conceptPneumococcal pneumonia is a pneumonia caused by Streptococcus pneumoniaeStreptococcus pneumoniae is the most common cause of bacteria
Pneumococcal pneumonia is a pneumonia caused by Streptococcus pneumoniae
Streptococcus pneumoniae is the most common cause of bacterial pneumonia, accounting for bacterial community-acquired pneumonia 2/3. pneumococcal pneumonia in general throughout the visible, but in winter the most. The most common disease in old age too small or too sick. The bacterial examination showed that the carriers of 5%~25% aureus pneumonia healthy people, children and children in winter the parents had the highest detection rate. According to the classification of pneumococcal capsular polysaccharide antigen, serotype 80 or more.
Pathology and pathogenesis
Pneumococcus through inhalation, the upper respiratory tract to the lungs. They stay in the proliferation of bronchioles and cause inflammation, began to produce large amount of protein liquid in the alveolar cavity, the liquid culture medium for bacteria plays a role, and can help germs global spread to the adjacent lung, the typical result is the cause of lobar pneumonia.
The initial stage of lobar pneumonia is congestion, is characterized by a lot of serous exudate, vascular dilatation and bacterial proliferation. The next stage is called "red hepatization", namely the consolidation of lung showed liver appearance: gas cavity filled with polymorphonuclear cells, vascular congestion and extravasation of red blood cells, so the visual inspection is light red. Then is "gray hepatization" period, the period of fiber protein concentration and at different decomposition stages of red and white blood cells, alveolar cavity filled with inflammatory exudate. The final stage is characterized by the absorption and dissipation stage exudate.
Symptoms and signs
Often there are upper respiratory tract infection before pneumococcal pneumonia. Usually start with the short burst chills; continued for another disease that chills. Then, usually have a fever, respiratory ipsilateral pain (Xiong Moyan), cough, dyspnea and cough. The pain was radioactive, when the lesions in the lower lobe, may be suspected for intraperitoneal sepsis infection, such as pancreatitis. Temperature increased rapidly to 38~40.5 DEG C; the pulse usually reached 100~140 / min; breathing speed up to 20~45 / min. Other common symptoms include nausea, vomiting, muscle aches and pain. The cough may start without sputum, but gradually become with pus, blood or rust "sputum. These characteristics are typical manifestations of the original health had pneumococcal pneumonia. In many cases, especially in infants and elderly patients, the disease is insidious.
People without fixed positive signs, the stage of visual inspection and pathological characteristics of patients. With lobar consolidation or pleural effusion. The typical signs of pulmonary bronchial pneumonia is a common finding rales.
Where a fever with acute chest pain, dyspnea and cough should be suspected pneumococcal pneumonia. According to history, chest X-ray changes, proper specimen culture and Gram stain, capsule swelling reaction may make a preliminary diagnosis. The exact diagnosis requires that the pleural fluid, blood, lung or transtracheal aspirates with Streptococcus pneumoniae.
Blood tests often show an increase in white blood cells and a shift in the left. Positive blood cultures are the definitive evidence of Streptococcus pneumoniae infection, which may be due to a decrease in pulmonary ventilation, and respiratory alkalosis due to hyperventilation
Sputum Gram staining in typical cases were gram positive willow short chain arrangement shaped diplococcus. With polyvalent pneumococcal capsular swelling can obviously antiserum showed that these streptococci are Streptococcus pneumoniae; this is the "capsule swelling reaction, this reaction can provide direct information, but the inspectors must have experience of this technology at present has been rarely used. Using type specific antiserum identified isolates. Type anti immune electrophoresis with some laboratory (CIE) to determine the serotype strains, or the use of sputum, urine or other body fluid specimens were measured.
Chest X-ray examination can show pulmonary infiltration, but in the first few hours may be not obvious or difficult to find. The X-ray manifestation of bronchopneumonia is the most common, but the real variable is limited to a lobar pneumonia with typical air bronchogram is a special form of pneumococcal infection.
Serious and may lead to death in complications of pneumonia, sometimes associated with adult respiratory distress syndrome and / or septic shock. Chest X-ray examination can be found in about 25% of patients with pleural effusion, and only about 1% of the patients had empyema. Some patients have lesions proximal to the site of infection (such as empyema or purulent pericarditis). Bacteremia can cause infection of lung lesions outside, including septic arthritis, endocarditis, meningitis and peritonitis (ascites). Some patients had lung infection were repeated, in the course of treatment, after the temporary improvement of fever and pulmonary infiltrates and new condition.
Sensitive to penicillin pneumococcal strains, G penicillin is the drug of choice for patients with severe oral penicillin. Non G or v250~500mg, every 6 hours for 1 times. No complications of pneumococcal pneumonia recommend penicillin g50~200 000 u intravenous injection, every 4~6 hours 1 times.
