Lung abscess

Introduction to lung abscess Lungabscess is a purulent lesion of the lung tissue caused by a variety of causes, early purulent inflammation, followed by necrosis to form abscess. It happens mostly in the prime of life, more men than women. According to the cause of the disease, there are three types of infections caused by tracheal infection, blood-borne infection, multiple abscesses and lung cancer. Lung abscess can also be classified according to related pathogens, such as staphylococcal and anaerobic bacteria. Or Aspergillus lung abscess, the incidence of lung abscess has been greatly reduced since the widespread use of antibiotics. basic knowledge The proportion of illness: 0.1% - 1.5% Susceptible people: Most occur in the prime of life, more men than women. Mode of infection: non-infectious Complications: empyema, pneumothorax

Cause of lung abscess

The cause of lung abscess is bacterial infection, bronchial obstruction, and reduced systemic resistance. The primary abscess is caused by inhalation of pathogenic bacteria or pneumonia. The secondary abscess is based on existing lesions (such as obstruction). Caused by extrapulmonary dissemination, bronchiectasis and/or immunosuppression, common pathogenic factors:

Inhalation of oropharyngeal bacteria (20%):

1, teeth, periodontal infection: unconscious, abuse of alcohol or sedatives, epilepsy, head trauma, cerebrovascular accident, diabetes coma and other diseases caused by cough reflex disappeared aspiration.

2, swallowing disorder: benign or malignant esophageal stenosis, medullary paralysis, achalasia, pharyngeal sac presence caused by aspiration.

Primary or secondary immunodeficiency (20%):

There are many bacteria that can cause lung abscess, and most of them are mixed infections, generally consistent with upper respiratory tract and oral bacteria, including aerobic, facultative anaerobic and anaerobic bacteria: such as pneumococcus, Staphylococcus aureus, hemolytic chain Cocci, Proteus, Klebsiella, Escherichia coli, Pseudomonas aeruginosa, Proteus, etc.; Anaerobic bacteria such as Streptococcus mutans, Aspergillus, Clostridium nucleatum, etc. In recent years, due to advances in culture techniques, The rate of inhaled anaerobic infection can be as high as 90%.

The occurrence and development of lung abscess often have the following three factors: 1 bacterial infection. 2 Bronchial obstruction. 3 systemic resistance is reduced, clinical common causes are two major categories: blood source infection and tracheal infection, blood source infection, mainly caused by sepsis and sepsis, lesions are often frequent, mainly using drug treatment, mainly tracheal infection Bacterial secretions from the respiratory tract or upper digestive tract, after sleep, coma, drunkenness, anesthesia or seizures, cerebrovascular accident, inhalation into the trachea and lungs, causing obstruction of the small bronchus, reducing the body's resistance Next, it will induce lung abscess.

Abdominal and inflammatory changes occur in the lung segment of the distal end of the bronchial obstruction, which in turn causes pulmonary tissue necrosis and liquefaction in the pulmonary vascular embolism. An inflammatory reaction occurs in the surrounding pleural lung tissue, and finally a certain amount of abscess is formed. After the abscess is formed, In the acute and subacute stages, such as bronchial drainage is not smooth, infection control is not complete, then gradually transferred to the chronic stage, in the process of repeated episodes of infection, staggered and degenerated, the affected lung and bronchi are both damaged and organized repair; There are lesions of the lung tissue, and there are lesions of the bronchial pleura; both acute inflammation and chronic inflammation; mainly manifested as a abscess in the lung tissue, surrounded by interstitial inflammation and varying degrees of fibrosis, related bronchi Produces varying degrees of obstruction and dilation.

Chronic lung abscess has the following three characteristics:

1. The abscess is initially located in the superficial part of the lung segment or lung lobe.

2. The abscess is always connected to one or more small bronchi.

3, the abscess spreads outward, and in the late stage, it is not restricted by the lung segment and the boundary of the lung, but can form a destructive lesion of multi-chamber cavity that communicates with each other across the segment and across the leaf.

Mixed infection of various bacteria (20%):

Causes necrotizing pneumonia. Such as urinary tract infection, abdominal pelvic abscess, left heart endocarditis, infection caused by various cannula, infectious thrombotic vasculitis.

