Small Group 5 Obstructive Diseases

Question 1

Alpha-1 antitrypsin concentration that is severely reduced leads to what disease?

Answer 1

emphysema

Question 2

Pulsus paradoxus is associated with which obstructive disease?

Answer 2

asthma; asthma when serious acute attacks occur present over a long period of time with intercostal retractions, low diaphragms, prolonged expiratory phase– barrel chested

Question 3

Which lab test key in differentiating asthma from other inflammatory obstructive disorders?

Answer 3

CBC will show elevated eosinophils, also increase in respiratory capacities with use of albuterol; DLCO should be normal

Question 4

What is the major distinguishing signs of chronic bronchitis?

Answer 4

usual history of smoking
significant sputum production
paradoxical pulmonary vasoconstriction
high hematocrit (compensatory)

Question 5

What organisms are likely to be found in the sputum of a patient with cystic fibrosis.

Answer 5

Staphylococcus aureus

Pseudomonas aeruginosa

Question 6

Airflow obstruction in pure emphysema is due to what two causes?

Answer 6

loss of driving pressure at the alveolus from loss of elastic recoil
loss of elastic fibers which normally tend to tether the airways open

Question 7

Would you expect a change in DLCO in an patent with emphysema?

Answer 7

yes, a decrease because of the destruction of the capillary bed and reduction in the alveolar-capillary membrane

Question 8

What would you expect concerning CO2 levels in a patient with moderate asthma v. very severe asthma exacerbation.

Answer 8

low CO2 due to hyperventilation in moderate cases but normal or rising CO2 levels signal respiratory decompensation

Question 9

A patient with chronic bronchitis is given oxygen on admission to the hospital, his pulsox improves but his PaCO2 continues to climb, why?

Answer 9

chronic hypoxemia has “reset” the ventilatory rate of this patient, even with removal of the hypoxia, the tidal volume decreases and Vd/Vt increases, leading to increased PaCO2 and reparatory acidosis

due to increase in dead space and lack of compensatory change in minute ventilation

Question 10

Why is heart failure more likely in the theoretical “blue bloater?”

Answer 10

heart failure occurs due to pulmonary HTN as a result of chronic hypoxic-pulmonary vasoconstriction; most likely in the blue bloater due to concomitant obstructive sleep apnea and nocturnal worsening of hypoxemia

Question 11

What is the the cause of gas exchange abnormality in a patient with cystic fibrosis?

Answer 11

ventilation perfusion mismatch plays an important role in causing hypoxemia in cystic fibrosis

infection can lead to increased airway secretions, airway obstruction, atelectasis and bronchopneumonia