What Is a Lung Abscess?

Lung abscess is a purulent lesion of the lung tissue caused by a variety of causes. The early stage is purulent inflammation, followed by necrosis to form an abscess. Occurs in middle age, more men than women. According to the cause of infection, there are infections caused by tracheal infection, blood-borne infection, multiple abscesses and blockages of lung cancer. Lung abscesses can also be classified according to the relevant pathogen, such as staphylococcal, anaerobic, or aspergillous lung abscesses. Since the widespread use of antibiotics, the incidence of lung abscesses has been greatly reduced.

Basic Information

English name: lungabscess
Visiting department: Respiratory Medicine

Multiple groups: Strong male
Common causes: Bacterial infections, bronchial blockages, and reduced body resistance

Causes of lung abscess

Lung abscesses are caused by bacterial infections, bronchial obstructions, and decreased systemic resistance. Primary abscess is caused by inhalation of pathogenic bacteria or pneumonia, and secondary abscess is caused by extra-pulmonary spread, bronchiectasis and / or immunosuppressive status based on existing lesions (such as obstruction).

Clinical manifestations of pulmonary abscess

Symptoms

(1) Acute inhaled pulmonary abscess has a rapid onset, and the patient has chills and fever, and the body temperature can reach 39 ° C to 40 ° C. With cough, mucus or mucus. Inflammation spread to the local pleura can cause chest pain. The range of lesions is large and shortness of breath may occur. In addition, there are also weakness, fatigue, and poor appetite. After 7 to 10 days, the cough intensified, the abscess ulcerated in the bronchi, and a large amount of pus and odorous sputum was coughed up to 300 to 500 ml per day. Due to anaerobic infection, the sputum smelled, and it was divided into 3 layers after standing. From the top to the bottom, there are foam, mucus and pus. After the pus is discharged, the general symptoms improve and the temperature drops. If effective antibiotics can be applied in time, the lesions can gradually improve within a few weeks. Sometimes there is blood in the sputum or moderate hemoptysis. If the treatment is not timely and thorough, the lesion may gradually become chronic. Some break into the chest to form pneumothorax or bronchopleural fistula.

(2) Chronic lung abscesses include chronic cough, purulent sputum, repeated hemoptysis, secondary infections, and irregular fevers, etc., often with chronic consumption such as anemia and weight loss.

(3) Blood-borne lung abscesses usually have symptoms of systemic sepsis such as chills and fever caused by the primary lesion. Pulmonary symptoms such as cough and sputum do not appear until several days to two weeks. Usually there is not much sputum and rarely hemoptysis.

2. Signs

Related to the size and location of the lung abscess. The lesions are small or deep in the lungs, and there may be no abnormal signs. The lesions are large, there is a large amount of inflammation around the abscess, dull or solid sounds on percussion, decreased auscultation breath sounds, and sometimes wet rales can be heard. Signs of blood-borne lung abscess are mostly negative. Patients with chronic lung abscess had a slightly collapsed thorax, dullness on percussion, and reduced breath sounds. May have clubbing fingers (toes). The rib cage also has deformities and poor mobility.

Lung abscess examination

Laboratory inspection

(1) Leukocyte count may increase and the nucleus shifts to the left when the blood test is followed by infection. Patients with a long course or severe hemoptysis may have anemia and rapid increase in erythrocyte sedimentation.

(2) Sputum examination Sputum smear can find Gram-positive and negative bacteria, culture can detect pathogenic bacteria, sputum culture can help sensitive antibiotic selection.

2. Auxiliary inspection

(1) Chest X-ray examination is the main diagnostic method for lung abscess. Because the abscess has the characteristic of spreading to different leaves, it can spread to multiple leaves and even the entire lung.

(2) CT tomography (including CT) can better understand the extent, location and cavity of the lesion. In a few abscesses, the pus is not discharged, and appears as a round block shadow, but there are small holes in the visible, and there are not many solid blocks. Significant fibrosis reduces the lung volume and complete occlusion of the bronchi may have atelectasis. Visible inter-leaf pleura thickening. The abscess broke into the thorax to form empyema or pneumothorax, with corresponding changes on the film.

