Pulmonary Hypertension & RDS - Pathoma

Question 1

What is the normal pressure in the pulmonary circuit?

Answer 1

about 10 mmHg

Question 2

What elevated pressure defines pulmonary hypertension?

Answer 2

> 25 mmHg

Question 3

What pathologic changes characterize pulmonary hypertension?

Answer 3

• Atherosclerosis of pulmonary trunk
• Smooth muscle hypertrophy of pulmonary arteries
• Intimal fibrosis
• **Plexiform lesions are seen with severe, long-standing disease (tuft of capillaries that arise together)

Question 4

What cardiac condition does pulmonary hypertension lead to?

Answer 4

Right ventricular hypertrophy & cor pulmonale

Question 5

How do patients with pulmonary hypertension present?

Answer 5

Exertional dyspnea or right-sided heart failure

Question 6

What is the etiology of primary pulmonary hypertension?

Answer 6

Primary: Unknown

• classically seen in young adult females
• familial forms are related to inactivating mutations of ***BMPR2 (leads to excess proliferation of vascular smooth muscle => thickening)

Question 7

What is the etiology of secodary pulmonary hypertension?

Answer 7

1) HYPOXEMIA
- e.g. COPD and interstitial lung disease
2) Increased volume in pulmonary circuit.
- e.g. congenital heart disease
3) May also arise with recurrent pulmonary embolism (with recannalization)

Question 8

What is ARDS?

Answer 8

Acute Respiratory Distress Syndrome:

• diffuse damage to alveolar-capillary interface (diffuse alveolar damage)
• leakage of protein-rich fluid leads to edema and formation of hyaline membranes in alveoli

Question 9

What are the two problems with hyaline membrane deposition in ARDS?

Answer 9

1) Thickened diffusion barrier => not able to exchange gases well => HYPOXEMIA & CYANOSIS
2) Sticky hyaline membranes => increase surface tension of alveolar air sac => diffuse collapse of air sacs and lung

Question 10

What are the CXR findings in ARDS?

Answer 10

-Diffuse white out of the lung

Question 11

What are some of the etiologies of ARDS?

Answer 11

Sepsis, infection, shock, trauma, aspiration, pancreatitis, DIC, hypersensitivity reactions, drugs, etc., etc.!

Question 12

Pathologically what happens in ARDS?

Answer 12

Activation of neutrophils induces protease-mediated and free radical damage of type I and II pneumocytes

Question 13

What does the treatment of ARDS involve?

Answer 13

• Address underlying cause
• Ventilation with positive-end expiratory pressure (PEEP)
• **Recovery may be complicated by interstitial fibrosis => knocked out Type II pneumocytes)

Question 14

What does Neonatal Respiratory Distress Syndrome arise due to?

Answer 14

Inadequate surfactant levels.

Question 15

What are the key clinical features in Neonatal Respiratory Distress Syndrome?

Answer 15

• Increasing respiratory effort after birth
• Tachypnea with use of accessory muscles and grunting
• Hypoxemia and cyanosis
• Diffuse granularity of lung on x-ray

Question 16

What conditions is Neonatal Respiratory Distress Syndrome associated with?

Answer 16

• Prematurity; screen with lecithin to sphingomyelin ratio
• C-section delivery
• Maternal diabetes

Question 17

What are the importent potential complications in Neonatal Respiratory Distress Syndrome?

Answer 17

• Hypoxemia increases risk for persistence of patent ductus arteriosus and necrotizing enterocolitis
• Supplemental oxygen increases risk for free radical injury (get in blood and damage retinas => blindness, bronchopulmonary dysplasia)