Pathoma - Pulmonary HTN and RDS

Question 1

Normal pressure in the pulmonary circuit compared to what is considered high pressure

Answer 1

Normal is about 10mmHg

High pressure is > 25mmHg

Question 2

pulmonary HTN is characterized by what?

Answer 2

Atherosclerosis of the pulmonary trunk

Smooth muscle hypertrophy of pulmonary arteries

Intimal fibrosis

Plexiform lesions

Question 3

Pulmonary HTN leads to ______

Answer 3

Right ventricular hypertrophy/right sided heart failure

Question 4

Presentation of pulmonary HTN

Answer 4

Exertional dyspnea, especially in younger women

Question 5

Primary pulmonary HTN

Answer 5

Seen in young adult females unknown etiology

Question 6

Genetic correlation with primary pulmonary HTN

Answer 6

Familial forms are related to inactivating mutations of BMPR2, which leads to proliferation of vascular smooth muscle

Question 7

Secondary Pulmonary HTN is caused by what

Answer 7

Arises from hypoxemia (like in COPD and ILD) or increased volume in the pulmonary circuit (like in congenital heart disease)

May also arise with recurrent pulmonary embolism

Question 8

Acute Respiratory Distress Syndrome (ARDS)

Answer 8

Damage to alveolar capillary interface in the alveolar sacs leads to leaking of protein rich fluid that builds up a hyaline membrane diffusely in the lung.

Question 9

Histology of ARDS

Answer 9

Alveolar sacks with hyaline rings around the inside

Question 10

Problems with ARDS

Answer 10

1. Exchange barrier in alveolar sacs leads to cyanosis
2. Membranes are sticky, causing pressure on the sacs to collapse.

Overall: Hypoxemia and cyanosis with respiratory Distress

Question 11

CXR of ARDS

Answer 11

White out diffusely

Question 12

Cause of ARDS

Answer 12

Many.

Sepsis, infection, shock, car accident, pancreatitis, etc.

Activation of neutrophils induces protease mediated and FR damage of Type I and type II pneumocytes

Question 13

Treatment of ARDS

Answer 13

Addressss underlying cause…

Ventilation with positive and expiratory pressure (PEEP)

Recovery may be complicated by insterstitial fibrosis

Question 14

Why do we get fibrosis?

Answer 14

Problem with pneumocyte type II, which is the regeneration stem cell of the lung. Without this, you have to do repair instead of regeneration, leading to the interstitial fibrosis

Question 15

Neonatal respiratory distress syndrome

Answer 15

Respiratory distress due to inadequate surfactant levels

Question 16

____ pneumocytes produce surfactant which _____

Answer 16

Type II pneumocyte

Reduces surface tension of the lungs so the alveolar sacs don’t collapse

Question 17

Clinical features of neonatal respiratory distress syndrome

Answer 17

1. Increasing respiratory effort after birth, tachypnea with use of accessory muscles, and grunting
2. Hypoxemia with cyanosis
3. Diffuse granularity ofl ung on CXR

Question 18

Neonatal respiratory distress syndrome is associated with what 3 things?

Answer 18

1. Prematurity which we can screen with L:S (>2) ratio to screen for surfactant levels (Lethicin (AKA phosphatidylcholine) and sphingomyelin make surfactant)
2. C-section delivery
3. Maternal diabetes

Question 19

How is maternal diabetes related to neonatal respiratory distress syndrome?

Answer 19

Mom makes too much sugar and sends it to baby who has an ormal pancreas that dishes out insulin. The insulin breaks down surfactant

Question 20

Complications of neonatal respiratory distress syndrome

Answer 20

1. Hypoxemia - increases risk for persistence of patent ductus arteriosus and necrotizing enterocolitis
2. Supplemental oxygen increases risk for free radical injury

Question 21

Supplemental oxygen, which increases risk for free radical injury, can lead to what?

Answer 21

• Blindness

- Damage to lungs during earlyl ung development