PBL 5-COPD

Question 1

Describe the management of COPD

Answer 1

- Smoking Cessation
Bronchodilators:
- B2 agonist
salbutamol (short acting)
Formoterol (long acting)

• Anticholinergic agents
  Tiotropium (long acting)
  Ipratropium (short acting)

Corticosteroids

• inhaled
• used in combination with long acting beta agonists

Question 2

Define FEV1.

Answer 2

Forced Expiratory Volume.

The maximum volume of gas that can be expired from the lungs during a forced expiration in 1 second.

Question 3

What factors affect FEV1?

Answer 3

• Height (arm span)
• age
• gender

Question 4

Define FVC

Answer 4

Forced Vital Capacity

The maximum volume of gas that can be expired from the lungs during a forced expiration from full inspiration.

Question 5

Define FEV1/FVC.

Answer 5

The proportion of the FVC which is expelled during the 1st second of expiration, expressed as a percentage.

Question 6

Define PEF.

Answer 6

Peak Expiratory Flow

The maximum expiratory flow that can be sustained for a minimum of 10mmsec

Question 7

What are obstructive lung disease.

Answer 7

Obstruction of the airways
FEV1/FVC ratio is <70%
Asthma, COPD and Cystic Fibrosis

Question 8

What are restrictive lung disease.

Answer 8

They restrict lung expansion
FEV1/FVC ratio may be normal or higher.
Scoliosis, Pulmonary fibrosis

Question 9

What is normal FEV1/FVC ratio.

Answer 9

70%

Question 10

What are the signs and symptoms of COPD

Answer 10

• persistent cough
• sputum production
• difficulty in breathing

Question 11

What diagnostic test would you use for COPD

Answer 11

Spirometry:
- FEV1/FVC ratio <70%
- asthma is also <70% so difficult to distinguish between both
Chest X-ray:
- hyper inflation is seen with flattened diaphragms
- hyper expansion of lungs
Pulse oximetry- check for O2 saturation due to hypoxemia
Blood test- to check for A1-antitrypsin deficiency

Question 12

Define respiratory acidosis

Answer 12

Decreased ventilation results in excess CO2 in the body which causes pH of the body to become acidic.

Question 13

Describe the acid-base compensatory mechanism that occurs in respiratory acidosis

Answer 13

Buffer systems of the body:

• bicarbonate
• proteins
• phosphate

Respiratory control:
Control of carbonic acid concentration by changing the rate and depth of breathing.

Renal Control:
Bicarbonate is converted to carbonic acid in the renal tubular cells. Carbonic acid disassociates into H+ and bicarbonate ion