Original lung lesions (10%):

Such as bronchiectasis, bronchial blockage (tumor, foreign body, congenital abnormalities).

Pathogenesis:

Lung abscess can be classified according to the onset time and pathogenic bacteria. The acute lung abscess does not exceed 4-6 weeks, and the chronic abscess time is longer.

Inhalation of bacteria-containing pollutants into the lungs through the mouth and nose, blocking a segment or a small segment of the bronchus, causing distal atelectasis, local bacteria rapidly multiply and grow, produce inflammation, small blood vessel embolism, lung tissue is quickly necrotic, liquefaction after about 1 week As a abscess, the abscess enlarges, destroys the surrounding small bronchi, pus can be discharged from the atmospheric tube, forming a purulent cavity, the volume varies, single or multiple, can occur in any part of the lung, multiple small abscess (<2cm) The formation is related to pneumonia or lung gangrene. The abscess after partial necrosis is a solid tumor. It does not discharge pus into the bronchus. It is like a tumor. The abscess is mostly under the pleura of the lung. However, there is inflammation adhesion in the early stage of the pleura. There is not much rupture into the pleura into the empyema or pus pneumothorax. In the acute phase, if the drainage is smooth, the pus is discharged smoothly, and with the drug treatment, the lesion can gradually heal, leaving a small amount of fibrous tissue, such as strong virulence and inappropriate treatment. If the bronchial drainage is not smooth, the lesions will expand, and the pulmonary fissure will have little effect on the infection. The lesions often invade the adjacent segments and adjacent leaves, and even spread to the whole lung. If the bronchi has a occlusion, it can form. Tensionable cavity, easy to break into the chest.

If the acute abscess is not controlled in time, the lung inflammation and the abscess prolonged to 2 to 3 months, it becomes a chronic lung abscess, the lungs are destroyed in many places, the sinus is twisted in the middle, and the lesion is destroyed at the same time. Organized repair, the abscess gradually thickens the wall of the fiber, the bronchus is invaded by inflammation and the opening is blocked, resulting in different degrees of expansion, the abscess can be at rest, or the infection can be spread due to sputum spill, lung tissue Fibrosis and contraction, the pleura forms a tight adhesion due to repeated inflammation. The systemic circulation forms many vascular communication with the pulmonary circulation. There are thick blood vessels in the adhesion, and even systolic or continuous vascular murmur (pleural adhesion murmur) can be heard on the body surface. The adhesion of the hilar is very tight, and the bronchial artery is enlarged and enlarged.

Gravity and aspiration are the determinants of the diseased lung segment. Therefore, the anterior and posterior superior anterior and posterior segments of the lower lung are aspirational sites, accounting for 85% of the lung abscess. The supine lung abscess occurs in the supine lung. The right side is more than the left side, the right lower back leaf section is the most common, because the right total bronchus and the midline angle are small, and thicker, the pollutants are easy to enter, the same reason, the lower leaf back section, the upper part of the upper lobe, "" is multiple, in the right anterior segment, the middle lobe and the tongue segment of the lung abscess, should be suspected of some obstruction of the trachea or swallowing abnormalities and other incentives.

Lung abscess prevention

1. Pay attention to the prevention and treatment of oral and upper respiratory tract chronic infections, so as to prevent the chance of inhalation of the lower respiratory tract by contaminated secretions. For oral and thoracic and abdominal surgery cases, it is necessary to carefully prepare for the operation and pay attention to the depth of anesthesia during surgery. Timely removal of oral cavity, respiratory clots and secretions, strengthen postoperative oral respiratory care, such as careful use of sedation, analgesic and cough medicine, emphasis on respiratory humidification, dilute secretions, encourage patients to cough, keep the circulation of the respiratory tract, and effectively prevent Inhalation infection of the respiratory tract.

2, active treatment of skin spasm or extrapulmonary purulent lesions, do not squeeze sputum, can prevent the incidence of blood-borne lung abscess, active treatment of respiratory infections such as sinusitis, tonsillitis, etc., especially the importance of juvenile measles The prevention and treatment of hundred cough, bronchial pneumonia, lung abscess and tuberculosis are important for preventing the occurrence of lung abscess. For patients with lung abscess, inhaling toxic smoke and harmful dust, it has the effect of reducing the severity of lung abscess.

