OVERVIEW

What is Chronic Obstructive Pulmonary Disease?

Chronic Obstructive Pulmonary Disease (COPD), commonly referred to as COPD, is a lung ventilation disorder characterized by persistent airflow limitation (the airflow limitation is not fully reversible, meaning that after removing triggering factors and controlling the condition, the airways cannot return to normal ventilation and still exhibit partial airflow restriction)^[1].

As the disease progresses, shortness of breath after activity gradually worsens, often associated with abnormal inflammatory responses to harmful particles or gases^[2].

SYMPTOMS

What are the common manifestations of chronic obstructive pulmonary disease?

1. Chronic cough: More pronounced in the morning. As the condition progresses, coughing may persist for life.
2. Sputum production: Typically more common in the morning, with small amounts of white, sticky sputum coughed up after coughing. If accompanied by infection, the sputum may be purulent, and blood streaks may appear in the sputum during severe coughing.
3. Shortness of breath or dyspnea: Patients often experience progressively worsening dyspnea on top of coughing and sputum production. Initially, it may only be noticeable during physical exertion, climbing stairs, or hiking, but as the disease progresses, it can occur during normal activities or even at rest. During acute exacerbations of COPD, shortness of breath worsens, and severe cases may lead to respiratory failure.
4. Wheezing and chest tightness: Wheezing usually occurs during exacerbations or acute episodes, while chest tightness often appears after physical exertion.
5. Systemic symptoms: In advanced stages, patients may experience loss of appetite, weight loss, and other manifestations^[1,3].

What are the risks of poorly controlled chronic obstructive pulmonary disease?

Early symptoms are often mild and easily overlooked. As the disease progresses, symptoms gradually worsen, potentially affecting daily life and even leading to complications.

1. Worsening symptoms: As the condition advances, coughing may become incurable, and dyspnea may occur even at rest.
2. Impact on daily activities: Severe cases may prevent patients from walking long distances (about 100 meters) or even leaving the house. Additionally, late-stage patients may experience loss of appetite.
3. Complications:
   • If left untreated, cor pulmonale (pulmonary heart disease) may develop. During stable periods of cor pulmonale, symptoms like coughing, palpitations, shortness of breath, fatigue, and reduced activity tolerance may persist, but patients can still engage in light physical activities.
   • During acute exacerbations of cor pulmonale, respiratory failure and heart failure may occur, manifesting as the need to sleep with high pillows or sit upright, lower limb edema, cyanosis (bluish lips), and loss of appetite.
   • Severe cases may lead to pulmonary encephalopathy, with symptoms such as insomnia, restlessness, headaches, drowsiness, or coma^[1].

What are emphysema and pulmonary bullae?

1. Emphysema: Emphysema is a pathological feature of chronic obstructive pulmonary disease^[1]. Air in the lungs moves in and out with breathing, similar to inflating and deflating a balloon. However, if the balloon loses elasticity or the airway becomes obstructed, the lungs become "swollen" with air, a condition medically termed emphysema, which is a prerequisite for COPD.

   Specific causes of emphysema include recurrent infections, asthma, smoking, long-term exposure to harmful gases, and genetic disorders (such as α1-antitrypsin deficiency)^[1].

2. Pulmonary bullae: If localized structural damage occurs in emphysema, gas may become trapped, forming cavities larger than 1 cm in diameter, known as pulmonary bullae (commonly referred to as "lung bubbles"). Medically, this is also called bullous emphysema^[4].

What is the relationship between chronic obstructive pulmonary disease and cor pulmonale?

Chronic obstructive pulmonary disease is the most common cause of cor pulmonale^[1].

Cor pulmonale, short for pulmonary heart disease, refers to heart disease caused by bronchopulmonary or pulmonary vascular disorders that increase pulmonary artery pressure and burden the heart.

