ASTHMA (PATHOGENESIS & CLINICAL MANIFESTATION) BRONCHIACTASIS (DEFINITION, ETIOLOGY & PATHOGENESIS) LEARNING OBJECTIVES

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1 ASTHMA (PATHOGENESIS & CLINICAL MANIFESTATION) BRONCHIACTASIS (DEFINITION, ETIOLOGY & PATHOGENESIS) LEARNING OBJECTIVES At the end of the lecture student should be able to Define chronic obstructive lung diseases (COPD) Enlighten the types of COPD Discuss their common features Identify the causes, underlying patho-physiology, morphology, and clinical features of chronic bronchitis DIFFUSE PULMONARY DISEASES Diffuse pulmonary diseases are divided into Obstructive disease: characterized by limitation of airflow owing to partial or complete obstruction at any level from trachea to respiratory bronchioles. Pulmonary function test: limitation of maximal airflow rate during forced expiration (FEVI). Restrictive disease: characterized by reduced expansion of lung parenchyma with decreased total lung capacity while the expiratory flow rate is near normal. Occur in: 1. Chest wall disorder. 2. Acute or chronic, interstitial and infiltrative diseases, e.g. ARDS and pneumoconiosis. CHRONIC OBSTRUCTIVE PULMONARY DISEASE Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease state characterized by air flow limitation that is not fully reversible. Air flow limitation is usually progressive and is associated with an

2 abnormal inflammatory response of lungs to noxious particles or gases, primarily caused by cigarette smoking. CHRONIC OBSTRUCTIVE PULMONARY DISEASE Chronic obstruction to airflow due to chronic bronchitis and/or emphysema. Degree of obstruction may be less when the patient is free from respiratory infection and may improve with bronchodilator drugs Significant obstruction is always present WHY COPD IS IMPORTANT? COPD is the only chronic disease that is showing progressive upward trend in both mortality and morbidity It is expected to be the third leading cause of death by 2020 Approximately 14 million Indians are currently suffering form COPD* Currently there are 94 million smokers in India 10 lacs Indians die in a year due to smoking related diseases *The Indian J Chest Dis & Allied Sciences 2001; 43: CHRONIC OBSTRUCTIVE PULMONARY DISEASE

3 CHRONIC OBSTRUCTIVE PULMONARY DISEASE Chronic Bronchitis COPD Emphysema Asthma Mixed Disease PATHOPHYSIOLOGY OF COPD Increased mucus production and reduced mucociliary clearance - cough and sputum production Loss of elastic recoil - airway collapse Increase smooth muscle tone Pulmonary hyperinflation Gas exchange abnormalities - hypoxemia and/or hypercapnia

4 KEY INDICATORS FOR COPD DIAGNOSIS Chronic cough Chronic sputum production Dyspnoea Acute bronchitis History of exposure to risk factors Present intermittently or every day often present throughout the day; seldom only nocturnal Present for many years, worst in winters. Initially mucoid becomes purulent with exacerbation Progressive (worsens over time) Persistent (present every day) Worse on exercise Worse during respiratory infections Repeated episodes Tobacco smoke, occupational dusts and chemical smoke from home cooking and heating fuel Chronic nonspecific inflammation Symptoms of cough and sputum production with or without gasping Recurrent attacks Chronic proceeding Clinical and epidemiological term Defined clinically as the presence of productive cough not attributable to other causes on most days for at least 3 months over 2 consecutive years. Different forms Simple chronic bronchitis No airway obstruction

5 Chronic mucopurulent bronchitis Associated with infection Chronic asthmaticus bronchitis Chronic obstructive bronchitis Airflow obstruction is due to: Inflammation, fibrosis, narrowing of bronchioles (chronic bronchiolitis) Co-existent emphysema Stages of Chronic Bronchitis Stages Exacerbation Time Courses In a week Chronic lag phase One month or longer stable Lasts for two months Chronic irritation defensive increase in mucus production with increase in numbers of epithelial cells (esp goblet cells) Poor relation to functional obstruction Role in sputum production and increased tendency to infection Non-reversible obstruction In some patients there may be a reversible ( asthmatic ) component

6 Pathogenesis: Smoking increase mucus secretion inflammation epithelial injury metaplasia and hypertrophy of mucus glands Morphology: Enlarged mucus gland, edema Squamous metaplasia, dysplasia Inflammation Chronic bronchiolitis Goblet cells in small bronchioles, inflammation, fibrosis, smooth muscle hypertrophy NORMAL VS.

7 CLINICAL: Cough and sputum Cyanosis, blue bloater Hyperinflated chest Reduced expansion Increased resonance on percussion Reduced breath sounds with end expiratory wheeze Right ventricular failure PRIMARY SYMPTOMS Chronic Bronchitis Chronic cough Shortness of breath Increased mucus Frequent clearing of throat Emphysema Chronic cough Shortness of breath Limited activity level Diagnosis of chronic bronchitis Cough & Sputum expectoration & Gasping Three months /per year or longer Continuously longer than two years Exclude other lung and heart disease If shorter than three months /per year then definite objective evidences are demanded (such as X-Ray and lung function et al.)to diagnose. AUXILLARY EXAMINATION Chest Radiograph(X-Ray) Non apparent abnormality

8 Or thickened and increased lung markings are noted. REFERNCES BASIC PATHOLOGY 8 th EDITION PAGE # THANK YOU