Case 2 - Asthma Flashcards
How do you diagnose asthma?
History and examination
Recurrence of Symptoms
Expiratory wheeze
Diurnal and seasonal variability of symptoms and peak flow
History of atopy
Absence of symptoms suggesting another diagnosis
What is the initial management depending on the probability that the patient has asthma?
High probability=start treating them assess the response. If treatment doesn’t help > medium probability
Medium probability=test for airway obstruction(spirometry + bronchodilator reversibility) > test for variability (PEF, reversibility challenge tests, atopy testing, IgE, eosinophils) > watchful waiting or commence treatment
Low=investigate and treat for the diagnosis that is most likely
How do you categorise the severity of asthma?
Moderate and severe acute only
Moderate acute:
- Increasing symptoms
- Peak flow>50-75% best/predicted
- No features of severe
Severe acute: Any one of: -peak flow 50-33% of best or predicted -RR 25+ -HR 110+ -Unable to speak in full sentences
How do you categorise the severity of asthma?
Life-threatening and near fatal only
Life-threatening: Any one of the following in a patient with severe acute: -normal CO2 -Peak flow less than 33% of best/predicted -Sats<92% -Hypoxic (O2<8kPa) -Silent chest -Cyanosis -reduced respiratory effort -Arryhtmia -Exhaustion -Hypotension -reduced consciousness/drowsy
Near fatal:
-high CO2
What are the investigations you could perform for asthma?
Spirometry with bronchodilator reversibility
Bronchial Challenge test
Peak flow
FeNO testing
What would spirometry show in asthma?
An obstructive picture that is reversible with bronchodilators (ie. increases by 15% following salbutamol administration)
FEV1:FVC reduced ie. less than 70%
FEV1 reduced
FVC stays the same or slightly reduced
Curve on graph would take longer but eventually reaches the same plateau
How would you perform bronchodilator reversibility in asthma?
Perform spirometry
Take 2 puffs of salbutamol
Repeat after 15-20 mins
What would a restrictive picture show in spirometry?
FEV1:FVC the same ie. over 70%
But with both FEV1 and FVC being reduced
How do you perform bronchial challenge testing in asthma?
Perform spirometry
Breathe in the irritant - metacholine/histamine/allergens/occupational triggers - through a neb for 2 mins
Wait 30s
Re-do spirometry
What would peak flow show in asthma?
Should make a peak flow diary BD for 2-4 weeks
Would see diurnal variation - worse in the morning, and seasonal
Should do every few hours in occupational asthma
May be used to diagnose or monitor treatment
With inhalers, should see overall improved peak flow and a smaller diurnal variation
What would FeNO testing show in asthma?
NO is released as a bronchodilator in response to inflammation
Therefore, in allergic asthma, will have a higher level of FeNO
Can distinguish allergic asthma from non-allergic asthma
Breathe out slowly and deeply into a monitor
What is the treatment of an acute exacerbation of asthma?
If at home, take one puff of reliever every 30-60s, up to a maximum of 10 puffs
A - patent, talking? Sit upright
B - sats, oxygen, resp exam (wheeze or silent chest, stridor on inspiration=upper airway obstruction), RR, peak flow if possible, give salbutamol 5mg and ipratropium nebs
C - HR, BP, CRT, IV access (hydrocortisone 100mg - or ORAL pred 50mg), ECG
D - check glucose
E - GCS/AVPU
re-assess patient every 20-30 mins
Give magnesium or theophylline if no improvement shown, under senior guidance
When can you discharge a patient after an acute exacerbation of asthma?
When they have been off nebs for 24 hours, have needed no PRN nebs and PEF is >70%
Discharge with a 5-6 day course of oral steroids
What is the treatment of chronic asthma?
1) SABA PRN - step up when using 3x week or more
2) Add low dose ICS and monitor
3) Regular low dose ICS - for those with PRN SABA/symptoms 3/7, waking at night 1/7 or attack in the last year
4) Low dose ICS + LABA - r/v in 4-8 weeks
5) One of:
- Stop LABA and use high dose ICS
- LABA and high dose ICS
- LABA and low dose ICS and another
6) Either V high dose ICS, 4th drug, specialist treatment
4th drug could be:
- Leukotriene receptor antagonist e.g. montelukast
- LAMA e.g. tiotropium
- Adenosine receptor blocker e.g. theophylline
What should be checked at an annual asthma review?
Does asthma affect ADL
Have asthma symptoms been present during the day?
Height
Weight
Any difficulty sleeping due to cough/SOB?
