Acute empyema

Introduction to acute empyema Acute suppurative pleurisy, referred to as empyema, is also known as acute empyema, which is caused by the accumulation of purulent exudate in the pleural cavity. According to the extent of pleural involvement, it can be divided into localized (encapsulated) empyema and total empyema. If combined with pleural effusion, it is called pneumothorax, the disease is acute, and more infections from nearby organs, such as the lungs, esophagus or abdomen; or sepsis, sepsis involving the pleural cavity; Complications of complication of chest wall penetrating trauma or chest surgery. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: pleural effusion, pneumothorax, chronic empyema

Acute empyema cause

(1) Causes of the disease

Acute empyema is caused by purulent bacteria. Common bacteria are pneumococci, Staphylococcus aureus and Streptococcus faecalis, and can also be found in Klebsiella, Pseudomonas aeruginosa and hemolytic influenza bacilli, such as bronchial pleural effusion Most of them are mixed bacterial infections. About 40% to 94% of pleural effusion cultures are positive for anaerobic infections, mainly Bacteroides and anaerobic streptococci and Clostridium.

The main ways of pleural infection are:

1 pulmonary infection: a small abscess on the surface of the lung rupture, or suppurative lesions directly invade the pleura, lung infections such as pneumonia directly invade the pleura or lesions directly into the chest, can produce acute empyema, common The pathogens are pneumococci, streptococci, Staphylococcus aureus, and children with Staphylococcus aureus empyema are common. Other common pathogens are Gram-negative bacilli such as Escherichia coli, Proteus, gas production. Bacillus and Salmonella, etc., Mycobacterium tuberculosis and fungi are relatively rare, bacteria can directly penetrate the pleura into the pleural cavity, lung abscess rupture often produces pus gas chest, and even produce tension pus pus, can form bronchopleural fistula, and become a mixture Infection, if there is anaerobic infection, it forms a spoiled empyema. The pus contains necrotic tissue and has a foul smell.

2 iatrogenic empyema: thoracotomy, pneumonectomy, thoracentesis, thoracoscopic examination, bronchopleural fistula caused by fiberoptic bronchoscopy lung biopsy, dilatation of esophageal stricture and esophageal perforation caused by fiber esophagoscopy, Liver abscess or abdominal abscess puncture caused by pleural cavity infection caused by empyema, spontaneous pneumothorax caused by rupture of pulmonary bullae is mostly not infected, but during treatment, such as repeated thoracentesis or long-term closed drainage, secondary may occur Infection forms a pus and esophagus, trachea, bronchial and lung surgery are contaminated surgery, not aseptic surgery, such as improper use of antibiotics after surgery, infection may still occur, and the formation of empyema, if esophageal anastomotic or bronchial residual End sputum, it is more prone to empyema.

3 suppurative infections in adjacent areas: mediastinal inflammation, underarm abscess, liver abscess, suppurative pericarditis, perirenal abscess, lymph node abscess, rib or vertebrae osteomyelitis can directly erode, pierce, or cause pus through lymphatic drainage chest.

4 traumatic empyema: pathogenic bacteria in chest trauma, and even some foreign bodies such as clothing debris, bone fragments, warheads, knife tips, etc. are brought into the chest, and remain in the chest cavity, it is easy to form empyema, if the trauma caused the chest wall Open wounds, or damage to the esophagus, bronchus, lungs, etc., so that the chest cavity is connected with the outside world, it will also form empyema, which is caused by hematoma infection after penetrating trauma. It is also seen in the chest wall open wound, chest closed wound hemorrhage Caused by infection.

5 blood-borne infections: infants or frail patients with sepsis or sepsis, pathogenic bacteria through the blood circulation to the pleural cavity, resulting in empyema, part of the systemic sepsis, the condition is heavier, poor prognosis.

6 other: lung cancer, mediastinal teratoma, bronchial cyst secondary infection and rupture can also cause empyema, spontaneous esophageal rupture, mediastinal teratoma secondary infection into the chest cavity is also the cause of empyema.

