Obstructive sleep apnoea (OSA)

• More common in men (by 3 fold)
• However women are likely underdiagnosed (esp. postmenopausal, not on HRT)
• Prevalence increases with age (esp. over age 60 years old)
• is characterized by partial (hypopnea) or complete (apnea) closure of the upper airway despite ongoing respiratory efforts.
• OSA leads to excessive daytime sleepiness, cognitive impairment, occupational accidents, and motor vehicle crashes.
• Evidence suggests that OSA also causes hypertension

Causes

• Narrow airway (key factor)
• Narrows most in the hypopharynx (below Tongue)
• Can narrow to pencil diameter in some patients
• Obesity and short neck
• Hypognathia
• Jaw deformities
• Large Tongue and uvula
• Neurologic deficits (central or peripheral)

Risk Factors

• Sleep deprivation or excessive Daytime Sleepiness
• CNS Depressant medications
• Craniofacial abnormalities
• Chronic nasal congestion
• Obesity (especially morbid Obesity qualifying for Bariatric Surgery, BMI >35 kg/m2)
• neck circumference
  • >43 cm in men
  • >40 cm in women
• Middle age or older (ages 40-70 years old)
• Male gender (or post-menopausal women not on HRT)
• Alcohol Abuse
• Tobacco abuse
• Family History of Obstructive Sleep Apnea
• Enlarged Tonsils, adenoids, Macroglossia
• Ethnicity – Asians, Polynesians

Associated Conditions

• Atrial Fibrillation
• Major Depression
• Congestive Heart Failure 
• Cerebrovascular Accident 
• Hypertension, especially Refractory Hypertension
• Coronary Artery Disease
• Type 2 Diabetes Mellitus
• Nocturnal cardiac arrhythmia
• Pulmonary Hypertension

Differentials

• Respiratory disease- COPD – nocturnal desaturation
• Narcolepsy
• Sleep deprivation- shift work
• Depression
• Hypothyroidism

Symptoms: Adults

• Loud snoring
• Excessive Daytime Sleepiness (daytime Somnolence)
• Unrefreshing sleep
• Sleepiness is often more marked in passive or monotonous situations (e.g. watching tele-vision, reading and driving)
• Fatigue
• Tiredness
• Lack of energy
• Gasping or Choking during sleep
• Nocturnal Hypertension and arrhythmias
• Morning Headache
• Nocturia
• Nocturnal confusion
• Poor concentration
• Intellectual deterioration or cognitive Impairment

Symptoms: Children

• Minimal Hypersomnolence if any
• Nocturnal Enuresis
• Excessing nighttime sweating
• Developmental Delay
• Learning difficulties (e.g. ADHD)

Signs

• General appearance
  • Short neck
  • Overweight (Obesity in 70% of cases)
• Nasopharynx
  • Nasal Polyps
  • Severe septal deviation
  • Large residual adenoid tissue
• Oropharynx
  • Macroglossia
  • Large Tonsils
  • High arched Palate and narrow oropharyngeal opening
  • Micrognathia (small jaw) and Retrognathia (posterior chin position)
• Larynx and trachea
  • Large obstructive lesions
• Neck circumference (best predictor of Sleep Apnea)
  • Men: >17 inch (42.5 cm) neck circumference
  • Women: >16 inch (40.6 cm) neck circumference

Diagnostics

• Screening Tools
  • STOP-Bang Questionnaire
  • Epworth sleepiness scale

• Maintenance of Wakefulness Test (MWT)

• Sleep study/ overnight polysomnography
  • Oxygen saturation
  • Arousals per hour of sleep and times spent in different sleep stages
  • Number of complete apnoeas and partial (hypopnoeas)obstructions per hour of sleep – known as the apnoea–hypopnoea index (AHI)
    •     None/Minimal: AHI < 5 per hour
    •     Mild: AHI ≥ 5, but < 15 per hour
    •     Moderate: AHI ≥ 15, but < 30 per hour
    •     Severe: AHI ≥ 30 per hour
• 24 hour urine cathecholamines
• If clinically indicated or refractory:
  • Consider specialist referral

Management: 

