Chronic Bronchitis

Question 1

chronic bronchitis

Answer 1

inflmtn and obstruction of airway

Question 2

what characteristic of chronic bronchitis makes it chronic and not acute?

Answer 2

persistent coughing for 3 months over 2 consecutive years

Question 3

bronchitis

Answer 3

• inflamed airway

- can be acute or chronic

Question 4

what must you have to make a dx?

Answer 4

productive cough

Question 5

etiology

Answer 5

• d/t smoking and recurring infections

Question 6

how do recurring infections cause chronic bronchitis?

Answer 6

microbes get trapped in mucus and mucus can’t be expectorated -> bacteria proliferates b/c environment is warm, nutritive and moist -> increased inflmtn and damage

Question 7

histologic changes

Answer 7

• occurs in large airways first (terminal part of trachea and bronchi)
• affects small airways after
• obstr of a/w causing inhalation and exhalation issues -> inflmtn and fibrosis

Question 8

what histologic changes occur in the large airways?

Answer 8

smoking -> hypersecretion of mucus -> w/in submucosa, enlargement of secretory glands occurs -> hypertrophy, which if persistent can cause a/w obstr

Question 9

what histologic changes occur in the small airways?

Answer 9

increase in # of goblet cells -> increased mucus prod -> obstr -> hyperplasia

Question 10

patho

Answer 10

i. hypersecretion of mucus overwhelms mucociliary blanket
ii. infection occurs easily and is injurious; induces inflmtn in wall of a/w
iii. swelling and space-occupying lesion in lumen = obstr
iv. air becomes trapped distal to collapse
v. decreased alveolar ventilation
vi. ventilation:perfusion imbalance
vii. hypoxemia and hypoxia

Question 11

explain why the alveolar and a/w collapses and how this affects gas exchange

Answer 11

• @ alveolar level, alveoli filled w/ air will perform gas exchange w/ pulm capillaries and gas will diffuse into capillaries
• this leaves alveoli empty, but w/ obstr no more air can enter -> a/w collapses + alveolar collapses
• less SA for gas exchange and decreased alveolar ventilation

Question 12

explain why there is decreased alveolar ventilation

Answer 12

poor gas exchange is a result of decreased air supply to gas exchange surfaces d/t an obstr

Question 13

explain the ventilation perfusion imbalance

Answer 13

• ventilation : perfusion ratio -> for proper gas exchange, alveoli must fill w/ O2 and blood supply must be sufficient in pulm capillaries
• if either of these requirements (air or blood) are off, then ratio will not be w/in normal range

Question 14

explain how hypoxemia and hypoxia can occur

Answer 14

w/o adequate air and blood supply, hypoxemia occurs (decreased 02 in arterial blood) which can lead to hypoxia (decreased O2 in tissues)

Question 15

ventilation:perfusion

Answer 15

• on average, 4.2L of air is breathed in/out/min, while 5.5L of blood is pumped through the circuit/min
• V = 4.2L/min and P = 5.5L/min
• 4.2 : 5.5 = 4.2/5.5 = 0.8 (normal v:p)
• just b/c ratio is 0.8 does NOT mean that gas exchange is normal! it could mean a decrease in air and blood supply = imbalance