(two) pathogenesis

When there is inflammation in the pleura, the permeability of the mesothelial surface changes, causing the intravascular fluid to flow into the pleural cavity. Due to the release of chemical activin and intercellular adhesion molecules, the phagocytic cells flow to the pleural cavity, and the neutrophils enter through the subcutaneous capillaries. The pleural cavity, together with the mesothelial cells, acts to prevent the spread of bacteria. The following substances can stimulate the mesothelial cells to cause this acute phase reaction: tumor necrosis factor-, interleukin-1, lipopolysaccharide and other bacterial products. Peripheral effusion is a good medium to free bacteria from germicidal cells and proliferate rapidly, so that the infected pleural effusion can reach 1010 bacteria per ml. The infected pleural effusion lacks opsonization and is optimal. The necessary conditions for bactericidal function eventually develop into an acidic, hypoxic environment that further impairs local neutrophil function and antibiotic activity.

Pathological changes of pleural inflammation According to the development process, acute empyema can be divided into: 1 exudation period: pleural congestion, edema and exudation, initial serous, containing a small amount of multinucleated granulocytes, bacteria and fibrin, 2 fiber purulent Period: As the condition worsens, the fibrin and pus cells in the exudate increase, which is turbid to purulent. Fibrin is deposited on the surface of the pleura, which makes the pleura lose its luster. If the inflammation is extensive and the exudation is more, the whole pleural cavity is infiltrated. The liquid is full, such as not much exudate, and due to gravity, the exudate accumulates in the lower part of the pleural cavity. The above is called the whole empyema. When the chest is filled with a lot of pus, the lungs can be crushed and collapsed, and the mediastinum is moved to the healthy side. Displacement, such as combined with bronchopleural fistula or esophageal pleural fistula, can be complicated by tension pus pneumothorax, leading to respiratory dysfunction, due to the release of cellulose from the pus and deposition on the visceral and parietal surfaces of the pleura, between the pleura The adhesion is caused to separate the pus, forming a localized or multi-atrial empyema, often located between the lungs, above the iliac crest, the posterior aspect of the pleural cavity and the mediastinum, and sometimes the empyema can invade the chest wall and subcutaneous, forming itself Empyema.

The nature, morphology and pathological changes of pus may vary depending on the type of pathogenic bacteria. When pneumococcal infection, the pus is yellow-green, thick, contains a lot of cellulose, and is prone to adhesion, hemolytic streptococcus. The pus is pale yellow, thinner, less adherent, and less confined. When Staphylococcus aureus is infected, the coagulase can promote more cellulose to be released from the exudate, the pus is yellow, thicker, and the adhesion is obvious. The most common form of multiple atrial empyema, single anaerobic infection generally does not cause empyema, such as anaerobic infection, pus is stench.

After the acute empyema is delayed, it enters the mechanized phase to form chronic empyema.

Acute empyema prevention

Acute empyema is caused by infection of other diseases. Therefore, the prevention of this disease is first of all to treat primary diseases, and to treat patients with anti-infective treatment, especially in some operations, strictly follow the aseptic operation to prevent Infection due to the surgical procedure, the second acute empyema must be actively treated once it is diagnosed to prevent further development and produce more serious complications.

Acute empyema complications Complications, pleural effusion, pneumothorax, chronic empyema

Acute empyema will gradually turn into chronic empyema without strict treatment. The cellulose in the pus deposits on the pleura, and the capillaries and fibroblasts in the pleura grow into cellulose and become granulation tissue. The thicker, dense capsule, ie the pleural fiberboard, is a mechanized period. The extensive, hard pleural fiberboard wraps the lung tissue and severely restricts the movement of the thorax, causing the thoracic invagination, mediastinal shift, and severely reduced respiratory function. Has always caused diseases in the respiratory system.

