(1) The integrity of the intrabronchial mucus-ciliary delivery system, alveolar macrophages and other cellular defenses keeps the respiratory tract below the tracheal carina sterile.

(2) Whether pneumonia occurs depends on two factors: pathogen and host factors.

Community-acquired pneumonia (CAP)

Hospital-acquired pneumonia (HAP)

Lobar pneumonia

Lobular pneumonia

interstitial pneumonia

bacterial pneumonia

atypical pneumonia

viral pneumonia

fungal pneumonia

Pneumonia caused by other pathogens

pneumonia caused by specific factors

Community-acquired pneumonia (CAP)

Hospital-acquired pneumonia (HAP)

① Cough, expectoration, or original respiratory symptoms worsen, and purulent sputum or bloody sputum appears, with or without chest pain

②Most patients have fever

③Those with large lesions may have difficulty breathing and respiratory distress.

① There are no obvious abnormalities in early pulmonary signs; severe cases may have increased respiratory rate, nose flaring, and cyanosis.

② There are typical signs of pulmonary consolidation, such as percussion dullness, increased tremor, and bronchial breath sounds. Wet rales may also be heard; in patients with pleural effusion, percussion dullness in the chest on the affected side, weakened tremor, and weakened breath sounds

① If the concentration of pathogenic bacteria or conditional pathogenic bacteria isolated by quantitative culture is ≥10^7cfu/ml, they can be considered to be the pathogenic bacteria of pulmonary infection.

②≤10^4cfu/ml indicates contaminating bacteria

③If it is between the two, it is recommended to repeat the sputum culture; if the same bacteria are continuously isolated, 10^5~10^6cfu/ml more than two times in a row, it can also be considered a pathogenic bacteria

The chance of being contaminated by oropharyngeal bacteria is less than that of expectoration. If the concentration of bacterial culture in the aspirate is ≥10^5cfu/ml, it can be considered to be pathogenic bacteria. If the concentration is lower than this, it is mostly contaminating bacteria.

If bacteria ≥10^3cA/ml, they can be considered pathogenic bacteria

If the bacteria are ≥10^4cfu/ml and the bacteria in the anti-contamination BAL specimen are ≥10^3cfu/ml, they can be considered pathogenic bacteria.

The sensitivity and specificity are very good, but because it is an invasive examination, it can easily cause complications, such as pneumothorax, etc.

Includes Legionella and Streptococcus pneumoniae urinary antigens

Specific lgM antibody titers, such as a 4-fold increase in antibody titers between the acute phase and the recovery phase, can be used to diagnose infections such as Mycoplasma, Chlamydia, Legionella pneumophila, and viral infections, which are mostly retrospective diagnoses.

It is a key link in the treatment of pneumonia, including empirical treatment and anti-pathogen treatment.

Population and preferred antibiotics

First of all, broad-spectrum and powerful antibiotics should be selected, and they should be used in sufficient amounts and in combination.

Types and methods of administration

Antibiotic treatment should be carried out as early as possible. Once pneumonia is suspected, the first dose of antibiotics should be given immediately. The earlier the treatment, the better the prognosis. After the condition stabilizes, the intravenous route can be switched to oral treatment.

Deactivation criteria (should all be met)

The condition should be evaluated 48 to 72 hours after antibiotic treatment.

If symptoms do not improve after 72 hours, the reasons may be: