Respiratory Disorders - COPD

Question 1

What is COPD?

Answer 1

Chronic Obstructive Pulmonary Disease (COPD) Is a umbrella term which includes Chronic Bronchitis and Emphysema. It is persistent inflammation of the air way, parenchyma, and vasculature. The inflammation is acute, recurrent and chronic obstruction of the airway.

Question 2

What is causing the obstructive nature of COPD?

Answer 2

An underlying problem.

Question 3

Where is the obsturction in COPD?

Answer 3

The obstruction occurs in the airways.

Question 4

How can COPD be acute and chronic at the same time?

Answer 4

It can be both because the patient experiences episodes of acute obstruction which reoccur chronically.

Question 5

What other condition does COPD sometimes co-exist with?

Answer 5

Asthma

Question 6

What is the etiology and risk factors associated with COPD?

Answer 6

Smoking (80-90% of cases), Recurrent Respiratory Infections, Ageig, Genetic Defiency of Alpha1-antitrypsin.

Question 7

Why is ageing a risk factor in COPD?

Answer 7

As we age there is degenerative changes of tissues. This results in reduced elasticity of tissue.

Question 8

What are irritants? What is the effect when we inhale irritants?

Answer 8

Irritants are things like cigarette smoke, toxic fumes which we inhale. They have several negative effects on the body. 1) Increased mucus secretions. 2) Destruction of cilia lining the respiratory tract. 3) Induces inflammation leading to damage. 4)Damage to aveoli and vessels. 5)Induces coughing which can cause damage d/t speed of cough.

Question 9

What is the function of Alpha1-antitrypsin? What is the result in COPD is there is a genetic defect in A1-antitrypsin?

Answer 9

A1-antitrypsin is a protease inhibitor which protects tissues from inflammatory cells like neutrophil elastase. When there is a definicy in A1-anittrypsin neutrophil elastase is free to break down elastin which results in less elasticity resulting in COPD and emphysema. The deficiency leads to chronic uninhibited tissue breakdown.

Question 10

What is Chronic Bronchitis?

Answer 10

Chronic bronchitis is inflammation and obstruction of the air way.

Question 11

What is the cause of chronic bronchitis?

Answer 11

Smoking and chronic/recurrent infection.

Question 12

Does chronic bronchitis occur in the large or the small airways?

Answer 12

Both!

Question 13

What are the characteristics of chronic bronchitis in the large airways?

Answer 13

Chronic bronchitis occurs in the large airways first. It is characterized by hypertrophy of submucosal glands and hypersecretion of mucus.

Question 14

Why are the large airways affected first?

Answer 14

The large airways are affect by bronchitis first because they are the first line defense for the respiratory system. As the injurious agent persists the protective mechanisims of the large airways fail to protect the smaller airways.

Question 15

What are the characteristics of chronic bronchitis in the small airways?

Answer 15

Chronic bronchitis in the small airways is characterised by an increase in goblet cells which results in an increase of mucus secretion.

Question 16

Mucus secretion is a defense mechanism, why is this not beneficial in COPD and Chronic Bronchitis?

Answer 16

An overproduction of mucus results in a layer of mucus which is too thick. This impaires the silica from properly expectorating any foreign objects and creates an ideal site for infection.

Question 17

What is the pathophysiology of Chronic Bronchitis?

Answer 17

Excess mucus which impairs the mucociliary defences. Infection establishes in the mucus. Bronchial walls become inflammed which obstructs the lumen. Airways collapse due to the obstruction and air becomes trapped in parts of the lung (alveoli). Decreased alveolar ventilation results in a perfusion imbalance which results in hypoxemia.

Question 18

What is hypoxemia?

Answer 18

An abnormally low concentration of oxygen in the blood.

Question 19

What is the normal ratio for measuring blood and air?

Answer 19

Ventillation:Perfusion Ratio

Question 20

What is the normal ventillation of the lungs? What is the normal perfusion of the lungs? What is a normal ratio?

Answer 20

Normal ventiallation of the lungs is 4.2L/min. Normal blood volume of the lungs is 5.5L/min. 4.2/5.5 = 0.8 Ventillation:Perfusion Ratio.

