Week 3

Question 1

Question: Which of these is true about asthma?

1. Patients will have an increased FEV1/FVC ratio
2. Diffusing capacity is increased in patients with asthma
3. Methacholine administration improves the expiratory airflow obstruction in asthmatics, which distinguishes them from those with COPD
4. Common pulmonary function test findings in asthma include a flattened inspiratory loop

Answer 1

Answer: B is correct.

Others – FEV1/FVC ratio is decreased in asthma (A); bronchodilators improve airflow obstruction in asthmatics (methacholine is used for bronchoprovocation testing) (C).

Learning Objective: SM 176a (Explain the pathophysiology of asthma)

Question 2

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Question: Which of these is true about the TST and the IGRA tests?

1. IGRAs do not have a false-positive reaction in those with prior BCG vaccination, while TSTs do
2. In the TST, the transverse diameter of the erythema of the DTH skin reaction response is measured
3. The main advantage of the IGRAs over the TST is that they can differentiate between latent and active TB
4. The main advantage of the TST is that it does not require return visits to the physician

Answer 2

Answer: A is correct

Others- B) In the TST, the transverse diameter of the induration (not the erythema) of the DTH skin reaction response is measured. C) Neither the TST nor IGRAs can differentiate between latent and active TB ) The TST does require return to the physician after 48-72 hours to measure the diameter of the DTH reaction.

Learning Objective: SM 182a (Explain the advantages and disadvantages of the PPD-TB skin test (TST) and the IGRA tests)

Question 3

Question: Which of these sums of volumes/capacities is the largest?

1. RV + IRV
2. FRC + TV
3. TV + IRV + ERV
4. RV + ERV
5. FRC + IC

Answer 3

Answer: Choice 5 is correct – functional residual capacity + inspiratory capacity = total lung capacity

A. FRC (functional residual capacity) = resting lung volume, the volume in the lung at the end of a quiet tidal breath. It is determined by the inward elastic recoil of lung and the outward elastic recoil of the chest wall.

B. IC (inspiratory capacity) = TLC - FRC

C. TLC (total lung capacity) = the amount of air present within the lungs when they are maximally inflated

D. RV (residual volume) = the amount of air present within the lungs when they are maximally deflated

E. ERV (expiratory reserve volume) = FRC - RV

F. IRV (inspiratory reserve volume) = IC - TV

G. TV (tidal volume) = amount of air inspired during a quiet breath

Learning Objective: SM 174a (Define the main lung volumes and capacities: TLC, FRC, RV, FVC, FEV1)

Question 4

Question: Which of these is true about the influenza virus?

1. The H antigen helps the virus bind to cells, while the N antigen helps the virus replicate within the cell
2. Changes in the H and N antigenic types (such H1N1 to H2N1) of the virus are examples of antigenic drift
3. Flu epidemics are usually caused by type A or type B
4. It is a double-stranded DNA virus

Answer 4

Answer: C is correct

The H antigen helps the virus bind to cells, while the N antigen helps the mature virus escape from within the cell (A); Changes in the H and N antigenic types (such H1N1 to H2N1) of the virus are examples of antigenic shift (B); It is a single stranded RNA virus

Learning Objective: SM 179a (Describe the pathogenesis and epidemiology associated with viral respiratory pathogens)

Question 5

Question:

1. What are the 3 anatomic variants of emphysema and their etiologies?
2. What is the Reid index and how is it used in the diagnosis of chronic bronchitis?

Answer 5

Answer:

1. Emphysema anatomic variants
   
   1. Centriacinar = related to smoking, most common
   2. Pan-acinar = related to A1AT deficiency
   3. Distal acinar = sporadic cases related to pre-existing lung scarring
2. Reid index = ratio of submucosal gland size to the distance from the epithelium surface to the bronchial cartilage
   
   1. Reid index > 0.4 is consistent with chronic bronchitis

Learning Objective: SM 167a (Explain the pathology and pathogenesis of COPD, including emphysema and chronic bronchitis.)

Question 6

Question: Fill in the following blanks:

COPD causes inspiratory/expiratory airflow obstruction via 3 mechanisms.

