Lung abscess in the elderly
Introduction
Introduction to lung abscess in the elderly Abscessoflung (abscessoflung) is a centrally containing cavity, limited lung purulent and necrotizing lesions, can be caused by a variety of purulent bacteria, clinically characterized by high fever, cough, cough, large pus sputum, X-ray chest X-ray There is a cavity in the lung parenchyma. The disease is more common in young adults, more men than women, penicillin is widely used, the incidence of lung abscess is significantly reduced, accounting for about 2% of all pneumonia, but lung abscess secondary to bronchial lung cancer has increased, should cause height Pay attention to it. basic knowledge The proportion of illness: 0.012% Susceptible people: the elderly Mode of infection: non-infectious Complications: empyema, massive hemoptysis
Cause
Causes of lung abscess in the elderly
(1) Causes of the disease
Lung abscess disease is caused by various purulent bacteria, mycobacteria, fungi or parasitic infections. The most common pathogens are anaerobes, such as Streptococcus pneumoniae, Fusobacterium, melane producing bacteria, Bacteroides fragilis, purple Monocytogenes, etc.; followed by a variety of Gram-negative and Gram-positive bacteria, such as Escherichia coli, Klebsiella, Enterobacter cloacae, F. faecalis, Acinetobacter mobilis, influenza Haemophilus, Haemophilus parainfluenzae, Legionella, Staphylococcus aureus, Streptococcus, Enterococcus faecalis, rare bacteria such as Pseudomonas aeruginosa, Streptococcus pneumoniae, etc.; in addition, certain in diabetic patients and immune suppressors Fungal infections can cause voids, such as Nocardia, actinomycetes; parasites such as amoeba, an important, but uncommon pathogen of lung abscess, mainly causing abscesses in the base of the lower lobe; Mycobacteria such as Mycobacterium tuberculosis, Mycobacterium avium and Mycobacterium intracellularus can also cause lung abscesses. In lung abscesses obtained outside the hospital, anaerobic infections account for 60% to 85%, and many are pessimistic. Oxygen bacteria mixed infection Recent studies have shown that 10% to 15% of Bacteroides fragilis, 60% of non-fragile bacilli and 40% of Fusarium can produce beta-lactamase in isolated anaerobic bacteria, thus penicillin-resistant Oxygen bacteria infection has become a problem that cannot be ignored. In the hospital acquired lung abscess, it is often mixed infection of Gram-negative bacilli and positive cocci.
(two) pathogenesis
There are three types of clinical (Figure 1).
1. aspiration lung abscess caused by the inhalation of the contents of the oropharynx and the nose. In the lung abscess caused by anaerobic infection, 85% to 90% of cases have inhaled oral contents or have teeth Risk factors such as weekly disease, disturbance of consciousness (anaesthesia, alcohol overdose, use of sedatives, head injury, cerebrovascular accident and epileptic seizures), dysphagia caused by various causes, gastroesophageal reflux, degenerative or acute neurological diseases After the destruction of the normal airway defense system and inhibition of cough reflex, it will become the cause of aspiration. The periodontal disease can change the quality of the oral contents, which can also be the cause of lung abscess, but there are also 10 % to 15% of patients have no significant periodontal disease or risk factors for inhalation.
The inhalation moves with the gravity to block the bronchus in a certain segment of the lung. Therefore, the location of the inhaled lung abscess is related to the anatomical features of the bronchus. Since the angle of the left main bronchus is larger than the right side and the diameter of the bronchial tube is thicker, the right lung occurs. The lung abscess is twice as likely as the left lung. In the supine position, the lung abscess occurs in the dorsal segment of the lower lobe or the posterior segment of the upper lobe. The lung abscess that occurs in these two sites accounts for 75% of all lung abscess cases. In critically ill patients in the intensive care unit, due to the use of the antacid histamine H2-receptor antagonist to prevent stress ulcers, the colonization of oral Gram-negative bacilli is increased, so these patients are prone to lung abscess caused by Gram-negative bacilli infection. .
