Bronchiectasis: Bronchiectasis is an irreversible, abnormal dilatation of the bronchi and bronchioles. It typically results from damage to the bronchial walls due to infections such as Staphylococci, Klebsiella, Mycobacteria, etc., and it usually follows a chronic course. It’s often associated with cystic fibrosis, Kartagener’s syndrome, lung cancers, COPD, and allergic bronchopulmonary aspergillosis. Some cases may be congenital.
Bronchiectasis may be:
In bronchiectasis, bronchial secretions can’t be cleared effectively, which predisposes to secondary infections. Clinical features include cough with expectoration, hemoptysis, dyspnea, clubbing, etc.
CxR may show dilated bronchi, “tram-track” opacities, increased bronchovascular markings, and air-fluid levels. HRCT is the investigation of choice for diagnosis.
Pneumothorax and atelectasis: Pneumothorax is the abnormal accumulation of air in the pleural space. It may lead to partial or complete atelectasis (collapse) of the lung.
Pneumothorax may be primary or secondary.
Primary spontaneous pneumothorax is caused by rupture of subpleural blebs. It’s more common in tall, young men and in smokers. Mutations in the FLCN gene (which codes for folliculin protein, acts as a tumor suppressor gene, and is involved in connective tissue formation) are associated with primary spontaneous pneumothorax.
Secondary spontaneous pneumothorax occurs in the setting of underlying lung disorders such as emphysema, COPD, asthma, TB, bronchiectasis, etc. Systemic disorders such as rheumatoid arthritis, ankylosing spondylitis, polymyositis and dermatomyositis, systemic sclerosis, Marfan’s syndrome, and Ehlers-Danlos syndrome can also cause secondary spontaneous pneumothorax.
Traumatic pneumothorax occurs after penetrating trauma to the chest. It can follow gunshot or stab wounds, or occur as a complication of invasive procedures such as subclavian vein catheterization, lung biopsy, etc. It may also be associated with mechanical ventilation.
Tension pneumothorax is a life-threatening form of pneumothorax. The defect in the lung acts as a one-way flap valve, allowing air to flow in but not out. This leads to progressive air trapping under high pressure. With each inspiration, more air accumulates in the pleural space, which interferes with venous return to the heart and causes atelectasis and shock.
On examination in tension pneumothorax:
Pneumothorax typically presents with sudden onset dyspnea, chest tightness, pleuritic chest pain, hypoxia. Cardiorespiratory collapse may occur in tension pneumothorax.
For treating tension pneumothorax, insert a large-bore needle into the 2nd intercostal space in the midclavicular line as an emergency procedure, even before an X ray is taken. This should be followed by tube thoracostomy. Any penetrating chest wounds should be sealed immediately.
In primary spontaneous pneumothorax, treatment depends on the presentation and the size of the pneumothorax. If the pneumothorax is <50% of the hemithorax and the patient is asymptomatic, observation may be done because spontaneous regression is common.
In secondary spontaneous pneumothorax, high-flow oxygen is given and conservative management is done if the size is small (i.e., 1 cm or less air rim). Aspiration and chest tube drainage can be done for more severe cases. Serial chest X rays are used to monitor response.
CxR shows absent lung markings, most commonly at the apices in an upright patient. “Deep sulcus sign” is seen when air collects in the inferior sulci. In addition, a collapsed lung and mediastinal shift are seen in tension pneumothorax.
Hemothorax: Hemothorax is the accumulation of blood in the pleural cavity. Causes include trauma, ruptured aortic aneurysm, malignancy, anticoagulants, etc. It may occur with a pneumothorax. Tension hemothorax may cause lung compression and mediastinal displacement to the opposite side. On CxR, it can resemble pleural effusion with blunting of the costophrenic angle and an air-fluid interface.
Pulmonary contusion: Pulmonary contusion is characterized by parenchymal damage with alveolar haematoma and edema, along with damage to the interstitial tissues of the lung. It is caused by chest trauma, traffic accidents, deceleration injury, blast injuries, etc.
It presents with hypoxia, dyspnea, tachypnea, tachycardia, chest pain, hemoptysis, atelectasis, ARDS, and respiratory failure. Reduced breath sounds are heard on auscultation.
CxR (not sensitive in early stages), chest ultrasound, or CT scan can help in diagnosis. CxR shows patchy consolidation that is ill-defined and non-segmental, and it may be confused with pneumonia.
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