obstructive airway diseases

Question 1

what are examples of COPD

Answer 1

chronic bronchitis and emphysema

Question 2

what is FEV1

Answer 2

forced expiratory volume of air exiting the lung in the first second of exercise

Question 3

what is FVC

Answer 3

the final total amount of air expired

Question 4

what is the usual value of FEV1

Answer 4

ABOUT 70-80% OF FVC
NORMALY ABOUT 3.5-4L
FVC IS ABOUT 5
NORMAL RATIO OF FEV1:FVC IS0.7:0.8

Question 5

what’s another way that obstructive lung disease may be demonstrated

Answer 5

PEFR - peak expiratory flow rate
normally - 400 -600 litres
normal range is 80-100% of best value
50-80% is moderate fall and below 50 is marked fall

Question 6

what are key features of obstructive king disease

Answer 6

airflow limitation 
PEFR is reduced 
FEV1 reduced 
FVC may be reduced 
FEV1 is less than 70% of FVC

Question 7

what is bronchial asthma

Answer 7

type 1 hypersensitivity in the airways

Question 8

describe bronchial asthma

Answer 8

generally considered to be reversible airways obstruction either spontaneously or as a result of medical intervention
bronchial smooth muscle contraction and inflammation can be modified by drugs

Question 9

describe the aetiology of chronic bronchitis and emphysema

Answer 9

smoking
atmospheric pollution
occupation:dust
alpha anti protease (anti trypsin) deficiency is an extremely rate cause of emphysema
effect of age and susceptibility
prévalence - men>women but increasing in developing countries

Question 10

how is chronic bronchitis defined clinically

Answer 10

cough productive of sputum most days in at least 3 consecutive months for 2 or more consecutive years
complicated when sputum turns mucopurulent (acute infective exacerbation) or FEV1 falls

Question 11

what are morphological changes in chronic bronchitis

Answer 11

large airways - mucous gland hyperplasia, goblet cell hyperplasia and inflammation and fibrosis is a minor component
small airways - goblet cells appear, inflammation and fibrosis in long standing disease

Question 12

what is the pathological definition of emphysema

Answer 12

increase beyond the normal size of airspace’s distal to the terminal bronchiole arising either from dilation or from destruction of their walls and without obvious fibrosis

Question 13

what are the diff forms of emphysema

Answer 13

centriacinar
panacinar
periacinar
scar ‘irregular’ ‘bullous emphysema’

Question 14

what is centriacinar

Answer 14

most common type of pulmonary emphysema mainly localised to the proximal resp bronchioles and predominantly found in upper lung zones

Question 15

what is panacinar

Answer 15

dilation of air space from resp bronchioles to alveoli

Question 16

what is a bullous emphysema

Answer 16

known as vanishing king syndrome. most often treated by surgical removal of bulls which can grow to 20 cm

Question 17

why can COPD lead to hypoxaemia

Answer 17

airway obstruction
reduced resp drive
loss of alveolar surface area
shunt - only during severe acute infective exacerbation

Question 18

what are the pulmonary vascular changes in hypoxia

Answer 18

physiological pulmonary arteriolar vasoconstriction

• when alveolar oxygen tension falls
• can be localised effect
• all vessels construct is there is hypoxaemia

protective mechanism
- do not send blood to alveoli short of oxygen

Question 19

what is chronic (hypoxic) cor pulmonale

Answer 19

hypertrophy of the right ventricle resulting from disease affecting function and/or structure of lung, except where pulmonary alterations are the result of diseases primarily affecting left side of the heart or congenital heart disease

Question 20

hypoxic for pulmonale

why can it lead to pulmonary hypertension

Answer 20

pulmonary vasoconstriction 
pulmonary artérioles - muscle hypertrophy and intimal fibrosis 
loss of capillary bed 
secondary polycythaemia 
bronchopulmonary arterial anastomoses