Asthma

Question 1

What is Asthma?

Answer 1

A chronic inflammatory airway disease characterised by intermittent airway obstruction and bronchial hyper-reactivity. May include cells like mast cells, eosinophils, T lymphocytes, macrophages, neutrophils and epithelial cells.

Question 2

What are the risk factors of asthma?

Answer 2

Family history
Allergens
Atopic history (bronchoconstriction and airway oedema)
Cold air/ smoking/ exercise/ infection/ NSAIDs
Nasal polyposis
Obesity
Gastro oesophageal reflux
Inflammatory cells, goblet cells, smooth muscle constriction

Question 3

What are the signs and symptoms of asthma?

Answer 3

Intermittent dyspnoea
Wheeze (exploratory polyphonic)
Chest tightness
Cough
Sputum
Diurnal variation/ disturbed sleep
Tachypnoea; audible wheeze; hyperinflated chest; hyperresonant percussion note; air entry decreased ; widespread, polyphonic wheeze.

Question 4

What is the epidemiology of asthma?

Answer 4

Affects 5-8% of the population. 10-15% in UK
Can have ‘childhood asthma’
50% 0f asthma deaths in >65 yrs
340 million people globally

Question 5

What investigations do you do for asthma?

Answer 5

PEFR- <33 (life threatening), 33-50 (severe), chronic is variable
Sputum culture- for bugs or eosinophils

Bloods
FBC- eosinophilia or neutrophilia
U&E
CRP
Culture
IgE total and specific 

ABG
PaCO2 normal or raised, transfer to ITU

Spirometry 
Obstructive defect (reduced ratio, under 0.7)

CXR (excludes pneumothorax or infection)
FeNO 
fractional exhaled nitric oxide 
Measures eosinophilic inflammation
Measures responsiveness to steroid 
Positive = 40 ppb (smoking lowers)

Bronchodilator reversibility test
looking for improvement > 12%
Also volume improvement of 200ml

Bronchial challenge
nebuliser histamine
PC20 < 8mg/ml is positive (20% fall in FEV1)

Question 6

What is the management of acute asthma?

Answer 6

Acute
Nebulised salbutamol O2 
IV hydrocortisone and PO prednisolone
Budesonide (INH)
Salmeterol (LABA)
aminophylline

Question 7

What is the prognosis of asthma?

Answer 7

Relatively normal
Higher risk of airway related issues
ICS can pose risks

Question 8

What is the difference between a severe and life threatening asthma attack?

Answer 8

Severe attack: inability to complete sentences; pulse >110bpm; respiratory rate >25/min; PEF 33–50% predicted.

Life-threatening attack: silent chest; confusion; exhaustion; cyanosis (PaO2 <8 kPa
but PaCO2 4.6–6.0, SpO2 <92%); bradycardia; PEF <33% predicted. Near fatal: increased PaCO2.

Question 9

What are the complications of asthma?

Answer 9

Exacerbations- oxygen, nebulisers, hydration
Airway remodelling-
Candidiasis (INH steroids)- anti fungals like fluconazole
Dysphonia (INH steroids)- change inhalers

Question 10

What is the management of chronic asthma?

Answer 10

Chronic
SABA (salbutamol)
INH corticosteroid (budesonide/ beclomethasone)
LABA (salmeterol)
Leukotriene receptor antagonist (montelukast)/ theophylline/ nedocromil or cromoglicate