2. Hematogenous lung abscess
Bacteria or emboli in sepsis or sepsis can reach the lungs through the blood circulation, causing embolism of the pulmonary arterioles, forming a blood-borne lung abscess, more common in staphylococcal septicemia, acute suppurative osteomyelitis, suppurative appendicitis, otitis media Postpartum endometritis and subacute bacterial endocarditis can also be seen in suppurative infections of the face and skin.
3. Secondary lung abscess
Some bacterial pneumonia such as staphylococcal pneumonia, pneumococcal pneumonia, Haemophilus influenzae pneumonia and Legionella pneumonia can develop a cavity lesion with secondary lung abscess. When the tumor or foreign body blocks the bronchi, it can cause distal secretion. Retention of the substance, secondary bacterial infection caused by lung abscess.
Infections of organs near the lungs, such as mediastinal inflammation, liver abscesses, and underarm abscesses can also cause secondary lung abscesses.
The pathological feature of lung abscess is local inflammation caused by obstruction of bronchioles, followed by embolization of small blood vessels, which causes rapid necrosis of lung tissue. After aspiration occurs, X-ray abscess can be formed within 7 to 10 days, such as inhalation. The abscess is usually single and connected to the bronchus; if it is bloody, the abscess is multiple and does not communicate with the bronchus; the tensional pulmonary air sac caused by Staphylococcus aureus pneumonia is mostly round, thin, and the surrounding tissue can be affected. Squeezing into atelectasis, such as abscess on the surface of the lungs, can cause localized fibrinous pleurisy, such as tension abscess into the chest, the formation of pus pus, after the treatment of abscess closure more scars, such as lung abscess or improper treatment , the formation of scar tissue wrapped in the abscess, prolonged unhealed formation of chronic lung abscess, due to hemangioma of the abscess wall of the lung abscess formation of hemangioma, can cause repeated large or moderate hemoptysis; venous tissue of the abscess wall can also cause small vascular Blood hemoptysis.
Prevention
Elderly lung abscess prevention
There are limited preventive measures for lung abscess caused by anaerobic bacteria, and strengthen the care for people with disturbance of consciousness to prevent the inhalation of secretions and vomit; attention should be paid to oral hygiene, treatment of oral and periodontal diseases, and timely use of antibiotics to treat pulmonary infections.
Complication
Elderly lung abscess complications Complications, empyema, massive hemoptysis
Concomitant empyema, purulent pneumothorax, bronchopleural fistula, massive hemoptysis and other metastatic abscesses.
Symptom
Older lung abscess symptoms Common symptoms High heat fatigue, weight loss, purulent mucus, purulent sputum, appetite, chills, low fever, pleural effusion, empyema
Symptom
(1) Onset: Patients with acute lung abscess may have oropharyngeal infections and risk factors for aspiration, or have a history of cold and exertion. The onset may be rapid, the patient is chills, high fever, and the lungs are empty after 8 to 14 days. The cavity is formed, the patient coughs a lot of purulent odor, the body temperature drops significantly, and in a few patients can also conceal the onset, fatigue, cough and low heat for several weeks, or even longer, lung abscess secondary to pneumonia can be Two to three weeks after the onset of the disease, pneumonia should be cured, but high fever, increased purulent volume, often fatigue symptoms.
(2) cough, a large amount of purulent sputum: initial cough mucus or mucopurulent sputum, after 8 to 14 days of pulmonary cavity formation, 40% to 70% of cases cough up a lot of pus sputum, stinky sputum prompted Anaerobic infection.
(3) hemoptysis: not uncommon, even can cause fatal hemoptysis.
(4) Chest pain: Inflammatory lesions are caused by the pleura, and the pain is aggravated during breathing. If the abscess breaks into the chest, it can form empyema, pus pneumothorax (pyopneumothorax), or encapsulated empyema due to cellulose encapsulation. Empyema), the patient's breathing movement is limited, and the shortness of breath is aggravated.
(5) Others: fatigue, weight loss, loss of appetite, etc., blood-borne lung abscesses have symptoms first caused by the primary disease, anemia and other symptoms are common in chronic lung abscess (chronic lung abscess) and empyema patients.
