Term
| How is the clinical diagnosis of COPD made? |
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Definition
| Symptom matching. Chronic cough + sputum. Pathological diagnosis cannot be made without dissecting the lung. (which can't be done while the pt is living) |
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Term
| What is emphysema? (general description) |
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Definition
| Dilation and destruction of airspaces distal to the terminal bronchioles. |
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Term
| How does continued smoking further complicate COPD? |
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Definition
| In COPD the lung tissues is already inflamed, and has excess mucus. Smoking causes the lung to produce even more mucus in an attempt to clean the smoking byproducts out of the lung. |
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Term
| What is it about inflammation that aids destruction of the airways? |
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Definition
| Neutrophils and eosinophils release elastases, which degrade the elastic fibers and proteases within the lung. When this happens chronically, the fibers that hold airways open weaken, and proteases degrade the protein which decrease structural stability leading to floppiness of alveolar walls. |
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Term
| How does a narrow airway directly relate to ease of breathing? |
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Definition
| The narrower the airway, the more resistance to air movement there is, making it hard to inhale as well as exhale. |
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Term
| Explain the effects of emphysema, including the effect of elasticity, positive pressure, and the end effect on the alveoli. |
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Definition
| Air can't get out of the lung because the weakened, de-elastized airways get forced shut by the positive pressure created at expiration. The alveoli can never fully empty, and slowly keep filling up and up and up, and eventually they burst. |
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Term
| How, specifically, does emphysema create a V/Q mismatch? |
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Definition
| Gas exchange surface is decreased (because of bursting alveoli). |
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Term
| What is the most debilitating part of COPD? |
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Definition
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Term
| How do pO2, pCo2 and SOB relate? |
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Definition
| They don't. SOB occurs independently of ABGs. |
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Term
| What happens to the resting lung volume of the COPD pt over time? |
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Definition
| It increases b/c they can't expire all of the air they inhale. |
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Term
| What happens to the compliance of the lung tissue in COPD pts? Why? |
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Definition
| It decreases because there is an increased resting volume. The more volume there is in the lung the harder it is to get in more air. |
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Term
| The respiratory muscles must work harder in the COPD pt. Why? |
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Definition
| to overcome the decreased lung compliance. |
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Term
| How does decreased lung compliance result in an increased oxygen demand? |
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Definition
| It requires the respiratory muscles, both inspiratory and expiratory, as well as the accessory muscles to work harder. Working muscles require more oxygen. |
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Term
| The dome shaped diaphragm is necessary to maintain two functions. What are they? |
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Definition
| Proper angle of pull on the ribs, and expansion into the zone of apposition. |
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Term
| How does increased resting volume affect the functioning of the diaphragm? |
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Definition
| It flattens the diaphragm by pushing it down, which makes it much less efficient. It becomes a less effective force generator. The respiratory muscles are functionally weakened. |
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Term
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Definition
| The force load generated by the muscles at the end of expiration to stop the alveolus from collapsing and forcing all of the air out with recoil pressure, and create enough negative pressure to create the next breath. |
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Term
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Definition
| sense of shortness of breath (SOB) |
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Term
| How does COPD result in a downward spiral of decreased physical activity and deconditioning? |
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Definition
| Increased activity results in an increased ventilatory drive - the body wants you to breathe more. In the COPD pt this results in dyspnea, which is very scary. They become afraid of dyspnea, and avoid that feeling of SOB by avoiding activity. Decreased activity leads to decreased conditioning, which leads to decreased function of the lung. |
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Term
| How does COPD affect quality of life? |
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Definition
| Negatively. Decoditioning and dyspnea result in decreased exercise tolerance, decreased tolerance for ADLs which greatly affects quality of life, and the pts often end up with depression. |
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Term
| Define Transmural Pressure. |
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Definition
| The pressure across the airway wall. (Inside pressure - outside pressure) |
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Term
| See the Dynamic Airway Compression in Health and Disease handout for 9/13 for diagrams and more info re: transmural pressures and its effect on exhalation in the COPD pt. |
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Definition
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Term
| What are the signs and symptoms of COPD? (9) |
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Definition
Hypercapnia (too much CO2)
Hypoxemia (too little O2)
Abnormal Breath Sounds
Increased Respiratory Rate
Peripheral Edema
Cyanosis
Accessory muscles use/hypertrophy
Lower Respiratory Tract infections |
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Term
| What causes frequent LRT infections in COPD pts? What is the Txs (3)? |
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Definition
| Retained secretions, compromised immune response. Tx is airway clearance, antibiotics, and optimized nutrition. |
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Term
| Why does COPD result in abnormal breath sounds? What is the Tx? |
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Definition
| Airway obstruction, atelectasis, retained secretions. Tx = none. |
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Term
| What causes increased respiratory rate in COPD pts? |
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Definition
| Increased ventilatory demand -> decreased O2, Increased CO2, decreased dynamic lung compliance. |
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Term
| How does COPD cause peripheral edema? |
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Definition
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Term
| What causes accessory muscle use/hypertrophy in COPD pts? What can be done for Tx? (7) |
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Definition
| Increased ventilatory demand, diaphragm weakness/decreased endurance. Tx: Improve respiratory muscle function by improving mechanical efficiency, strength and endurance of the muscles, optimize nutrition and oxygenation, decrease airway obstruction, rest, surgery, reduce infections, correct metabolic disturbance. |
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