Pediatric Staphylococcus aureus pneumonia

Introduction to Staphylococcus aureus pneumonia in children Staphylococcus aureus pneumonia is a pneumonia caused by Staphylococcus aureus. Most of the disease is caused by staphylococcal septicemia. It is more common in infants and newborns. It can also occur in older children. It is a common bacterial disease in pediatrics. One of the pneumonia, the disease is prone to complications. Due to the emergence of drug-resistant strains, treatment is also more difficult, and the disease can occur throughout the year, with more winter and spring. basic knowledge The proportion of illness: the incidence rate is about 0.01% - 0.02% Susceptible people: children Mode of infection: non-infectious Complications: shock bacteremia meningitis sepsis

Pediatric Staphylococcus aureus pneumonia

(1) Causes of the disease

Staphylococcus can produce a variety of toxins and enzymes, such as hemolysin, staphylokinase, coagulase, etc. It is generally believed that coagulase has a certain relationship with bacterial toxicity, such as coagulase negative (such as Staphylococcus epidermidis), which is mostly conditional Pathogens, rarely cause serious diseases, but one of the common bacteria in hospital infections, in children, especially neonatal immune dysfunction is an important susceptibility factor for Staphylococcus aureus infection, foreign studies have shown that the body weight is too small and Insufficient gestational age is two high risk factors for sepsis, and coagulase-negative staphylococci can not be ignored in neonatal blood culture. Pathogens enter the body from the body surface or mucous membranes. Due to the above-mentioned toxins and enzymes, it is not easy to be killed. Exhausted, and spread with the blood circulation to the whole body, the lungs are easily involved, there may be other migratory lesions, and the lungs may be directly affected by the respiratory tract infection.

(two) pathogenesis

Staphylococcus aureus has strong virulence, can produce hemolytic toxin, plasma coagulase, deoxyribonuclease, leukocidin, Staphylococcus aureus pneumonia occurs in the subpleural tissue, with extensive hemorrhage and necrosis The formation of abscess is characterized by necrosis of the bronchioles and the surrounding alveoli. The gas in the airway enters the interstitial lung and alveoli around the necrotic area. As the purulent secretions fill the bronchi, it becomes a valve-like blockage and the tension is gradually increased. Pulmonary bullae (lung balloon swelling), empyema adjacent to the pleura, empyema, pneumothorax or pus.

Pathological change

Primary bronchopneumonia caused by Staphylococcus aureus is characterized by extensive hemorrhagic necrosis and multiple small abscesses. The pleural surface of the lung is covered with a thick layer of fibrinous purulent secretion, and there is gold in the abscess. Staphylococcus aureus, white blood cells, red blood cells and necrotic tissue fragments, subpleural small abscess rupture, the formation of empyema or pus gas chest, sometimes can erode the bronchial bronchial pleural effusion, if secondary to sepsis, in addition to lung abscess, other Abscesses can occur in organs such as subcutaneous tissue, bone marrow, heart, kidney, adrenal gland and brain.

Pediatric Staphylococcus aureus pneumonia prevention

1. Enhancing physical fitness and improving your own immunity is an effective way to prevent pneumonia.

2. Vaccine pneumococcal vaccination is injected subcutaneously on the lateral side of the upper arm, only once (0.5 ml), the protection period can be more than 5 years. After vaccination, a small number of people can have slight swelling and pain in the injection, very few people ( Less than 1%) can occur with low heat and can be recovered within 2 to 3 days.

3. It is necessary to pay attention to the hygiene and cleaning of the room of the child care institution, and should promptly check whether the staff is carrying the bacteria, and the carrier should promptly handle it properly.

Pediatric Staphylococcus aureus pneumonia complications Complications shock bacteremia meningitis sepsis

The serious and potentially complication of death is progressive pneumonia, sometimes accompanied by respiratory distress syndrome and/or septic shock. Chest X-rays can be found in about 25% of patients with pleural effusion and a few with empyema. The patient develops an infection in the vicinity of the lesion (eg, empyema or suppurative pericarditis). Bacteremia can cause infections other than the lungs, including septic arthritis, endocarditis, meningitis, and (ascites). Some patients Repeated infections of the lungs appear as a result of a temporary improvement in the treatment, followed by fever and new lung infiltration leading to a worsening of the condition.

