang Questionnaire
      1. Consider as part of preoperative assessment
    2. Elbow Signs
      1. Of those with Sleep Apnea, 97% report being elbowed by their bed partner due to apnea or snoring
      2. Fenton (2014) Chest 145(3): 518-24 [PubMed]
  2. See Polysomnogram (Sleep Study)
  3. Portable home monitoring devices (overnight oximetry)
    1. Less specific than Polysomnogram
    2. Unable to distinguish CHF, COPD or parasomnias from Sleep Apnea
  • Management
  • Non-surgical
  1. See Sleep Hygiene
  2. Airway Management Measures
    1. Continuous Positive Airway Pressure (CPAP)
      1. See CPAP for Obstructive Sleep Apnea
      2. Do not use without Sleep Study (will worsen Central Sleep Apnea)
      3. Available with auto-titrating positive airway pressure (machine adjusted)
        1. Auto-titrating machines are contraindicated in patients with significant comorbidity
      4. Encourage at least 4 hours per night usage (50% discontinuation rate at 1 year)
        1. See CPAP for improving compliance
      5. Available as nasal pillows (preferred by patients) or full face mask
      6. Improves sleep, decreases snoring, less daytime Somnolence, better quality of life
      7. Decreases systolic Blood Pressure, LVEF, Insulin Resistance and serum Triglycerides
    2. Bilevel Pap (BIPAP) Indications
      1. Hypoventilation during sleep
      2. High airway pressures required
      3. Difficulty exhaling against fixed pressure
  3. Weight loss
    1. Sleep Apnea significantly improved with 9-14 kg loss
    2. Snoring in 19 asymptomatic obese male snorers
      1. Only mild decrease with interventions
        1. Oxymetazoline Nasal Decongestant
        2. Foam wedge support to sleep on side
      2. Marked decrease with weight loss
        1. Three kilogram weight loss
          1. Snores cut in half (176/hour)
        2. Six kilogram weight loss
          1. Snoring nearly eliminated
    3. Reference
      1. Braver (1995) Chest 107:1283-8 [PubMed]
  4. Avoid supine body position during sleep
    1. Sew a tennis ball in the back of a night shirt (or vests with posterior bumpers)
      1. Makes sleeping on back too uncomfortable
    2. Propping pillows
    3. Position alarms
  5. Oral appliance (less effective alternatives to CPAP)
    1. Indicated in patients intolerant of CPAP
    2. Mandibular Advancement Device (preferred)
    3. Tongue retaining device (insufficient evidence)
  6. Potentially helpful Medications
    1. Intranasal Corticosteroids
      1. Chronic Rhinitis
      2. Nasal Polyps
      3. Septal deviation
    2. Tricyclic Antidepressants
  7. Avoid harmful medications
    1. Avoid CNS Depressant or sedative medications (e.g. Benzodiazepines, Benzodiazepine Receptor Agonists)
    2. Sedatives may worsen Sleep Apnea
  8. Hospitalized patients with undiagnosed OSA
    1. Elevate head of bed
    2. Provide Supplemental Oxygen while sleeping
    3. Schedule outpatient Sleep Study
    4. Do not use empiric CPAP (worsens central apnea)
      1. BIPAP is safer if empiric treatment is used
  9. Other experimental measures that may be helpful
    1. Neurostimulators to Hypoglossal Nerve (increases tone of upper airway muscles)
  • Management
  • Surgery
  1. Precautions
    1. Bariatric Surgery is effective in improving Sleep Apnea in 75% of obese patients
    2. No other surgical intervention (e.g. UPPP or mandibular advancement) has shown significant or consistent benefit
  2. Uvulopalatopharyngoplasty (UPPP)
    1. No longer recommended due to low efficacy
    2. Laser or excision of redundant posterior pharynx
    3. Only effective in 30-50% of patients
      1. Airway narrows below level where surgery occurs
    4. Modified procedures
      1. Laser-assisted uvulopalatoplasty
      2. Radiofrequency ablation
  3. Maxillomandibular advancement
    1. Indicated for receding chin and jaw
  4. Tracheotomy
    1. Measure of last resort only