Chronic cor pulmonale not only presents with pulmonary symptoms (cough, sputum production, dyspnea, etc.) but also cardiac symptoms, such as palpitations and fatigue after exertion. As the condition progresses to heart failure, symptoms like loss of appetite, nausea, bloating, and even lower limb edema may occur^[1].

CAUSES

Which populations are more susceptible to chronic obstructive pulmonary disease?

1. Smokers, including both active and passive smokers. Long-term active smoking, in particular, is considered the most significant risk factor for chronic obstructive pulmonary disease;
2. Residents living in areas with severe air pollution (such as vehicle exhaust);
3. Workers exposed to harmful dust and chemicals (such as sulfur dioxide, chlorine, etc.) in their jobs;
4. Individuals with recurrent respiratory infections, especially infants and toddlers (from birth to age three) who experience respiratory infections^[1,3].

How does chronic obstructive pulmonary disease develop?

The development of chronic obstructive pulmonary disease is the result of the interaction between various environmental factors and genetics^[1].

Long-term exposure to various risk factors (such as smoking, vehicle exhaust, etc.) leads to repeated damage and repair of lung tissue, which can cause hyperplasia of bronchial surrounding tissues and varying degrees of atrophy and degeneration of cartilage in the bronchial walls. This results in stiffening or collapse of the bronchial lumen, particularly during exhalation. Prolonged collapse of the lumen can trap excessive gas in the alveoli, reducing alveolar elasticity or even causing alveolar rupture, leading to emphysema and bullae, ultimately resulting in impaired lung function.

What are the exacerbating factors for chronic obstructive pulmonary disease?

1. The primary cause is infection (including bacterial and viral infections), accounting for about 70%–80% of cases;
2. Non-infectious causes, including smoking, self-discontinuation of medication, air pollution, increased allergens, and climate (temperature, humidity, etc.), with continued smoking being the most significant factor;
3. The cause is unknown in some patients, accounting for about one-third^[2,5,6].

How does malnutrition affect chronic obstructive pulmonary disease?

Malnutrition can damage respiratory muscles, weakening respiratory strength and reducing cough efficiency (including frequency and force). This makes it difficult to effectively expel phlegm from the lungs. Additionally, malnutrition lowers immunity^[7], thereby increasing the incidence of respiratory infections to some extent.

In chronic obstructive pulmonary disease (COPD), a prominent feature of malnutrition is weight loss. The more severe the malnutrition, the shorter the life expectancy of COPD patients, along with significant declines in quality of life and physical activity^[7].

What is the relationship between chronic obstructive pulmonary disease and smoking?

Smoking is the most common risk factor for chronic obstructive pulmonary disease (COPD), and the amount of smoking is closely related to the incidence and severity of COPD. This may be because smoking disrupts the oxidant/antioxidant balance, reduces the activity of anti-trypsin, and damages alveolar epithelial cells^[2].

Passive smoking can also lead to chronic obstructive pulmonary disease, likely due to increased lung burden^[3].

Smoking during pregnancy increases the risk of the fetus developing the disease later in life, possibly because smoking affects fetal lung development and the immune system^[3].

However, not all smokers develop chronic obstructive pulmonary disease, as genetic factors also play a role^[2].

DIAGNOSIS

Are chronic obstructive pulmonary disease, chronic bronchitis, and emphysema the same condition?

Chronic obstructive pulmonary disease (COPD) is not the same as chronic bronchitis or emphysema^[1]. It results from the coexistence of chronic bronchitis and emphysema.

However, chronic bronchitis (manifested as coughing and sputum production for over 3 months per year for 2 consecutive years) or emphysema (with symptoms similar to COPD, such as coughing, wheezing, or shortness of breath) in elderly individuals or smokers can progress to COPD. In such cases, they may be considered "part of the same disease spectrum," as their symptoms and treatments are largely similar.

When patients with chronic bronchitis or emphysema exhibit persistent airflow limitation in pulmonary function tests, they can be diagnosed with COPD^[1].

What is an acute exacerbation of COPD?

