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
First aid for asthma: instructions
- DRS ABC
- 4 x 4 x 4: 4 puffs, in between each puff take 4 breaths, then wait 4 mins for improvement
- Do second round
- If not improvement on second round, call ambo
D/C after asthma attack - asthma d/c pack
- Review medications
- Check inhaler technique
- Family education
- Follow up plan/communicate with GP
- Written action plan
CLD for asthma
- 3-4hourly use of salbutamol
Ix to aid diagnosis of asthma, and requirements
- Major Ix is spirometry
○ For > 6 yo (or those who can perform it): FEV1 before and 10-15mins after bronchodilator
○ Minimum requirement of asthma in CHILDREN: 12% improvement in FEV1 with bronchodilator (salbutamol) only (not double req as adults) - Other Ix include:
○ Bronchial provocation tests
○ Cardiopulmonary exercise test - CXR generally not required
- ABG and spirometry not required in acute asthma in children
For long-term mx of asthma, what is the progression of medications used?
- SABA - reliever (salbutamol/ventolin)
- ICS - preventer
- If <12yo (general rule): If not ICS, then montelukast i.e. singulair tablet/cromone (preventers too) … then only LABA
- If >12yo (general rule): try + LABA, then switch ICS -> montelukast/cromone
- Increase ICS dose
Outline the major LABA/ICS combos (and compare)
- Symbicort (budesonide, eformoterol)
○ 2 min onset - acts as reliever too - Seretide (fluticasone, salmeterol)
○20 min onset - need ventolin too
What is montelukast?
Leukotriene receptor antagonist
When should you consider preventer use?
- Wheezing attacks less than 6/52 apart
- Attacks becoming more frequent and severe
- Increasing interval Sx
What should you counsel re:
- preventer use
- spacer vs MDI
- ICS use
- Preventers must be used every day
- Spacer always more effective
- rinse mouth (and use every day)
OSCE: inhaler technique:-
- General things to do
- Common mistakes
- Check pts technique by getting them to show you, not just ask
- Then show them, don’t just tell
- Inhalers, common mistakes:
○ Must check dose counter
○ Failing to shake inhaler
○ Inability to seal lips - need tight seal (without biting)
○ Wrong position - not tilted, upright
○ Failing to exhale fully before inhaling, then inhaling weakly and slowly
○ Not holding their breath for long enough
○ exhaling into the device mouthpiece before or after inhaling
○ Using past expiry date
Correct spacer technique
- Put together the spacer following the instructions that came with it.
- Remove the protective cap from the puffer.
- Shake the puffer well and insert (place)it firmly into the end of the spacer.
- Place mouthpiece in mouth between teeth + create tight seal/make sure mask covers mouth and nose, creating tight seal
- Hold level - not tilted
- Breathe out gently.
- Press the puffer ONCE to release a dose of the medicine into the spacer. Do not remove the puffer.
- Breathe in very slowly until you have taken a deep breath. You will hear a whistle sound if you are breathing in too fast. Hold your breath for a few seconds, then breathe out slowly and deeply through your mouth. Breathe in and out4 or 5 times (do not remove in between each breath - there is a 2 way valve system which will prevent any of the medication from escaping from the chamber).
- If a second dose is needed,shake the puffer againand repeat steps 4-7.You can shake the puffer while it is still attached/connected to the spacer.
How to care for a spacer: instructions.
- The spacer should be cleaned once a week.
- Take the spacer apart and wash it in warm water containing a little dishwashing detergent or mild soap.
- DO NOT RINSE.
- Allow the spacer to drip dry. Do not wipe the spacer dry with a tea towel or kitchen paper but allow it to air dry. This can be done overnight.
- Put the spacer back together.
- Do not allow anyone else to use your spacer.
Interpreting spirometry: obstructive vs restrictive.
FEV/FVC:
- Reduced ratio and scalloped flow/volume graph = obstructive
- normal ratio = restrictive
