Spherical pneumonia

　　How is spherical pneumonia caused? Briefly described as follows:

　　1, Etiology

　　A scholar reported that after repeated sputum culture, only 3 cases were found to have pathogenic bacteria (pneumococcus, Haemophilus influenzae, and Escherichia coli).

　　2, Pathogenesis

　　It is not very clear. One theory is that the patient's immune function is low, leading to external infection, especially bacterial infection. There is also a theory that the patient's immune function is still good, and the invasive infection is quickly surrounded and localized to form a round shape. As spherical pneumonia patients often have underlying diseases, and the lesions are mostly in the posterior segment of the upper lobe and the dorsal segment of the lower lobe, there is also a theory of aspiration through the airway. The pathology of spherical pneumonia is inflammatory exudation and edema, which spreads centrifugally around the alveoli.

　　Severe spherical pneumonia can lead to infectious shock, even ARDS, with high fever, but also with body temperature not rising, blood pressure dropping, cold extremities, sweating, and cyanosis of the lips; when myocarditis occurs, arrhythmias may appear, such as premature ventricular contractions, paroxysmal tachycardia, or atrial fibrillation. Chest X-ray examination can find about 25% of patients with pleural effusion, but only about 1% have empyema. After the widespread use of antibiotics, empyema is rare. Some patients have incomplete absorption of fibrin in the alveoli, even with the formation of fibroblasts and fibrosis, resulting in organizing pneumonia.

　　The clinical characteristics of this disease are: most patients have acute inflammatory manifestations, such as fever, cough, sputum, elevated white blood cells, and accelerated erythrocyte sedimentation rate, and there are also patients with underlying diseases. In addition to the above clinical manifestations, in the cases of Li, there were 10 cases of chest pain (47.6%), 7 cases of sputum with blood (33.3%); in the cases of Ma et al., there were 4 cases with rust-colored sputum and blood in the sputum; in the case reports from Japan, it was considered that a history of upper respiratory tract infection a few weeks ago was a characteristic, and the symptoms of the patients were relatively mild, concealed, and shoulder pain was another characteristic. There was a patient with a history of 'common cold', taking medication at will during a business trip, with cough and left shoulder pain, and an X-ray showed a left upper spherical shadow, suspected of lung cancer, and surgery was planned. The lesion disappeared on the routine chest X-ray examination 1 day before the operation, because from about two weeks after taking cefadroxil 4 to 1 day before the operation, the patient was cured.

　　Pneumococcal vaccine can be administered to susceptible populations. Pneumococcal vaccine was used in the 1920s and was abandoned due to the rise of antibiotics, but with the increase of drug-resistant bacteria, vaccination has been revalued in the past decade. Pure capsular polysaccharide vaccines with multivalent combinations are commonly used. Currently, vaccines available on the market contain 23 antigens of pneumococcal type-specific polysaccharides, covering 85% to 90% of the pneumococcal strains that cause infection. Although the precise level of protection is not well understood, as it is usually not possible to perform antibody titer tests, it is generally believed that after 2 to 3 weeks of injection of pneumococcal vaccine, antibodies appear in the serum, and the antibody titer continues to increase for 4 to 8 weeks, which can reduce the incidence of pneumococcal pneumonia and the efficacy is over 50%. The duration of protection is at least 1 year. For high-risk populations, revaccination is required after 5 to 10 years.

　　The suitable population for vaccination is children and adults over 2 years old who are susceptible to Streptococcus pneumoniae, including the elderly over 65 years old, patients with chronic cardiovascular and pulmonary diseases, patients with splenic dysfunction or asplenia, Hodgkin's disease, multiple myeloma, diabetes, liver cirrhosis, renal failure, HIV infection, organ transplantation, and patients with other immune-related diseases. Recurrent upper respiratory tract infections including otitis media and sinusitis are generally not considered as indications for vaccination. About half of the people who receive the vaccine have redness and (or) pain at the injection site, 1% have fever, myalgia, or local significant reaction, 5% have allergic reactions or other significant reactions, and those who are re-vaccinated within 5 years are more likely to have strong local reactions.