(3) Fiber bronchoscopy Fiber bronchoscopy is best performed when the patient's condition is stable, and not when the fever and severe inflammation of the respiratory tract are severe.

(4) Bronchial bronchography: The bronchial changes of the lung abscess are quite obvious. The bronchogram can understand the location and scope of the lesion, and it is found that the lesion is not seen on plain film or the tomography is not clear. The angiography can see dilated bronchus, filled pus cavity, twisted and deformed bronchi, stenosis and bronchopleural fistula.

(5) Pulmonary function tests are mainly manifested as obstructive ventilation disorder. In the later stage, there may be a decrease in arterial blood oxygen partial pressure and a decrease in arterial blood oxygen saturation.

Diagnosis of lung abscess

Based on the history of oral surgery, coma, vomiting, foreign body inhalation, acute episodes of chills, high fever, cough and a lot of purulent sputum, combined with a significant increase in the total number of white blood cells and neutrophils, there is a pus cavity in the dense inflammatory shadow of the lung field And the X-ray signs of the liquid plane can make a diagnosis. Blood and sputum cultures, including anaerobic cultures, isolate bacteria and help make a pathogen diagnosis. There are skin trauma infections, purulent lesions such as ridges and ridges, persistent fever and cough, sputum and other symptoms. Chest X-ray examination shows multiple small abscesses in both lungs, which can be diagnosed as blood-borne pulmonary abscess.

Surrounding blood

Blood leukocyte counts and neutrophils increased significantly, with neutrophils above 80% to 90%. Patients with chronic lung abscess have no significant changes in white blood cells, but may have mild anemia.

2. Pathogen examination of sputum and blood

Gram staining of sputum smears, sputum cultures, including anaerobic cultures and bacterial drug sensitivity tests, can help identify pathogens and select effective antibiotic treatments. Pathogens can be found in blood cultures of patients with blood-borne lung abscess.

Lung abscess treatment

The upper respiratory tract and oral infections must be cured. As much as possible during oral surgery. Patients with coma or general anesthesia should strengthen their care to prevent lung infections. Early and thorough treatment is the key to radical lung abscess.

Treatment principles are anti-inflammatory and drainage.

Antibiotic

Infective bacteria for treating acute lung abscesses, including most anaerobic bacteria, are sensitive to penicillin and have better curative effect, so they are the most commonly used. The dose depends on the condition. Generally, acute lung abscess can be cured by penicillin treatment. B. fragile is not sensitive to penicillin and can be injected intramuscularly with lincomycin; in severe cases, intravenous drip can be used. Or clindamycin orally. Or metronidazole orally. For pulmonary abscess caused by Legionella pneumophila, erythromycin treatment is effective. On the basis of systemic administration, local treatments such as cyclomembrane puncture, intranasal catheter trachea or fiber bronchoscopy drops are usually used. Penicillin is commonly used. After dropping, take appropriate positions according to the abscess area and lie still for 1 hour.

Hematogenous pulmonary abscess is a complication of sepsis and should be treated as sepsis.

2. Sputum drainage

Expectorants are taken orally to make sputum easier to cough. Those with thick sputum can use airway humidification such as steam inhalation, ultrasonic atomization inhalation to facilitate the drainage of sputum. Patients are generally better, those with low fever, and postural drainage can help the discharge of pus. Make the abscess part high, and pat it on the affected part, there are obvious signs of sputum obstruction, which can be washed and attracted by bronchoscopy.

3. Surgical treatment

Bronchial obstruction is suspected of bronchial cancer. Chronic pulmonary abscess is still undiminished and infection cannot be controlled after 3 months of medical treatment. Or bronchiectasis, empyema, and bronchopleural fistula may occur. Large hemoptysis may be life-threatening. For surgical treatment.