Pulmonary effusion, also known as pleural effusion, is a serious disease, especially in the elderly. For example, pleural effusion can often occur in the elderly due to heart failure, which is a critical disease in itself, and the formation of pleural effusion can lead to significant clinical symptoms such as chest tightness and shortness of breath. It can also be seen in infected pleural effusion. Once the elderly have chest infection, such as infection by bacteria or tuberculosis bacilli, if not treated in time, it can easily lead to the formation of abscess chest and encapsulated pleural effusion, and the corresponding complications and sequelae. For malignant pleural effusion caused by malignant tumor, the condition is more serious, especially for elderly patients, who cannot tolerate chemotherapy treatment at this time, so that their tumor progresses faster and the survival of patients is obviously affected.