Pleuropneumonic pleural effusion

　　Pleuropneumonic pleural effusion often occurs due to bacterial pneumonia involving the pleura, especially in the elderly and weak, those who do not receive timely treatment, those with low immune function, or those receiving immunosuppressive therapy. It can also be seen in lung abscess, bronchiectasis, or lung cancer with infection, etc.

　　Any bacteria that can cause lung infection can produce pleural effusion. In the past, pleuropneumonic pleural effusion was most commonly caused by Streptococcus pneumoniae or hemolytic Streptococcus. After the widespread use of antibiotics, Staphylococcus aureus has become the main cause. In recent years, there has been an increasing trend in anaerobic bacteria and Gram-negative bacilli infections. The pathogens of pleuropneumonic pleural effusion have the following characteristics:

　　1. Aerobic bacteria are slightly more common than anaerobic bacteria.

　　2. Staphylococcus aureus and Streptococcus pneumoniae account for 70% of Gram-positive bacterial infections.

　　3. If the pleural fluid is infected with a single Gram-positive bacterium, the main pathogenic bacteria in order are Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus pyogenes.

　　4. The chance of infection by Gram-positive bacteria is twice that of Gram-negative bacteria.

　　5. Escherichia coli is the most common Gram-negative bacillus, but it is rare to cause empyema alone.

　　6. In addition to Escherichia coli, Klebsiella, Pseudomonas, and Haemophilus influenzae are the most common Gram-negative bacilli, accounting for about 75% of Gram-negative bacterial empyema.

　　7. Bacillus fragilis and peptostreptococcus are the most common two anaerobic bacteria causing infectious pleural effusion.

　　8. A single anaerobic infection generally does not cause empyema.

　　Pneumonia accompanied by pleural effusion is prone to the following complications:

　　One, lower respiratory tract infection

　　Patients with pleural effusion and pleurisy are prone to lower respiratory tract infection due to factors such as frailty, malnutrition, decreased immune function, airway stenosis, and secretions retention. Patients often transition from stable to severe stages due to this. It is noteworthy that elderly patients often do not have fever and the total white blood cell count is not high when they have an infection. Severe cough, shortness of breath, increased sputum volume, and purulent sputum are the earliest and most important signs of lower respiratory tract infection.

　　Two, spontaneous pneumothorax

　　It usually occurs due to the rupture of pulmonary bullae. There may be severe cough or exertion as triggers, or no triggers at all. The typical manifestations are chest pain and sudden onset of dyspnea, with hyperresonant percussion over the affected area. Elderly patients often do not have chest pain but only progressive worsening of dyspnea. X-ray examination may show signs of pleural air. Due to poor baseline pulmonary function in elderly patients, even a small amount of lung collapse may present severely, and timely rescue is required.

　　Three, respiratory failure

　　Severe elderly emphysema patients are prone to respiratory muscle fatigue due to increased work of breathing, flattened diaphragm, increased curvature radius, and malnutrition. On this basis, respiratory failure is often induced by factors such as lower respiratory tract infection, associated diseases, surgery, fatigue, etc. Improper use of oxygen therapy, sedatives, cough suppressants, and other iatrogenic factors may also trigger respiratory failure.

　　Four, pulmonary embolism

　　Elderly patients with emphysema, especially those with chronic obstructive pulmonary disease, may develop pulmonary embolism due to hypercoagulability, hyper viscosity, long-term bed rest, arrhythmias, and sepsis. Elderly patients with emphysema should be vigilant about the possibility of pulmonary embolism if they suddenly experience increased dyspnea, palpitations, and cyanosis.

　　The clinical manifestations of atypical pleural effusion are mainly determined by whether the patient is infected with aerobic bacteria or anaerobic bacteria.

　　The clinical manifestations of pneumonia with pleural effusion and pneumonia without pleural effusion are basically the same. Patients present with acute onset, fever, chills, chest pain, cough, sputum, and increased blood leukocyte count. There are signs of pulmonary inflammation and effusion. The incidence of pleuritic chest pain in patients without pleural effusion is 59%, and 64% in those with pleural effusion. The peripheral blood leukocyte count in patients with pneumonia without pleural effusion is 17.1×10^9/L, and 17.8×10^9/L in those with effusion, with no significant difference. The longer the patient does not receive timely treatment, the greater the possibility of pleural effusion. If the fever persists for more than 48 hours after antibiotic treatment, it suggests a complex atypical pleural effusion. If the patient first presents with pneumonia and then with pleural effusion, it is easier to diagnose as atypical pleural effusion. Elderly and weak patients and/or those receiving glucocorticoids and immunosuppressants may not have the above acute symptoms and develop the disease.

　　The specific preventive methods for pneumonia accompanied by pleural effusion are as follows:

　　The amount of pleural fluid aspiration should not be too much or too fast to avoid accidents.

