Pathoma - Pulmonary HTN, Respiratory distress syndromes, Pleura

Question 1

What is the normal mean pulmonary arterial pressure vs. definitive pulmonary HTN pressure

Answer 1

Normal: 10-14 mm Hg

Pulmonary HTN: >25 mm Hg

Question 2

What are the 3 charactistics of pulmonary HTN

Answer 2

Atherosclerosis of the pulmonary trunk

Smooth muscle hypertrophy of pulmonary arteries

Intimal fibrosis

Question 3

What is a plexiform lesion

Answer 3

Group of capillaries appearing together after long-standing pulmonary HTN - remodelled pulmonary arteries

Question 4

What population is primary pulmonary HTN most often seen in?

Answer 4

Young adult females

Question 5

What type of mutation and in what gene is often seen in hereditary pulmonary arterial HTN

Answer 5

Inactivating mutation in BMPR2 (normally inhibits vascular smooth muscle proliferation)

Question 6

Describe the pathogenesis + histology behind acute respiratory distress syndrome (ARDS)

Answer 6

Damage to the alveolar-capilary interface leads to leakage of protein-rick fluid into the air sacs

Leads to edema that combines with necrotic epithelial cells to form hyaline membranes in alveoli

Question 7

Describe the cause of hypoxemia in ARDS

Answer 7

Hyaline membrane leads to thickened diffusion barrier

Increases surface tension leads to collapse of air sacs

Question 8

What will you see on x-ray in ARDS

Answer 8

“White out”

Question 9

Which pneumocytes are damages in ARDS?

Answer 9

Type I and Type II

Question 10

What is the cause of neonatal respiratory distress syndrome

Answer 10

Inadequate surfactant levels

Question 11

What is the main component of surfactant?

Answer 11

Lecithin aka phosphatidylcholine

Question 12

What are the 3 associations with neonatal respiratory distress syndrome?

Answer 12

(1) Prematurity
(2) C-section
(3) Maternal diabetes

Question 13

What can you use to screen for lung maturity in utero?

Answer 13

Amniotic fluid lecithin to sphingomyelin ratio (L:S)

Ratio > 2 indicates adequate surfactant levels

Question 14

Why are C-sections associated with neonatal respiratory distress syndrome

Answer 14

Due to lack of stress-induced steroids, which usually increase surfactant levels

Question 15

Why is maternal diabetes associated with neonatal respiratory distress syndrome

Answer 15

Baby makes insulin in response to mom’s glucose

Insulin is an inhibitor of surfactant production

Question 16

What are some complications associated with neonatal respiratory distress syndrome

Answer 16

Persistance of patent ductus arteriosus

Necrotizing enterocolitis

Question 17

What are some risks of giving supplemental oxygen in neonatal respiratory distress syndrome

Answer 17

Free radical injury leading to:

• Blindness (retinal injury)
• Bronchopulmonary dysplasia

Question 18

What is the cause of spontaneous pneumothorax and how will the trachea appear on X-ray

Answer 18

Rupture of emphsematous bleb

Trachea shifted to side of collapse (because the part of the lung collapses)

Question 19

What is the cause of tension pneumothorax and how will the trachea appear on x-ray

Answer 19

Chest wall injury

Trachea will be pushed opposite to the site of injury

Question 20

What is cancer of lung pleura called?

Answer 20

mesothelioma

Question 21

What occupational exposure is associated with mesothelioma

Answer 21

Asbestos