An acute exacerbation refers to a sudden worsening of symptoms, including increased coughing, sputum production, and shortness of breath; thicker, purulent (yellow) sputum; and the inability to relieve these symptoms with usual medications^[1].

How can patients self-assess an acute exacerbation of COPD?

Patients can evaluate whether their COPD is worsening based on symptoms and medication effectiveness:

1. Worsening respiratory symptoms: Increased difficulty breathing, even during rest or climbing stairs; wheezing or chest tightness; increased sputum volume with yellow, purulent phlegm.
2. Systemic symptoms: Fever (axillary temperature over 37.2°C), chills (involuntary shivering), or night sweats (excessive sweating during sleep).
3. Other signs: Palpitations, drowsiness, or leg swelling.
4. Usual medications no longer provide symptom relief^[8].

What tests help diagnose COPD early?

Early-stage COPD may not cause noticeable symptoms like coughing, sputum, or breathlessness. Once these appear, the disease is often advanced.

Pulmonary function tests can detect impaired exhalation before symptoms arise, showing slowed airflow and prolonged exhalation^[1].

What role do X-rays and CT scans play in COPD diagnosis?

X-rays do not directly diagnose COPD but help rule out other conditions with similar symptoms (e.g., tuberculosis, lung cancer, or interstitial lung disease). Skipping X-rays may lead to missed diagnoses.

Chest CT scans serve the same purpose but detect finer abnormalities, lesions obscured by ribs on X-rays, and more clearly define emphysema extent and distribution^[1].

How is COPD diagnosed?

1. The primary diagnostic tool is pulmonary function testing to confirm persistent airflow limitation.
2. Clinicians also consider symptoms (e.g., chronic cough, sputum, dyspnea) and risk factors (e.g., smoking, air pollution exposure).
3. Other conditions causing lung function decline (e.g., bronchiectasis) must be excluded^[1].

TREATMENT

What are the treatment methods for stable chronic obstructive pulmonary disease?

The treatment methods for stable chronic obstructive pulmonary disease include education and management, respiratory training, drug therapy, surgical treatment, etc. The details are as follows^[6,9,10]:

1. Lifestyle changes: Smoking cessation is the most critical measure. Additionally, it is necessary to avoid polluted environments and reduce exposure to related dust and gases, such as wearing protective masks and using pollution-free stoves.
2. Respiratory training: Includes pursed-lip breathing (inhale slowly through the nose, then exhale slowly for 4–6 seconds while contracting the abdomen, as if whistling) and diaphragmatic breathing (the abdomen expands when inhaling).
3. Drug therapy:
   • Bronchodilators are the main treatment drugs, such as salbutamol, salmeterol, formoterol, tiotropium, and ipratropium. They alleviate respiratory symptoms like shortness of breath and dyspnea by improving airflow limitation. Common side effects include involuntary hand tremors, dizziness, and headaches. Theophylline drugs, including aminophylline, theophylline sustained-release, and theophylline controlled-release tablets, relieve airway smooth muscle spasms. Common side effects include nausea, vomiting, and abdominal pain.
   • Inhaled corticosteroids, such as budesonide, fluticasone propionate, and triamcinolone acetonide, primarily provide anti-inflammatory treatment with a low incidence of adverse effects. However, they may increase the risk of pneumonia and oral candidiasis. Currently, combination inhalers of bronchodilators and corticosteroids, as well as dual bronchodilators, are mainly used, such as Seretide (salmeterol and fluticasone propionate), Symbicort (budesonide and formoterol), Anoro Ellipta (umeclidinium and vilanterol), and Trelegy Ellipta (fluticasone furoate, umeclidinium, and vilanterol).
4. Oxygen therapy: Refers to long-term low-flow oxygen inhalation, usually via a nasal cannula, with an oxygen flow rate of 1–2 L per minute for more than 15 hours daily. It addresses hypoxia caused by ventilation disorders by increasing oxygen content in the existing ventilation. This therapy only relieves symptoms temporarily and cannot cure the disease fundamentally. It must be combined with traditional drug therapy.
5. Vaccination: Influenza and pneumococcal vaccines can reduce the severity of chronic obstructive pulmonary disease^[6].
6. Surgical treatment:
   • Lung volume reduction surgery (LVRS): Endobronchial valve placement is the most widely used and approved method internationally. It involves using one-way valves to expel residual gas from the lung lobes, causing atelectasis and reducing lung volume, thereby improving lung function, relieving dyspnea, and enhancing quality of life. Common complications include pneumothorax and valve displacement. Surgical lung volume reduction involves removing non-functional lung tissue to allow the remaining relatively healthy lung tissue to expand, thereby increasing ventilation. This method has significant drawbacks: high risk, excessive bleeding, high mortality, and numerous postoperative complications (e.g., wound infections, pneumonia, especially in advanced patients), with slow recovery.
   • Lung transplantation: Involves transplanting a healthy lung into a COPD patient to replace the diseased lung. The mortality rate within three months post-transplantation is 8%–9%, with an average survival time of 7.1 years^[6]. Transplant recipients must take immunosuppressants for life. Additionally, donor lungs are difficult to obtain, treatment costs are high, and few hospitals offer this technology, making it accessible to only a very small number of patients.

