Airway diseases

• Smoking cessation reduces mortality
• Management of COPD

  Low-flow oxygen therapy for 18 hours per day or more with resting hypoxemia, especially nocturnal oxygen therapy, reduces mortality
• Vaccinations:

  • Influenza vaccination reduces serious illness, death, and acute exacerbations
  • Pneumococcal vaccination
• Long-acting bronchodilators:

  • Start with LAMA or LABA (Long-acting preferred option)
  • New guidelines suggest starting with LABA + LAMA or combining LAMA + LABA with persistent symptoms
• + ICS:

  • Consider adding ICS with a history of repeated acute exacerbations, blood eosinophils > 300, sputum eosinophils > 2%, and FEV1 below 50% predicted
  • Problem with ICS: Increased risk of Pneumonia
• Causes of clubbing of digits:

  • Lung cancer, lung abscess, bronchiectasis, Idiopathic lung fibrosis
• Dullness to percussion of chest:

  • Normal dullness: cardiac dullness
  • Liver dullness at 5th intercostal space right anterior chest
• Pleural effusion:

  • Reduced breath sounds
  • Reduced voice sounds
  • Trachea pushed over to the opposite side
  • Common causes of pleural effusion: TB, Pneumonia, heart failure, malignancy
• Lung collapse:

  • Reduced breath sounds and voice sounds
  • Trachea pulled towards the side of collapse
• Lobar consolidation:

  • Commonly due to pneumonia
  • Breath sounds increased (bronchial breathing)
  • Increased voice sounds
  • Trachea central
• COPD (neutrophilic inflammation):

  • Extra-pulmonary effects include muscle wasting, osteoporosis, malnutrition, emphysema, chronic bronchitis
• Small Airways disease (<2mm):

  • Disease starts here
  • Not diagnosed initially (Silent Zone)
  • FEV1 normal
  • "Holes" on CT scan
  • Alpha-I antitrypsin role
  • Smoking and indoor biomass fuel burning are causes of COPD
  • SA: HIV and TB also play a role
• Poor lung development:

  • Compromised intra-uterine development
  • Reduced lung growth in childhood (maternal smoking, respiratory infections, paternal/maternal asthma)
• Excess lung damage:

  • Tobacco use (Smoking, Vaping, Cannabis)
  • Air pollution
  • Indoor burning of biomass fuel
  • Viral infections (Rhino virus and Rhino-C virus)
• Screen patients with risk factors + Symptoms: do Spirometry with FEV1

  • Clinical exam and Chest X-ray are not very reliable, especially early in the disease
  • FEV1/FVC ratio < 0.70 post-bronchodilator is currently the best to confirm diagnosis
  • CT-lung (High-resolution) shows "Holes" in lung (Emphysema)
  • Acute exacerbation of COPD is a significant prognostic factor
• There are 2 types of lung emphysema:
• Centrilobular emphysema:

  • Associated with smoking
  • Mainly occurs in the upper lobes of the lung
• Panacinar emphysema:

  • Associated with a deficiency of alpha-I-antitrypsin
  • Mainly occurs in the lower lobes of the lung
• Clinical Picture of Airway diseases: Differential Diagnosis
• Outstanding sign: Wheeze

  • Obstructive PE
  • Sleep Apnoea
  • Bronchial Asthma
  • COPD
  • Gastroesophageal Reflux
• Accelerated decline of FEV1:

  • FEV1 normal in all smokers, some asthma, and COPD
  • Age-related decline of FEV1
  • Childhood disadvantage factors affect FEV1 growth and decline
• Hyperinflation:

  • Seen in severe airway disease or COPD with Lung Emphysema
  • Significant contributor to persistent dyspnea
• Signs of Airway Obstruction:

  • Wheeze
  • Prolonged expiration time
  • Coarse crackles
  • Use of active respiratory muscles
• Mechanisms Of Airway Narrowing/Obstruction
• Bronchospasm

  • Irritable airways
  • Inflammation
  • Destruction of airway (small airways < 2mm)
  • Airway remodeling
  • Airway collapse
• Muco-purulent:

  • Cystic Fibrosis (Bronchiectasis)
  • Non-CF Bronchiectasis
  • Asthma (Eosinophils)
  • COPD (Neutrophils)
  • ACO (Asthma COPD overlap)
• Chronic Airway Diseases
• Heterogeneous conditions with different Pathophysiologies

  • Common features include epithelial injury/damage, inflammation, airway obstruction
  • Increase morbidity/mortality