Overview
This lecture covers chronic and acute respiratory diseases including COPD, cystic fibrosis, lung cancer, pleural conditions, ARDS, and atelectasis, along with their causes, symptoms, and basic treatment concepts.
Chronic Obstructive Pulmonary Disease (COPD)
- COPD involves chronic airway and lung damage, leading to hypoxia (low oxygen) and hypercapnia (high CO2).
- In healthy people, CO2 drives respiration; in advanced COPD, low oxygen also becomes a respiratory driver.
- COPD can cause right-sided heart failure due to increased pulmonary resistance.
- Risk factors: smoking, pollution, chemical exposure, and genetic mutations.
- Early symptoms may be masked by smoking-induced sympathetic activity.
Chronic Bronchitis vs. Emphysema
- Chronic bronchitis: persistent bronchial inflammation, productive cough, excess mucus, increased infection risk, hypoxia, cyanosis, and clubbing.
- Emphysema: destruction of alveolar walls, reduced gas exchange surface, dyspnea, diminished breath sounds, wheezing, chest tightness, barrel chest.
- Alpha-1 antitrypsin deficiency is a genetic cause of emphysema, leading to unchecked lung inflammation and tissue destruction.
Cystic Fibrosis
- Autosomal recessive disorder (chromosome 7) causing thick, salty secretions in mucus, sweat, saliva, and digestion.
- Leads to blocked pancreatic duct, poor nutrient absorption, chronic cough, fatty stools, delayed growth, and frequent infections.
- Treatments include enzyme supplements, medications to thin mucus, and physiotherapy (cupping) to clear mucus.
Lung Cancer
- Second most common cancer; most deadly in both sexes; can be primary or metastatic.
- Main types: small cell carcinoma (central, rapid spread, hormone-producing), non-small cell carcinoma (includes squamous cell, adenocarcinoma, large cell).
- Symptoms: persistent cough, hemoptysis (blood in cough), dyspnea, chest pain, hoarseness, weight loss, anemia, fatigue.
- Hormone production by tumors can cause systemic effects (e.g., Cushing’s or hypercalcemia).
Pleural Diseases: Effusion & Pneumothorax
- Pleural effusion: fluid in pleural space (can be exudate or transudate), causing chest pain, dyspnea, possible friction rub.
- Pneumothorax: air in pleural space, leading to lung collapse; may be spontaneous, traumatic, or tension (most severe).
- Treatment may involve thoracentesis or chest tube.
Acute Respiratory Distress Syndrome (ARDS)
- Rapid-onset respiratory failure with alveolar fluid buildup, decreased gas exchange, and metabolic acidosis.
- Causes: shock, burns, aspiration, smoke inhalation.
- Damage to type 1 alveolar cells can lead to fibrosis and lasting scarring if not resolved.
Atelectasis
- Collapse of alveoli and lung tissue due to surfactant deficiency, obstruction, or compression.
- Results in diminished breath sounds, asymmetric lung movement, and tracheal deviation.
Key Terms & Definitions
- Hypoxia — low oxygen levels in tissues.
- Hypercapnia — elevated carbon dioxide in blood.
- Alpha-1 antitrypsin — enzyme protecting lungs from inflammation; deficiency leads to emphysema.
- Cystic fibrosis — genetic disorder causing thick, sticky bodily secretions.
- Pleural effusion — fluid collection in pleural space.
- Pneumothorax — air in pleural cavity causing lung collapse.
- ARDS (Acute Respiratory Distress Syndrome) — severe, rapid-onset lung failure due to alveolar damage.
- Atelectasis — collapse of lung tissue or alveoli.
Action Items / Next Steps
- Review the different types and causes of COPD, lung cancer, pleural diseases, and ARDS.
- Watch the supplemental video on lung cancer as suggested by the lecture.
- Prepare for possible questions on distinguishing symptoms, causes, and complications of these respiratory diseases.