Chronic Obstructive Airways Disease

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Chronic Obstructive Airways Disease

(Chronic obstructive pulmonary disease, COPD, COAD)

Definitions

  • Chronic bronchitis
    • "cough productive of sputum on most days for at least 3 months of the year for two consecutive years"
  • Emphysema
    • Dilatation and destruction of lung tissue distal to the terminal bronchioles

Diagnosis

  • chronic, slowly progressive
  • FEV1- less than 80%/< 2 SD below predicted
  • FEV1/VC ratio <70%
  • no marked change over several months
  • largely fixed (may be partially reversible by therapy)

Aetiology

Chronic Bronchitis

  • Increased mucus expectoration
    • increased number of goblet cells
    • hypertrophy of mucus secreting glands
  • Widespread airway narrowing
    • inflamed bronchi
    • squamous metaplasia
    • fibrosis

Emphysema

  • Expiratory airflow limitation
  • air trapping
  • Loss elastic recoil
  • V/Q mismatch
  • reduced PaO2 , increased PaCO2

Symptoms / History

  • cough (years)
  • smoking habit (pack years)
  • increasing breathlessness, exercise intolerance
  • worsened by cold, foggy weather, pollution
  • colds worse
    • often to stage of admission (infective exacerbation)

Family history

  • consider alpha1 antitrypsin deficiency if young (<40)

DHx

  • inhaled bronchodilators / steroids
  • home oxygen

SHx

  • excercise tolerance

Examination

  • pink puffers
    • breathless
    • heart failure
  • blue bloaters
    • hypercapnia
    • vasodilatation
    • bounding pulse
    • flap
    • confusion
    • drowsiness / coma

General

  • dyspnoea
  • cyanosed
  • febrile
  • tar-stained fingers
  • plethoric

CVS

  • Cor pulmonale
    • parasternal heave may be obliterated by hyper-inflated lungs

Respiratory

  • tachypnoea
  • accessory muscles
  • lip-pursing
  • tracheal tug
  • recession
  • decreased expansion
  • increased PN resonance
  • quiet breath sounds
  • prolonged expiration,
  • widespread wheeze
  • hyperinflation

Abdomen

  • liver pushed down

Investigations

  • Lung function tests with reversibility testing
    • >20% reversibility suggests asthma
  • CXR
  • FBC
    • polycythaemia 2° to chronic hypoxaemia
  • ABG
  • Sputum MCS
  • ECG
  • Echocardiogram
  • alpha1-antitrypsin

Treatment

  • STOP SMOKING
  • bronchodilators
    • short acting beta2-agonitst
    • long acting beta2-agonist
    • anticholinergics (have greater effect than in asthma)
  • corticosteroids (if reversibility shown)
  • improve exercise, nutrition
  • O2 >19 hours / day reduced mortality if
    • FEV1 < 1.5l
    • PaO2 < 7.3 kPa
    • peripheral oedema
  • physiotherapy
    • loosen secretions
  • Nocturnal hypoxia
    • Bipap
    • no sleeping tablets
  • Prevention of infection
    • vaccines
    • antibiotics
    • mucolytics
  • Breathlessness
    • promethazine 125mg / day
    • dihydrocodeine 1mg/kg
  • alpha1- antitrypsin
  • surgery
  • diuretics

Complications

 

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