Anti-infection therapy is the most important link in the treatment of pneumonia. The treatment of bacterial pneumonia includes empirical treatment and pathogen-specific treatment. The former mainly selects antibacterial drugs that may cover pathogens according to the epidemiological data of pneumonia pathogens in this area and unit; According to the results of culture and drug sensitivity test of respiratory tract or lung tissue samples, the latter selects antibacterial drugs sensitive in vitro. In addition, we should also choose antibacterial drugs and administration routes according to the age of patients, whether they have basic diseases, whether they are inhaled by mistake, whether they live in general wards or intensive care units, the length of hospitalization, the severity of pneumonia and other factors. Penicillins and first-generation cephalosporins are commonly used in young adults and patients with community-acquired pneumonia without basic diseases. Because of the high resistance rate of Streptococcus pneumoniae to macrolides in China, it is not necessary to treat pneumonia caused by this bacteria with macrolides alone, but quinolones (moxifloxacin, gemmoxifloxacin and levofloxacin) with special effects on respiratory infection can be used for resistant Streptococcus pneumoniae. The elderly, patients with basic diseases or patients with community-acquired pneumonia who need hospitalization are commonly used with voronone, second-generation and third-generation cephalosporins, β-lactams/β-lactamase inhibitors, or ertapenem, which can be used in combination with macrolides. The second and third generation cephalosporins, β -lactamase inhibitors, quinolones or carbapenems are commonly used in hospital-acquired pneumonia. The treatment of severe pneumonia should first choose broad-spectrum powerful antibacterial drugs, and should be fully combined. The initial empirical treatment is insufficient or unreasonable, and then the mortality rate of using antibacterial drugs is significantly higher than that of the initial treatment. Severe community-acquired pneumonia is often treated with β -lactams combined with macrolides or quinolones. Quinolones and aztreonam are used for people who are allergic to penicillin. Hospital-acquired pneumonia can be treated with quinolones or aminoglycosides combined with any one of β-lactams, ampicillin, β -lactamase inhibitors and carbapenems, and vancomycin, teicoplanin or linezolid can be combined if necessary.

Antibacterial treatment of pneumonia should be carried out as soon as possible, and once pneumonia is suspected, the first dose of antibiotics should be given. After the condition is stable, it can be converted from intravenous route to oral treatment. The course of antibiotic treatment for pneumonia is at least 5 days, and most patients need 7 ~ 10 days or more. If the body temperature returns to normal for 48 ~ 72 hours and there is no sign of clinical instability of pneumonia, antibiotics can be stopped. The clinical stability criteria of pneumonia are: ① T ≤ 37.8℃; ② Heart rate ≤ 100 beats/min; ③ Respiratory frequency ≤ 24 beats/min; ④ Blood pressure: systolic blood pressure ≥ 90 mmHg; ; ⑤ Arterial oxygen saturation ≥ 90% or PAO _ 2≥60 mmHg； under the condition of breathing indoor air; 6. Be able to take orally; All landowners mental state is normal.

The condition should be evaluated after 48 ~ 72 hours of antibiotic treatment. The effective manifestations of treatment are hypothermia, improvement of symptoms, stable clinical state, gradual decrease or return to normal of white blood cells, but the absorption of X-ray chest film lesions is late. If the symptoms do not improve after 72 hours, the reasons may be ① the drugs failed to cover the pathogenic bacteria, or the bacteria developed drug resistance. ② Infection by special pathogens such as Mycobacterium tuberculosis, fungi and viruses. ③ Complications or host factors (such as immunosuppression) affect the curative effect. ④ Non-infectious diseases were misdiagnosed as pneumonia. ⑤ Drug fever. It needs careful analysis, necessary inspection and corresponding treatment.