Lung abscess complications Complications

Complications include bronchial pneumonia, pulmonary fibrosis, pleural thickening, emphysema, empyema, pneumothorax, and pulmonary heart disease.

Pulmonary abscess symptoms Common symptoms Sputum with bloodshot cough with clubbing finger sticky or purulent sputum with... Pus sputum chest pain Lung pain lung rounded substantial... Yokohama low level lung cavity

symptom:

1, acute inhalation lung abscess sudden onset, patients with chills, fever, body temperature can be as high as 39 ~ 40 ° C, with cough, cough mucus or mucus purulent, inflammation and local pleura can cause chest pain, the lesion range is large, There is an impatience, in addition, there is still lack of energy, fatigue, poor appetite, about 7 to 10 days later, the cough is intensified, the abscess ruptures in the bronchi, cough up a lot of pus sputum, up to 300 ~ 500ml per day, due to anaerobic Infected with bacteria, it has odor. After standing, it is divided into 3 layers. From top to bottom, it is foam, mucus and pus. After pus discharge, the systemic symptoms are improved and the body temperature is lowered. If effective antibiotics can be applied in time, the lesions can be Within a few weeks, the body temperature tends to be normal, the amount of sputum is reduced, and the general condition returns to normal. Sometimes there is blood or moderate hemoptysis in the sputum. If the treatment is not timely, the medication is not suitable, the medicine is not adequate, the body resistance is low, and the lesion is low. It can be gradually turned into chronic, and some break into the chest to form a pus or chest bronchial pleural fistula. At this time, the symptoms are light and heavy, mainly cough, cough and sputum, many have hemoptysis, blood from sputum to large hemoptysis, intermittent fever And chest pain, etc.

2, chronic lung abscess patients have chronic cough, cough and sputum, repeated hemoptysis, secondary infection and irregular fever, etc., often anemia, weight loss chronic consumption sickness.

3, blood-borne lung abscess more than the original lesion caused by chills, high fever and other symptoms of systemic sepsis, after a few days to two weeks before the emergence of lung symptoms, such as cough, cough, etc., usually sputum Not much, very little hemoptysis.

Signs :

It is related to the size and location of lung abscess. The lesion is small or located in the deep part of the lung. There are no abnormal signs, the lesion is large, there is a lot of inflammation around the abscess, the percussion is voiced or real, the auscultation is reduced, sometimes it can be smelled wet. Sound, blood-borne lung abscess is mostly negative, chronic lung abscess patients with side of the chest slightly collapsed, percussive dullness, decreased breath sounds, may have clubbing (toe), thoracic congestion also deformed, poor activity, purulent pectoral, bronchial The pleural sputum examination can be seen with corresponding signs.

Lung abscess check

1, blood test : secondary infection may have increased white fine brain count, nuclear left shift, long course or hemoptysis may have anemia, ESR increased.

2, sputum examination : sputum smear can be found Gram positive and negative bacteria, culture can detect pathogenic bacteria, sputum culture helps the selection of sensitive antibiotics.

3, chest X-ray examination: is the main diagnostic method of lung abscess, because the abscess has the characteristics of spreading to different leaves, can spread more leaves or even the whole lung, but if it occurs at the beginning of the above, it is suspected that there are special causes For example, tumor abscess abscess or pulmonary cyst infection, lung abscess has great pathological changes at different stages, and X-ray is also very different. In the acute phase (within 1 week), there is a large dense blurring shadow, which is wedge-shaped according to the distribution of leaf segments. , pointed to the hilar, the lateral side close to the thorax, mediastinum or interlobular pleural surface; under treatment, the shadow changes faster.

When the abscess communicates with the bronchus, a cavity appears. Because the drainage bronchus is not smooth, and the positional factors, the pus cannot be completely discharged. The common liquid level on the tablet, due to the wall thickness, plus inflammation around, is thick outside the cavity. Layer, cloud-like inflammation infiltrates, chronic fibrosis, cavity size, shape, round, oval or irregular shape, many are multi-room, if improved after treatment, then The cavity gradually shrinks and disappears, leaving a fibrous cord shadow and a pleural thickening shadow.

