Acute lung abscess

Introduction to acute lung abscess Acute lung abscess refers to a purulent infection of the lung caused by a variety of pathogenic bacteria. In the early stage, it is an infectious inflammation of the lung tissue, followed by necrosis, liquefaction, and peripheral granulation tissue to form an abscess. Infected bacteria of acute lung abscess are common bacteria in the upper respiratory tract and oral cavity. Often mixed infections, including aerobic and anaerobic Gram-positive and negative cocci and bacilli. The most common pathogens are staphylococcus, streptococcus, pneumococcus, fusiforms and spirochetes. The importance of anaerobic bacteria for purulent infections in the lungs has only received attention in recent years due to improvements in culture techniques. The more important anaerobic bacteria are Streptococcus faecium, Fusarium, Clostridium nucleatum, Bacteroides, V. sphaeroides, spirochetes, and the like. In addition to the above anaerobic bacteria, there are also aerobic or facultative anaerobic bacteria. In recent years, foreign countries have reported pneumonia caused by Legionella pneumophila, and about 25% form abscesses. basic knowledge The proportion of illness: 0.005% - 0.008% Susceptible people: no specific population Mode of infection: non-infectious Complications: lung abscess

Cause of acute lung abscess

Infected bacteria of acute lung abscess, common upper respiratory tract, oral common bacteria, often mixed infection, including aerobic and anaerobic Gram-positive and negative cocci and bacilli, the most common pathogen is staphylococcus, chain Cocci, pneumococcal, fusiform and spirochete, the importance of anaerobic bacteria for pulmonary suppurative infection, has been paid attention to in recent years due to improvements in culture techniques, Gorbach and Bartlett et al., 1974 report, aspiration pneumonia and lung The anaerobic infection of abscess accounts for about 85% to 90%. Bartlett et al reported that 114 cases of anaerobic bacteria were isolated from 45 cases of acute lung abscess, accounting for 58% of anaerobic infections, aerobic and anaerobic bacteria. Mixed infection accounted for 42%, the more important anaerobic bacteria are Streptococcus faecium, Fusarium, Clostridium nucleatum, Bacteroides, V. vaginalis, spirochetes, etc. In addition to the above anaerobic bacteria, there is aerobic or Facultative anaerobic bacteria exist. In recent years, pneumonia caused by Legionella pneumophila has been reported abroad, and about 25% of them form abscesses.

The pathogenesis of lung abscess is closely related to the cause, and can be divided into the following types.

Infection (35%):

Inhaled lung abscess pathogen oral, nasopharyngeal cavity inhalation, is the most common cause of lung abscess, tonsil inflammation, sinusitis, alveolar pyorrhage or age teeth and other purulent secretions, oral, nasal, pharyngeal surgery Blood clots; tartar or vomit, etc., in the case of conscious coma, general anesthesia, etc., the trachea is inhaled into the lungs, causing obstruction of the bronchioles, and the pathogens can reproduce and cause disease. In addition, some patients fail to find obvious incentives. The reported cases are 29.3% and 23%, respectively. It may be due to cold, extreme fatigue and other incentives. The systemic immune status and respiratory defense function are reduced, and the secretions of the oral cavity are inhaled during deep sleep. For a single hair style, its occurrence is related to anatomical structure and body position. Since the right common bronchus is straight and the diameter is relatively thick, the inhaled secretion is easily inhaled into the right lung. Therefore, the right lung has more incidence than the left lung. When lying on the back, good In the posterior segment of the upper lobe or the dorsal segment of the inferior lobe, in the sitting position, it occurs in the posterior segment of the lower lobe, and in the right position, it occurs in the sub-segment formed in the anterior and posterior segments of the right upper lobe.

Skin trauma (20%):

Blood-borne lung abscess skin trauma, infection, sputum, osteomyelitis, postpartum pelvic infection, subacute bacterial endocarditis and other sepsis and sepsis, pathogens (mostly Staphylococcus aureus), sepsis The embolus is brought to the lungs through a small circulation, causing embolization of small blood vessels, inflammation and necrosis of the lung tissue, formation of abscesses, lesions often multiple, no distribution, often occurring at the edge of both lungs.

