Pulmonary Vascular Disease, Bronchial Asthma

What are the 4 Pulmonary Vascular diseases?

Pulmonary Vascular diseases:

PPCP

1. Pulmonary embolism

2. Pulmonary hypertension

3. Cor pulmonale

4. Pulmonary edema

What most commonly causes a pulmonary embolism?

Most common cause is a clot formed from deep venous thrombosis in the leg

What does pulmonary embolism cause?

V/Q mismatch

If the pulmonary embolism is not dissolved rapidly, what does it lead to?

It can lead to hypertension, resulting to right heart failure

What is Pulmonary hypertension?

Pulmonary hypertension is higher pulmonary artery pressure

What do most cases of Pulmonary hypertension develop as a result of?

Most cases develop as a serious complication of many acute and chronic pulmonary disorders such as COPD

What most commonly causes Pulmonary hypertension? (exposure)

Most common cause is continued exposure of pulmonary vessels to hypoxemia, which causes these vessels to constrict

What is Cor pulmonale?

Cor pulmonale is right heart failure in response to a respiratory disease or infection

What is Pulmonary edema?

Pulmonary edema is excess water in the lungs

What is the most common cause of Pulmonary edema?

Left heart failure is the most common cause of pulmonary edema

What happens when there is too much interstitial fluid for the lymph system to collect during Pulmonary edema?

Fluid eventually leaks into the alveoli

What does this fluid do to the respiratory membrane?

This fluid thickens the respiratory membrane, which is increased distance for gas diffusion

What does reduced oxygen diffusion rate lead to?

Reduced oxygen diffusion rate → hypoxemia

What causes Obstructive lung diseases? (exhalation)

Airway obstruction causes obstructive lung disease, which leads to problems with exhalation

What is Obstructive lung diseases unifying symptom?

Unifying symptom: Dyspnea

What is Obstructive lung diseases unifying sign?

Unifying sign: wheezing

What is an example of Obstructive lung disease?

Bronchial asthma

What is Bronchial asthma?

Bronchial asthma is a chronic inflammatory disorder to the bronchial mucosa that causes constriction of the airways

What are the two phases of response of Bronchial asthma?

1. Early (acute) phase

2. Late Phase

Describe Acute Phase Response

Early Phase

1. Allergen exposure causes B cells to produce IgE, which attach to mast cells

2. Mast cells release histamine which causes vasodilation and increased capillary permeability

   1. Mast cells also cause bronchospasm, edema and mucous secretion

When does Late Phase response begin?

Late Phase response begins around 4-8 hours after early response

Describe Late Phase part 1 (chemokines)

Late Phase part 1

1. Chemokines attract neutrophils, eosinophils and lymphocytes

2. Inflammatory chemicals released by these cells causes further bronchospasm, edema and mucous secretion

3. Damage also affects ciliated epithelial cells, where mucous accumulates and obstructs airways

Describe Late Phase part 2 (air trapping)

Late Phase part 2

4. Obstructed airways makes it difficult to exhale, causing air trapping

5. Air trapping leads to hypoxemia

6. Hypoxemia stimulates the respiratory centre for hyperventilation

7. Hyperventilation causes carbon dioxide to be exhaled too quickly, causing hypocania and respiratory alkalosis

Describe Late phase part 3 (increased air trapping)

8. The continued obstruction of the airways increases air trapping (incomplete exhalations), which hyperexpands the lungs and thorax

   1. This decreases tidal volume

9. Carbon dioxide levels rise, leading to hypercapnia and respiratory acidosis