bubble_chart Overview

A lung abscess is a suppurative and cavitary lesion within the lung. Most acute lung abscesses can be cured with medication, but if treatment is insufficient or incomplete, they may become chronic lung abscesses, which then require surgical intervention.

bubble_chart Etiology

The occurrence and development of lung abscess are often influenced by the following three factors: ① bacterial infection; ② bronchial obstruction; ③ reduced systemic resistance. Clinically, there are two major categories of disease causes: hematogenous infection and tracheal infection. Hematogenous infection is mainly caused by sepsis and pyemia, with widespread and often multiple lesions, primarily treated with medication. Tracheal infection mainly originates from respiratory secretions or upper digestive tract secretions containing bacteria, which are inhaled into the trachea and lungs during sleep, unconsciousness, intoxication, anesthesia, epileptic seizures, or cerebrovascular accidents, leading to small bronchial obstruction. When the body's resistance is reduced, this can trigger a lung abscess.

bubble_chart Pathological Changes

Atelectasis and inflammation occur in the pulmonary segment distal to the bronchial obstruction, followed by pulmonary segmental vascular embolism, leading to necrosis and liquefaction of the lung tissue. The surrounding pleural and pulmonary tissues undergo inflammatory reactions, eventually forming an abscess with a defined range. After the abscess forms, it progresses through acute and subacute stages. If bronchial drainage remains inadequate and infection control is incomplete, it gradually transitions into a chronic stage. During the recurrent and alternating evolution of infection, the affected lung and bronchi experience both destruction and tissue repair, exhibiting both pulmonary lesions and bronchopleural lesions, as well as both acute and chronic inflammation. The primary manifestation is a purulent cavity within the lung tissue, surrounded by interstitial pneumonia and varying degrees of fibrosis, with associated bronchi developing varying levels of obstruction and dilation.

Chronic lung abscess has the following three characteristics: ① The abscess initially tends to be located in the superficial part of the affected pulmonary segment or lobe; ② The abscess cavity is always connected to one or more small bronchi; ③ The abscess spreads outward, and in the advanced stage, it is no longer confined by the boundaries of the pulmonary segment or lobe, instead crossing segments and lobes to form interconnected multiloculated destructive lesions of sexually transmitted disease.

bubble_chart Clinical Manifestations

Chronic lung abscess is characterized by pleural adhesions, within which collateral circulation forms, with blood flow directed from the higher-pressure systemic circulation of the chest wall to the lower-pressure pulmonary circulation. Clinically, a continuous vascular murmur intensified during systole can be heard over the affected area. Patients with this murmur tend to experience significant intraoperative bleeding, necessitating adequate preparations for tonifying blood and hemostatic techniques. Chronic lung abscess patients present with chronic cough disease, hemoptysis, purulent sputum, systemic toxic symptoms, poor nutritional status, impaired respiratory function, anemia, emaciation, edema, and clubbing fingers, among others.

Lung abscess typically has an acute onset, often following upper respiratory tract infections, pneumonia, bronchitis, or oral infections. The initial stage [first stage] symptoms include chills, fever, general malaise, chest pain, and dry cough. Although acute symptoms may improve with medication, they are not entirely resolved, gradually progressing to chronic lung abscess, with main symptoms such as cough, purulent sputum, hemoptysis, intermittent fever, and chest pain. The sputum is copious, viscous, purulent, and foul-smelling.

Physical examination reveals dullness on percussion over the affected lung, various rales and tubular breath sounds on auscultation, and in a few cases, vascular murmurs due to pleural adhesions may be heard. Patients with a prolonged course often exhibit clubbing fingers.

bubble_chart Diagnosis

In addition to analyzing medical history, symptoms, and physical examination, X-ray examination is essential. Chest radiographs may reveal pulmonary cavities with thick walls, often containing air-fluid levels, surrounded by infiltrates and linear shadows, accompanied by pleural thickening. Bronchography is highly useful for determining the presence of concurrent bronchiectasis and the extent of lesion resection. For patients experiencing choking during swallowing, iodized oil or barium esophagography should be performed to confirm the presence of a tracheoesophageal fistula. If differentiation from lung cancer is required, bronchoscopy with biopsy should be conducted.

bubble_chart Treatment Measures

Treatment For lung abscesses with a disease duration of less than three months, systemic and drug therapy should be employed. This includes systemic antibiotic application, postural drainage, local instillation of medication, aerosol inhalation, and bronchoscopic sputum aspiration. If the above treatments prove ineffective, surgical intervention should be considered.

Surgical Indications:

1. Disease duration exceeding three months, with no significant absorption of lesions after medical treatment, and persistent or recurrent symptoms.

2. Chronic lung abscess with a sudden life-threatening massive hemoptysis, or massive hemoptysis that persists despite aggressive drug therapy, requires prompt surgical intervention.

3. Chronic lung abscess with difficult-to-control infection due to severe bronchial obstruction should undergo lung resection after appropriate preparation.

4. Chronic lung abscess coexisting with other lesions or indistinguishable from conditions such as subcutaneous nodules, lung cancer, or fungal infections also necessitates lung resection.

Preoperative Preparation: Includes improving the patient's general condition, enhancing nutrition, intermittent blood transfusions, systemic antibiotic use, postural sputum drainage, local aerosol inhalation, and intratracheal medication instillation. After 3–6 weeks of hospitalization, surgery can be performed if sputum volume decreases to below 50ml per day; sputum changes from thick yellow pus to thin white mucus; appetite and weight improve; hemoglobin levels approach normal; and temperature and pulse stabilize.

Surgical Scope: Lung abscess surgery is challenging and often involves significant bleeding. Lesions frequently extend across lobes, so the surgical approach should not be overly conservative. Lobectomy or partial lobectomy is generally avoided, with most cases requiring resection beyond a single lobe or even pneumonectomy.

Surgical Complications: Common complications include hemorrhagic shock, bronchopleural fistula, empyema, aspiration pneumonia, and esophageal fistula.

Prognosis: Most chronic lung abscesses treated surgically show satisfactory outcomes, with symptoms disappearing and patients resuming normal work.