Secondary to other diseases (20%):

Secondary lung abscess is secondary to other diseases, such as Staphylococcus aureus and pneumococcal pneumonia, cavitary tuberculosis, bronchiectasis, bronchial cysts and bronchial cancer and other secondary infections, can cause lung abscess, lung adjacent organs suppuration Sexual lesions or traumatic infections, underarm abscesses, perirenal abscesses, paraspinal abscesses, perforation of the esophagus, etc., can also form abscesses when worn through the lungs.

The amoebic lung abscess is secondary to the amoebic liver abscess. Because the liver abscess occurs at the top of the right lobe of the liver, it is easy to break through the diaphragm to the right lower lobe, forming an amoebic lung abscess.

Early bronchiole obstruction, inflammation of lung tissue, embolization of small blood vessels, suppuration of the lung tissue, necrosis, formation of abscess, lesions can spread to the surrounding, and even beyond the interlobular fissure to invade adjacent lung segments, the thrombus causes local tissue ischemia, and encourages Anaerobic infection, aggravation of tissue necrosis, liquefied pus, accumulation in the abscess causes increased tension, and finally rupture into the bronchi, coughing up a large amount of purulent, if the air enters the abscess, the liquid level appears in the abscess, sometimes inflammation Spread to the surrounding lung tissue, can form a uniform number of abscesses, if the abscess is close to the pleura, localized fibrin pleurisy can occur, causing pleural adhesions, tension abscess at the edge of the lung, if it ruptures into the pleural cavity, The pus pneumothorax is formed. If the bronchial drainage is smooth, the necrotic tissue remains in the abscess cavity, and the inflammation persists, then it becomes a chronic lung abscess, the fibrous tissue around the abscess is hyperplasia, the wall of the abscess is thickened, and the surrounding bronchioles are involved, causing deformation. Or expansion.

Acute lung abscess prevention

Lung abscess is a purulent inflammation of the lung parenchyma caused by a mixture of various pyogenic bacteria. The secretion of the mouth, nose and pharyngeal secretions containing the pathogen is the main cause of the disease. Therefore, the key to prevent this disease is to actively remove and Treatment of chronic infections of the mouth, nose and pharynx, such as dental caries, tonsillitis, paranasal sinusitis, alveolar pus, etc., to avoid excessive use of sedation, hypnosis, anesthetics and alcohol abuse, upper respiratory tract surgery and coma, general anesthesia People should strengthen nursing, prevent lung infection, treat early use of strong antibiotics, sputum drainage is also an important measure to improve the efficacy, the disease can be cured after active and effective treatment, for chronic lung abscess, especially antibiotic treatment After 3 months, there are still thick-walled cavities or repeated hemoptysis, and surgical resection can be considered.

Acute lung abscess complications Complications lung abscess

If the acute stage of lung abscess is not treated promptly and effectively, such as poor bronchial drainage, anti-infective treatment is not effective, inadequate, incomplete, prolonged more than 3 months is chronic lung abscess.

Symptoms of acute lung abscess Common symptoms Rotten peach-like blood stasis, high fever, cold war, sputum, mucus, purulent cough, foamy mucus, fatigue, irritability, viscous or purulent... Congestive chills are white viscous jelly-like high fever

1. Anxiety chills, high fever, with weak body weakness, excessive sweating, poor appetite, weight loss, etc.

2. Cough, chest pain, a large amount of purulent sputum on the 5th to 15th day of onset, stench.

3. The formation of tension hollow, thin wall, can compress the surrounding lung tissue or mediastinum.

4. May be accompanied by a small amount of pleural effusion, empyema or pus.

Examination of acute lung abscess

(1) The blood white blood cell count and neutrophils of the peripheral blood were significantly increased, the total number was up to 20,000 to 30,000/mm3, and the neutrophils were above 80% to 90%. The white blood cells of patients with chronic lung abscess did not change significantly. But there may be mild anemia.

(B) and blood pathogens check sputum smear Gram stain test, sputum culture, including anaerobic culture and bacterial drug sensitivity test, help determine pathogens and choose effective antibiotic treatment, blood-borne lung Blood cells in patients with abscess can be found in pathogenic bacteria.

X-ray inspection:

X-ray findings of lung abscess vary depending on type, stage of disease, bronchial drainage, and presence or absence of pleural complications.