One of these mechanisms is alveolar destruction resulting in increased/decreased elastic recoil

The airflow obstruction in COPD is marked by a low/high FEV1/FVC ratio, and this ratio does/does not return to normal after administration of a bronchodilator

Patients with the PiMM/PiMZ/PiZZ alleles of the alpha-1-antitrypsin gene are at an increased risk of COPD

How does alpha-1 antitrypsin deficiency cause COPD?

Answer 6

Answer:

COPD causes expiratory airflow obstruction via 3 mechanisms

One of these mechanisms is alveolar destruction resulting in /decreased elastic recoil

The airflow obstruction in COPD is marked by a low FEV1/FVC ratio, and this ratio does not return to normal after administration of a bronchodilator (in asthma, this ratio does return to normal after a bronchodilator)

Patients with the PiZZ and PiMZ alleles of the alpha-1-antitrypsin gene are at an increased risk of COPD

• ~90% of severely deficient patients are homozygous for Z allele = PiZZ
• Normal phenotype = PiMM
• PiMZ is at an increased risk compared with the normal phenotype, especially in smokers
• PiSZ, Pi null-null, Pi null-Z are also deficient

Alpha-one antitrypsin is a protective antiprotease; when it is deficient, there is an imbalance between harmful proteases and protective anti-proteases, resulting in lung damage

Learning Objective: SM 177a (Describe the development of COPD)

Question 7

Question:

Match the following flow-volume loops with the following disease states

1. Normal lung flow volume loop
2. Vocal cord paralysis
3. Pulmonary fibrosis
4. Chronic bronchitis

Answer 7

Answer:

1. Normal lung flow volume loop = 2
2. Vocal cord paralysis = 4
3. Pulmonary fibrosis = 1
4. Chronic bronchitis = 3

Learning Objective: SM 175a (Draw a flow-volume loop and volume-time curve that demonstrates 1) lower airway obstruction, 2) a restrictive defect and 3) upper airway obstruction)

Question 8

Question:

1. What type of compensation is there in metabolic acidosis?
2. How can you determine if there is appropriate compensation occurring?
3. What is measured in each segment of the electrolyte tree (as shown in SM 173a lecture/LG)?
4. How is the anion gap calculated and what values are normal?
5. What are examples of conditions that cause anion gap vs non-AG metabolic acidosis?

Answer 8

1. What type of compensation is there in metabolic acidosis?
   
   1. Respiratory compensation: increased ventilation to blow off CO₂ and elevate pH
2. How can you determine if there is appropriate compensation occurring?
   
   1. Winter’s formula: expected PaCO­₂ = 1.5 x bicarbonate + 8 +/- 2
   2. Compare expected PaCO­₂ from Winter’s formula to actual PaCO­₂ to see if there is appropriate compensation
3. What is measured in each segment of the electrolyte tree (as shown in SM 173a lecture/LG)? (picture is attached)
4. How is the anion gap calculated and what values are normal?
   
   1. Normal AG = Na – Cl – HCO₃ = 10 meq/L +/- 2
5. What are examples of conditions that cause anion gap vs non-AG metabolic acidosis?
   
   1. Elevated AG metabolic acidosis (MUDPILES)
      
      • Methanol, Uremia, Diabetic ketoacidosis/KA from something else, Propylene glycol, Isoniazid, Lactic acidosis, Ethylene glycol, Salicylates
   2. Non-elevated AG metabolic acidosis (USED CARS)
      
      • Uretero-enterostomy, Saline, Endocrine (adrenal insufficiency), Diarrhea, Carbonic anhydrase inhibitors (acetazolamide), Ammonium chloride, Renal tubular acidosis, Spironolactone

Learning Objective: SM 173a (Describe the relationship between PaCO₂, serum bicarbonate and pH in simple and mixed acid base disorders: acute and chronic respiratory alkalosis and acidosis, and metabolic acidosis and alkalosis. Describe respiratory and metabolic compensation. Calculate the anion gap and explain its importance in acid base disturbances)

Question 9

What are the 3 components of Light’s Criteria?