The empyema complicated with pseudo-thoracic wall sputum is rare. The disease is characterized by: semi-circular cyst of the chest wall, soft, easy to be compressed, and partially abnormal breathing. This disease is more common in patients with acute empyema who are not treated in time. Because the muscle wall of the chest wall of infants is weak, the ribs are soft and easy to be opened, and a large number of long-term intrathoracic high-pressure impacts such as pleural effusion, cough, crying may force the parietal pleura to open the intercostal and muscular layers to the skin, resulting in this The occurrence of the disease, the predilection of this disease is the upper chest wall, this is because the upper chest wall is more fixed, the anterior chest wall rib gap is wider, the buffering capacity of the chest pressure is worse than the lower chest wall, under the same intrathoracic pressure, on The pressure on the chest wall is relatively increased, and the pseudo-thoracic wall tendon does not need to be treated locally. As the primary disease is cured, the negative pressure in the chest gradually recovers, and the cyst will shrink or disappear by itself.

And easy to merge with pus gas chest.

Acute empyema symptoms Common symptoms Shortness of breath, dyspnea, pleural effusion, chest pain, pneumothorax, breath sounds, weakened edema, fatigue, cold, chest tightness

Mainly manifested as acute inflammation of the chest and effusion symptoms, often high fever, chest pain, chest tightness, shortness of breath, cough, loss of appetite, general malaise, fatigue, etc., the symptoms of infection of empyema after pneumonia in infants are more obvious, when lung abscess or The abscess of the adjacent tissue collapses into the chest cavity, often with sudden severe chest pain and difficulty in breathing, chills, high fever, even shock, and postoperative empyema, often with high fever and chest symptoms after the postoperative surgical heat subsides.

The physical examination showed shortness of breath, the thoracic side of the affected side was slightly full, the respiratory movement was weakened, the vocal fibrillation was weakened, the percussion was turbid, the breath sounds weakened or disappeared, the tracheal mediastinum was shifted to the contralateral side, and the signs of localized empyema were often not obvious or had lesions. Local signs of the site.

Acute empyema secondary to pulmonary infection is often caused by high fever, chest pain, difficulty breathing, cough, general malaise, loss of appetite, etc. after the symptoms of lung infection have improved. Patients often have acute illness and cannot be supine or Coughing when changing position, cyanosis can occur in severe cases, respiratory movement of the affected side is weakened, the intercostal space is full, widened, and the affected side has a real sound and a slap pain, such as the unclear boundary of the left effusion. On the right side of the effusion, the lung and liver are unclear, the mediastinum shifts to the healthy side, and the trachea is biased to the healthy side. The auscultation side has a weakened or disappeared respiratory sound or a tubeatic breath sound, and the tremor is weakened.

The positive symptoms of the conserved empyema are mostly atypical, and there are some positive symptoms in the lesions, which are difficult to find.

The patient's body temperature is high, with relaxation heat, white blood cell count increased, neutrophils increased to more than 80%, and the nucleus moved to the left.

Chest X-ray examination is the main diagnostic method for empyema. Free pleural effusion is first deposited on the bottom of the chest cavity, generally between the lung base and the diaphragm, so that the lung tissue floats up slightly, and the rib angle is small when the fluid is accumulated. Blunt, the amount is about 200ml, if the patient can not take the chest film in the sitting position or standing position for some reason, pay attention to the density of the two sides of the chest piece, the density of one side of the effusion is generally increased, and it can also be used. The lateral side of the lower side is horizontally projected, and a small amount of effusion can be displayed on the lateral wall of the affected side of the chest, with a uniform darkening shadow between the inner edge of the rib and the outer edge of the lung.

When the amount of fluid is moderate, the X-ray shows the shadow of the dense and dense fluid in the lower part of the lower chest, and the shadow covers the entire face. The amount of fluid is about 500-1000 ml.

When a large amount of fluid is accumulated, the liquid can reach the tip of the lung, the lung tissue is atrophied by pressure, the permeability of the affected side is further reduced, the volume of the thoracic cavity is increased, the intercostal space is widened, the position of the rib is flattened, the mediastinum is displaced to the healthy side, and the transverse diaphragm is lowered. The left side is easy to show due to the contrast of the air in the stomach cavity, and it is difficult to distinguish on the right side because the density of the liver and the fluid is similar.

When the effusion is combined with atelectasis, the changes of the mediastinum, diaphragm and thorax are often not obvious. The images of the effusion with high external and low angulation also have different manifestations depending on the location of atelectasis, which is more atypical.

When the pneumothorax or bronchial pleural sputum is combined, the liquid-gas surface can be seen.