Non-surgical

• General health measures:
  • Weight Loss: Excess weight is a significant risk factor for OSA. Weight loss through diet, exercise, and behavioral changes can significantly reduce symptoms.
  • Exercise: Regular physical activity can improve respiratory function and contribute to weight loss.
  • Avoid Alcohol and Sedatives: Reduce or avoid alcohol and sedative medications, particularly in the evening, as these can relax throat muscles and worsen OSA.
  • Encourage to stop smoking. Consider statins
• Avoid supine body position during sleep
  • Sew a tennis ball in the back of a night shirt (or vests with posterior bumpers)
• Sleep Hygiene
  • Establish a regular sleep schedule
    • Go to bed at same time each night
    • Get up at same time each day
    • Avoid “sleeping-in” on Sunday morning
  • Cut down time in bed (if not asleep, get up)
    • Avoid trying to force yourself to sleep
    • Use your bed only for sleep and sex
    • Do not read or watch Television in bed
  • Make the bedroom comfortable
    • Keep Temperature in your bedroom comfortable
    • Keep bedroom quiet when sleeping
      • Consider ear plugs (silicon)
  • Keep bedroom dark enough
    • Use dark blinds or wear an eye mask if needed
  • Relax at bedtime
  • Perform measures to make you tired at bedtime
    • Regular Exercise improves sleep
    • Eat a light bedtime snack or warm drink
• Airway Management Measures
  • Continuous Positive Airway Pressure (CPAP)
    • CPAP Machine: CPAP is the gold standard treatment for moderate to severe OSA. It delivers air pressure through a mask to keep airways open during sleep.
    • Adherence and Support:
      • can take time to get used to CPAP therapy
      • Adherence is crucial for its effectiveness.
      • ensure proper mask fit and comfort
• Oral appliance (less effective alternatives to CPAP)
  • For mild to moderate OSA
  • just as good as CPAP
  • need a dentist
  • Indicated in patients intolerant of CPAP
  • Mandibular Advancement Device (preferred)
  • Tongue retaining device (insufficient evidence)
• Potentially helpful Medications
  • Intranasal Corticosteroids – For patients with nasal congestion, treating this can improve CPAP effectiveness and comfort.
    • Chronic Rhinitis
    • Nasal Polyps
    • Septal deviation
  • Tricyclic Antidepressants
  • Sedatives may worsen Sleep Apnea
• Psychosocial
  • How is this affecting marital relationship? 
  • Partner’s sleep/may be very frightened during apnoeas. 
  • May be sleeping separately because of snoring. 
  • Offer support and counselling.
• Safety Measures
  • Avoid High-Risk Activities if Drowsy: Avoid driving or operating heavy machinery if experiencing excessive daytime sleepiness.
  • Inform Relevant Others: If appropriate, inform family members or caregivers about the condition so they can assist with adherence and provide support.

Management

• Tips for driving:
  • Never drive if you are feeling drowsy, tired sleepy or fatigued
  • Share the driving with other people in the car when possible
  • Take a 5-10 minute break every 2 hours when travelling long distances
  • Avoid using the heater when driving – keeping the inside of your car cool will help fight drowsiness
  • Avoid heavy meals when driving – this tends to keep your blood sugar level down
  • Do not use cruise control, so you can slow down or speed up when necessary
  • Avoid staring at oncoming head-lights when driving at night

Drivers licensing

• it is essential to keep with treatment (CPAP)
• have regular check-ups (preferably once per year
• A patient positive for moderate to severe OSA + denies symptoms + declines treatment on polysomnography do:
  • Maintenance of Wakefulness Test
  • MWT 
  • a drug screen 
  • if normal MWT, the driver licensing authority may consider a conditional licence without OSA treatment subject to review in one year
• Commercial vehicle drivers.
  • Commercial vehicle drivers who are diagnosed with OSA syndrome and require treatment are required to have annual review by a sleep specialist to ensure that adequate treatment is maintained. 
  • For drivers who are treated with CPAP, it is recommended that they should use CPAP machines with a usage meter to allow objective assessment and recording of treatment compliance. 
  • An assessment of sleepiness should be made and an objective measurement of sleepiness should be considered (MWT), particularly if there is concern regarding persisting sleepiness or treatment compliance. 
  • Mandibular splints with a usage meter are also acceptable