PART II Obstructive Airway Diseases
Obstructive Lung Diseases Chronic Bronchitis Emphysema Cystic Fibrosis Asthma Bronchiectasis The most common obstructive lung diseases
Chapter 11Chronic Obstructive Pulmonary Disease (COPD) Chronic Bronchitis and Emphysema
Figure 11-1. Chronic bronchitis, one of the most common airway diseases.
C A B Figure 11-2. Panlobular emphysema. A, Normal alveoli for comparison purposes. B, Panlobular emphysema. C, Excessive bronchial secretions from bronchitis, a common alteration of the lungs.
Figure 11-3. Centrilobular emphysema. Abnormal weakening and enlargement of the respiratory bronchioles in the proximal portion of the acinus.
The American Thoracic Society (ATS) • Guidelines for • Chronic obstructive pulmonary disease (COPD) • Chronic bronchitis, • Emphysema
Chronic Obstructive PulmonaryDisease • Is a preventable and treatable disease state characterized by airflow limitation that is not fully reversible. • The airflow limitation is usually progressive and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases, primarily caused by cigarette smoking. • Although COPD affects the lungs, it also produces significant systemic consequences.
Chronic Bronchitis • Is defined clinically as chronic productive cough for 3 months in each of 2 successive years in a patient in whom other causes of productive chronic cough have been excluded.
Emphysema • Is defined pathologically as the presence of permanent enlargement of the airspaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis.
In patients with COPD: • Either or both of those conditions may be present. • However, the relative contribution of each to the disease process is often difficult to discern.”
Note that the ATS’s definition for • Chronic bronchitis is based on the major "clinical manifestations" associated with the disease. • Emphysema is based on the pathology, or the "anatomic alterations of the lung," associated with the disorder.
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) provides this working definition:
Chronic Obstructive Pulmonary Disease (COPD) is….. • A preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients. • Its pulmonary component is characterized by airflow limitation that is not fully reversible. • The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases.
The bottom line is this: • Even though chronic bronchitis and emphysema can each develop alone, they often occur together as one disease complex. • When this happens, the disease entity is called chronic obstructive pulmonary disease (COPD).
GOLD Website Address http://www.goldcopd.org
Anatomic Alterations of the LungsAssociated with Chronic Bronchitis • Chronic inflammation and swelling of the peripheral airways • Excessive mucus production and accumulation • Partial or total mucus plugging of the airways • Smooth muscle constriction of bronchial airways (bronchospasm) • Air trapping and hyperinflation of alveoli—occasionally in the late stages
Anatomic Alterations of the Lungs Associated with Emphysema • Permanent enlargement and deterioration of the air spaces distal to the terminal bronchioles • Destruction of pulmonary capillaries • Weakening of the distal airways, primarily the respiratory bronchioles • Air trapping and hyperinflation of alveoli (air-trapping)
Epidemiology • It is estimated that between 10 and 15 million people in the United States either have chronic bronchitis, emphysema, or a combination of both. • Most authorities agree that COPD is under-diagnosed.
Risk FactorsAccording to GOLD • Tobacco smoke • Occupational dusts and chemicals • Indoor air pollution • Outdoor air pollution • Conditions that affect normal lung growth • Genetic predisposition • Alpha 1-antitrypsin deficiency
Diagnosis of COPDAccording to GOLD • Key Indicators for Considering a COPD Diagnosis: • Dysypnea • Chronic cough • Chronic sputum production • History of exposure to risk factors
Pulmonary Function Study in the Diagnosis of COPDAccording to GOLD • The three main spirometry tests for COPD are the : • FVC • FEV1 • FEV1/FVC ratio
Figure 11-4 Normal spirogram and spirogram typical of patients with mild to moderate chronic obstructive pulmonary disease.
Pulmonary Function Study in the Diagnosis of COPD (Cont’d) • The presence of COPD is confirmed when both the FEV1 and FEV1/FVC ratio are decreased
Stages of COPDAccording to GOLD • Stage I: Mild COPD • Stage II: Moderate COPD • Stage III: severe COPD • Stage IV: Very severe COPD
Additional Diagnostic Studies of COPDAccording to GOLD • Bronchodilator reversibility testing • Chest x-ray • Arterial blood gas measurement • Alpha1 antitrypsin deficiency screening
Overview of the Cardiopulmonary Clinical Manifestations Associated with Chronic Bronchitis and Emphysema (COPD) The following clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by • Excessive Bronchial Secretions • Bronchospasm • Distal Airway and Alveolar Weakening