This study evaluates the integrated traditional Chinese and Western medicine in the treatment of severe community acquired pneumonia in adults. Half of participants will receive traditional Chinese and Western medicine in combination, while the other half will receive a placebo traditional Chinese and Western medicine.

Improving the care of patients with community-acquired pneumonia (CAP) has been the focus of many different organizations. Such efforts at improvement in care are warranted, because CAP, especially severe CAP remains the leading cause of death in the world. Despite advances in antimicrobial therapy, rates of mortality due to severe CAP have not decreased significantly since penicillin became routinely available.

traditional Chinese Medicine, has been used for thousands of years in treating pneumonia. To date, it has become popular and widely practiced in many countries around the world. In the past decades, Evidences from both clinicians and patients suggest that there is some beneficial effect of TCM on severe CAP.

At present, there are many therapies available for patients with severe CAP, it is difficult for us to identify the most suitable therapy. Thus, this study aims to compare the efficacy of combination conventional drug and TCM to the conventional drug and placebo, and then determine which one is the better therapy, providing a scientific basis for clinical decision.

This is a multi-center, randomized, controlled trial to compare the efficacy of two therapies for patients with severe CAP. 198 subjects will be randomly assigned to one therapies (conventional drug, and the combination of conventional drug and TCM) for 28 days treatment. After the treatment period, subjects in two arms will be followed up for 12 weeks. The primary outcomes will include treatment failure, and secondary outcomes Time to clinical stability, length hospital stays, in-hospital mortality, SOFA questionnaire, quality of life (CAP-PRO ) and health economics.

Inclusion Criteria:

• were aged 18 years to 80 years.
• met severe community-acquired pneumonia criteria (defined by modified American Thoracic Society criteria).
• Syndrome differentiation meets criteria of phlegm-heat obstructing in the lung syndrome, pulmonary stagnation of phlegm syndrome, Pathogenic heat trapping the pericardium syndrome, or Pathogenic depression is taking off syndrome.

Exclusion Criteria:

• Pregnant and lactating women.
• trauma, hematologic malignancies, various solid tumors, and obstetric complications.
• Aspiration pneumonia, fungal pneumonia, HIV related Pneumocystis carinii pneumonia, tuberculosis, Bronchiectasis with infection and pulmonary abscess;
• Dementia, mental disorders and reluctant partners.
• Be discharged from hospital within 2 days or require operation.
• reported severe immunosupression (human immunodeficiency virus infection, immunosuppressive conditions or medications).
• Neuromuscular disorders affecting respiratory motor function.
• Patients with severe cardiovascular，with severe liver and kidney disease.
• Patients who have participated in other clinical studies in the past 4 weeks.
• Patients unwilling to sign informed consent.