Staphylococcus pneumoniae

Staphylococcal pneumonia is an inflammation of the lungs characterized by a severe course, sometimes up to sepsis, frequent recurrence and the formation of abscess foci in the lung tissue. This type of pneumonia is caused by St.aureus.

Staphylococcus aureus causes approximately 1% of community-acquired pneumonia and 10-15% of hospital-acquired pneumonia.

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Risk factors for staph pneumonia

The following groups of people are most susceptible to developing this pneumonia:

• infants;
• elderly people;
• weakened individuals who have suffered from any serious illnesses or surgeries;
• patients suffering from cystic fibrosis;
• patients with impaired immune system function;
• injection drug addicts;
• patients who have recently had viral pneumonia.

Symptoms of Staph Pneumonia

In general, the clinical symptoms of staphylococcal pneumonia are similar to pneumococcal pneumonia, but there are also significant differences:

• Staphylococcal pneumonia is characterized by recurrent chills, while pneumococcal pneumonia usually causes a single chill at the onset of the disease;
• staphylococcal pneumonia is often a manifestation of sepsis;
• the course of pneumonia is usually severe, with high body temperature, severe intoxication and shortness of breath;
• Destructive changes in the lungs are often observed.

The following clinical forms of staphylococcal pneumonia are distinguished:

Staphylococcal destruction of the lungs (bullous form)

This is the most common form. It is characterized by the fact that already during the first days of the disease, against the background of non-homogeneous infiltration of the lung, destruction cavities with thin walls - "staphylococcal bullae" - are formed. These cavities are not an abscess, they do not contain liquid content, they quickly appear and disappear within 6-12 weeks during treatment. The role of the valve mechanism in the occurrence of bullae is assumed.

Unlike a lung abscess, amphoric breathing is not heard over the destruction zone, and there is no symptom complex of "breakthrough into the bronchus" characteristic of an abscess. The prognosis for this form is considered relatively favorable - recovery occurs, an air (residual) cyst may remain at the site of the destruction cavities.

Staphylococcal infiltrate

In this variant of staphylococcal pneumonia, the condition of patients is severe, intoxication is pronounced, the clinical condition resembles septic. Physical examination of the lungs reveals significant dullness of percussion sound in the affected area of the lung, auscultation reveals a sharp weakening of vesicular breathing, crepitation (at the beginning of the infiltrate formation and during its resolution), and auscultation of bronchial breathing is possible.

X-ray examination reveals infiltrative darkening in a limited area of varying size. Staphylococcal infiltrate resolves slowly, over 4-6 weeks or more, and focal pneumosclerosis may subsequently develop.

Staphylococcal abscessing form

During the course of the disease, two periods are distinguished: before and after the abscess breaks through into the draining bronchus.

The first period (before the breakthrough into the bronchus) is characterized by a very severe course, fever with chills, severe intoxication, chest pain in the projection of the abscess, shortness of breath. X-ray examination reveals a focus of infiltration of the lung tissue. After the breakthrough into the bronchus, the patient coughs up a large amount of purulent sputum, sometimes with blood, after which the body temperature decreases, intoxication decreases. When auscultating the lungs in the projection of the abscess, fine bubbling rales are heard, sometimes amphoric breathing. X-ray examination reveals a cavity with a horizontal level against the background of the focus of infiltration, sometimes several abscesses are formed and then multiple cavities are determined.

Metastatic staphylococcal destruction of the lungs

This form of staphylococcal pneumonia develops as a result of hematogenous infection in the lungs from a purulent focus and is very severe. As a rule, the lesion is bilateral, a septic condition develops. X-ray examination of the lungs reveals multiple foci of abscess formation (cavities with horizontal fluid levels in the infiltration areas), combined with bullae.

Pulmonary-pleural form

This form of staphylococcal pneumonia is characterized by the development of infiltrative or abscessing foci in the affected lung, combined with the involvement of the pleura in the pathological process and the appearance of pyopneumothorax, pleural empyema. The clinical symptoms of these complications are described in the relevant chapters.

Laboratory test data for staphylococcal pneumonia are similar to those for pneumococcal pneumonia, but in a number of cases, toxic granularity of leukocytes is very pronounced, and there is a significant increase in the number of young and band neutrophils.

Diagnosis of staphylococcal pneumonia

The diagnosis of staphylococcal pneumonia is made on the basis of the following provisions:

• the presence of corresponding symptoms in the clinical picture and in X-ray examination of the lungs;
• detection of gram-positive staphylococci in the form of clusters during microscopy of sputum smears stained according to Gram;
• Staphylococcus culture from blood, pleural cavity contents in case of pleural empyema. Staphylococcus is easily detected by culture, false negative results are very rare;
• positive serological tests (increase in antitoxin titer, increase in agglutinins to the body's own strain of staphylococci).

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Treatment of staphylococcal pneumonia

For penicillin-sensitive Staph. aureus strains, high doses of benzylpenicillin are prescribed - up to 20,000,000 U/day and more. Usually, they start with intravenous administration, at the same time part of the daily dose is administered intramuscularly, then they switch to intramuscular administration of the antibiotic. In case of penicillin intolerance, high doses of macrolides (erythromycin, spiramycin), chloramphenicol or lincosamines can be used parenterally.

In case of isolation of penicillin-resistant strains, semi-synthetic penicillins (oxacillin) are prescribed.

The average daily dose of oxacillin is 8-10 g. Initially, parenteral administration is advisable, then switching to oral administration is possible. In severe cases of the disease, a combination of oxacillin with aminoglycosides is justified.

A good clinical effect is achieved with first and second generation cephalosporins in submaximal doses (for example, cefazolin 3-4 g per day intravenously or intramuscularly).

Lincomycin or clindamycin (1.8-2.4 g per day), fusidin (1.5 g per day), parenteral macrolides in maximum doses may be effective. They are administered intravenously, then switched to intramuscular administration or oral administration.

In staphylococcal pneumonia caused by oxacillin-resistant strains of Staph. aureus, it is advisable to administer intravenous vancomycin (30 mg/kg per day) or teicomanin (3-6 mg/kg per day, in severe cases up to 9.5 mg/kg per day with an interval between infusions of 12 hours) in combination with fosfomycin (200 mg/kg per day every 6 hours at an infusion rate of 1 g/hour). In recent years, fluoroquinolones have come into widespread use.

You can use the antistaphylococcal drug chlorophyllipt intravenously - 8-10 ml of 0.25% solution in 150 ml of isotonic sodium chloride solution with 5000 U of heparin 2 times a day. The course of treatment is 14-15 days.

Intravenous administration of antistaphylococcal plasma is also mandatory.