Asthma Flashcards
What is asthma?
chronic inflammatory disease of the airways characterised by reversible airways obstruction and bronchospasm
In children < 12mo, what other DDx should you consider besides asthma?
Bronchiolitis
How would you define when someone has poorly controlled asthma?
- > 3 uses of reliever/week
- > 3 night time wakenings/month
What are some triggers for asthma?
• Allergens • Pollutants, tobacco smoke, occupational fumes • URTIs - concurrent viral infection - MOST common • Exercise • Changes in weather - cold • Emotion, anxiety • Food, additives • Medication (aspirin, beta blockers) • GORD
What are the most important parameters in the examination of asthma? What are less important ones? What are not reliable ones?
Most important:
- general appearance/mental stat
- WOB
Less reliable:
- initial SaO2 in air
- HR
- ability to talk
Not reliable:
- Wheeze intensity
- pulsus paradoxus
- peak expiratory flow rate
If asymmetry is found on auscultation in asthma, what might be the cause, but what might another DDx be?
- Asthma - mucous plugging
- Other ddx: foreign body
How might you differentiate between mild, mod, severe and critical asthma attack?
Mild:
- Normal mental state
- can finish whole sentences in one breath
- subtle change in WOB, wheeze/normal auscultation
- no tachy
Mod:
- inc WOB, with tachy
- some limitation of talking
Severe:
- agitated/distressed
- few words in one breath
- mod-severe WOB, wheeze can be loud/little - not indicator of severity
- tachycardia
Critical:
- Confused/drowsy
- can’t vocalise
- Maximal WOB, silent chest, cyanotic, exhausted
- Marked tachy
Risk factors for asthma attack
- Previous ICU admission
- Poor compliance to asthma therapy
- Poorly controlled - significant interval symptoms
What might you see on derm exam for an asthma patient?
- atopic dermatitis (eczema)
- ‘allergic shiners’ (darkness and swelling under eyes caused by sinus congestion)
What signs on resp auscultation and percussion might you find with asthma?
○ Hyperresonance on percussion (airway oedema)
○ auscultation of chest
• Reduced breath sounds (airway oedema)
• Expiratory, polyphonic wheeze
(or silent chest)
Outline the interventions for an acute asthma attack, in order for severity.
- Salbutamol: MDI/spacer, 6-12 puffs, wait 20 mins
- Oral pred: 2mg/kg, 60mg max initially
- Ipratropium: MDI/spacer, wait 20 mins - 1 hour only
- IV Mg sulfate
- IV aminophylline (if deteriorating): loading dose then continuous/6h dose
- Consider IV pred
• O2 (when <92%), aim 92-96%
• Escalate care
○ Inc. adrenaline
○ ICU for resp support: positive pressure ventilation (CPAP, BiPAP), intubation
CPAP vs BiPAP
- CPAP helps oxygenate, continuous pressure to keep open
- BiPAP helps ventilation, pushes and pulls pressure
How many puffs of salbutamol in an asthma attack? Ipatropium?
- Salbutamol: 6 puffs if < 6 years old, 12 puffs if > 6 years old
- Ipratropium (Atrovent 20mcg/puff) dose: 4 puffs if < 6 years old, 8 puffs if >6 years old
SEs of aminophylline
N/V, arrhythmias, convulsions
Signs of salbutamol toxicity
Tremor, tachycardia, tachypnoea, metabolic acidosis, high lactate