Taking the patients with chronic respiratory failure caused by COPD as the research object and the acute exacerbation of COPD as the main outcome index, the investigators hope to establish the syndrome differentiation and treatment scheme of COPD treated by traditional Chinese medicine, reduce the acute exacerbation of AECOPD, improve the clinical symptoms, improve the quality of life, reduce the mortality, preliminarily explore the mechanism of action, and lay the foundation for further research.

Chronic respiratory failure of chronic obstructive pulmonary disease belongs to the category of "lung distention", "asthma syndrome", "dyspnea" and "phlegm drink" in traditional Chinese medicine. According to traditional Chinese medicine, the pathology of this disease is mainly the dysfunction of lung ventilation. The basic pathogenesis is that the viscera are repeatedly affected by evil, the lung qi is damaged due to long-term disease, the lung function is damaged, the air mechanism is blocked, the application is publicized, the phlegm is turbid, the blood stasis is inevitable for a long time, and the lung qi is further damaged. The main clinical manifestations are shortness of breath, wheezing, shortness of breath, superficial shortness of breath and "drama of wheezing when moving", which may be accompanied by cough, expectoration, chest tightness, palpitation, lips, purple darkness, swelling of floating limbs, etc. The treatment of chronic respiratory failure patients with COPD can be significantly improved clinical symptoms such as shortness of breath and wheezing, reduce the number of acute exacerbations of patients, but there is still a lack of high-level evidence-based medicine research. Therefore, this project puts forward the hypothesis that "syndrome differentiation therapy can reduce AECOPD of COPD".It is proposed to adopt a multicenter, randomized, double-blind, placebo-controlled trial design, taking the patients with chronic respiratory failure caused by chronic obstructive pulmonary disease as the research object. The patients who meet the inclusion criteria, are divided into heart lung qi deficiency and lung kidney qi deficiency according to syndrome differentiation. The participants are randomly divided into the experimental group of 60 cases and the control group of 60 cases. The control group is given placebo treatment, and the experimental group is given Chinese medicine granules. The patients were followed up for 26 weeks. The main outcome indicators include the number of times of acute exacerbation of COPD, and the secondary outcome indicators include all-cause mortality, severity of acute exacerbation of COPD, clinical symptoms, CCQ score of COPD clinical questionnaire, quality of life score, dyspnea score, 6MWD, arterial blood gas analysis index, incidence and use time of mechanical ventilation, use time of oxygen therapy, serology index, health and economy Learning indicators, safety indicators, etc. To establish the TCM treatment scheme of chronic respiratory failure of COPD, reduce the acute aggravation of AECOPD, improve the clinical symptoms, improve the quality of life, reduce the mortality rate, preliminarily explore the mechanism of action, and lay the foundation for further research.

Inclusion criteria

1. patients who meet the diagnostic criteria of COPD in stable stage;
2. patients whose blood gas analysis meets PaO2 < 60mmhg and / or PaCO2 > 50mmhg in calm breathing at sea level;
3. patients whose syndrome differentiation meets the syndrome of heart lung qi deficiency and lung kidney qi deficiency;
4. patients whose age is ≥ 40 years and ≤ 80 years;
5. patients who are willing to receive treatment and sign the informed consent.

exclusion criteria:

1. chronic respiratory failure caused by bronchial asthma, bronchiectasis, cystic pulmonary fibrosis, lung cancer and other respiratory diseases;
2. acute aggravation of the original chronic respiratory failure;
3. patients with tumor, serious cardiovascular and cerebrovascular diseases (acute myocardial infarction, cardiac function level 3 and above, stroke, cerebral hemorrhage, etc.) and serious liver and kidney diseases (serious liver disease refers to liver cirrhosis, portal hypertension and varicose bleeding, and serious kidney disease includes dialysis and kidney transplantation) and other people who cannot participate in clinical research;
4. pregnant and lactating women;
5. patients with mental diseases and mental disorders;
6. those who are participating in clinical trials of other drugs, known to be allergic to treatment drugs.

It is jointly completed by the person in charge of the project, the drug preparation personnel and the statistician, and the two-level blind method is adopted. Blinding at the first level: that is to say, blinding is set for experimental Chinese medicine. The test drug and the control drug shall be packed uniformly; the second level shall be provided with blindness, that is, the number of the test drug packaging box shall be provided with blindness.