SGA RESP CARDS Flashcards
A 56-year-old male with a 65-pack-per-year smoking history presents to his family physician for a checkup. He has not seen a doctor in 15 years. His vital signs are temperature of 98.7°F, respiratory rate of 16 breaths per minute, heart rate of 85 bpm, and blood pressure of 159/85 mm Hg. During the history, he relates that he has been coughing up thick yellow green material for about the last three years, on and off, but more frequently for at least half of the year. Physical examination reveals some ronchi, but no crackles. His fingernail beds are slightly blue, and a pulse oximeter reveals an oxygen saturation of 88%. Which of the following microscopic findings is most likely to be present in the lungs of this patient?
A. Bronchial smooth muscle hypertrophy with the proliferation of eosinophils
B. Leakage of protein-poor fluid into alveolar spaces
C. Dilation of air spaces with the destruction of alveolar walls
D. Hyperplasia of bronchial mucus secreting submucosal glands
E. Permanent bronchial dilation caused by chronic infection with bronchi filled with mucus and neutrophils
D. Hyperplasia of bronchial mucus secreting submucosal gland
Image
Which of the following is the best pathologic index of the severity of the disease in the image shown?
Chronic Bronchitis
BC/AD
How do we assess Reid Index?
it is the ratio of the thickness of the mucous gland layer to the thickness of the wall between the epithelium and cartilage
Diagnostic Features
Bronchial smooth muscle hypertrophy with the proliferation of eosinophils
Bronchial Asthma
Diagnostic Feature
Leakage of protein-poor fluid into alveolar spaces
Acute Left Ventricular failure
Diagnostic Feature
Dilation of air spaces with the destruction of alveolar walls-
Emphysema
Permanent bronchial dilation caused by chronic infection with bronchi filled with mucus and neutrophils
Bronchiectasis
Another patient of COPD was admitted to the hospital with an acute pulmonary exacerbation. When given 100% oxygen to breathe, his arterial Pco2 increased from 50 to 80 mm Hg. Explain the pathophysiology of this rise in Pco2.
When oxygen is administered, there is a rise in the PaCO2, which can lead to a dangerous hypercapnia. There are 3 basic causes:
1. V/Q mismatching: the administration of O2 decreases the vasoconstriction associated with the usual COPD-induced hypoxia.
2. Haldane effect: the administered O2 displaces the CO2 bound to hemoglobin, increasing the free CO2.
3. Decreased ventilation: this is only of minor importance and loss of hypoxic drive is mostly transient over 10-15 minutes.
Which of the following pulmonary function test remains normal in this patient with Chronic Bronchitis?
A. Residual volume
B. Diffusing capacity
C. Total lung capacity
D. Peak expiratory flow rate
E. Functional residual capacity
Ans: B. DLCO remains normal in chronic bronchitis as this is a disease of bronchi and does not affect the alveolar surface as the diffusion properties of the alveolar membrane depend on its thickness and area . A, C, E are increased in chronic bronchitis but D is decreased.
Explain the molecular mechanism of albuterol in the treatment of COPD.
Human bronchial smooth muscle contains large numbers of β2 adrenergic receptors stimulation of β2-adrenoceptorGs Activation of adenylyl cyclase [AC] increase cyclic AMP activation of protein kinase A [PKA] PKA phosphorylates a variety of target substrates opening of calcium activated potassium channels Hyperpolarization and other non-cyclic AMP mechanisms relaxation of airway smooth muscle.
Also, there are β2 receptors on other pertinent cell types including mast cells, eosinophils, and lymphocytes; stimulation of these receptors tends to inhibit the release of these mediators
What is the mechanism of action of tiotropium/ipratropium?
Ans. Tiotropium Blocks the M3 receptors of bronchial smooth muscle Decreases Gq activation Inhibits IP3 -induced calcium release prevents the formation of calcium and calmodulin complex inhibits myosin light chain kinase activity Decrease myosin phosphate formation Prevents bronchial smooth muscle contraction
Why is tiopropium/ipratropium preferred over other anticholinergics?
Ipratropium and tiotropium are muscarinic receptor antagonists. Ipratropium is the isopropyl derivative of atropine. The addition of the isopropyl group results in a quaternary ammonium compound that is not well absorbed into the circulation. Tiotropium is a synthetic quaternary ammonium compound. Both drugs are administered by oral inhalation for pulmonary disease and produce very few systemic side effects
What is the diagnosis?
A 58-year-old man with a 60-pack-year history of smoking comes to the clinic because of worsening dyspnea. On examination , he is a thin man with scattered musical sounds heard on auscultation and a prolonged expiratory phase. Spirometry performed in clinic shows flow–volume loop depicted in the figure below. The blue dots show the predicted values. Which of the following explains the pathophysiologic mechanism of shape of flow volume loop?
A. Fibrosis of the lung parenchyma
B. Increased radial traction on the airways
C. Increased elastic recoil
D. Increased airway secretions
E. Increased number of pneumocytes
Correct D. **The flow–volume loop has a “scooped out” appearance often seen in patients with airflow obstruction as seen in COPD and bronchial asthma (at the time of attack). Of the items on the list of choices, increased airway secretions is the one that could cause airflow obstruction by increasing airway resistance. **
Incorrect:
A. Fibrosis of the lung parenchyma and (C) increased elastic recoil as seen in pulmonary fibrosis would be associated with increased or normal flows but decreased total lung capacity.
B. Increased radial traction on the airways (feature of interstitial lung diseases) would improve rather than limit airflow.
E. The increased number of type II pneumocytes are observed in idiopathic pulmonary fibrosis and flow volume loop will show restrictive pattern
