Wk 14: Asthma Flashcards
What is the pathophysiology of early phase asthma?
- Initiation of inflammatory cascade - IgE antibodies released
- IgE activates mast cells
- Leads to release of: leukotrienes, cytokines + histamines
- Smooth muscle constriction + inflammation
How is asthma diagnosed in suspected asthma?
- 6 wk treatment of ICS + SABA
- Asses response: baseline, questionnaire, lung function test (spirometry/peak expiratory flow)
- Improvement in symptoms + tests = asthma
- Lack of improvement = alt diagnosis
What are the results of an obstructive patient in spirometry testing?
- Low forced vital capacity (FVC)
- Low forced expiratory volume in 1 second (FEV1)
What is suggestive of asthma in spirometry results?
- Obstructive: FEV1/FVC <0.7
- Positive: improvement in FEV1 of ≥ 12% w/ inc in vol of 200ml
- Improvement in FEV1 of ≥ 400ml = asthma
Which objective lung function test is suitable for children?
Peak flow
How do you perform a peak flow?
- Deep breath in + hold for 2 secs
- Rapidly breathe out + record value
- Do 3x morning + night + record best
- Repeat twice daily for 2 wks
- Take average from day + night
- Take highest + lowest reading as percentage
- 20% diff. = asthma
What is the BTS approach?
SABA prn for relief + ICS BD for prevention
What are used for relievers + preventers?
- Relievers: SABA (salbutamol, terbutaline)
- Preventers: ICS + leukotriene receptor antagonists + LABAs
What are the steps for the management of asthma?
- Regular preventer: low dose ICS
- Initial add on: + inhaled LABA
- Additional: Inc ICS to medium or add LTRA, if no response to LABA - stop
When would you step up therapies?
- Asthma attack in last 2 years
- Inhaled SABA 3x per wk
- Symptomatic 3x per wk
- Waking 1 night per wk
- Affects daily activities
What happens when a patient is stable?
Dec ICS dose 25-50% every 3 months
SABA: examples, onset, duration of action + s/e
- Salbutamol + terbutaline
- Onset: 5-110 mins
- Duration:4-6hrs
- Fine tremor + tachycardia
ICS: examples, onset, duration of action + s/e
- Beclomethasone, budesonide
- Onset: 60 mins
- Duration: 12hrs
- Oral thrush
LABA: examples, onset, duration of action + s/e
- Formoterol, Salmeterol
- Onset: 5-10 mins (formeterol), 1-2 hrs
- Duration: 12hrs
- Tremors + tachycardia
LTRA: examples, onset, duration of action + s/e
- Montelukast
- Onset: 3 hrs
- Duration: 24hrs
- Neuropsychiatric
Do you need a SABA if initiated on MART regime?
No
What are the important points of ICS?
- Prescribed ALL stages
- Growth retardation
- Brand prescribing
What are examples of combination inhalers?
- Fostair
- DuoResp
- Seretide
- Relvar
How do you monitor theophylline?
- 5 days after starting
- 3 days after dose change
- 4-6hrs after dose
What is MART regimes?
- One inhaler for reliever + preventer
- Contains last acting LABA + ICS
- For: 18+, poor control despite regular preventatives, prefer one inhaler
- Maintenance in morning + evening
- If symptoms, can use extra puffs
Which inhalers are licensed for MART regimes?
- Fostair 100/6
- DuoResp 160/4.5
- Symbicort 100/6 or 200/6
What are examples of pMDI?
- Salbutamol evohaler
- Fostair + seretide evohaler
What is an example of a soft mist inhaler?
Spiriva respimat
What are examples of dry powder inhalers?
- Turbohaler
- Breath actuated
- NEXThaler
- Accuhaler
- Ellipta
- Breezhaler
- Genuair
What are the symptoms of acute asthma?
- Deteriorating symptoms over hrs + days
- Inc breathlessness, wheezing, coughing, tightness
- Difficulty talking
- Tachycardia
- Red PEFR
- Red oxygen sats
What classifies as moderate asthma?
- PEF >50-75%
- SpO2 >92%
- Normal speech
- Respiration <25
- Pulse <110
What classifies as acute severe asthma?
- PEF 33-50%
- SpO2 >92%
- Can’t complete sentence
- Respiration >25
- Pulse >110
What classifies as life threatening asthma?
- PEF <33%
- SpO2 <92%
- Silent
- Arrhythmia
- Exhausted
How do you manage and treat moderate asthma?
- B2 bronchodilator (4 puffs then 2 every 2 mins)
PEF >50-75%:
- Nebuliser (salbutamol 5mg)
- Pred 40-50mg
How do you manage + treat acute severe asthma/life threatening asthma?
- Oxygen
- B2 bronchodilator (4 puffs then 2 every 2 mins)
- Nebuliser (salbutamol 5mg)
- Pred 40-50mg or IV hydrocortisone 100mg
- No response: admit
What are the key treatments of acute asthma?
- Oxygen
- Steroids
- SABA
- SAMA
- Mg sulphate
Give examples of support self management that can be offered
- Education
- Avoid triggers
- Stop smoking
- Breathing exercise
- Ideal Body weight