An effusion is classified as exudative if it meets ___ out of 3 parts of Light’s Criteria

______ effusions occur when the pleural membrane is inflamed and leaky, permitting protein-rich fluid to cross

______ effusions occur when changes in hydrostatic forces cause increased fluid movement across a norma pleural membrane

Answer 9

Lights Criteria: An effusion is classified as an exudate if it meets ANY of the following criteria:

1. Pleural fluid total protein/serum total protein >0.5
2. Pleural fluid lactate dehydrogenase (LDH)/serum LDH > 0.6
3. Pleural fluid LDH > 2/3 of the upper normal value of serum LDH

An effusion is classified as exudative if it meets 1 out of 3 parts of Light’s Criteria

Exudative effusions occur when the pleural membrane is inflamed and leaky, permitting protein-rich fluid to cross

Transudative effusions occur when changes in hydrostatic forces cause increased fluid movement across a norma pleural membrane

Learning Objective: SM 172a (Distinguish between an exudate and transudate using Light’s criteria and know the causes of transudative effusions)

Question 10

Question: What endemic fungi matches with the following features?

• Dimorphic: exist as a spherule or mycelium
• Dimorphic: exist as a yeast or mycelium
• Most common site of dissemination is the skin
• Complications include mediastinal lymphadenitis and fibrosis
• Common in the Southwestern US
• Common in the Mississippi and Ohio River basins and Great Lakes regions
• Common in the Ohio and Mississippi River valleys

Answer 10

Answer:

• Dimorphic: exist as a spherule or mycelium = Coccidioides
• Dimorphic: exist as a yeast or mycelium = Histoplasma, Blastomyces
• Most common site of dissemination is the skin = Coccidioides
• Complications include mediastinal lymphadenitis and fibrosis = Histoplasma
• Common in the Southwestern US = Coccidioides
• Common in the Mississippi and Ohio River basins and Great Lakes regions = Blastomyces
• Common in the Ohio and Mississippi River valleys = Histoplasma

Learning Objective: SM 178a (. Describe the pathophysiology of fungal pneumonia; Identify the pathogens responsible for endemic fungal pneumonia and describe their geographic range)

Question 11

Question: Which of these describes a respiratory pathogen that can cause otitis media?

1. Gram-positive cocci that is also the leading cause of hospital-acquired pneumonia
2. Gram-positive, club-shaped bacillus
3. Obligate intracellular bacteria, related to the gram-negative bacteria that cause psittacosis
4. Gram-positive, lancet-shaped pathogen that’s the most common bacterial cause of community-acquired pneumonia

Answer 11

Answer: D is correct

1. Gram-positive cocci that is also the leading cause of hospital-acquired pneumonia (Staphylococcus aureus)
2. Gram-positive, club-shaped bacillus (Corynebacterium diphtheria)
3. Obligate intracellular bacteria, related to the gram-negative bacteria that cause psittacosis (Chlamydia pneumoniae)
4. Gram-positive, lancet-shaped pathogen that’s the most common bacterial cause of community-acquired pneumonia (Streptococcus pneumoniae)

Otitis Media is caused by: Streptococcus pneumoniae, Haemophilus influenzae, S. pyogenes, Moraxella catarrhalis

Gram positive lancet shaped diplococci, gram negative coccobacilli, gram positive cocci, gram negative aerobic diplococci

Learning Objective: SM 181a (You should have an understanding of the disease manifestations caused by bacteria that cause respiratory infections as well as tests and therapies used to diagnose and treat them.)

Question 12

Question: Match each of the following with its predominant pathologic finding:

1. Acute bacterial pneumonia
2. Acute lung injury
3. Infectious granuloma
4. Viral pneumonia

• Increased lymphocytes and plasma cells (lymphoid infiltrates) involving the alveolar septae and interstitium
• Intraalveolar dense pink hyaline membranes + increased inflammatory cells (diffuse alveolar damage)
• Neutrophils and hyaline membranes within the alveolar spaces
• Epithelioid histiocytes in a ball with pink cytoplasm and unclear cell borders

Answer 12

Answer:

1. Acute bacterial pneumonia = Neutrophils and hyaline membranes within the alveolar spaces
2. Acute lung injury = Intraalveolar dense pink hyaline membranes + increased inflammatory cells (diffuse alveolar damage)
3. Infectious granuloma = Epithelioid histiocytes in a ball with pink cytoplasm and unclear cell borders
4. Viral pneumonia = Increased lymphocytes and plasma cells (lymphoid infiltrates) involving the alveolar septae and interstitium

Learning Objective: SM 167a (Acute Lung Injury/Infectious Lung Disease) (Describe the pathology and differential diagnosis for granulomatous lung disease. Explain the pathophysiology and pathology of acute lung inj)