Localized empyema is more common in the posterior wall and side wall of the thoracic cavity. X-rays show a local density increase. The density in the central part is deeper and the surrounding is shallower. In the tangential position, the density of the breast is attached to the chest wall. Uniform shadow, wide base, clear inner edge, flat or semi-circular protrusion to the lung field, can also be expressed as inter-leaf effusion, pulmonary effusion, mediastinal effusion, etc. (Figure 2), often Identification with pleural lesions, lung tumors, underarm abscesses, and liver abscesses.

Inter-leaf effusion refers to the pleural effusion located in the interlobular fissure. It must be observed in multiple directions under fluoroscopy to show the edge of the empyema shadow when the X-ray and the interlobular direction are consistent. Most of the edges are clear and the density is uniform. Fusiform, both ends are long, the long axis of the shadow is consistent with the direction of the interlobular fissure, and the effusion can also be spherical.

The X-ray of the effusion of the lung bottom showed that the highest point of the transverse apex shifted outward on the posterior anterior slice, shifted backward on the lateral slice, or saw the machine shadow thickening, when a shadow similar to the horizontal elevation was found. At the time, it is suspected that there is a effusion of the lungs, and the horizontal position or the side of the affected side is horizontally projected. After the fluid flows from the sputum, it can show the true diaphragm position.

CT examination: the empyema appears as a uniform and dense shadow of the arch parallel to the chest wall. The changing position can determine whether the effusion can move. A large amount of fluid enters the lung fissure, and the lower lung can be pressed backwards and backwards. A large amount of fluid is adjacent to the liver. At the posterior edge of the leaf, CT scan showed that the posterior margin of the right lobe of the liver was blurred and could not be distinguished. This is a characteristic change of pleural effusion, which is called interface sign.

B-ultrasound: In the early stage, when there is no cellulose deposition to form pleural hypertrophy, there is no sediment in the liquid, the liquid dark area is clear, and there is no light spot in it. When there is a large amount of fluid, the lung tissue is compressed and the gas in the lung is absorbed. Ultrasound can be seen in a large liquid dark area with a triangular dense shadow, and with the floating of the breath, when the probe is close to the cross, the shadow of the arc-shaped light band is visible, and the latter forms a wedge-shaped angle with the chest wall. That is, the rib angle.

Thoracic puncture can be finally diagnosed. The appearance, traits, color and odor of pus can help determine the type of pathogenic bacteria. Bacterial culture and drug sensitivity tests can help to select effective antibiotics.

After the pathogen enters the thoracic cavity, it causes inflammatory changes in the tissue. The pleural effusion of the visceral wall is congested, edema, loss of luster and lubricity of the pleura, exudation of a thin, clear serum, exudate containing white blood cells and fibrin, but cells Less ingredients, this is a period of exudation, such as the effective treatment of each sputum at this time, timely discharge of effusion, the lungs can be fully re-expanded, has little effect on lung function.

If the inflammation is not gradually and effectively developed during the exudation period, the exudate, fibrin and neutrophils and even pus cells gradually increase, and the effusion turns from clarification to confusion, further becoming purulent, fibrin deposition in the dirty The surface of the pleural membrane becomes a cellulose membrane. At this time, it is a fibrinolytic stage. The cellulose membrane is soft and brittle. It gradually strengthens the sputum and forms pleural adhesions, which makes the empyema tend to be localized, that is, it forms a limitation or a package. Sexual empyema, lung tissue expansion is limited, but the impact on the respiratory cycle is relatively small, localized or encapsulated empyema can occur between the lungs, the lung base and diaphragm, the posterior thoracic cavity and mediastinum, etc. The infection is not controlled, continues to develop, and the scope expands and spreads throughout the chest cavity, forming a total empyema, accumulating hydraulically forced lung tissue to collapse, and pushing the mediastinum to the healthy side, causing respiratory circulatory disorders, if combined with bronchial pleural palsy or Esophageal pleural fistula, the formation of pus pus, has a greater impact on the respiratory cycle.

