Complications of pulmonary tuberculosis

Main complications and the role of cavities

Pathological processes in secondary pulmonary tuberculosis are primarily caused by tissue destruction and the formation of decay cavities. The presence of cavities serves as a triggering factor for the development of life-threatening conditions.

Key complications include:

• Pulmonary hemorrhage and hemoptysis. These occur due to damage to large blood vessels passing through the walls of the cavity. Recurrent episodes lead to severe post-hemorrhagic anemia.
• Rupture of a cavity. The breakthrough of cavity contents into the pleural cavity provokes the development of exudative pleurisy, tuberculous empyema, and the formation of persistent bronchopleural fistulas.
• Secondary amyloidosis. Characteristic of a prolonged, relapsing course of the infection (especially in the fibro-cavitary form). Pathological protein is deposited in internal organs, most commonly affecting the kidneys.
• Chronic cor pulmonale. Forms as a consequence of extensive pneumosclerosis, emphysema, and persistent chronic inflammation.

Additionally, the infectious process may be complicated by bronchial stenosis and the development of pulmonary atelectasis.

Spontaneous pneumothorax

If the destructive process affects the visceral pleura over the cavity, its rupture occurs with air entering the pleural cavity. This condition is accompanied by the characteristic clinical triad:

1. Acute pain — occurs directly at the moment of visceral pleural leaflet rupture.
2. Dyspnea — caused by compressive atelectasis (compression of lung tissue by air accumulated in the cavity).
3. Drop in blood pressure (collapse) — associated with mediastinal shift due to a sharp change in intrathoracic pressure.

Clinical nuance: if pneumothorax is accompanied by air penetration into the mediastinal tissue (mediastinal emphysema), the pain syndrome can be so intense that it mimics a myocardial infarction.

Causes of death

Death in progressive tuberculosis directly stems from its complications. Severe forms, such as caseous pneumonia or fibro-cavitary tuberculosis, can lead to death from pronounced cachexia (extreme physical exhaustion).

Other direct causes of death and their pathogenesis:

Residual changes after recovery

It is important to understand that complete morphological restoration of lung tissue after tuberculosis is impossible. Even with successful clinical recovery of the respiratory organs, residual phenomena persist forever.

These irreversible consequences include:

• Fibrous and fibro-focal changes — replacement of specific inflammatory foci with dense connective tissue.
• Calcinosis / calcified nodules — deposition of calcium salts in healed foci (formed both in the lung parenchyma itself and in intrathoracic lymph nodes).
• Bullous-dystrophic changes — formation of air spaces (bullae) against the background of tissue structure destruction.
• Pleuropneumosclerosis and lung cirrhosis — massive proliferation of scar tissue, deforming the bronchial tree and disrupting the normal organ anatomy.

Class and exam questions

What else to study on this topic

• Pathomorphology and structure of a tuberculous cavity
• Mechanisms of development of secondary renal amyloidosis in chronic inflammation
• Pathogenesis of chronic cor pulmonale formation
• Differences between caseous pneumonia and other progressive forms of tuberculosis
• Types and classification of residual changes in the respiratory organs

Other topics in the "Additional Topics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.