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25 Cards in this Set
- Front
- Back
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What defined COPD?
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-A group of chronic respiratory disorders characterized by gradual and progressive loss of lung
-Airflow limitation is NOT reversible, PROGRESSIVE, and assocd w/abnl INFLAMMATION of lungs |
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What two processes comprise COPD? How do they differ?
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Emphysema: permanent, destructive enlargement of airspaces; no fibrosis
Chronic bronchitis: presence of cough with sputum on most days for at least 3 months over 2 consecutive years |
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Primary cause of COPD.
Risk factors? |
Smoking
Risks: Smoking Env factors, occupational Lung growth (premature births, chronic lung infections as a child) Airway hyper-responsiveness Genetics |
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Why and how does smoking cause COPD?
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High concentrations of oxygen free-radicals induce oxidant stress; primarily a NEUTROPHIL response
Causes release of TNF-alpha, IL-9-->widespread destructive changes Mucus hypersecretion; imbalance between proteases and antiproteases |
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Genetic cause of OCPD.
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alpha1-AT deficiency: lack of ability to inhibit elastase and proteases
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When does a-AT deficiency present?
Treatment? |
Presents early 3rd or 4th decade--tobacco is an impt co-factor
Therapy involves enzyme replacement if caught early enough |
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Effect of COPD on airways:
Which airways affected? Gross and histologic How does histology perpetuate process? |
Small airways are major site of airflow limitation
Effects: Narrowing due to persistent inflammn (and mucous)--edema, peribronchial FIBROSIS, intraluminal mucus plugs Squamous metaplasia, atrophy of ciliated cells, hypertrophy of mucus glands Remodeled epithelium produces cytokines that perpetuate inflammatory process |
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Effect of COPD on parenchyma
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Destruction of alveolar walls, enlargement of terminal airspaces
Classified by pattern of acini involement (panacinar--AAT deficiency, centriacinar--smokers) |
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Which form of OCPD is seen in those with AAT deficiency?
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Panacinar
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Which form of OCPD is seen in smokers?
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Centriacinar
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Effect of OCPD on vasculature.
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-Thickening of pulmonary vessels
-Vasoconstriction if hypoxia present -Loss of vasc be w/parenchymal destruction |
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How does hyperinflation occur in OCPD and why does it result in dyspnea?
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Hyperinflation = major trigger of dyspnea
Due to structural changes: difficult to exhale in airways-->larger residual volume in lungs -->diaphragmatic flattening -->increased work of breathing |
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Lung volume and elasticity changes in OCPD.
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-Loss of elastic recoil-->collapsibility of airways (diminished flow rates and air trapping)
-Inc'd lung volumes (TLC, FRC, RV) |
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What is the main cause of hypoxia due to OCPD?
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V/Q mismatch: maldistribution of inspired air and blood flow
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How does OCPD result in pulmonary hypertension?
Effect on cardiac function? |
Primary cause: Hypoxia-->vasoconstriction/vascular remodeling
-Polycythemia, reduction in vascular bed, hypercapnia -Occurs with ADVANCED DZ, worsens w/exercise -Can lead to cor pulmonale (Right Heart Failure) |
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Patients with OCPD are more likely to die of ________ than pulmonary disease.
Why? |
Cardiovascular event
Lung inflammatory factors can reach systemic circulation (go to heart), and destabilize plaques-->Heart Attacks + Strokes |
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Type A vs Type B COPD
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A: Pink Puffer (thin, breathing quickly); assocd with emphysema
PaO2 preserved Less V/Q mismatch Type B: Blue Bloater Chronic bronchitis Significant hypoxemia, hypercapnia Obese w/peripheral edema due to RVF More V/Q mismatch |
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Smoking history suspicious for OCPD.
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AT LEAST 20 PACK YEAR HISTORY
Presenting in 5th decade w/cough, sputum +/- wheezing Exertional dyspnea by sixth/seventh decade |
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How does COPD lead to disabilit?
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COPD-->Breathleassness-->Inactivity + Deconditioning-->Reduced exercise capacity-->Dec'd activity-->Disability
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By how much does FEV1 have to drop before manifesting as exertional dyspnea? Dyspnea at rest?
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40% FEV1-->Exertional dyspnea
20% FEV1-->Dyspnea at rest |
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Physical Exam Findings for OCPD
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Lung Sounds:
Coarse rhonci or wheezes on forced expiration Prolonged expiration Hyperinflation: Inc'd AP diameter Inspiratory retraction of lower libs Distant heart and breath sounds Cor Pulmonale and Pulm Htn (enlarged liver, JVD) |
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X-ray findings in COPD
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X-ray findings are not diagnostic!
Can count over 8 ribs-->hyperinflation Flattened diaphragm |
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GOLD Guidelines for Severity of COPD
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Note: COPD defined as FEV1/FVC < 70%
Mild I: FEV1/FVC<70% Mod: 50-80% Sev: 30-50% V Sev: <30% |
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When is ABG warranted in patients with COPD?
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In moderate and severe disease; significant changes not seen until FEV1<1L
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What is a COPD exacerbation?
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Event in natural course of dz characterized by change in pt's baseline dyspnea, cough and/or sputum beyond day-to-day variability sufficient to warrant change in management.
Pts report increase use of rapid-acting bronchodilator. Only patient can determine an exacerbation! |