4, CT examination : the fault (including CT) can better understand the extent of the lesion, the location, the cavity, a small amount of abscess in the abscess is not discharged, showing a circular shadow, but there is a small hollow in the visible, real solid block Not much, easy to mistake for the tumor, fibrosis significantly reduced lung volume, complete occlusion of the bronchus may have atelectasis, visible inter-leaf pleural thickening, abscess to the chest cavity to form empyema or pus pneumothorax, the film has a corresponding change.

5, fiberoptic bronchoscopy: fiberoptic bronchoscopy is best carried out when the patient's condition is relatively stable, do not check in high heat and respiratory tract inflammation, the purpose of the inspection:

(1) Except for foreign bodies and tumors in the bronchi, if there is foreign matter, it can be taken out, and biopsy and brushing of the suspected tumor are performed.

(2) Understand the condition of the bronchus, generally see bronchial congestion, edema, inflammatory or scarring stenosis, easy to further determine the treatment. If there is scarring, the distal lung may have a dilatation or ablation, and more surgery is needed.

(3) Understand the source of pus, clear the lesion, and simultaneously absorb pus, inject bronchodilators and antibiotics, etc. This therapeutic test can be performed once a week, or can be placed into the abscess through the bronchial biopsy hole. Absorption and injection, the effect is better.

(4) If the bacteriological diagnosis is unclear or tuberculosis cannot be excluded, the secretions can be taken from the deep bronchus to check tuberculosis and general bacterial culture and drug sensitivity tests.

6, bronchography: bronchial changes in lung abscess is quite obvious, bronchography can understand the location and extent of the lesion, found that the plain film is not seen or the lesion is not clear on the fault, to determine the treatment principles and surgical methods, angiography Can see the expansion of the bronchi, the filling of the abscess, the distortion of the bronchi, the stenosis and the bronchopleural sputum, the characteristics of the lung abscess "three more" can be seen in the angiography, namely:

(1) multiple rooms of the abscess, connected by irregular sinus.

(2) Multiple drainage, that is, more than one bronchial drainage in a abscess.

(3) Multi-leaf invasion.

The angiography is best done without hemoptysis and sputum. If necessary, the sputum is sucked clean and then the contrast agent is injected. The filling is good, and the contrast agent can be sucked out after the filming. The angiography has certain pain and danger ( If it causes massive hemoptysis, if you are ready for pneumonectomy, you can not do it.

7, pulmonary function test : mainly manifested as obstructive ventilatory disorders, advanced arterial oxygen partial pressure and arterial oxygen saturation decreased.

Diagnosis and identification of 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.

1. The blood white blood cell count and neutrophils of the surrounding blood are significantly increased, the total number can reach 20,000 to 30,000/mm3, and the neutrophils are above 80% to 90%. The white blood cells of patients with chronic lung abscess have no obvious changes, but There may be mild anemia.

2, sputum 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 abscess The pathogen can be found in the blood culture of the patient.

Differential diagnosis

Must be associated with pneumonia, empyema, lung cancer, pulmonary embolism, sarcoidosis, tuberculosis, Wegener granulomatosis, bullous bullae, pulmonary hematoma, cavitation pneumoconiosis, hiatal hernia, pulmonary parasitic disease, actinomycosis, lung infarction, Identification of cavitary nodule disease.

1, slow bronchitis: more than 40 years old patients, cough, cough cancer with winter, spring for soil, sputum is white foam like sputum, infection can be pus in acute attack, but less sputum There is no history of repeated hemoptysis; the lower part of the lungs is distributed in the c to distinguish it from bronchodilation.

2, tuberculosis: may have chronic cough, cough, but often have afternoon fever, night sweats, weight loss and other symptoms of systemic tuberculosis, and less sputum, lesions are located in the upper lobe, typical signs for the lung tip or sub-clavicular area slightly dull And fine wet voice, x-ray examination can find lesions, calcification is often more obvious, tuberculosis can be found in the sputum.

3, bronchial lung cancer: dry bronchiectasis with hemoptysis as the main performance, sometimes difficult to identify with lung cancer, but the backup is more common in men over 40 years old, smoking patients, often accompanied by unexplained weight loss, some patients may also appear ectopic Endocrine and other associated syndrome manifestations. Chest x-ray examination, fiberoptic bronchoscopy, sputum cytology, etc., can be identified.

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