Different pathogenic bacteria produce pus with different traits. The pus of pneumococcal empyema is mostly yellow or yellowish green, more viscous, contains a lot of cellulose, and is more likely to form adhesions, hemolytic streptococcal empyema. The pus is light yellow and thin, the cellulose is less, the pleural adhesion is light, and it is not easy to be limited. The pus liquid of the Staphylococcus aureus is a thick yellow liquid, sometimes a paste, a lot of cellulose, and the adhesion appears fast and heavy. Often formed a multi-atrial abscess, the pus of Pseudomonas aeruginosa empyema is green, Escherichia coli, the pus of the Alcaligenes emerative empyema is often with fecal odor, tissue necrosis is serious, not easy to limit often formed Pus, anaerobic streptococci, Clostridium, spiropelt spastic pus often have a strong stench of rancid smell, gas-producing bacterial empyema, often forming pus.

Acute empyema is treated with effective antibiotics and the pus is discharged in time. The inflammation can gradually disappear. Only certain adhesions and pleural hypertrophy remain in the pleural cavity. If the timely and effective treatment is not obtained, the acute empyema gradually turns into chronic empyema. The cellulose in the pus deposits on the pleura, and the capillaries and fibroblasts in the pleura grow into the granulation tissue, which becomes a thick, dense capsule, ie the pleural fiberboard. During the chemooning period, a wide, hard pleural fiberboard wraps the lung tissue and severely restricts the movement of the thorax, causing the thoracic invagination, mediastinal shift, and severe respiratory function.

Acute empyema examination

Pleural effusion specific gravity>1.018, white blood cell count (white blood cell)>0.5×109/L, or pleural effusion protein concentration>25g/L, Vianna believes that pleural effusion culture positive or white blood cell count (white blood cell)>15.0×109/L And protein levels above 30g / L.

(1) Chest X-ray examination is the main diagnostic method for empyema. Free pleural effusion is first deposited on the bottom of the chest cavity, usually between the lung base and the diaphragm, so that the lung tissue floats up slightly, when a small amount of fluid is accumulated. The rib angle becomes dull and the amount is about 200ml. If the patient cannot take the chest film in the sitting position or standing position for some reason, pay attention to the density on both sides of the lying chest piece, and the density of one side of the effusion is generally increased. The lateral side of the affected side can be used for horizontal projection. A small amount of effusion can be displayed on the lateral wall of the affected side of the chest. There is a uniform darkening shadow between the inner edge of the rib and the outer edge of the lung.

(2) CT examination: CT is a valuable examination method for the diagnosis of peri-pulmonary effusion. The empyema is characterized by a uniform and dense shadow of the arch parallel to the chest wall. The change of position can determine whether the effusion can move, and a large amount of fluid enters the lung fissure. The lower lung can be pressed backwards inward and backward, and a large amount of effusion is adjacent to the posterior edge of the right lobe of the liver. CT scan shows that the posterior margin of the right lobe of the liver is blurred and the boundary is unclear. This is a characteristic change of pleural effusion, called Intersection interface, dirty, parietal pleura separated by pus, resulting in "pleural tear", thickening of the soft tissue under the pleura and an increase in the attenuation of extra-pleural fat.

(3) B-ultrasound: It can be seen that there is no echo zone or a bit echo in the empyema area. When there is no cellulose deposition in the early stage to form pleural hypertrophy, there is no sediment in the liquid, and the liquid dark area is clear, there is no light spot in it. When there is a large amount of effusion, the lung tissue is compressed, the gas in the lung is absorbed, and the ultrasound can be seen to have a triangular dense shadow in the large liquid dark area, and float with the breathing. When the probe is close to the transverse ridge, the arc is visible. The shadow of the light band, the latter forms a wedge-shaped angle with the chest wall, that is, the rib angle, when the pus is thick, the point echo in the anechoic region is increased and thickened, and the ultrasound is for the non-free chest cavity displayed by the chest chest. Specimen collection of effusion is very useful, and clearer effusion and solid degenerative lesions are more clearly distinguished than X-ray. For multi-cavity, it is more suitable to separate the effusion, which is helpful for positioning and guiding the emphysema.

