Flashcards in Asthma Deck (14)
What is asthma?
• Chronic Inflammatory Airway Disease • Variable & Reversible Airway Obstruction • Airway Hyper responsiveness • Bronchial Inflammation
• Affects Children & Adults
What is the epidemiology of asthma?
• Asthma prevalence is thought to have plateaued since the late 1990s, although the UK still has some of the highest rates in Europe and on average 3 people a day die from asthma.
It affects M=F.
It is the most common long term condition in children.
What's the aetiology of asthma?
• Environment vs Genetic
– Influence severity & responsiveness
– Allergens / Air Pollution
– Smoking during Pregnancy
– Low air quality
– Formaldehyde (attack)
– Indoor Allergens (dust mites / cockroaches / animal dander / mould)
• HygieneHypothesis – Reduced expose to non pathogenic bacteria / virus
– Increased Cleanliness
– Decreased Family Size
– Exposure to bact. Endotoxin in child hood protective
– Exposure to bact. Endotoxin in adulthood may provoke bronchoconstriction
– Antiobiotic Usage – C-Section
• Medical Conditions – Atopic Eczema, Allergic Rhinitis, Asthma – Atopy
• Obesity • Beta Blocker - propanolol
– Cardioselective are safer • NSAIDS / ACEi
What is the pathophysiology of asthma?
– Exposure to allergen
– Cross linking of IgE
– Mast Cell Degranulation
– Histamine release
– Mucous Hypersecretion
– Bronchoconstriction leading to Airway Obstruction
– Late phase: mixed inflammatory cell infiltrate & acculumation leading to further bronchial hyper responsiveness
– High power: Luminal Mucous Plugs, Epithelial Shedding, Mixed Cell infiltrate, Odema, submucosal gland hyperplasia, smooth muscle hypertrophy
What would a patient's history be like with asthma?
• Episodes of Wheeze
• Chest Tightness
• Cough – worse in morning / night • Related to exercise / cold weather
• Associated with: GORD / OSA / Rhinosinusitis
On examination what would you find?
• Tachypnoea • Use of Accessory Muscles • Prolonged Expiratory phase • Polyphonic Wheeze • Hyperinflated chest
• Severe Attack: PEFR 110/min RR>25/min, inability to complete sentences
• Life Threatening Attack: PEFR<33%, silent chest, cyanosis, bradycardia, hypotension, confusion, coma.
Is a chest x-ray necessary?
No, unless worried about an alrernative diagnosis.
How do you measure FEV? (forced expiratory volume)
With the blowey tube thing.
What's the blue inhaler for?
• Generally a Beta Agonist
• For Treatment of an attack
What's the brown inhaler for?
• It's a Preventer
• A Steroid (to reduce inflammation)
What are some non pharmacological methods to prevent asthma?
• Numerous – many with no evidence
• Breast Feeding
• Avoidance of Tobacco Smoke
• Weight Reduction
• House Dust Mites
• Allergen Specific Immunotherapy
• Buteyko Technique
What's the pharmacological therapy for asthma?
• Aim for control: no daytime symptoms, no night time awakening, no need for rescue medication, no exacerbations, no exercise limitation, normal lung function (>80% predicted)
• Regular review, Step down treatment as required.
What's the treatment for each severity of asthma?
1. Mild intermittent asthma = Inhaled Beta Agonist PRN
2. Regular Preventer Therapy = Add inhaled steroid
3. Initial add – on therapy = Add LABA / Increase Steroid / Trial Alternative Agent
4. Persistent Poor Control = Increase Steroid / Leukotriene RA, Theophylline, Oral Beta Agonist
5. Frequent use of Oral Steroids = Oral steroid