What precautions should be taken when using inhaled medications for chronic obstructive pulmonary disease?

After inhaling the medication, hold your breath for a few seconds (about 10 seconds) to allow the drug to fully enter the alveoli. Otherwise, the medication may be exhaled, reducing its effectiveness. Rinse your mouth after using the medication because inhaled drugs usually contain hormones (such as fluticasone or budesonide). Long-term failure to rinse may lead to oral fungal growth^[9].

What are the treatment goals for chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease is a chronic condition that gradually worsens over time. Its treatment goals are divided into stable and acute phases, as follows^[6]:

1. Goals for the stable phase:
   • Alleviate symptoms, including respiratory symptoms like coughing, sputum production, and dyspnea; slow the decline in lung function; improve physical activity (e.g., long-distance walking or climbing gentle slopes); and enhance quality of life.
   • Reduce future risks, including controlling disease progression, preventing acute exacerbations, and lowering mortality.
2. Goals for the acute exacerbation phase: Minimize the impact of the current acute exacerbation and prevent future exacerbations.

What are the main medications for acute exacerbations of chronic obstructive pulmonary disease?

Drug therapy for acute exacerbations includes bronchodilators, antibiotics, and corticosteroids, as follows^[6]:

1. Bronchodilators: Similar to stable-phase drug therapy, including β2-adrenergic agonists (e.g., salbutamol, terbutaline), anticholinergics (e.g., ipratropium), and theophylline (theophylline or aminophylline). However, long-acting bronchodilators (e.g., tiotropium, indacaterol) are not recommended during the acute phase.
2. Expectorants: Suitable for patients with difficulty expectorating sputum, such as ambroxol hydrochloride and acetylcysteine. Common side effects include nausea and abdominal pain.
3. Corticosteroids: Oral prednisone or methylprednisolone can be used. The incidence of adverse effects is low, but there is a risk of pneumonia and oral candidiasis.
4. Antibiotics: Suitable for patients with respiratory infections accompanied by worsening dyspnea, increased sputum volume, or purulent sputum. Medications such as cefuroxime and ceftriaxone can be used. Common side effects include nausea and diarrhea.

What precautions should be taken when using antibiotics for acute exacerbations of chronic obstructive pulmonary disease?

Antibiotics are only effective when bacterial infections are present. Common indicators include yellow purulent sputum, increased sputum volume, and worsening dyspnea. Yellow purulent sputum is a key feature of bacterial infections^[6].

Random or excessive use of antibiotics not only increases adverse drug reactions but also fosters drug-resistant bacteria, potentially leading to untreatable infections. Therefore, patients must not self-medicate and should consult a professional doctor for evaluation and follow medical advice.

