Asthma

Question 1

What drives respiration?

Answer 1

Chemoreceptors in carotid bodies, aortic arch, brainstem cause reflex signals based on levels of carbon dioxide and therefore pH level

Question 2

Where are signals to do with respiration coordinated from

Answer 2

The respiratory centre located in the brainstem (medulla, pons & midbrain)

Question 3

How does air flow into the lungs?

Answer 3

Ribs move up and out due to muscle contraction. Lung volume increases causing a decrease in pressure. Diaphragm contracts and flattens, air flows in

Question 4

What are the 4 types of resp disease?

Answer 4

DROV

DIFFUSION - alveolar damage & pulmonary oedema
-LVF & hypersensitivity reactions
RESTRICTIVE - Rigidity of chest wall & pulmonary fibrosis & resp pain
- Obesity, Emphysema, Pneumonia
OBSTRUCTIVE - blockage or spasm of airways
- COPD, asthma & emphysema
VENTILATORY - Nerve damage & depressed nerve transmission
- stroke & infection

Question 5

What are some mediators of asthma?

Answer 5

Histamine, kininase, leukotrienes, PAF

Question 6

What happens when concentration of CO2 increases?

Answer 6

Decrease in pH. Hydrogen ions will reach the respiratory centre by CSF and blood and cause the response of inhalation

Question 7

What is the important parameter controlling diffusion?

Answer 7

Functional Membrane Area

Question 8

What is Tidal volume?

Answer 8

The amplitude of oscillation in lung volume during quiet breathing - 0.5L

Question 9

What is inspiratory reserve volume?

Answer 9

The maximum volume of air that can be inspired in excess of normal inspiration

Question 10

What is expiratory reserve volume?

Answer 10

The maximum volume of air that can be expired in excess of normal expiration

Question 11

What is residual volume?

Answer 11

Not all gas is expired. This is the volume of gas remaining following ERV. Calculated by : RV = FRC - ERV

Question 12

What is total lung capacity?

Answer 12

Total of all ventilatory volumes including RV

Question 13

What is vital capacity?

Answer 13

The sum of all ventilatory volumes not including RV

Question 14

What defines asthma?

Answer 14

Bronchial Hyper-reactivity
Inflammation of the airways
Reversible airway obstruction

Question 15

What occurs in an acute attack?

Answer 15

Epithelium lining the lungs experience an influx of pro-inflammatories such as neurotoxins resulting in damage to the epithelium.

Question 16

What occurs in lung remodeling?

Answer 16

Fibroblast to myofibroblast formation - increases contractibility
Goblet Cell hyperplasia - increased mucous secretion
Collagen deposition - decreased flexibility
Airway smooth muscle proliferation

Question 17

What are symptoms of asthma?

Answer 17

Wheezing, chest tightness & breathlessness

Question 18

What is nocturnal asthma?

Answer 18

In the morning patients peak flow may decrease by 50%. This is exacerbated by allergies

Question 19

What are triggers of asthma attacks?

Answer 19

Drugs - propanolol-beta blockers, NSAIDs- Aspirin
Dust, cigarette smoke
Occupation - industrialised countries

Question 20

What are signs of controlled asthma?

Answer 20

No daytime symptoms, no nighttime awakening, no need for rescue meds, normal lung function

Question 21

What is the stepwise treatment of asthma?

Answer 21

Step 1 - Regular prevention - Low dose ICS
Step 2 - Initial add-on therapy - Alongside Low dose ICS - add LABA
Step 3 - Additional controlled therapies - consider increasing low dose ICS to MEDIUM or start on a LTRA. If LABA not working - consider stopping
Step 4 - Refer to a specialist

REMEMBER THESE ARE STEPWISE & MOVE IN BOTH DIRECTIONS