Pediatric Staphylococcus aureus pneumonia symptoms Common symptoms Drowsiness, high fever, breath sounds, weakened bloating, low fever, scarlet fever, fever, rash, irritability, diarrhea, swelling, subcutaneous emphysema

Early Staphylococcus aureus pneumonia is often difficult to recognize, and the onset is urgent. The disease can be considered when the symptoms of pneumonia develop rapidly. For example, the recent history of upper respiratory tract infection, small skin swelling or mastitis in masturbation can help diagnose.

Symptoms and signs

Staphylococcus aureus pneumonia is common in infants under 1 year of age. After 1 to 2 days of upper respiratory tract infection or small pustules on the skin for a few days to 1 week, there is a sudden high fever. Most of the elderly have relaxation fever. Newborns can be hypothermia or no fever, pneumonia develops rapidly, showing respiratory and heart rate growth, convulsions, cough, bruising, etc. Sometimes there are scarlet fever-like rashes and gastrointestinal symptoms such as vomiting, diarrhea, and bloating (due to toxic intestinal paralysis) ), children with lethargy or irritability, severe cases can be horrified, symptoms of poisoning are often more obvious, even in shock state, lung signs appear earlier, early breath sounds are reduced, there are scattered wet rales, appearing rapidly in the development process Lung abscess, often scattered small abscess, empyema and pus pneumothorax is the characteristic of this disease, and when empyema or pus pneumothorax, percussion dullness, tremor and breath sounds weakened or disappeared.

Examination of children with Staphylococcus aureus pneumonia

1. Blood picture White blood cells generally exceed (15 ~ 30) × 109 / L, neutrophils increased, poisoning particles may appear in white blood cells, half of small infants can be reduced to below 5 × 109 / L, while the percentage of neutrophils is still relatively High, the total number of white blood cells decreased more often showed a serious prognosis.

2. C-reactive protein increased.

3. Bacterial culture Bacterial culture is performed on tracheal sputum or aspirate and thoracic puncture extract, and the positive one has diagnostic significance.

4. Mural acid is a complex polymer containing phosphorus in the outer layer of Staphylococcus, which can stimulate the body to produce corresponding antibodies. The detection of cell wall acid antibody is helpful for pathogenic diagnosis.

5. X-ray inspection

(1) The clinical symptoms are inconsistent with those seen in the chest radiograph. When the pneumonia starts, the clinical symptoms are very heavy, but the X-ray signs are few, only the lung texture is heavy, and a small piece of infiltrates appears on one or both sides; When the clinical symptoms have improved significantly, obvious lesions such as lung abscess and pulmonary bullae can be seen on the chest radiograph.

(2) The lesion develops rapidly, and even within a few hours, the small piece of inflammation can develop into an abscess (Fig. 1A).

(3) In the course of the disease, multiple small abscesses, pus and pneumothorax, pulmonary bullae (Fig. 1B), severe mediastinal gas, subcutaneous emphysema and bronchopleural fistula.

(4) The duration of lesions on the chest radiograph is longer than that of general bacterial pneumonia. The shadow cannot still disappear completely in about 2 months.

6. B-ultrasound can have hepatosplenomegaly, pleural effusion, pericardial effusion and so on.

7. Electrocardiogram can detect myocardial damage.

Diagnosis and identification of staphylococcus aureus pneumonia in children

diagnosis

Diagnosis can be based on medical history, clinical symptoms, and laboratory tests.

Differential diagnosis

Clinically, Staphylococcus aureus pneumonia must be differentiated from pneumococci, streptococci and other Gram-negative bacilli, Haemophilus influenzae or pneumoniae pneumonia, primary tuberculosis with cavity formation or caseous pneumonia, and tracheal foreign body following Lung abscess and diaphragmatic sputum, X-ray features, such as lung abscess, bullous emphysema and empyema or pus pneumothorax can be used as a basis for the diagnosis of Staphylococcus aureus pneumonia; but with other bacterial pneumonia The cause of empyema and pus gas is identified, so pathogenic diagnosis is very important.

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