Med in Small Doses - Asthma

This is part of the Med in Small Doses series, which aims to give you a snapshot of a disease or disorder.  

Inflamed small airways due to hypersensitivity. Multifactorial – genetics + environmental influences

PATHO: Inflammation (T2H, IL-5, etc) → bronchoconstriction → oedema → ↑ mucus secretion → smooth muscle hypertrophy → damage to epithelium and shedding.

CFs: Classic Triad - Wheeze, Cough (dry, or productive of mucoid or pale yellow sputum), Dyspnoea. Nasal mucosal swelling, ↑nasal secretions

RFs: mnemonic - FEAR UP
F amily history
E czema
A cid reflux
R hinitis (allergic)
U rticaria
P olyps (nasal) 

Ix: Chest x-ray, Allergy testing, Eosinophil count 

Spirometry: ↓ FEV1/FVC, ↓ PEF, ↓ FVC 

The different PFTs:

SPIROMEtry

S pirometry

P EFR

I nhalation tests:

R eversibilty of

O bstruction with beta-agonist

M etacholine challenge

E xhaled NO 

Tx & Mgmt: Monitoring & scheduled visits, education and avoid triggers.
Relief vs prevention, B2-Agonists: airway dilation. Glucocorticoids: anti-inflammatory. 

Treatment of Status Asthmaticus: (severe acute asthma) 

1. Oxygen
2. Nebulised salbutamol
3. IV hydrocortisone
4. Oral prednisolone 

Mnemonic

A drenergics

S teroids

T heophyllines (althouigh not used as much now though)

H ydration

M ask

A ntibiotics if necessary.

Rule of 2's
Treatment needs to be changed if there are more than:

• 2 uses of relief inhalers per week
• 2 nocturnal awakenings per month
• 2 canisters of relief inhaler used per year

For a review of respiratory pathology checkout an Introduction to Respiratory Pathology & Pulmonary Tumours.