About 25% of the penicillin resistant pneumococci. In the United States, the clinical isolates of penicillin, relative or highly resistant rate of 15%~30%, while in other parts of the world, especially in Spain, Japan, Israel, South Africa and Western Europe, the resistance rate is high. Many penicillin resistant strains resistant to other antibiotics. Dish containing the same 1 g for oxacillin resistant strains were detected. Isolates of bacteriostatic ring is smaller than 19mm should be using broth detection. Treatment of diluent highly resistant strains, according to drug sensitivity test in vitro. Large dose of penicillin, cefotaxime or ceftriaxone head is effective for most resistant strains. A new generation of quinolones (levofloxacin, sparfloxacin, grepafloxacin and sparfloxacin) support method is often choose the drug penicillin resistant strains, or alternative drug treatment for penicillin sensitive strains of vancomycin as the only. A drug with a persistent activity, which has antibacterial activity against all pneumococcus, and can be used as the first choice for most patients with severe penicillin resistance in most cases
Other effective drugs including cephalosporins, erythromycin and clindamycin. Poor reliability of tetracycline anti pneumococcal effect, seriously ill patients should not use oral medication. Including erythromycin or lincomycin 300mg, every 6 hours for 1 times. Parenteral medication including cefotaxime intravenous 1~2g every 6 hours for 1 times; ceftriaxone 1~2g intravenous injection, 1 times every 12 hours; cefazolin 500mg intravenous injection, 1 times every 8 hours, erythromycin 0.5~1g intravenous injection, 1 times every 6 hours; or clindamycin intravenous 300~600mg every 6~8 hours 1 times. In addition to cefotaxime and ceftriaxone, third generation cephalosporin for most pneumococcal relative no antimicrobial activity.
Such as suspected meningitis, patients should be given cefotaxime intravenous injection of 2G, every 4~6 hours 1 or ceftriaxone 1~2g intravenously every 12 hours for 1 times, while giving the vancomycin 1g intravenous injection, 1 times every 12 hours, with or without rifampicin 600mg/d orally, until the result of drug sensitivity. To know in addition to empyema patients, antibiotics, treatment should include appropriate drainage.
Treatment includes bed rest, and to supplement liquid pleural pain using analgesics. There are obvious cyanosis, severe hypoxia, dyspnea, circulatory disorder or delirium patients should give oxygen. Oxygen to constantly check blood, especially for chronic lung disease patients.
Advocate General of patients over the age of 35 years of follow-up X-ray. Chest X-ray examination may be in a few weeks to see the infiltration of dissipation, especially serious illness and bacteremia or preexisting chronic lung disease patients. After treatment for 6 weeks or 6 weeks still have infiltration, that may have the primary bronchial new biological or tb.
Although the discovery of penicillin pneumococcal pneumonia greatly reduced the morbidity and mortality of the patients, but get pneumonia death in known pathogen communities, pneumococcal pneumonia accounted for 85%. of the total disease mortality rate was 10%, and the treatment effect on the disease mortality rate during the first 5 days is very small. The poor prognostic factors: age. Small or too old, especially under the age of 1 and 60 years of age; positive blood culture; the lesion more than 1 leaves; the peripheral white blood cell count is less than 5000/ml; there are other diseases (such as liver cirrhosis, heart failure, immune suppression, agammaglobulinemia, loss, splenectomy or splenic function in uremia); some serotypes (especially the third and eighth) of the pathogen and occurrence of extrapulmonary complications (such as meningitis or endocarditis).
Accept the light treatment earlier, generally in 24~48 hours hypothermia; but seriously ill patients, especially with the poor prognosis of disease patients often need 4 days or 4 days or more to fever. If the clinical symptoms improved gradually, and the cause is clear, should not change the treatment guidelines.
When the patient is still no improvement, need to consider the following factors: the causes of errors in diagnosis, adverse drug reaction, the disease is advanced or repeated infection, disease related to patients with low resistance, non medication methods do not meet the requirements, the pathogenic strains of Streptococcus pneumoniae were resistant, and complications (such as empyema) and drainage or there is a need to increase the dose of penicillin metastatic foci of infection (such as meningitis, endocarditis, septic arthritis).
There is a kind of available vaccine containing type specific pneumococcal polysaccharide antigens in 23 kinds of antigens, 85%~90% caused severe pneumococcal infection of pneumococcal serotypes. Although belonging to this class is not accurate because of the level of protection, thus cannot make the determination of antibody titer, but most children over 2 years old and adults in antigen reaction 2~3 weeks after inoculation. About 50% of the vaccinated patients with erythema and / or pain at the injection site; about 1% people have a fever, myalgia, or severe local reactions; 5% people allergic or other serious reaction. After repeated inoculation of severe reactions are more common. The general claims of a vaccine for 2 children over the age and the incidence of pneumococcal disease and complications of large adults. Injection object should also include chronic diseases, especially cardiovascular disease and pulmonary disease; with spleen insufficiency or anatomy Asplenia, Hodgkin's disease, multiple myeloma, HIV infection, liver cirrhosis, diabetes, alcoholism, renal failure, organ transplantation and other immunosuppressive diseases related to patients suffering from kidney disease; children; the elderly, especially the normal but has more than 65 years old, and a leakage of cerebrospinal fluid of patients. Patients with decreased antibody response to immunosuppression. Sickle cell anemia or other causes of asplenia in children, in addition to the injection of pneumococcal vaccine, should also prevent the injection of penicillin. Recurrent upper respiratory tract infection (including otitis and sinusitis) generally not vaccinated indications. The duration of protection is unknown but, it seems long; for high-risk groups, sometimes after 5~10 years of repeated inoculation.5 years of repeated inoculation to strong local reactions.