Question 21

How is Chronic Bronchitis diagnosed?

Answer 21

Chronic productive cough which is sustained for >3month/year in two consequtive years.

Question 22

What are the manifestations of Chronic Bronchitis?

Answer 22

Impaired respiratory function resulting in hypoxemia and hypercapnia. Activity intolerance. Increased sputum production. Dyspnea. Wheezing and wet crackles from fluid build-up in lungs. Prolonged expiration.

Question 23

What is Emphysema?

Answer 23

Emphysema is destruction of alveolar tissue and capillary beds causing loss of compliance and enlarged distal airspaces.

Question 24

What does compliance mean when in discussions of of respiratory system?

Answer 24

Compliance is the ease in which you fill and empty the lungs.

Question 25

What happens with-in the aveoli in the lungs when one has Emphysema?

Answer 25

The aveolar walls under go tissue damage, which reduces the amount of surface area of the aveoli causing the enlarged distal airways, and reducing the gas exchange of the lungs.

Question 26

What are the causes of Emphysema?

Answer 26

Smoking, Genetic defect of Alpha1-Antitrypsin.

Question 27

What is Alpha1-Antitrypsin?

Answer 27

A1-antitrypsin is a protease inhibitor which protects tissues from inflammatory cells like neutrophil elastase. When there is a definicy in A1-anittrypsin neutrophil elastase is free to break down elastin which results in less elasticity resulting in COPD

Question 28

What is the pathophysiology of Emphysema?

Answer 28

Alpha1-Antitrypsin (Antiprotease) protects the lungs. Smoking inhibits A1-antitrypsin and attracts inflammatory cells into the respiratory tract. The increased levels of proteases destroys alveolar walls causing the alveoli to merge and decreasing their surface area. Permenant distended air spaces causes impared vetilation. Air trapped between the alveoli leads to increased dead space further increasing the work of breathing. Capillary walls become destroyed leading to impaired perfusion.

Question 29

What are the two variables of Emphysema pathophysiology?

Answer 29

1. Impared ventillation due to decreased surface area and permanent distended air spaces. 2. Impaired perfusion due to capillary wall destruction.

Question 30

What are some excessory muscles of respiration?

Answer 30

sternocleidomastoid, serratus anterior, pectoralis major, pectoralis minor, trapezius, latissimus dorsi, erector spinae, subclavius.

Question 31

What is Centriacinar emphysema?

Answer 31

Centriacinar emphysema is emphysema that is confined to the terminal and respiratory bronchioles. It is the most common type of emphysema, and there in minimal destruction to the alveoli.

Question 32

What is Panacinar emphysema?

Answer 32

In Panacinar emphysema the peripheral alveoli and terminal airways are also involved. It is characterized by large distended spaces.

Question 33

What is a Bulla? What is the plural of Bulla?

Answer 33

Bulla is an airpocket in the lung that occurs between aveoli and pushes against the plural membrane. They occur as a result of lung tissue destruction. The plural of Bulla is Bullae.

Question 34

What are Blebs?

Answer 34

Plumonary blebs are small subpleural thin walled air containing space less that 1-2cm in diameter.

Question 35

What are the manifestations of Emphysema?

Answer 35

Dyspnea, Increased ventilatory effort, Barrel chest, Nasal flaring and pursed-lip breathing.

Question 36

How is COPD diagnosed?

Answer 36

Patient history, Physical exam, labs (cvc and ABGs), Chest X-ray, Pulmonary Fx tests.

Question 37

What is the treatment for COPD?

Answer 37

The goal is to limit the progression of the disease, as it is irreversible. First, you must quit smoking and avoid any airway irritants. Flu and pneumococcal vaccines. Drugs: short-acting Beta agonist and anticholinergics. Inhaled steriods. Long-acting Beta agonists. Theophylline.

Question 38

What is accomplished with beta agonists?

Answer 38

Beta agonists cause broncho dilation, opening up the airway.

Question 39

What is the purpose of the anticholinergics?

Answer 39

Block acetocholine. Acetocholine causes vasoconstriction, so we want to block that action.

Question 40

What is Theophylline?

Answer 40

A bronchodilator which also has some anti-inflammatory response.