Asthma

Question 1

Describe asthma

Answer 1

A chronic inflammatory disease associated with a variable degree of airway hyper responsiveness to endogenous and exogenous stimuli

Question 2

Symptoms of asthma

Answer 2

Wheezing, coughing, sputum production, chest tightness, shortness of breath, dyspnea

Question 3

Prevalence in New Zealand

Answer 3

One in six Nz adults and 1 in 4 children

Question 4

dyspnoea

Answer 4

Difficult of laboured breathing

Question 5

Diagnosis of asthma

Answer 5

Physical exam- wheezing high pitched whistling (non-specific)
Hx of cough, recurrent wheeze, dyspnoea, chest tightness, reversible airflow limitation and diurnal variation.
Lung function test- evidence of variable air flow obstruction.

Question 6

Lab studies and asthma

Answer 6

Not routinely indicated but may be used to exclude other pathologies.
Test include assays for eosinophilia and immunoglobulin E
Excesses in each may be supportive of asthma but low specificity.

Question 7

Imaging studies

Answer 7

Most patients chest radiography findings are normal or indicate hyperinflation. Findings may help rule out other diseases.

Question 8

Pulmonary function testing. Describe pros and cons of PEF

Answer 8

Peak Expiratory Flow.
Cheap and easy
Good for monitoring progress
Not good for diagnosis as too much variation between patients

Question 9

Spirometry

Answer 9

Measures FVC- the maximal amount of air that can be expired from the point of maximal inhalation; and the FEV1- the volume of air forcefully expired in 1 second. FVC/FEV1 ratio generated and plotted against predicted values.

Question 10

What is a reduction in FVC/FEV1 ratio suggestive of

Answer 10

A reduction in FVC/FEV1 ratio suggests the presence of an obstructive pulmonary disease.

Question 11

What is decreased FVC suggestive of

Answer 11

A restrictive pulmonary disease

Question 12

Name three techniques of measuring static lung volumes

Answer 12

Helium dilution, plethysmography, N2 washout

Question 13

Plethysmography

Answer 13

?

Question 14

Describe helium dilution

Answer 14

The subject is connected to a container with a known volume of helium in it. Through breathing in and out the subject is able to equilibriate the concentration of helium in the lungs with that in the container.

Question 15

Two categories of asthma treatment

Answer 15

Relievers (bronchodilators) and preventers (Anti inflammatory agents and mast cell stabilisers)

Question 16

What are the two categories of inhaled beta adrenergic agonists

Answer 16

SABAS and LABA

Short acting beta agonists and long acting beta agonists

Question 17

Indication/ use of SABAs

Answer 17

Acute bronchospasm
Prevention of exercise induced asthma
Not recommended for regular use
Rapid onset of action

Question 18

Three types of SABA

Answer 18

Adrenaline, isoprenaline, fast acting beta 2 agonists salbutamol and terbutaline.

Question 19

Describe adrenaline treatment

Answer 19

SABA, Beta 2 receptors respond to circulating adrenaline which stimulates cAMP and results in smooth muscle relaxation. Activate both alpha and beta receptors so also caused vasoconstriction.

Question 20

Describe isoprenaline treatment

Answer 20

SABA. Beta 1 and 2 agonist. Increases HR and relaxes smooth muscle.

Question 21

Describe advantage of fast acting beta 2 agonists salbutamol and terbutaline

Answer 21

Resistant to break down by COMT so effect last 4-5 hours.

Question 22

Benefit of drug administration through inhalers

Answer 22

Fewer side effects as more drug to lungs and less systemic

Question 23

Problems with inhalers

Answer 23

Tachyphylaxis (resistance)

Mucous plugging, where mucous plugs stop the full amount of medication from reaching the distal lung sites.

Question 24

Describe long acting B agonists

Answer 24

Act for 12 hour or more as stay in the cell membrane so bind to B2 receptors for longer.
Used for maintenance and control
Used for moderate-persistant, severve persistant asthma.

Question 25

Adverse effect os SABAs and LABAs

Answer 25

Due to activation of beta 2 receptors in other non target tissues. Effects include cardiac stimulation, tremor, hypokalemia (potassium deficiency).

Question 26

Describe inhaled cholinergic agent. 2 drug names

Answer 26

Inhaled bronchodilator. M1-M5 agonists. The M3 receptor causes smooth muscles to contract and mucous glands to secrete.
Includes atropine and tiotropium. Atropine causes smooth muscle dilatation for 6-8 hours. Tiotropium acts over 24 hours used as COPD treatment.

Question 27

Describe asthma anti-infammatory drugs

Answer 27

Glucocorticoids. A class of steroid hormone that bind to GCR. This causes up regulation of anti-inflammatory proteins (transactivation), and repression of anti inflammatory proteins in the cytosol (transrepression).
Considered the most effective class of medication for acute and long term control of asthma.

Question 28

Name some anti inflammatory asthma drugs

Answer 28

Systemic: Cortisone, prednisone, hydrocortisone, dexamethasone.
Inhaled: Flixotide
Pulmicort

Question 29

Adverse effects of GCs

Answer 29

Hypercortisolism
Diabetes
Osteoporosis
Increased BP
Psychosis
Hoarseness, cough, oral candidiasis