Chronic Obstructive Pulmonary Disease (COPD)

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CHRONIC LUNG DISEASE: CLINICAL DESCRIPTIONA common disease that is preventable, treatable, and progressive and that is characterized by:

  • Persistent respiratory symptoms
  • Frequent exacerbations - infective and non-infective
  • Airflow limitation that is not fully reversible
  • Associated with abnormal inflammatory response of the airways / alveoli to noxious particles or gases
  • Pulmonary and systemic effects

Risk factors 

  • Indoor cooking of solid fuels (biomass fuel exposure to firewood, charcoal, dung, crop residues, stove) – main risk factor in malawi
  • Cigarette smoking (tobacco / cannabis, active or passive): Main risk factor globally
  • Urban air pollution destructive lung disease (e.g., Tb, bronchiectasis)
  • Low socioeconomic status
  • aging population (longevity ↑ exposure time to risk factors)
  • Poorly controlled asthma
  • Impaired foetal and childhood lung growth (prematurity, childhood infections, hiv infection, maternal smoking)
  • Genetic (e.g., Α1-antitrypsin deficiency).

CLINICAL FEATURESSIGNS AND SYMPTOMS

  • Chronic dyspnea/shortness of breath (common symptom)
  • Sputum production
  • Pursed lip breathing
  • Prolonged expiration
  • Cyanosis
  • Paradoxical retraction of lower intercostal spaces during inspiration
  • Decreased crico-sternal distance
  • Barrel chest (hyper-inflated chest)
  • Mild wheezing, even when they are not under acute distress
  • Hyperresonance percussion note
  • Coarse basal crackles
  • Apex beat difficult to localize
  • Loss of cardiac dullness
  • Distant heart sounds
  • Liver displaced inferiorly
  • Raised Jugular Vein Pressure, hepatomegaly and pedal oedema if right heart failure (in severe COPD)

Complications of COPD

  • Acute exacerbations
  • Spontaneous pneumothorax
  • Cor pulmonale and right heart failure
  • Arrhythmias
  • Polycythaemia
  • Skeletal muscle wasting/cachexia
  • Worsening of comorbidities (heart failure, obstructive sleep apnoea)
  • Osteoporosis (recurrent use of oral steroids)
  • Diabetes mellitus (recurrent use of oral steroids)
  • Metabolic syndrome (multiple use of oral steroids and inactivity)
  • Normocytic anaemia
  • Depression / anxiety
  • Lung cancer (if smoker)
  • Death

INVESTIGATIONS

  • Oxygen saturation: hypoxia (if severe COPD)
  • CXR can reveal hyper-inflated lungs
  • flattened diaphragms
  • small heart shadow
  • teardrop shaped heart shadow
  • increased retrosternal air space
  • Spirometry is needed to confirm the diagnosis of COPD
  • Post-bronchodilator FEV1 / FVC < 70%

TREATMENT

Treatment objectives  

  • Advise patients to stop smoking if they are smokers.
  • Avoid indoor cooking in poorly ventilated kitchen / homes if possible

NON-PHARMACOLOGICAL

  • Advise to stop smoking and exposure to biomass fuel

PHARMACOLOGICAL

  • Step 1: Inhaled Salbutamol 2puffs prn or Ipratropium bromide inhaler
  • Step 2: if not improving on step 1 treatment: add Aminophylline 100mg 8 hourly PO or long-acting beta –agonists inhaler (Salmeterol or Formoterol) or long-acting muscarinic antagonists (Tiotropium inhaler) if available. Refer to specialist clinic.
  • Step 3: add inhaled corticosteroid (e.g., Beclomethasone, Fluticasone) if frequent exacerbator- ≥ 2 exacerbations in past 12 months or FEV1 <50% predicted

Note: 

  • If COPD patient requires surgery, please stabilize the COPD first before surgery and refer to specialist if need be.
  • Refer to specialist if COPD patient has chronic hypoxia for further evaluation

 

ACUTE EXACERBATION OF COPD

CLINICAL DESCRIPTION

Acute worsening of dyspnoea, increased sputum volume, purulent sputum (+/-fever) that requires additional treatment.

COPD Exacerbations or progression can result in loss of lung function and poor quality of life and can be mild, moderate, or severe.

Causes of exacerbations

  • tracheobronchial infections main trigger - viral (rhinovirus) > bacterial (S. pneumoniae, H. influenzae, Moraxella catarrhalis. Consider Pseudomonas aeruginosa if frequent exacerbator and recent hospital admission)
  • environmental exposure / air pollution (respirable particles, ozone)
  • allergens
  • aspiration and GORD
  • weather changes
  • discontinuation of maintenance treatment

Differential diagnosis of exacerbations

  • non-pulmonary infections
  • pulmonary embolism
  • pneumothorax
  • pleural effusion
  • CCF with pulmonary oedema

CLINICAL FEATURESINVESTIGATIONS

  • FBC, blood culture, sputum analysis, CXR

TREATMENT

  • Exacerbations need bronchodilators, antibiotics, and steroids
    • Nebulized Salbutamol 5mg / Ipratroprium bromide and oral Aminophylline 100 mg 8 hourly PO.  Can use Salbutamol inhaler with spacer if no nebulised Salbutamol
    • Prednisolone 40 mg daily PO for 5 days (5 days course is enough). Steroids shorten hospital stay/recovery time and improve lung function oxygenation and clinical outcome.
    • Antibiotics (if bacterial infection trigger suspected)
      • Amoxicillin 1g 8 hourly PO for 7 days. Alternatively, Amoxicillin + Clavulanic acid (Augmentin) 625mg 8 hourly PO or Doxycycline 100mg 12 hourly  or Azithromycin 500mg daily. Ceftriaxone 2g daily IV (if severe exacerbation)
      • if frequent exacerbation with recent hospital admission and antibiotic use: cover for Pseudomonas spp e.g., with Ciprofloxacin 500mg 12 hourly for 7 days
  • Oxygen saturation and the use of oxygen
    • COPD patients often have lower SpO2 than asthma patients, even when stable.
    • in asthma, if SpO2 drops below 95%, it is worrisome.
    • a COPD patient may be stable with SpO2 as low as 87%.
    • avoid the use of high flow oxygen in COPD patients wherever possible (as oxygen may remove their hypoxia dependent respiratory drive and cause hypoventilation→ CO2 retention, narcosis → coma).
    • use 2 L / min oxygen as treatment or less, or to target SpO2 to 88 - 92 %.
  • NIV (non-invasive ventilation) for severe exacerbation: CPAP is preferred if no contraindications
    • Improves oxygenation / gas exchange / survival
    • Reduce work of breathing and need for intubation
    • Reduce hospital stay
    • Improves respiratory acidosis

Before discharge

  • start inhaled bronchodilators asap when stable before hospital discharge
  • if frequent exacerbator: regular salbutal 2 puffs 6hrly through spacer
  • long term use of oral steroid is not required
  • plan for follow-up within 1 month: 20% of patients may not recover at 8 weeks