Clinical Obstructive Lung Disease: COPD/Asthma/CF Flashcards
What are the two major causes of airflow obstruction?
- Intrinsic airway narrowing
- Bronchospasm, plugging, inflammation/edema
- “Floppy” airways
- Decreased radial tethering or decreased integrity
To what degree is airway resistance inversely proportional to the radius of an airway?
Aiway resistance is inversely proportional to the _fourth powe_r of the radius of the airway
- Resistance changes dramatically with samll changes in diameter
How does airflow obstruction increase lung volumes?
- Incomplete emptying of alveoli
- Breaths begin to stack up on each other
What is a common CXR finding of obstructive lung disease? ( as it regards to the diaphram?)
Flat and rounded diaphram
Why is a flat and rounded diaphram problematic?
Diaphrams are normaly rounded, and become flatter as they go down (and you breath in).
- If it’s already flat at the beginining of your breath, then there becomes no mech advantage to breath in so you begin to use accessory muscles
Asthma
- What is Asthma?
- What are common symptoms?
- Is asthma obstructive or restrictive?
- Is asthma reversible?
- Is the DLCO normal, elevated or decreased?
- Chronic inflammatory disorder of the airways
- Recureent episodes of wheezing, breathlessness, chest tightness, coughing particularly at night or during day
- Obstructive
- Reversible with treatment and/or spontaneously
- Normal to increased DLCO
What are the two types of asthma? Describe each
- Extrinsic - allergic
- Response to environmental antigens
- IgE mediated mostly
- Intrinsic - nonseasonal, non allergic form
- Chronic & persistent
- Post-viral - epithelial injury leads to bronchial narrowing
- Altered arachidonic acid metabolites - > incr leukotrienes, decreased prostaglandins (e.g. aspirin)
T/F: Asthma can be exacerbated by cold air?
True
T/F: In an asthma patient you will hear inspiratory stridor on physical exam?
- False - obstructive diseases have issues with expiration (wheezing) not inspiration
What test can you use to check for Asthma?
Methylcoline challege
T/F: Patients often use accessory muscles during an asthma attack?
True
Describe the PV curve of as acute asthma attack versus normal
Follows the same curve as the normal but is shifted up
What is the physical exam finding that differentiates Asthma from Vocal Cord Dysfunction (VCD)?
INSPIRATORY STRIDOR
What is Vocal Cord Dysfunction?
VCD: Inappropriate vocal cord motion results in airflow obstruction
- Symptoms mimic asthma
COPD
- What is the broad definition, and what two diseases fall under this diagnosis?
- What do the FEV1/FVC ratio have to be, in COPD?
- What is the biggest risk factor for COPD?
- COPD is defined by fixed airflow obstruction
- Emphysema & Chronic Bronchitis
- FEV1/FVC < 70%
- Tobacco users
Chronic Bronchitis
- What is the clinical criterion to make this diagnosis?
- Describe the pathophysiology of it
- Productive cough at least 3 months over the past 2 yrs w/o other cause
- Increased airway resisitance due to changes in airway structure
- edema, mucus, fibrosis
- May have overlapping features w/ asthma
Emphysema
- What is Emphysema?
- Is compliance of the lung in emphysema more or less than normal?
- Does this make it more or less stretchy
- What is the only gene that we know is a risk factor for emphysema?
- Loss of normal alveolar spaces with enlargement of distal spaces resulting in impaired gas exchange
- Increased compliance of the lung
- More stretchy due to decreased elastic tissue
- Alpha-1-antitrypsin deficiency
- causes a loss of balance between proteases and antiproteases
Emphysema causes permanent ____ of the distal airspaces (acini)
Enlargement
Multiple Choice
Alpha-1-antitrypsisn deficiency in emphysema patients leads to which of the following?
a) pan-acinar enlargement
b) centri-acinar enlargment
Answer: Pan-acinar enlargement
- Pan acinar involves the entire acinus, typically seen in older patients and those with A1AT deficiency
- Centri-acinar is smoking related and incolves only the respiratory bronchioles
What does the P-V curve of an emphysema patient look like?
See attached - but take away point is the slope is steepened and the curve is shifted upwards
Clinical Vignette: You have a patient with diminished breath sounds, and hyperresonance on percussion.
What does this patient have based soley on these findings?
Emphysema
*Note: Common exam findins in patients with both emphysema and chronic bronchitis includes
- Prolonged expiratory phase
- Pursed-lip breathing
Clinical Vignette: You have a patient who has exam findings including a productive cough, rhonchi and wheezing on ausculatation.
What does this patient most likely have based only on these findings?
Chronic Bornchitis
*Note: Common exam findins in patients with both emphysema and chronic bronchitis includes
- Prolonged expiratory phase
- Pursed-lip breathing
What are common symptoms of COPD exacerbation?
- Increased cough
- Increased wheezing
- Worsening obstruction on PFT
- Unchanged CXR
- Precipitated by infxn, pollution, PE
How does COPD lead to death?
- Respiratory failure
- Right ventricular failure
- Pneumonia
- Spontaneous pneumothorax
- Pulm Embolism
Emphysema
- Is there marked hyperinflation or _hypo_inflation?
- Are the symptoms reversible w/ bronchodialators?
- Is the DLCO normal, increased or decreased?
- Marked hyperinflation
- No reversibility to bronchodialators
- Decreased DLCO
