Common Lung Diseases — Overview and Investigations

Range of lung diseases

The Big 4 Lung Diseases

1. COPD — the most common cause of acute medical admissions
2. Asthma — the most common chronic respiratory disease
3. Lung cancer — the most common fatal cancer in the Western world for both men and women
4. Pneumonia — the most common serious infectious disease

Other common respiratory diseases

• Infectious: tuberculosis, empyema
• Pulmonary emboli
• Bronchiectasis
• Interstitial lung disease and sarcoidosis
• Pleural effusions and pneumothorax
• Obstructive sleep apnea

Range of Lung Diseases

Diseases of the airways

Range of lung diseases

Lung parenchyma (alveoli and interstitium)

Circulation

Range of lung diseases

Pleural diseases

Other

Investigation of Lung Disease

Different Causes of Large Airway Obstruction

Acute upper airway obstruction

Chronic upper airway obstruction

Large Airway Obstructions: Clues

1. 

   ‘Squared off’ flow volume loop of tracheal obstruction

   Minimal variability in peak flow/ spirometry

2. Positional symptoms rather than diurnal
3. Inspiratory wheeze (Stridor)
4. Past history of intubation/ tracheal disease
5. Characteristic flow-volume loop
6. Fall in PEFR relatively greater than fall in FEV1

Bronchoscopy

• Visual confirmation
• Biopsies to confirm the cause (but can bleed…)
• Treatment as well

Treatment of acute presentation

1. Sit the patient up
2. High flow oxygen or heliox (a mixture of oxygen and helium) via a mask
3. Intravenous high-dose corticosteroids (reduce edema around obstruction)
4. Nebulized salbutamol and adrenaline
5. Intravenous fluid replacement
6. Potentially urgent intubation or tracheostomy or bronchoscopy intervention

Treatment of chronic obstruction

Chronic—relieve the obstruction by

1. Treat underlying cause if possible
2. Bronchoscopic interventions e.g.
   • Stents
   • Laser ablation
3. Surgical interventions
   • Remove cause
   • Tracheostomy