Inhalation lung abscess in the early stage of purulent inflammation, the typical X-ray signs are large thick fuzzy inflammatory infiltrating shadows, unclear edges, distributed in one or several lung segments, similar to bacterial pneumonia, after abscess formation, large pieces In the dense inflammatory shadow, a circular translucent area and a liquid level appear. In the dissipative period, the inflammation around the abscess gradually absorbs, the abscess narrows and disappears, and finally a little fibrous strip shadow remains, and the chronic lung abscess wall thickens, the inner wall Irregular, the surrounding inflammation is slightly dissipated, but incomplete, with fibrous tissue significantly hyperplasia, and varying degrees of lung lobe contraction, pleural thickening, mediastinal shift to the affected side, and other healthy lungs with compensatory emphysema.

Blood-borne lung abscess has multiple scattered spherical lesions with small patches of inflammation or neat margins on the edge of the lungs or both lungs. The abscess and fluid plane can be seen. The lesions can be focally fibrotic or small after inflammation absorption. Airbag.

In patients with empyema, the affected chest has a large thick shadow; if accompanied by a pneumothorax, the liquid level is visible.

Lateral X-ray examination can determine the location of the abscess in the lung and its extent, which is helpful for positional drainage or surgical treatment.

CT scans of the chest are mostly round-shaped thick wall abscesses, and there may be a liquid level in the abscess. The inner wall of the abscess is often irregular, with blurred inflammatory shadows around it.

Fiberoptic bronchoscopy:

It can help to find the cause. If it is a bronchial tumor, it can be taken for biopsy. If you can see that the foreign body can be removed, the drainage can be restored smoothly. You can also use the fiberoptic bronchoscope anti-contamination brush to sample the bacterial culture and attract the pus and the lesion to inject the antibiotic. Promote bronchial drainage and healing of the abscess.

Diagnosis and diagnosis of acute lung abscess

diagnosis

According to oral surgery, coma and vomiting, foreign body inhalation, acute onset of chills, high fever, cough and cough, a large number of pus sputum and other medical history, combined with the total number of white blood cells and neutrophils significantly increased, the lung field large thick inflammatory shadows have abscess And X-ray signs of the liquid level, can make diagnosis, blood, sputum culture, including anaerobic culture, separation of bacteria, help to make pathogen diagnosis, skin wound infection, sputum, sputum and other purulent lesions, fever does not retreat There are cough, cough and other symptoms, chest X-ray examination showed multiple small abscesses in both lungs, can be diagnosed as blood-borne lung abscess.

Differential diagnosis

(1) Bacterial pneumonia

Early lung abscess and bacterial pneumonia are similar in symptoms and X-ray findings. Pneumococcal pneumonia is the most common in bacterial pneumonia. It often has herpes labia, rust-colored sputum without massive yellow purulent sputum, and chest X-ray shows lung lobe or segment. Sturdy or flaky inflammatory lesions with blurred edges, but no abscess formation, other staphylococcal strains of staphylococcus, pneumonia bacilli pneumonia, etc., bacterial or blood bacterial isolation can be identified.

(2) Cavity tuberculosis

Slow onset, long course, often accompanied by tuberculosis toxic symptoms, such as low fever in the afternoon, fatigue, night sweats, long-term cough, hemoptysis, etc., chest X-ray film shows thick cavity wall, surrounded by tuberculosis infiltrating lesions, or accompanied by spots, knots Nodular lesions, generally no fluid plane in the cavity, sometimes accompanied by ipsilateral or contralateral tuberculosis disseminated lesions, tuberculosis can be found in the sputum, secondary infections, there may be a large number of yellow purulent sputum, should be combined with past history, In the treatment of secondary infections, repeated investigations can confirm the diagnosis.

(three) bronchial lung cancer

Tumor obstruction of the bronchus causes obstructive inflammation of the distal lung, showing the lobe, segmental distribution, cancerous necrosis and liquefaction to form a cancerous cavity, slow onset, often no or only low toxicity symptoms, chest X-ray film often showing eccentricity The wall is thicker, the inner wall is uneven, generally has no liquid plane, and there is no inflammatory reaction around the cavity. Because the cancer often metastasizes, it is common to the hilar lymph node, through X-ray tomography, chest CT scan, sputum exfoliated cells Examination and fiberoptic bronchoscopy can confirm the diagnosis.

(four) pulmonary cyst

Secondary infection of the lung cyst is round, the wall is thin and smooth, often accompanied by a liquid level, no inflammatory reaction around, patients often have no obvious symptoms of toxicity or cough, if the X-ray film before infection is easier to compare Identification.

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