M10.06.06 Common Respiratory Conditions

Understanding common respiratory conditions is paramount for medical students as these disorders represent a significant portion of clinical presentations. This section aims to provide an overview of prevalent respiratory conditions, their etiology, clinical features, and management strategies.

Asthma

• Definition: Chronic inflammatory disorder characterized by reversible airflow obstruction, bronchial hyperresponsiveness, and airway inflammation.
• Etiology: Genetic predisposition, environmental factors, and allergen exposure.
• Clinical Features: Wheezing, dyspnea, coughing, and chest tightness, often exacerbated by triggers.
• Management: Inhaler therapy (bronchodilators, corticosteroids), avoidance of triggers, and patient education.

Chronic Obstructive Pulmonary Disease (COPD)

• Definition: Progressive lung disease encompassing chronic bronchitis and emphysema, characterized by airflow limitation.
• Etiology: Smoking, environmental exposures (e.g., air pollution), and genetic factors.
• Clinical Features: Dyspnea, chronic cough, sputum production, and exacerbations.
• Management: Smoking cessation, bronchodilators, inhaled corticosteroids, pulmonary rehabilitation.

Pneumonia

• Definition: Infection of the lung parenchyma, often caused by bacteria, viruses, or fungi.
• Etiology: Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, and others.
• Clinical Features: Fever, productive cough, chest pain, dyspnea, and systemic symptoms.
• Management: Antibiotics (based on pathogen and severity), supportive care, and vaccination.

Pulmonary Embolism

• Definition: Blockage of pulmonary arteries by thrombi, typically originating from deep vein thrombosis (DVT).
• Etiology: Virchow’s triad (venous stasis, endothelial injury, hypercoagulability).
• Clinical Features: Dyspnea, pleuritic chest pain, tachycardia, hemoptysis, and signs of DVT.
• Management: Anticoagulation, thrombolytic therapy (in select cases), and supportive measures.

Key Points to Remember

• Asthma is characterized by reversible airflow obstruction and airway inflammation, managed with inhaler therapy and trigger avoidance.
• COPD presents with chronic airflow limitation, managed primarily with smoking cessation and bronchodilators.
• Pneumonia manifests with fever, cough, and chest pain, necessitating antibiotic treatment tailored to the causative pathogen.
• Pulmonary embolism is a life-threatening condition requiring prompt anticoagulation and supportive care.

Related Abnormal Conditions

1. Acute Respiratory Distress Syndrome (ARDS)
   • Definition: Severe acute lung injury leading to hypoxemia and respiratory failure.
   • Etiology: Sepsis, trauma, pneumonia, aspiration.
   • Clinical Features: Acute onset dyspnea, hypoxemia, bilateral infiltrates on chest imaging.
   • Management: Supportive care (mechanical ventilation, fluid management), treatment of underlying cause.
2. Chronic Bronchitis
   • Definition: Chronic inflammation of bronchial tubes leading to increased mucus production.
   • Etiology: Smoking, environmental irritants.
   • Clinical Features: Persistent cough with sputum production for at least 3 months in 2 consecutive years.
   • Management: Smoking cessation, bronchodilators, pulmonary rehabilitation.
3. Interstitial Lung Disease (ILD)
   • Definition: Group of disorders causing inflammation and scarring of lung tissue.
   • Etiology: Connective tissue diseases, environmental exposures, idiopathic.
   • Clinical Features: Dyspnea, dry cough, bibasilar crackles, restrictive pattern on pulmonary function tests.
   • Management: Treatment of underlying cause (e.g., immunosuppressants for connective tissue diseases), supportive care.

Bibliography

1. Broaddus, V. C., Mason, R. J., Ernst, J. D., King Jr, T. E., Lazarus, S. C., & Murray, J. F. (2015). Murray & Nadel’s Textbook of Respiratory Medicine. Elsevier.
2. Crapo, J. D., & Glassroth, J. (2019). Respiratory Medicine E-Book. Elsevier Health Sciences.
3. Mason, R. J., Broaddus, V. C., Martin, T. R., King Jr, T. E., Schraufnagel, D. E., & Murray, J. F. (2015). Murray and Nadel’s Textbook of Respiratory Medicine. Elsevier.
4. Vestbo, J., Hurd, S. S., Agustí, A. G., Jones, P. W., Vogelmeier, C., Anzueto, A., … & Stockley, R. A. (2013). Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. American Journal of Respiratory and Critical Care Medicine, 187(4), 347-365.