Asthma

Question 1

Asthma - means what in Greek?

Answer 1

Panting

Question 2

What type of hypersensitivity reaction?

Answer 2

Type 1 - because it is IgE mediated

Question 3

Overview of pathophysiology

- immunology bit

Answer 3

1) Environmental trigger - allergen
2) Dendritic cells munch allergen and present to Th2 cell
3) Th2 cell spurts out IL4 and IL5
4a) IL4 - causes masts cells to pump out histamine, leukotrienes and PGs
4b) IL5 - eosinophils release leukotrienes and cytokines

Question 4

Overview of pathophysiology

- Result

Answer 4

Smooth muscle spasms
Increased mucus secretion
More eosinophils get excited

Question 5

Symptoms

Answer 5

Night cough (dry-ish)
Chest tightness
Dyspnoea
Sputum (with mucus plugs etc* in)

• Very Small print - stuff that gets coughed up
• Curschmann spirals - the MVP of mucus
• Charcot-Leyden crystals - ‘needles’ formed from the breakdown of eosinophils

Question 6

Signs

Answer 6

Wheeze (exhalation)
inc. RR, HR
resonant percussion note 
reduced air entry
PEFR - less (33-50% predicted)*

*Less than 33% is not an ideal situation - life threatening in fact

Question 7

Life threatening signs

Answer 7

Silent chest
Confused, exhausted, cyanosed
Pa02 down, HR down, PEFR > 33%

When PaCO2 is up - near fatal

Question 8

Tests

Answer 8

Peak flow - improvement with SABA
Sputum
FBC, UEs, CRP, blood cultures
ABG
CXR

Question 9

Treatment (NICE) step 1

Answer 9

Salbutamol PRN

Question 10

Treatment (NICE) step 2

Answer 10

Add beclmatasone

Question 11

Treatment (NICE) step 3i

Answer 11

Add Leukotriene receptor antagonist (montelukast)

Question 12

Treatment (NICE) step 3ii

Answer 12

Add salmeterol

Question 13

Treatment (NICE) step 4

Answer 13

Whack up the betametasone

Consider theophylline

Question 14

Treatment (NICE) step 5

Answer 14

Oral prednisolone

Question 15

Salbutamol. Talk to me 1/2

• how/where does it work?
• what happens?
  ?- Side effects

Answer 15

Short acting beta2 agonist
(B2 receptors - smooth muscle of bronchi, GI tract, blood vessels and uterus)
Act via G protein magic

Cause smooth muscle relaxation

SE - tachycardia, palpitations, anxiety, tremor (think - what do B1 receptors cause) - so a patient with cardiovascular disease may not be your best friend if you give them this

Question 16

Salbutamol round 2/2

• B2 agonists stimulate Na/K ATPase pumps. Do we care about this?

Answer 16

Cause a shift of K ions to move INTO cells.
So used in hyperkalaemia.

We certainly do care - hyperkalaemia can lead to arrhythmias and bad days at the office

Question 17

Salmeterol

What is it, which step?

Answer 17

Long acting beta 2 agonist - same pharmacological mechanism

Step 3 of Rx

Can also cause muscle cramps

Formoterol is another LABA

Question 18

Beclometasone

Answer 18

Inhaled glucocorticoid steroid
Step 2 therapy
Interact with receptors WITHIN CYTOPLASMS. The receptor then wanders into the nucleus to modify gene transcription.
Genes downregulated - pro-inflammatory ILs, cyto/chemokines
Genes upregulated - Anti-inflammatory proteins

Result - less mucosal inflammation, wider airways, less mucus secreted.

Question 19

Montelukast

Answer 19

Leukotriene antagonist
Asthma prophylaxis

Alternative - zafirlukast

Question 20

Theophylline

Answer 20

Relaxes smooth bronchial muscle

Found naturally in tea. And is a breakdown product of caffeine