9.6, 9.7 Pulm HTN, RDS

Question 1

Pulm HTN

-what would you see if you took autopsy

Answer 1

1. atherosclerosis of pulm trunk
2. smooth m hypertrophy in pulm arteries
3. plexiform lesions (capillary tufts) in longstanding disease

Question 2

secondary pulm HTN:

main causes (know all 3)

Answer 2

1. hypoxemia in lung disease (COPD, interstitial disease)
2. increase blood volume in pulmonary circulation (eg congential Eisenmengers, L sided heart failure)
3. recurrent pulm embolism (thickens vascular walls)

Question 2

What complications can happen when giving supplemental O2 to newborn with Neonatal Resp distress syndrome?

Answer 2

Free radical damage:

1. blindness
2. lung dysplasia

Question 3

ARDS

-clinical presentation

Answer 3

• hypoxemia, cyanosis, resp distress.
  1. thickened diffusion (hyaline membrane)
  2. collapsed alveoli (hyaline membrane)
• ‘white out’ on CXR

Question 4

ARDS

-what lung disease complicates ARDS recovery?

Answer 4

• interstitial fibrosis.
• this damages type II pneumocytes, which are the stem cells. So regeneration of damaged pneumocytes is impaired.

Question 5

what is major component of surfactant?

Answer 5

lecithin (aka phosphatidylcholine)

Question 6

Pulm HTN

-definition

Answer 6

>25mm Hg in pulmonary circuit

normal is 10mm Hg

Question 6

Neonatal Resp distress syndrome

-complications at birth (3)

Answer 6

1. hypoxemia at birth: prevent closure of PDA
2. necrotizing enterocolitis (low O2 to gut at birth)
3. Blindness, lung dysplasia–Free radical damage from supplemental O2 tx at birth

Question 7

surfactant production, fetal:

• what week starts
• what week is adequate level reached

Answer 7

1. begins 28 weeks
2. finishes 34 weeks

Question 9

ARDS

-mech of disease

Answer 9

• damage to alveolar-capililary interfaces causes leakage of protein-rich fluid into alveoli. this forms a hyaline membrane in alveolar wall.
• caused by activated neutrophils, which induce protease and free radical damage of pneumocytes (Type I and II)

Question 10

Pulm HTN:

3 highest yield points, according to Pathoma

Answer 10

1. BMPR2 inactivating mutations, cause vascular smooth m proliferation in primary pulm HTN
2. Plexiform lesions (tufts of capillaries) in Pulm HTN
3. atherosclerosis of pulm artery

Question 10

Neonatal Resp distress syndrome

-causes (3)

Answer 10

1. premature (
2. C-section. Steroids from stress required for surfactant production. Normal birth induces steroid production, but C section does not.
3. Maternal diabetes. Insulin decreases surfactant production, and fetus makes lots of insulin to mom’s sugar

Question 10

Maternal diabetes:

what to worry about in newborn?

Answer 10

• neonatal resp distress syndrome
• lack of surfactant production b/c insulin inhibits its production. fetus’s pancreas is making insulin to mom’s high sugar

Question 12

primary Pulm HTN:

• mech
• classic population

Answer 12

• young women
• etiology unknown, some genetic forms caused by BMPR2 inactivating mutations–cause vascular smooth m proliferation

Question 13

Neonatal Resp distress syndrome

-appearance on CXR

Answer 13

-diffuse granular appearance (‘ground glass’ appearance)

Question 14

ARDS

-tx

Answer 14

1. tx underlying cause
2. use PEEP (positive end-expiratory pressure) ventilation to keep alveoli open at end of expiration (prevent them from collapsing, which takes a lot of energy to reopen)

Question 16

ARDS

-what do you see on CXR

Answer 16

“white-out” on CXR

Question 17

C-section delivery:

-what happens to baby’s lungs?

Answer 17

• Neonatal Resp distress syndrome, possible
• lack of surfactant production b/c its production is induced by the stress of vaginal birth

Question 19

Type II pneumocytes

-2 important functions

Answer 19

1. stem cells
2. produce surfactant

Question 20

Young, health woman with exertional dyspnea:

-suspect what

Answer 20

primary Pulm HTN.

-etiology unknown, some inherited forms caused by BMPR2 inactivating mutations. cause proliferation of vascular smooth m

Question 21

fetus: what to measure if surfactant production is adequate?

Answer 21

• measure L:S ratio (lecithin: sphingomyelin) in amniotic fluid
• Lecithin (phosphatidylcholine) is main component of surfactant and will increase over time, while sphingomyelin remains constant
• L:S ratio >2 is adequate surfactant

Question 22

ARDS

-causes

Answer 22

• too many to list. Remember it results in activated neutrophils, which induce protease and free radical damage of type I, II pneumocytes.
• sepsis, infection, shock, trauma, aspiration, pancreatitis, DIC, HSR, drugs