Obstructive lung disease: COPD-Emphysema

Question 1

What is meant by obstructive lung disease

Answer 1

Diffuse airway disease (at any level of the respiratory tract) resulting in increase in resistance to airflow (FEV1/FVC <0.7)

Question 2

List 3 obstructive lung disease

Answer 2

Chronic obstructive pulmonary disease
Asthma
Bronchiectasis

Question 3

What is COPD

Answer 3

is the diseases characterised by persistant respiratory symptoms and airflow limitation due to airway and/or alveolar abnormalities caused by exposure to noxious particles or gases

Question 4

List risk factors of COPD

Answer 4

1. Strongly associated with cigarette smoking
2. Poor lung development early in life
3. Exposure to environmental and occupational pollutants
4. Airway hyperresponsiveness
5. Genetic polymorphisms

Question 5

List 2 major clinicopathologic manifestation of COPD

Answer 5

Emphysema
Chronic bronchitis

Question 6

Permanent enlargement of airspaces distal to terminal bronchiole with destruction alveolar septae and walls of airways

Answer 6

Emphysema

Question 7

List the classifications of Emphysema

Answer 7

Centriacinar Emphysema
Panacinar Emphysem
Paraseptal Emphysema
Irregular Emphysema

Question 8

The emphysema that affects the respiratory bronchioles and involves the upper lobes associated with smoking

Answer 8

Centriacinar emphysema

Question 9

The emphysema that affects the alveolar and alveolar ducts and eventually the respiratory bronchioles and ivolves the lower lobes

Answer 9

Panacinar emphysema

Question 10

The panacinar emphysema is associated with defieceny of what?

Answer 10

alpha 1 antitypsin defiency

Question 11

The panacinar emphysema is exacerbated by?

Answer 11

Smoking

Question 12

Name the emphysemas that causes the clinically significant airway obstruction

Answer 12

Panacinar and Centriacinar emphysema

Question 13

The emphysema that manifests as spotaneous pneumothorax in young adults

Answer 13

Paraseptal emphysema

Question 14

Emphysema that is clinical insignificant

Answer 14

Irregular emphysema

Question 15

Explain the pathogenesis of emphysema in sequence

Answer 15

1. Alpha 1 antitrypsin deficiency
2. Decrease in antielastase alpha 1 antitrypsin
3. Smoking causes increase in elastase PMN/Mac which results in elastic damage-emphysema
4. Also the decrease in antielastase alpha 1 antitrypsin-elastic damage-emphysema

Question 16

Toxic injury from inhaled smoke and other noxious particles causes what?

Answer 16

Damage respiratory epithelium and cause inflammation as well as oxidative stress, resulting in parencymal destruction

Question 17

Both centri-acinar and panacinar emphysema are caused by imbalance of what?

Answer 17

Protease antiprotease
Oxidant-antioxidant

Question 18

The centri-acinar is associated with what from cigarette

Answer 18

Nicotine

Question 19

Explain the role of nicotine in Emphysema (4makrs)

Answer 19

1. Nicotine is a chemoattractant of neutrophils by induction of nuclear factor B and resultant production pf tumour necrosis factor (TNF) and interleukin 8 (IL8)
2. TNF and IL8 activate neutrophils, whihc release damaging proteases
3. Nicotine causes inactivation of antiproteases
4. Nicotine causes production of reactive oxygen species, which inactivates proteases and deplete antioxidants

Question 20

Explain how the deifiencey of alpha 1 antirypsin causes panacinar emphysema

Answer 20

the normal allele encoding alpha 1 antitrypsin is PiMM but 0.012% of the population has a PiZZ allele, which is associated with a significant decrease in the amount of alpha 1 antitrypsin
Alpha 1 antitrypsin major inhibitor of proteases especially elastase secreted by netrophil during inflammation

Question 21

Under mechanism of emphysema
The loss of pulomonary parenchyma results in what?

Answer 21

Loss of elastic tissue and recoil, increased lung compliance, increased pulmonary residual volume, increased total lung capacity

Question 22

Under mechanisms of emphysema the airway obstruction results to what?

Answer 22

Loss of elastic tissue in the alveolar walls that surrounds respiratory bronchioles leading to decreased radial traction and functional collapse of respiratory bronchioles during expiration

Question 23

What happens to diaphragmatic excursion and accessory muscles for breathing.
Mechanism of emphysema

Answer 23

Decreased diaphragmatic excursion and increased use of accessory muscles for breathing

Question 24

Under mechanism of emphysema
With over time, with reduced ventilation and air trapping what will happen

Answer 24

The partial pressure of oxygen (Pa O2) decreases, the partial pressure of carbon dioxide (Pa CO2) increases, and respiratory acidosis ensues, with renal compensation. This exacerbated by small airway changes in smokers

Question 25

Signs and symptoms of emphysema

Answer 25

Dyspnea, hypoxemia, hypercapnia, hyperventilation (referred to as “pink puffers”). Pursed lips Digital clubbing. Barrel shaped chest due to Hyperinflation Trapped air Decreased volume of breath sounds and longer (increased)expiratory phase on auscultation. Chronic respiratory acidosis with compensatory alkalosis Weight loss(pulmonary cachexia: utilises lots of calories just to breath)

Question 26

Chest radiograph of emphysema

Answer 26

Flattened diaphragm, Increase AP diameter, and expanded hyperlucent lung fields

Question 27

Microscopic features of emphysema

Answer 27

Loss of distal airspaces,bronchioles, alveolar ducts, and alveoli. Remaining airspaces become dilated as shown. There is less surface area for gas exchange..

Question 28

Explain the arterial blood gas under emphysema

Answer 28

Over time, with reduced ventilation and air trapping, the partial pressure of arterial oxygen (pa o 2 ) decreases, the partial pressure of carbon dioxide (pa co 2 ) increases, and respiratory acidosis ensues, with renal compensation.

Question 29

Explain the gross appearance of centriacinar emphysema

Answer 29

The central lobular loss of lung tissue with intense black anthracotic pigmentation (←) is apparent as “dirty holes

Question 30

Centriacinar emphysema initially involves what?

Answer 30

Loss of respiratory bronchioles in the proximal portion af the acinus, with sparing of distal alveoli, and this type is mots typical for cigarette smokers

Question 31

Gross appearance of panacinar emphysema

Answer 31

Panacinar emphysema occurs with loss of all portions of the acinus from the respiratory bronchiole to the alveoli. The bullae seen here are most prominent in the lower lobe (→) on the left 

Question 32

This emphysema follows focal scarring of the peripheral lung parenchyma with injury from infections and pullutants, including cigarette smoke.

Answer 32

Paraseptal emphysema

Question 33

Gross appearance of paraseptal emphysema

Answer 33

Gross Peripheral location of the bullae, along septa may lead to rupture into the pleural space =spontaneous pneumothorax >/= 2 cm in size or more,. Two small bullae (→↓) are seen here just beneath the pleural surface.