　　What tests should be done for spherical pneumonia? Briefly described as follows:

　　1. Blood routine. White blood cell count and erythrocyte sedimentation rate increase.

　　1. Blood routine. White blood cell count and erythrocyte sedimentation rate increase. The X-ray film shows that spherical lesions and medium to low density shadows are common, most of which are blurred at the edge without lobulation and spiculation; the hilar lymph nodes are not enlarged; tomography shows unclear lesion contours. Most patients have long cord-like shadows around the lesions and at the hilum, and so-called 'local congestion signs' suggest that the mass is inflamed.

　　The dietary principles for spherical pneumonia patients are briefly described as follows:

　　1. Prefer light and delicious food, eat more vegetables and fruits, reasonably match the diet, and pay attention to adequate nutrition.

　　2. Quit smoking and drinking, eat less spicy foods that stimulate the body, such as coffee, chili, etc.

　　3. Eat less greasy and salty foods.

　　The treatment methods for spherical pneumonia are briefly described as follows:

　　1. Treatment

　　Antibiotic treatment should be started immediately upon suspected diagnosis, without waiting for the results of bacterial culture. About 90% of clinical isolates in China are sensitive to penicillin G. For sensitive strains, penicillin G is the drug of choice. For uncomplicated Streptococcus pneumoniae pneumonia, it is recommended to administer 800,000 to 2.4 million units of penicillin G intravenously every 4 to 6 hours. For mild cases, oral penicillin V 250 to 500 mg can be taken every 6 hours. Other effective drugs include penicillins such as ampicillin, amoxicillin; cephalosporins such as cefazolin, cef丙烯、cef克罗、cef噻肟、cef曲松; new generation fluoroquinolones such as levofloxacin, sparfloxacin (sparfloxacin), moxifloxacin, gatifloxacin; as well as erythromycin, azithromycin, and clindamycin, etc. Oral cephalosporins and new fluoroquinolones have become substitute drugs for the treatment of penicillin-sensitive strains in outpatients and some areas. The course of antibacterial drugs is generally 5 to 7 days, or stop taking medication 3 days after fever subsides.

　　20% to 40% of Streptococcus pneumoniae in foreign countries are moderately or highly resistant to penicillin (PRSP). The resistance rate in China is still low, and moderate resistance can be treated effectively by increasing the dose of penicillin. Cef丙烯、Cef噻肟、Cef曲松 and new fluoroquinolone drugs are effective against most moderately resistant strains.

　　Currently, highly resistant penicillin strains are very rare in China, ranging from 0 to 5%. These strains are often resistant to many other antibiotics as well. The treatment of the pathogen should be based on in vitro drug sensitivity tests. Vancomycin has antibacterial activity against all Streptococcus pneumoniae and can be used as the first-line drug for severe patients with a high risk of penicillin-resistant strains.

　　If meningitis is suspected, the patient should be given cefotaxime 2g intravenous injection, once every 4-6 hours, or ceftriaxone 1-2g intravenous injection, once every 12 hours, while also giving vancomycin 1g intravenous injection, once every 12 hours. Rifampin 600mg/d can be added orally until the drug sensitivity results are obtained. For patients with empyema, in addition to antibiotics, treatment should include local drainage. Chronic encapsulated empyema should consider surgical intercostal drainage.

　　After appropriate antibiotic use, high fever usually subsides within 24 hours or decreases gradually over several days. If the body temperature rises again or does not subside after 3 days, consider extrapulmonary infections with Streptococcus pneumoniae, such as empyema, pericarditis, or arthritis, etc. Other causes of persistent fever include mixed bacterial infections, drug fever, or the presence of other coexisting diseases. If there is a tumor or foreign body blocking the bronchus, although pneumonia may resolve after treatment, the blocking factor remains and pneumonia may recur.

　　Supportive treatment includes bed rest, fluid supplementation, and the use of analgesics for pleuritic pain. Patients with cyanosis, significant hypoxia, severe respiratory distress, circulatory disorders, or delirium should be admitted to the ICU for monitoring. During the monitoring period, close follow-up of arterial blood gases should be conducted, especially in COPD patients.

　　It is generally recommended to follow up with X-ray examination for patients over 35 years old. Chest X-ray examination may take several weeks to show infiltration and resolution, especially for patients with severe illness and sepsis, or those with pre-existing chronic lung disease. If there is still infiltration after 6 weeks or more after the start of treatment, other diseases should be suspected, such as primary bronchogenic carcinoma or tuberculosis.

　　2. Prognosis

　　Treatment for the pathogen generally has a good prognosis.