　　Avoid using long-acting anesthetics, and also use analgesics sparingly after surgery, as such drugs suppress the cough reflex. It is advisable to infuse a mixture of air and oxygen into the lungs at the end of anesthesia, as the slow absorption of nitrogen can improve the stability of alveoli.

　　Encourage coughing and deep breathing, inhale bronchodilator aerosols, and use nebulized water or saline to liquefy secretions and facilitate their removal. Bronchial aspiration may be necessary if required.

　　Encourage coughing and deep breathing, inhale bronchodilator aerosols, and use nebulized water or saline to liquefy secretions and facilitate their removal. Bronchial aspiration may be necessary if required. Various physical therapy measures (percussion, vibration, postural drainage, and deep breathing) can also be used. Various physical therapy methods must be used properly, accompanied by routine measures to achieve effects.

　　It should be avoided to have mucosal, skin, soft tissue, and upper respiratory tract infections.

　　The clinical examination of pleural effusion associated with pneumonia is as follows:

　　In the early stage, pleural effusion can manifest as sterile serous exudate, with pH>7.30, with cell classification mainly of polymorphonuclear cells. As the condition worsens, it develops into typical pleural effusion associated with pneumonia, characterized by purulent exudate, with pH
　　In the early stage, pleural effusion can manifest as sterile serous exudate, with glucose >3.3mmol/L, with cell classification mainly of polymorphonuclear cells. As the condition worsens, it develops into typical pleural effusion associated with pneumonia, characterized by purulent exudate, with glucose
　　In the early stage, pleural effusion can manifest as sterile serous exudate, with LDH of 1000U/L. At this time, Gram staining or bacterial culture of pleural effusion smears can be positive.

　　In the early stage, pleural effusion can manifest as sterile serous exudate, with cell classification mainly of polymorphonuclear cells. As the condition worsens, it develops into typical pleural effusion associated with pneumonia, characterized by purulent exudate, with the total number of neutrophils above 10×10^9/L.

　　It is relatively easy to determine moderate to large amounts of pleural effusion through physical examination of the lungs combined with chest X-ray signs, while small amounts of pleural effusion can only be determined through detailed examination. Anteroposterior or lateral chest X-rays show blurred or blunt costodiaphragmatic angles, or a blurred diaphragm, indicating the presence of pleural effusion. The position can be confirmed by changing the position for透视 or lateral decubitus chest X-ray. At this time, the liquid spreads out, and the costodiaphragmatic angle or diaphragm becomes clear. CT has a higher diagnostic efficiency for pleural effusion and can also differentiate lung and pleural lesions, understand the location and characteristics of lung parenchymal lesions, which is helpful for differential diagnosis and guidance of treatment. In addition, ultrasonic examination can also determine the presence of pleural effusion and puncture localization.

　　Patients with pneumonia and pleural effusion should adopt a diet of liquid and semi-liquid foods, and pay attention to appropriately increasing the content of protein and vitamins. In addition, patients should also avoid spicy, greasy, and cold foods.

　　The treatment of pneumonia with pleural effusion mainly includes two aspects: the selection of antibiotics, and whether to perform pleural tube drainage. According to the development process of inflammatory pleural effusion, pleural effusion can be divided into seven types, which has great guiding significance for clinical management. Specifically as follows.

　　One, Nonsignificant Pleural Effusion (nonsignificant pleuraleffusion):Pleural effusion volume is small, lateral decubitus X-ray chest film effusion thickness
　　Two, Typical Pneumonic Pleural Effusion (typical parapneumonic pleural effusion):Lateral decubitus X-ray chest film effusion thickness > 10mm. Glucose in effusion > 2.2mmol/L, pH > 7.20, pleural effusion Gram stain or culture negative. Treatment with antibiotics alone.

　　Three, Marginal Complex Pneumonic Pleural Effusion (borderline complicated pleural effusion):7.001000U/L and glucose > 2.2mmol/L. Gram stain or culture of pleural effusion negative. Serial pleural puncture with antibiotics.

　　Four, Simple Complicated Pleural Effusion (simple complicated pleural effusion):pH
　　Five, Complex Complicated Pneumonic Pleural Effusion (complex complicated pleural effusion):pH
　　Six, Simple Empyema (simple empyema):Serous effusion with visible purulent appearance. Single encapsulated or free effusion. Thoracentesis drainage pleurectomy.

　　Seven, Complex Empyema (complex empyema):Multiple encapsulated effusions. Thoracentesis drainage thrombolytic drugs intrathoracic injection. Often requires thoracoscopy or pleurectomy.

　　The main principles for the selection of antibiotics are based on whether pneumonia is community-acquired or hospital-acquired. For community-acquired pneumonia with mild illness, the recommended antibiotics are second or third-generation cephalosporins, or beta-lactam antibiotics/beta-lactamase inhibitors (such as ticarcillin/clavulanate potassium) combined with macrolide antibiotics (such as erythromycin and clarithromycin). Severe community-acquired pneumonia can be treated with macrolides combined with third-generation cephalosporins with pseudomonas activity (such as ceftriaxone or cefoperazone).