2. Signs
Abscess is small, there is no positive sign when the site is deep; if the abscess is large, there may be signs of lung consolidation, such as an abscess near the chest wall, there may be an empty snoring; the empyema patient has signs of pleural effusion on the affected side; Refers to within a few weeks of onset, chronic lung abscess is often seen, and sometimes suggests the possibility of bronchial lung cancer, blood-borne lung abscess due to small lesions, scattered, often no lung positive signs.
Examine
Examination of lung abscess in the elderly
Blood picture
The total number of white blood cells is increased, the neutrophil nucleus is shifted to the left, and there may be poisoning particles. The decrease of hemoglobin is more common in patients with chronic lung abscess.
2. Bacteriology examination
(1) Smear: sputum smear Gram stain microscopic examination, such as seeing a large number of neutrophils, and there are a large number of bacteria inside and outside the cell, while sputum culture is negative, suggesting anaerobic infection.
(2) Culture: culture is the most widely used non-invasive method for understanding pathogenic bacteria, but it is easily contaminated by upper respiratory tract bacteria. For anaerobic bacteria, the positive rate of culture is often affected by exposure to air, and tracheal attraction and warp fibers are used. Bronchoscopy protective brush collection specimens or pleural fluid puncture to collect thoracic pus, immediate anaerobic bacteria and aerobic bacteria culture more meaningful, because the positive rate of pathogen culture is not too high, some new technologies such as gas chromatography to detect bacteria Metabolite identification bacteria, DNA probe hybridization techniques, etc. are being used for the rapid identification of bacteria, and blood culture can be used for the diagnosis of blood-borne lung abscesses.
X-ray examination: General X-ray chest radiograph can obtain clear images of lung abscess and X-ray imaging features of lung abscess.
CT examination can further detect multiple small abscesses that occur during necrotizing pneumonia.
Diagnosis
Diagnosis and diagnosis of lung abscess in the elderly
diagnosis
Have a history of inhalation and suffering from oral diseases, according to symptoms such as subacute or chronic onset, cough a lot of pus sputum, signs, chest X-ray shows lung abscess changes, diagnosis is generally not difficult.
Because the cavity-like lesions in the lungs are found in a variety of diseases, it is necessary to pay attention to the differential diagnosis, mainly:
Differential diagnosis
Bronchial lung cancer
Some tumor central tissues may undergo liquefaction and necrosis to form cavities due to insufficient blood supply. Such lesions are mostly single-shot, eccentric, thicker in wall, nodular or irregular in the inner wall, no fluid level, no obvious inflammation around. Sexual infiltration, patients often have hemoptysis, but no acute infection symptoms, and lung abscess is not difficult to identify, cancer tissue can also block the bronchial secondary infection, distal formation of lung abscess, especially need to identify with lung abscess, in age >40-year-old patients, such as isolated cavity-like lesions in the lungs, should pay special attention to sputum tumor cytology, fiberoptic bronchoscopy, is of great value for diagnosis, chest CT can help diagnose.
2. Tuberculosis
There are often symptoms of tuberculosis such as low fever, fatigue, night sweats, invasive pulmonary tuberculosis or caseous pneumonia, which are mostly large leaves in the upper lobe, including translucent areas, without wall cavities, without liquid level, ipsilateral or contralateral There may be disseminated patchy shadows, and sputum smear acid-fast staining can be found in tubercle bacilli.
3. Pulmonary cysts with infection
Pulmonary cysts on X-ray films show fluid cysts or cysts, round or oval, with clear boundaries. Sometimes there are gas-liquid planes in the cysts. The cysts under fluoroscopy can change with the size of the breathing, secondary infection. There may be high fever, cough and a large amount of purulent sputum, which needs to be differentiated from lung abscess. If the original X-ray is compared, it will be easy to make a diagnosis.
4. Lung isolation
It refers to the formation of cystic lung mass by partial lung tissue separation from the lungs due to abnormal development of the lungs, especially the intralobular type. The bronchus of the mass can communicate with the bronchial system of the body, often with local secondary infection, clinical manifestations of cough and cough. Hemorrhoids, hemoptysis and fever, such as repeated infections can cause malnutrition, anemia and other symptoms, X-ray showed that the inflammatory infiltration around the cyst is lighter than the lung abscess, mostly in the lower part, can be seen by aortic angiography, magnetic resonance imaging Abnormal arteries of the aorta.
