• Sleep apnoea
    Link:www.sign.ac.uk/pdf/sign73.pdf
    • Sleep apnoea
      • Central
      • Obstructive
    • OSAS: Affects 5-10% of the population, usually obese middle age males.
    • Symptoms: headache, tiredness, somnolence, snoring, restless sleep
    • STOP-BANG
      • Snore
        Tired
        Observed
        Pressure (BP)
        BMI (>35)
        Age (>50)
        Neck circumference (>40cm)
        Gender (m)
        • 3 or more indicates high likelihood of OSAS
    • Predisposing factors
      • Obesity
      • Male
      • Alcohol/sedatives
      • Smoking
      • Nasal obstruction
      • Pharyngeal obstruction
      • Craniofacial abnormality
      • Neuromuscular disorders
      • Connective tissue diseases
      • Chronic renal failure
    • Diagnosis
      • Cessation of airflow and hypopnoea with reduction in airflow of >50% for > 10s and occur >5x/hr
      • Diagnosis is by history, examination, sleep study/polysomnograohy (EEG, ECG, eye movements, EMG, airflow, pulse oximetry, snoring volume)
      • Severity is graded by the apnoea/hypopnoea index (AHI). There may be up to 300-500 sleep disruptions per night
    • Classification
      • Grade 0
        • AHI 0-10
          • Typical heavy snorer with few waking episodes
      • Grade 1
        • AHI 10-30
          • Moderately severe
      • Grade 2
        • AHI 30-80
          • Severe but sats return to baseline with each waking cycle
      • Grade 3
        • Associated with sustained hypoxaemia esp. during REM sleep
    • Treatments
      • CPAP 5-20 cmH₂O
        Weight loss
        Secondary risk factor Mx
        UPPP
        Mandibular repositioning devices
        Stop smoking
        Reduce alcohol
        Tracheostomy in the severest of cases
    • Pathophysiology
      • Hypoxaemia and hypercapnoea leads to wakening after period of tachycardia and hypertension (BP up to 240/120)
      • Mediated by pharyngeal, pulmonary and chemoreceptor mechanisms
    • Consequences
      • Neuro
        • Sleepiness
        • Impaired cognition
        • Anxiety
        • Depression
        • Intracranial hypertension
        • Chronic headache
      • CVS
        • HT
        • IHD
        • RVH and RVF
        • Cerebrovascular disease
      • Resp
        • Hypoxaemia
        • Hypercapnoea
        • PAH
      • Endocrine
        • Reduced GH/testosterone levels, Diabetes instability
      • GIT
        • Reflux
    • CEACCP
      Link:ceaccp.oxfordjournals.org/content/11/1/5.full.pdf