Under what circumstances should a patient with chronic obstructive pulmonary disease be hospitalized?

Hospitalization should be considered if any of the following occur^[6]:

1. Significant increase in symptom severity: Dyspnea at rest, changes in mental or consciousness status (e.g., drowsiness).
2. Acute respiratory failure: Manifested as cyanosis (bluish lips), shallow and rapid labored breathing, etc.
3. Poor response to outpatient or home treatment.
4. New symptoms, such as lower limb edema.
5. Coexisting other diseases, such as diabetes, hypertension, or heart disease.

Do patients with chronic obstructive pulmonary disease need lifelong medication?

Chronic obstructive pulmonary disease (COPD) is incurable, so lifelong medication is required.

Active treatment should be tailored to the severity of COPD to alleviate symptoms, reduce acute exacerbations, and slow disease progression. Otherwise, the condition may deteriorate rapidly.

When is home oxygen therapy needed for chronic obstructive pulmonary disease?

Home oxygen therapy is initiated under a doctor's guidance after evaluation when dyspnea is accompanied by hypoxemia. Specific criteria are as follows^[11]:

1. Arterial oxygen partial pressure (PaO₂) ≤ 55 mmHg or oxygen saturation (SpO₂) ≤ 88%.
2. If accompanied by polycythemia (may present as headache, dizziness, tinnitus), right heart failure (manifested as chest tightness, lower limb edema, cyanosis), or cor pulmonale (manifested as cough, sputum production, lower limb edema), PaO₂ ≤ 59 mmHg or SpO₂ ≤ 89%.
3. During sleep: PaO₂ ≤ 55 mmHg, SpO₂ ≤ 88%, PaO₂ drops by more than 10 mmHg, and/or SpO₂ drops by more than 5%, accompanied by insomnia, restlessness, or morning headaches due to hypoxia.
4. During exercise: Dyspnea or PaO₂ ≤ 55 mmHg, SpO₂ ≤ 88%.

What are the hazards of pulmonary bullae, and how are they treated?

First, the normal gas exchange function is almost lost, leading to dyspnea.

Second, there is a risk of gradual enlargement or even rupture, causing pneumothorax. Escaped gas compresses the lungs, worsening dyspnea. Even a small pneumothorax can severely exacerbate the condition of patients with already poor lung function, leading to rapid deterioration^[4].

Treatment involves addressing the underlying cause (e.g., COPD), preventing exacerbations, improving breathing, and slowing progression. The most important measure is smoking cessation. In advanced cases, surgical treatment such as bullectomy may be required^[4]. Therefore, regular follow-ups are necessary. Early-stage cases may not require surgery, while late-stage surgery carries higher risks. Careful consideration of the doctor's advice is essential.

DIET & LIFESTYLE

How can patients with chronic obstructive pulmonary disease perform whole-body exercise?

1. For outdoor exercise, choose a place with good air quality and flat ground. For indoor exercise, ensure proper ventilation by opening windows.
2. The intensity and duration of exercise should be adjusted based on individual conditions, gradually increasing over time. The principle is to avoid excessive fatigue. Activities like walking or jogging are recommended, with a minimum duration of 6–8 weeks, ideally continuing long-term^[6].
3. Exercise may trigger or worsen hypoxemia in some patients. For these individuals, oxygen saturation should be monitored during exercise (typically using a finger-clip device). If breathing difficulty, chest tightness, or oxygen saturation ≤ 88% occurs, oxygen therapy may be administered.

How can patients with chronic obstructive pulmonary disease perform home oxygen therapy?

Consult a respiratory specialist to develop a home oxygen therapy plan based on underlying conditions, symptoms, mental state, and lung function. The plan should include oxygen source, concentration, and duration.

1. Common oxygen sources include:

   • Steel compressed oxygen cylinders: Affordable and widely available, but heavy, with limited oxygen storage requiring frequent refills.
   • Oxygen concentrators (commonly called oxygen generators): Convenient for home use without storage needs, but require electricity, produce noise, need regular maintenance, are expensive, and lack portability.
   • Liquid oxygen: Offers high oxygen storage capacity but is costly.

