COPD summary from GOLD

Chronic Obstructive Pulmonary Disease
Definition:
a disease state characterized by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases.

Characteristic of COPD is caused by a mixture of:
1. small airway disease (obstructive bronchiolitis) à causing narrowing & remodeling of small airways.
2. and parenchymal destruction (emphysema)à leads to the loss of alveolar attachments to the small airways and decreases lung elastic recoil; in turn, these changes diminish the ability of the airways to remain open during expiration
Note:
· Emphysema = destruction of the gas exchanging surfaces of the lung.
· Chronic bronchitis = presence of cough and sputum production for at least 3 months in each of two consecutive years
Stage Characteristics
0: At Risk
• normal spirometry
• chronic symptoms (cough, sputum production)

I: Mild COPD
• FEV1/FVC < 70%
• FEV1 ≥ 80% predicted
• with or without chronic symptoms (cough, sputum production)

II: Moderate COPD
• FEV1/FVC < 70%
• 50% ≤ FEV1 < 80% predicted
• with or without chronic symptoms (cough, sputum production)

III: Severe COPD
• FEV1/FVC < 70%
• 30% ≤ FEV1 < 50% predicted
• with or without chronic symptoms (cough, sputum production)

IV: Very Severe COPD
• FEV1/FVC < 70%
• FEV1 < 30% predicted or FEV1 < 50% predicted plus chronic respiratory failure

RISK FACTORS FOR COPD:
A. Host Factors
1. Genes
The genetic risk factor that is best documented is a severe hereditary deficiency of alpha-1 antitrypsin12-14, a major circulating inhibitor of serine proteases.
2. Airway Hyporesposiveness
Asthma and airway hyperresponsiveness, identified as risk factors that contribute to the development of COPD,are complex disorders related to a number of genetic and environmental factors. Airway hyperresponsiveness may also develop after exposure to tobacco smoke or other environmental insults and thus may be a result of smoking-related airway disease.
3. Lung Growth
Lung growth is related to processes occurring during gestation, birth weight, and exposures during childhood. Reduced maximal attained lung function (as measured by spirometry) may identify individuals who are at increased risk for the development of COPD
B. Exposures
1. Tobacco smoke
Age at starting to smoke, total pack-years smoked, and current smoking status are predictive of COPD mortality.
2. Occupational Dusts & Chemicals
Occupational dusts and chemicals (vapors, irritants, and fumes) can also cause COPD when the exposures are sufficiently intense or prolonged.
3. Indoor & Outdoor Air Pollution
High levels of urban air pollution are harmful to individuals with existing heart or lung disease.
4. Infections
There may be an increased diagnosis of severe infections in children who have underlying airway hyperresponsiveness, itself considered a risk factor for COPD. Viral infections may be related to another factor, such as birth weight, that is related to COPD.
5. Low Socioeconomic status
reflects exposures to indoor and outdoor air pollutants, crowding, poor nutrition,or other factors that are related to low socioeconomic status.


Symptoms for COPD :
1. Cough
Initially, the cough may be intermittent, but later is present every day, often throughout the day, and is seldom entirely nocturnal. The chronic cough in COPD may be unproductive.
2. Sputum Production
Patient with COPD commonly raise small quantities of tenacious sputum after coughing bouts. Patients may swallow sputum rather than expectorate it.
3. Dyspnea
Dyspnea, the hallmark symptom of COPD, is the reason most patients seek medical attention and is a major cause of disability and anxiety associated with the disease. Typical COPD patients describe their dyspnea as a sense of increased effort to breathe, heaviness, air hunger, or gasping.
4. Wheezing & Chest Tightness
Wheezing and chest tightness are relatively non-specific symptoms that may vary between days, and over the course of a single day. Audible wheeze may arise at a laryngeal level and need not be accompanied by ausculatory abnormalities. Alternatively, widespread inspiratory or expiratory wheezes can be present on listening to the chest. Chest tightness often follows exertion, is poorly localized, is muscular in character, and may arise from isometric contraction of the intercostal muscles.
5. Additional symptoms in severe disease
Weight loss & anorexia
Hemoptysis à in respiratory tr. Inection.
Syncope à rapid increases in intrathoracic pressure during attacks of coughing
Coughing spells may also cause rib fractures, which are sometimes asymptomatic.
symptoms of depression and/or anxiety
Ankle swelling can be the only symptomatic pointer to the development of cor pulmonale

Exacerbations

Exacerbations in Stage I & II are associated with increase breathlessness, often accompanied by increased cough and sputum production.
Exacerbations in Stage IV are associated with acute respiratory failure.
Most common causes of exacerbation: air pollution & tracheobronchial tree infection.
Development of specific immune responses to the infecting bacterial strains, and the association of neutrophilic inflammation with bacterial exacerbations also support the bacterial causation of a proportion of exacerbations.
Conditions that may mimic an exacerbation include pneumonia, congestive heart failure, pneumothorax, pleural effusion, pulmonary embolism, and arrhythmia.