Chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease 

                                                                

Chronic obstructive pulmonary disease(COPD) is a chronic inflammatory lung disease that causes obstructed airflow from the lungs.  Most common associated with emphysema and 

chronic bronchitis

Pathophysiology: 

• COPD results from the combined processes of peripheral airway inflammation and narrowing of the airways.  

• This leads to airflow limitation and the destruction and loss of alveoli, terminal bronchioles and surrounding capillary vessels and tissues, which adds to airflow limitation and leads to decreased gas transfer capacity.  

• The extent of airflow limitation is determined by the severity of inflammation, development of fibrosis within the airway and presence of secretions or exudates.  

• Reduced airflow on exhalation leads to air trapping, resulting in reduced inspiratory capacity, which may cause breathlessness (also known as dyspnoea) on exertion and reduced exercise capacity. 

• Abnormalities in gas transfer occur due to reduced airflow/ventilation and as a result of loss of alveolar structure and pulmonary vascular bed.  

• Low blood oxygen levels (hypoxaemia) and raised blood carbon dioxide levels (hypercapnia) result from impaired gas transfer and can worsen as the disease inevitably progresses. 

Risk factors for COPD include: 

• Exposure to tobacco smoke:

1. The most significant risk factor for COPD is long-term cigarette smoking.  
2. The more years patient smoke and the more packs he smokes, the greater his risk.  
3. Pipe smokers, cigar smokers and marijuana smokers also may be at risk, as well as people exposed to large amounts of secondhand smoke

• People with asthma:

1. Asthma, a chronic inflammatory airway disease, may be a risk factor for developing COPD.  
2. The combination of asthma and smoking increases the risk of COPD even more. 

• Occupational exposure to dusts and chemicals:

1. Long-term exposure to chemical fumes, vapors and dusts in the workplace can irritate and inflame the lungs

• Exposure to fumes from burning fuel.  

1. In the developing world, people exposed to fumes from burning fuel for cooking and heating in poorly ventilated homes are at higher risk of developing COPD. 

• Genetics:

1. The uncommon genetic disorder alpha-1-antitrypsin deficiency is the cause of some cases of COPD.  
2. Other genetic factors likely make certain smokers more susceptible to the disease. 

Symptoms: 

COPD symptoms often don't appear until significant lung damage has occurred, and they usually worsen over time, particularly if smoking exposure continues. 

Signs and symptoms of COPD may include: 

• Shortness of breath, especially during physical activities 
• Wheezing 
• Chest tightness 
• A chronic cough that may produce mucus (sputum) that may be clear, white, yellow or greenish 
• Frequent respiratory infections 
• Lack of energy 
• Unintended weight loss (in later stages) 
• Swelling in ankles, feet or legs 

Diagnosis: 

• Lung (pulmonary) function tests. These tests measure the amount of air the patient can inhale and exhale, and whether his lungs deliver enough oxygen to the blood.  

• Chest X-ray. A chest X-ray can show emphysema, one of the main causes of COPD. An X-ray can also rule out other lung problems or heart failure. 

• CT scan. A CT scan of lungs can help detect emphysema and help determine if patient might benefit from surgery for COPD. CT scans can also be used to screen for lung cancer. 

• Arterial blood gas analysis. This blood test measures how well the lungs deliver oxygen to blood and removing carbon dioxide. 

Complications: 

• Respiratory infections.  

• Heart problems. For reasons that aren't fully understood, COPD can increase risk of heart disease, including heart attack 

• Lung cancer. People with COPD have a higher risk of developing lung cancer. 

• High blood pressure in lung arteries. COPD may cause high blood pressure in the arteries that lead to pulmonary hypertension. 

• Depression . Difficulty breathing can keep patient from doing activities that he enjoy. And dealing with serious illness can contribute to the development of depression. 

Treatment: 

1/ Reduction risk factors  

2/ Medications   (Several kinds of medications are used to treat the symptoms and complications of 

    COPD )

3/ Bronchodilators :

1. Usually come in inhalers — they relax the muscles around airways.  
2. Help relieve coughing and shortness of breath and make breathing easier.  
3. Depending on the severity of the disease, a short-acting bronchodilator before activities, a long-acting bronchodilator that he uses every day or both

4/ Inhaled steroids :

•   Inhaled corticosteroid medications can reduce airway inflammation and help prevent exacerbations

5/ Oral steroids :

1. For people who experience periods when their COPD becomes more severe, called moderate or severe acute exacerbation, short courses (for example, five days) of oral corticosteroids may prevent further worsening of COPD.  
2. However, long-term use of these medications can have serious side effects, such as weight gain, diabetes, osteoporosis, cataracts and an increased risk of infection. 

6/ Antibiotics 

7/ Oxygen therapy

8/ Pulmonary rehabilitation program.