2. Oxygen delivery devices:

• Nasal cannula or nasal prongs: Inexpensive, simple, and convenient, allowing eating, drinking, and coughing without interference, though effectiveness may vary with breathing depth, rate, or mouth breathing.
• Oxygen mask: More effective than nasal cannulas but less convenient, requiring removal for eating, drinking, or coughing.

3. Oxygen administration method: Controlled oxygen therapy is typically used. Initially (1–3 days), low-concentration oxygen (1–2 L/min) is given, followed by gradual adjustments or maintenance based on arterial oxygen partial pressure (measured via arterial blood draw, maintained at 60 mmHg)^[6].

How can patients with chronic obstructive pulmonary disease quit smoking?

Common smoking cessation medications and therapies in China include nicotine sprays/inhalers/gum/patches and bupropion tablets. However, the key to success lies in awareness of smoking hazards, determination, goals, and perseverance. Other methods only serve as aids^[6].

Successful cessation is defined as abstaining from smoking for at least 2 years.

How can patients with chronic obstructive pulmonary disease perform respiratory muscle training?

The goal of respiratory training is to improve respiratory muscle strength and endurance. Techniques include pursed-lip breathing and diaphragmatic breathing, practiced 3–4 times daily with 8–10 repetitions each^[9]:

1. Pursed-lip breathing: Inhale slowly through the nose, then exhale slowly (4–6 seconds) through pursed lips while contracting the abdomen.
2. Diaphragmatic breathing: Inhale while allowing the abdomen to expand (place a hand on the belly to feel the movement).

What should chronic obstructive pulmonary disease patients do if symptoms suddenly worsen at home?

If symptoms (e.g., increased sputum, purulent sputum, or dyspnea at rest) become significantly worse and are unrelieved by usual medications^[8], seek immediate medical attention.

Acute exacerbations are often caused by respiratory infections but may also result from heart failure, smoke, cold exposure, etc. Regardless of the cause, prompt treatment is crucial to prevent rapid deterioration, which may require costly emergency care or even become life-threatening^[2,5,6].

PREVENTION

Why is early detection of chronic obstructive pulmonary disease important?

Because chronic obstructive pulmonary disease is a progressive condition. In the early stages, lung damage is relatively mild, and some pathological changes can be reversed through smoking cessation and proper treatment, slowing disease progression^[1].

Is chronic obstructive pulmonary disease preventable?

Chronic obstructive pulmonary disease is preventable. Preventive measures include^[1]:

1. First and foremost, quitting or reducing smoking is the most crucial preventive measure;
2. Avoiding or improving exposure to toxic and harmful environments. Pay attention to weather and air quality forecasts, avoid strenuous outdoor activities during severe air pollution, and reduce visits to crowded public places during flu or other infectious respiratory disease outbreaks to minimize exposure to harmful substances and pathogens;
3. Engaging in regular physical exercise, such as walking 6,000 steps daily and exercising (e.g., jogging, swimming) for at least 150 minutes per week^[12], to improve physical fitness and adaptability to environmental changes;
4. Consuming foods rich in vitamins A and C, such as carrots, eggs, animal liver, and fresh fruits and vegetables, to enhance the repair and disease resistance of respiratory mucosa^[7];
5. Getting regular vaccinations, such as flu and pneumonia vaccines, to boost immunity against upper respiratory infections.

How to prevent sudden worsening of chronic obstructive pulmonary disease during cold seasons?

First, quit smoking and protect against cold to avoid catching a chill. Engage in appropriate respiratory function exercises (e.g., diaphragmatic breathing, where the abdomen expands during inhalation) to strengthen respiratory muscles and endurance. Get regular vaccinations (e.g., flu and pneumococcal vaccines) to enhance immunity, and consume high-protein foods like milk and eggs to improve overall nutritional status^[1,6,9].