Pulmonary hemorrhage

Inflammatory and destructive causes

One of the most frequent causes of blood in the sputum is infectious and inflammatory processes of the respiratory system.

• Acute pneumonias: especially lobar pneumonia, which is characterized by the production of "rusty sputum" (due to the presence of altered blood).
• Bronchiectasis: including "dry" bronchiectasis without purulent discharge. The pathogenesis is caused by erosion of the mucous membrane in areas of inflammation or atrophy, leading to direct damage to the walls of small vessels.
• Acute viral infections: bronchitis, tracheitis, laryngitis (against the background of acute respiratory viral infections).

A high risk of massive, life-threatening bleeding is characteristic of destructive processes, such as lung abscess and gangrene, as well as cavitary tuberculosis. The mechanism lies in the massive dissolution of lung tissue as a result of aseptic or infectious necrosis. In secondary tuberculosis (especially at the stage of "galloping consumption"), bleeding occurs due to the erosion of the wall of a large blood vessel passing through a cavity.

Cardiovascular pathology

Hemodynamic disorders and vascular catastrophes in the pulmonary circulation lead to the escape of blood into the lumen of the respiratory tract.

• Pulmonary embolism (PE) and subsequent pulmonary infarction. Clinically, pulmonary infarction manifests as chest pain, fever, and a cough (initially dry, then with bloody sputum or hemoptysis). Radiological examination reveals the pattern of focal pneumonia.
• Cardiac pathology: acute left ventricular and chronic congestive heart failure.
• Mitral stenosis and primary pulmonary hypertension. In mitral stenosis, the pathogenesis of bleeding is directly related to the development of pronounced pulmonary hypertension.

Systemic vasculitis and oncology

Hemorrhagic alveolitis in systemic vasculitis (e.g., in granulomatosis with polyangiitis or microscopic polyangiitis) causes severe pulmonary hemorrhages.

Microscopic polyangiitis is an immune disease of unknown etiology associated with pANCA. Unlike classic polyarteritis nodosa (which affects medium and small-sized arteries), inflammation here affects capillaries, venules, and arterioles. The disease manifests as a pulmonary-renal syndrome. Diffuse alveolar damage, capillaritis, and hemorrhagic infarctions develop in the lungs, which together produce the picture of hemorrhagic alveolitis. In later stages, carnification, hemosiderosis, and pulmonary fibrosis are formed. A fatal outcome is often caused by pulmonary hemorrhage or cor pulmonale.

Oncological diseases: bronchogenic lung cancer manifests with moderate but persistent hemoptysis. A rare, late sign of pronounced tumor breakdown is sputum resembling "raspberry jelly".

Traumatic, iatrogenic, and rare factors

Various mechanical and external influences also provoke pulmonary hemorrhage:

• Trauma: lung contusions, mechanical chest injuries, injuries to the pharynx and airways.
• Increased intrapulmonary pressure: intense, debilitating coughing can cause rupture of small vessels.
• Foreign bodies.
• Iatrogenesis: bronchoscopy with biopsy, pulmonary artery catheterization, and anticoagulant therapy.

Rare causes include hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease), which is diagnosed based on family history and the presence of telangiectasias on the skin and mucous membranes. If the cause cannot be identified after a complete examination, it is termed idiopathic (cryptogenic) hemoptysis.

Class and exam questions

What else to study on this topic

• Pathogenesis and morphology of hemorrhagic alveolitis in vasculitis.
• Clinical and morphological forms of secondary tuberculosis.
• Mechanisms of secondary amyloidosis development in tuberculosis.
• Chronic cor pulmonale against the background of total pneumosclerosis.
• Pathogenesis of spontaneous pneumothorax upon rupture of a tuberculous cavity.

Other topics in the "Additional Topics" section

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