Basic concepts of bronchitis, COPD

Bronchitis

Inflammation of lining of bronchial tubes, which carry air to and from the lungs (bronchial tubes) results in cough and mucus.

Bronchitis Types:

• Acute Bronchitis
• Chronic Bronchitis

Acute Bronchitis

• Condition remains for few days to 10 days
• Bacteria or virus that cause common cold or infection.
• Irritants like cigarette smoke, air pollution, dust, vapours or fumes.

Chronic Bronchitis

• Condition remains for months to years.
• Lining of bronchial tube is constantly irritated and inflamed.
• Cough with mucus for at least 3 months in a year.

chronic bronchitis Caused by

• Repeatedly breathing in irritants.
• Smoking major cause.
• Viruses or bacteria easily infect irritated tubes.
• Ongoing and serious

Causes and Risk factors

• Cold and flu season
• Viruses: Influenza Type A or B
• Bacteria: Mycoplasma pneumoniae
• Person inhaling irritants like dust, fumes.
• Gastroesophageal reflux disease (GERD)
• Weak immune system
• Smoking
• Unhealthy environment

Pathophysiology of bronchitis

• Virus, bacteria, smoke or other environment pollutants irritate airways
• Hypersecretion of mucus and inflammation
• Bronchial walls become thickened
• Bronchial lumen narrow, mucus plugged airways
• Alveoli adjacent to bronchioles may become damaged and fibrosis
• Fibrosis of bronchial and airflow limitation

Clinical features of Bronchitis

 Acute bronchitis clinical features

• Cough with or without phlegm
• Chest tightness
• Fever
• Mild headache, body aches
• Shortness of breath
• Wheezing sound

 Chronic bronchitis clinical features

• Daily, productive cough for at least 3 months of the year, 2 or more years in a row.

Asthma

Asthma is a common chronic inflammatory condition of the lung airways . It has three characteristics:

• Airflow limitationàwhich is usually reversible spontaneously or with treatment
• Airway hyper responsiveness àto a wide range of stimuli 
• Inflammation of the bronchi àwith eosinophils, T lymphocytes and mast cells that is associated with plasma exudation, edema, smooth muscle hypertrophy, mucus plugging and epithelial damage.

Epidemiology

• Asthma affects an estimated 300 million individuals worldwide.
• Annually, the World Health Organization (WHO) has estimated that 15 million disability-adjusted life-years are lost and
• 250,000 asthma deaths are reported worldwide.

Predisposing factors

Environmental allergens

• house dust mites;
• animal allergens, especially cat and dog;
• cockroach allergens;
•  fungi
• Viral respiratory tract infections
• Exercise, hyperventilation
• sinusitis or rhinitis

• Aspirin  and NSAID hypersensitivity
• Use of beta-adrenergic receptor blockers
• Obesity
• Environmental pollutants, tobacco smoke
• Occupational exposure
• Irritants (eg, household sprays, paint fumes)
• Emotional factors or stress
• Perinatal factors (prematurity and increased maternal age; maternal smoking and prenatal exposure to tobacco smoke)
•  

Clinical features

three most common symptoms

• cough,
•  dyspnea, and
• wheezing.

In some instances, cough may be the only symptom.

COPD

• Chronic obstructive pulmonary disease (COPD) is lung disease
• characterized by persistent airflow limitation that is usually progressive and
• associated with an enhanced chronic inflammatory response in the airways and the lung in response to noxious particles or gases.
• COPD Include   
  • Chronic Bronchitis
  • Emphysema
  • Irreversibale astma
  • Bronchetiasia

 Emphysema:

• Impaired gas exchange from destruction of the walls of over distended alveoli.

Chronic Bronchitis:

• Excessive accumulation of mucus due to inflammation and cause narrow airway.

 Irreversible asthma:

• Inflamed and constricted airways obstruct airflow.

Bronchiectasis:

•  Mucus sticks to bronchi leading to obstruction, infection and inflammation.

Epidemiology

• The Global Burden of Disease Study reports a prevalence of 251 million cases of COPD globally in 2016.
•  
• Globally, it is estimated that 3.17 million deaths were caused by the disease in 2015 (that is, 5% of all deaths globally in that year).
• More than 90% of COPD deaths occur in low­ and middle­ income countries.
•  
• Nepal have reported the prevalence of COPD ranging from 23% to 43%.

Risk factors and cause of COPD

• Smoking (Active or Passive)
• Indoor and outdoor pollution
• Genetic factors: alpha 1 antitrypsin deficiency
• Socioeconomic status
• Asthma & airway hyper-reactivity
• Emphysema
• Chronic bronchitis
• Infections
• Exposure to smoke

Pathophysiology of COPD

Due to causes and risk factors of COPD

CLINICAL FEATURES

• Chronic coughing (sputum)
• Dyspnea
• Wheezing
• Chest tightness
• Frequent respiratory infection
• Enlarged alveoli
• Weight loss

• Advanced symptoms
• Cyanosis
• Morning headache
• Weight loss
• Haemoptysis
• Swollen feet and ankles