(4). The diagnosis of empyema must be done by chest puncture and pus, and for smear microscopy, bacterial culture and antibiotic susceptibility test, according to the effective antibiotic treatment.

Diagnosis of acute empyema

diagnosis

According to the medical history (primary disease due to lesions in the chest and adjacent organs), clinical manifestations, chest imaging examination and ultrasonography, diagnosis can be made, diagnostic puncture can be pus and bacteriological examination can be confirmed.

Differential diagnosis

Acute empyema needs to be differentially diagnosed with the following diseases:

1, need to be differentiated from acute non-suppurative pleural effusion

(1) Diffuse pleural mesothelioma: general effusion volume, even directly to the top of the pneumonia, easy to invade the mediastinum, mediastinal shift is not obvious, taking high-voltage photos after taking liquid or after injecting gas, can show multiple knots A nodular or wavy mass attaches to the pleura, which is rare in children.

(2). Pleural metastases: effusion type pleural metastases, more effusion, faster growth, often accompanied by thoracic and rib destruction, primary malignant tumors can be detected, children are rare.

2, pulmonary embolism

There are many similarities between empyema and pulmonary embolism in clinical manifestations. Chest pain and dyspnea are the main clinical manifestations. Acute suppurative pleurisy is called empyema, which is a purulent pathogen infection in the pleural cavity, resulting in accumulation of purulent exudate. It is often caused by chest pain, fever, shortness of breath, fast pulse, discomfort, loss of appetite and other symptoms. The body can be seen with a fever, sometimes not lying, the chest tremor is weakened, and the percussion is voiced and has a slap pain. Auscultation breath sounds weakened or disappeared, blood routine white blood cell count increased, neutrophils increased, X-ray examination showed different pleural effusion volume and location, ultrasonic observation showed effluent reflected waves, can clear the effusion range Accurate positioning can be made to help determine the puncture site, the diagnosis of empyema, pus puncture must be done to pus, pulmonary embolism is a serious complication caused by a blockage of the pulmonary artery is blocked, the most common The embolus is a thrombus from the venous system. The clinical signs and symptoms are often non-specific and vary greatly. Acute large-area pulmonary embolism is a sudden onset. Severe dyspnea, myocardial infarction-like sternal pain, syncope, cyanosis, right heart failure, shock, sweating, coldness and convulsions in the extremities, even rapid death from cardiac arrest or ventricular fibrillation, moderate-sized pulmonary embolism Often there are post-sternal pain and hemoptysis. When the patient's original heart and lung disease compensation function is very poor, it can produce syncope and high blood pressure. The microembolism of the lung can produce adult respiratory distress syndrome. The lung infarction often has fever and lightness. Astragalus, routine laboratory tests such as chest X-ray, electrocardiogram, blood gas analysis, blood biochemical tests, fiberoptic bronchoscopy, sputum bacterial culture, etc., pulmonary perfusion imaging, pulmonary angiography and magnetic resonance imaging are helpful for diagnosis .

3, liver abscess

Misdiagnosis of acute empyema as a liver abscess is rare in clinical practice. The relevant reports indicate that it is mainly caused by the judgment of the clinician and the mistake of the examination. The following is a report of a case of acute empyema misdiagnosed as swollen abscess in a hospital. It is helpful for us to better identify these two diseases. The reasons for misdiagnosis are as follows: (1) The medical history is not detailed, only local symptoms are observed, and systemic symptoms and signs are not noticed; (2) The upper right is caused by inflammation of the diaphragm. Abdominal pain, and liver abscess can appear reactive right pleurisy and cause cough, cough, and thus mistakenly believe that the root of pain is in the liver; (3) super-examination and liver puncture are further misleading, the pus secretion extracted by liver puncture is because The doctor made a mistake, the puncture needle penetrated the diaphragm into the chest, and the wrong way was that the pus was from the liver; (4) The doctor did not check the patient carefully enough, considering that the cause was not comprehensive enough, neglecting the radiograph, and misdiagnosing.

4, in addition to pleural lesions, lung tumors, underarm abscess, primary lung lesions (lung abscess, atelectasis, tumor), simple pleural effusion and pleural tumors for differential diagnosis.

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