at 2 - Physiology in Clinical Practice

Question 1

What is asthma?

Answer 1

chronic inflammatory disorder of the airways leading to airflow obstruction

Question 2

Describe the appearance of a peak flow trace when its:

• normal
• obstructive
• restrictive

Answer 2

Normal = increases linearly, then plateaus
Obstructive = shallow gradient, can't blow out as quickly as possible but can blow out the same volume of air if given the time to do so. FEV1/FVC

Question 3

How is asthma diagnosed?

Answer 3

> 12% incerase in FEV1 post bronchodilator
or >20% in PEFR diurnal variability
- also can test for airway hyperresponsiveness, given drugs to induce this and spirometry performed

Question 4

Describe the pathogenesis of asthma.

Answer 4

Allergen activates dendritic cells, activate a Th2 lymphocyte cascade
B cells release IgE
Mast cells release inflamarotry mediators and leukotrienes
Other inflammatory cells are stimulated
eosinophils also attracted to lungs

Question 5

What occurs when asthma is triggered?

Answer 5

hypertrophy of muscle
increase in inflammatory cells
sputum in airway
smooth muscle contraction 
airways may become scarred
effects can be temporary or permanent

Question 6

What happens during an asthma attack?

Answer 6

airway narrowing caused by:

• contraction of smooth muscle
• swelling of epithelium
• increase mucus production

Question 7

What are the 4 asthma symptoms?

Answer 7

coughing usually dry
wheezing - whistley noise on expiration
chest tightness
SOB

Question 8

What are some asthma triggers?

Answer 8

allergens e.g. animal dander, pollen, foods
irritants e.g. smoke, aerosols, particulate matter
other e.g. viruses, changes in weather, exercise, endocrine factors

Question 9

Give four examples of substances that can cause occupational asthma

Answer 9

isocyanates - paints, varnishes, plastics
colophony - soldering
proteolytic enzymes - cleaners
flour dust - bakers

Question 10

What are the 4 components of an asthma management plan?

Answer 10

medication
identification of triggers
peak flow monitoring
emergency plan

Question 11

What are the 2 forms of inhaled asthma therapy?

Answer 11

bronchodilators, B2 agonist, targets smooth muscle contraction
steroids, targets inflammation

Question 12

When are oral steroids likely to be used?

Answer 12

rarely needed in maintenance therapy

play a role in acute exacerbations

Question 13

What are the 5 steps of asthma medication?

Answer 13

1 = SABA
2 = inhaled steroid
3 = LABA 
4 = increase steroid, try leukotriene antagonist or theophylline
5 = oral steroids

Question 14

What is COPD?

Answer 14

chronic obstructive pulmonary disease

characterised by obstruction that is not fully reversible

Question 15

What is the pathogenesis of COPD?

What are the components of COPD?

Answer 15

smoking
stimulate neutrophilic inflammation
release oxidants and proteases
parenchymal damage and mucus hypersecretion

• airway inflammation, bronchospasm, structural changes, mucociliary dysfunction, systemic components

Question 16

What are the severity gradings for COPD?

Answer 16

FEV1/FVC 80%
moderate 50-80%
severe 30-50%

Question 17

How do you differentiate between COPD and asthma:

1. smoking status
2. symptoms under age 35
3. chronic productive cough
4. breathlessness
5. night time waking with breathlessness or wheeze
6. signification diurnal variability of symptoms

Answer 17

COPD / ASTHMA

1. nearly all / possibly
2. rare / often
3. common / uncommon
4. persistent and progressive / variable
5. uncommon / common
6. uncommon / common

Question 18

How is COPD managed in terms of drugs?

Answer 18

1. SABA
2. LABA
3. ultimately use steroids

Question 19

What is the only thing you need to diagnose COPD?

Answer 19

spirometry

FEV1/FVC ratio

Question 20

What are the three features of an excacerbation in COPD?

What is the treatment?

Answer 20

increased breathlessness
green sputum
increased sputum volume

anitbiotics, steroids

Question 21

What is pulmonary fibrosis?

Answer 21

scarring of the lung parenchyma

usually happens after inflammation

Question 22

What are the clinical features of pulmonary fibrosis and the results of investigations>

Answer 22

dry cough and dyspnoea
fine end inspiratory reps at base of lungs
of the cause
cryptogenic

restrictive pattern on spirometry
CXR = reticular shadowing, honeycombing
High resolution CT = sub plural reticular shadowing

Question 23

How is pulmonary fibrosis managed?

Answer 23

depends on cause, histology, severity
immunosupression
transplantation
monitor using PFT’s

Question 24

What is the checklist for good asthma control?

Answer 24

no daytime symptoms
no night time waking
no need for reliever medication
no exacerbations
no limitation of physical activity
normal lung function