Lung Patho

Question 1

What are the types of emboli that can form?

Answer 1

• thromboemboli (>95% most common)
• atherosclerotic emboli
• gas (air) emboli
• fat emboli
• amniotic fluid emboli

-could also be tumour and bacterial

Question 2

What can cause gas emboli?

Answer 2

• Decompression sickness (divers; nitrogen precipitates out of blood too quickly in rapid descent)
  - -> chronic form known as Caisson disease; characterized by multifocal ischemic necrosis of bone
• Laparoscopic surgery (air pumped into abdomen)

Question 3

What is most common source of pulmonary embolism? Involving which specific vessels?

Answer 3

-> Deep vein thrombosis (DVT)
Involving commonly:
 -femoral vein 
-iliac v.
-popliteal v.

Question 4

When does sudden death occur in a pulmonary emboli?

Answer 4

When a large saddle embolus blocks both left and right pulmonary arteries (large enough thromboembolic blocking pulm. a bifurcation)
OR
Significant occlusion of large pulmonary artery

Question 5

What type of infarct is observed on gross examination of pulmonary infarction?

Answer 5

Wedge-shaped infarction

Question 6

Signs + symptoms of DVT:

Answer 6

Blood clot within deep vein:

• swelling
• redness
• warmth
• pain
• -> Predisposed by Virchow’s triad

Question 7

Treatment of DVT:

Answer 7

PROPHYLAXIS + ACUTE MANAGEMENT:
-LMWH (enoxaparin)
or
- unfractionated heparin

LONG TERM PREVENTION:
-oral anticoags (warfarin, rivaroxaban)

Question 8

What imaging is best used for DVT?

Answer 8

Compression ultrasound with Doppler

Question 9

Symptoms of pulmonary emboli?

Answer 9

• sudden-onset dyspnea
• tachypnea
• tachycardia
• pleuritic chest pain
  (pain due to visc and parietal pleura rubbing together from inflamed pleura)

Question 10

Causes for transudative pleural effusion?

Answer 10

• congestive heart failure
• liver cirrhosis
• nephrotic syndrome
• acute atelectasis
• myxedema

Question 11

Causes for exudative pleural effusion?

Answer 11

• bacterial pneumonia (most common)

-

Question 12

What is pleural effusion?

Answer 12

excessive fluid accumulating in pleural cavity

Question 13

Explain tuberculosis

Answer 13

It is a chronic granulomatous disease.
Caused by m. tuberculosis, causes caseating necrosis and hiller lymph nodes undergo fibrosis and calcification.
Form ghon complexes. Often asymptomatic in primary.
Secondary TB –> typically affects apex (high O2)
Can systemically spread to: meninges (meningitis), kidneys (sterile pyuria), lumbar vertebrae (Potts disease)

Question 14

What are the main pathological changes in
A) asthma
B) bronchitis
C) emphysema 
D) bronchiectasis

Answer 14

A) Asthma –> smooth muscle hyperplasia, excessive mucus, inflammation
B) bronchitis –> hypertrophy + hyperplasia of mucous glands
C) emphysema –> airspace enlargement, wall destruction
D) bronchiectasis –> dilation and scarring

Question 15

Describe microscopic changes in

a) acute pulmonary congestion
b) chronic pulmonary congestion

Answer 15

a) Acute –> blood engorged alveolar capillaries, and some alveolar septal edema and intra-alveolar hemorrhage
b) Chronic –> septa become thickened and fibrotic, and alveolar spaces contain hemosiderin-laden macrophages derived from phagocytosed RBCs

Question 16

What is the main cause of pulmonary congestion?

Answer 16

Left sided heart failure

Question 17

What can we find histologically in chronic bronchitis?

Answer 17

• enlargement of mucus-secreting glands
• goblet cell metaplasia
• bronchiolar wall fibrosis

Question 18

What is brown induration?

Answer 18

In progressive (chronic) pulmonary congestion, the hemosidern-laden macrophages together with interstitial fibrosis cause "brown" colouring 
--> Extensive fibrosis can lead to intra-pulmonary hypertension

Question 19

What is bronchiectasis caused by?

Answer 19

Necrotizing inflammation with damage to airway walls b/c of one of the following :

• cystic fibrosis
• Karteneger syndrome (dynein arm defect, needed by cilia, thus poor mucous clearance b/c cilia not working)
• tumor or foreign body
• necrotizing infection
• smoking
• allergic bronchopulmonary aspergillosis

Question 20

What is karteneger syndrome?

Answer 20

Inherited defect of dynein arm which is needed by cilia for movement. There is poor mucosal clearance in the lung due to lack of cilia function.
Can cause bronchiectasis (permanent dilation of bronchi + bronchioles)

Question 21

What is pneumoconiosis?

Answer 21

Interstitial fibrosis due to occupational exposure

–> requires chronic exposure

Question 22

What are the main types pneumoconiosis?

Answer 22

-asbestosis
-coal workers’ pneumoconiosis
-

Question 23

List restrictive lung diseases:

Answer 23

• idiopathic pulmonary fibrosis
• sarcoidosis
• pneumoconiosis (asbestosis, berrylliosis, silicosis, coal workers pneumoconiosis)
• hypersensitivity pneumonitis

Question 24

What can having asbestosis lead to?

Answer 24

Lung carcinoma and mesothelioma

>80% of mesotheliomas caused by exposure to asbestos

Question 25

What is sarcoidosis?

Answer 25

Systemic disease characterized by non-caseating granulomas in multiple organs. Granulomas typically in hillier lymph nodes and lung –> leading to restrictive lung disease

Question 26

What is the pathogenesis of ARDS?

Answer 26

Due to some underlying condition (i.e. sepsis, infection, pancreatitis, drugs, aspiration, trauma, shock) there is an activation of neutrophils which induces protease-mediated and free radical damage of type I and II pneumocytes. The capillary-alveolar barrier is damaged. Edema with protein-rich fluid occurs, collapse of air sacs (b/c of surfactant abnormality).