(2) Incidence and risk factors
At present, COPD ranks twelfth in the global incidence rate and fourth in the cause of death. It is predicted that by 2020, COPD will become the fifth most disabling and third most fatal disease in the world after coronary heart disease and cerebrovascular disease. In China, the mortality rate of chronic obstructive pulmonary disease also ranks fourth in the order of cause of death. The global prevalence of COPD published by the World Health Organization (WHO) 1996 is 0.8%, and the prevalence of COPD reported by other studies is 4% ~ 6%, which is much higher than the data of WHO. In China, experts estimate that the prevalence of COPD is about 2.5%. The risk factors of COPD mainly include smoking, air pollution, occupational exposure, nutrition, socio-economic status, gender, physical type (allergy, etc. ) and possible genetic factors. Among many risk factors, smoking (especially active smoking) is considered to be the most important risk factor for COPD, and about 10% ~ 15% of smokers will suffer from COPD. In addition, infection is the main cause of acute exacerbation of COPD patients.
(3) Clinical features
Chronic obstructive pulmonary disease (COPD) can cause different degrees of pulmonary dysfunction and affect daily life.
1. Symptoms (1) Chronic cough: usually the first symptom. Cough is intermittent at first, heavier in the morning, coughing in the morning and evening or all day, and coughing at night is not obvious. A few cases of cough without expectoration. There are also some cases with obvious airflow restriction, but no cough symptoms.
(2) expectoration: Generally, a small amount of mucus is expectorated after coughing, and some patients have more sputum in the morning; When complicated with infection, the amount of sputum increases, and pus and phlegm are often seen.
(3) Shortness of breath or dyspnea: This is a symbolic symptom of COPD and the main cause of anxiety. It only appeared in the early stage of labor, and then it gradually increased, so that daily activities and even rest were short of breath.
(4) wheezing and chest tightness: not specific symptoms of COPD. Some patients, especially severe patients, have wheezing; Chest tightness usually occurs after exertion, which is related to respiratory exertion and capacitive contraction of intercostal muscles.
(5) Systemic symptoms: In the clinical course of the disease, especially in severe patients, systemic symptoms may occur, such as weight loss, loss of appetite, atrophy and dysfunction of peripheral muscles, mental depression and/or anxiety. When complicated with infection, you can cough up blood, sputum or hemoptysis. Late patients often lose weight, lose appetite and suffer from malnutrition.
2. Signs The respiratory movement in the chest is weakened, and the chest is barrel. Percussion is unvoiced, the boundary of heart dullness narrows or disappears, the boundary of liver dullness decreases, and the voice tremor weakens. When auscultating, breathing sounds are weakened, including wheezing, dry and wet rales, etc. I can hear you. X-ray examination shows that the texture of the lower part of both lungs is thickened, or cord-shaped, or the transparency of the lungs is increased.
3. Characteristics of medical history The course of COPD has the following characteristics:
(1) Smoking history: Most of them have long-term and heavy smoking history.
(2) Occupational or environmental exposure history: such as long-term exposure history of dust, smoke, harmful particles or harmful gases.
(3) Family history: COPD has a tendency of family aggregation.
(4) Age of onset and prone season: There are more cases after middle age, and the symptoms are prone to occur in the cold season of autumn and winter, and there is often a history of repeated respiratory infections and acute exacerbations. With the progress of the disease, acute exacerbations become more and more frequent.
(5) History of chronic pulmonary heart disease: Hypoxemia and/or hypercapnia occurred in the late stage of COPD, which may be combined with chronic pulmonary heart disease and right heart failure.
(4) Diagnosis
Patients with the following characteristics should be considered to diagnose COPD: cough, expectoration, dyspnea and contact history of COPD risk factors. Diagnosis requires lung function examination. After using bronchodilator, forced expiratory volume (FEV 1)/ forced vital capacity (FVC) is less than 0.7 at 1 s, which can confirm the existence of irreversible airflow restriction.
(5) classification of lung function
In May, 2004, American Thoracic Association (ATS) and European Respiratory Association (ERS) officially promulgated the new "Guidelines for the Diagnosis and Treatment of Chronic Obstructive Pulmonary Disease". The new guideline holds that the Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) published in 200 1 has made great contributions to the diagnosis and treatment of chronic obstructive pulmonary disease (COPD). However, there are still many problems in Gold, which need to be revised and supplemented. The severity of Gold's disease is divided into 0 (high risk), I (mild), II (moderate) A, II (moderate) B and III (severe). The classification of pulmonary ventilation function in the new guidelines is slightly different from that in GOLD (see table below).
COPD pulmonary ventilation function classification table
(VI) Classification of functional dyspnea
The classification of functional dyspnea can be evaluated by the British Medical Research Council Dyspnea Scale:
Level 0: There is no obvious dyspnea unless strenuous activity.
1 grade: shortness of breath when walking fast or climbing a gentle slope.
Level 2: Due to breathing difficulties, you need to stop breathing when walking slower than your peers or walking at your own speed on the flat ground.
Level 3: You need to stop to catch your breath after walking on the flat ground 100m or a few minutes.
Level 4: unable to leave the house, obviously having difficulty breathing, or short of breath when getting dressed.