Asthma (Raf) Flashcards
What is the definition of severe asthma?
Key point: Treatment needed: high dose ICS and second controller for previous year / oral steroids >50% last year -asthma either uncontrolled despite these or needing the above for prevention of loss of control
Supplemental points:
1) Asthma diagnosis confirmed by history and objective measures
2) Environmental factors, comorbidities, adherence and inhaler technique addressed before labelling as severe asthma
Asthma control criteria as per CTS?
History: Daytime symptoms <4 days per week No night time symptoms SABA doses <4 doses per week No physical activity limitation Not missing any work or school Mild, infrequent exacerbations Objective testing: FEV1>=90% of personal best Diurnal variation of PEF <10-15% Sputum eosinophils <2-3%
Definition of uncontrolled asthma, as per ATS?
- Not meeting control criteria, as based on CTS criteria or standardized questionnaires
- Frequent severe exacerbations: 2 or more exacerbations needing oral steroids for >=3 days
- After bronchodilator withold, FEV1<80% of personal best or
ABPA criteria for asthma?
- Based on ISHAM 2013:
- Total IgE>1000
- positive Aspergillus specific IgE or skin prick test
- 2 or 3 out of:
- Eosinophils > 500
- radiological features consistent with ABPA
- raised aspergillus IgG or precipitating antibody
Normal values for FeNO in child (<12 years) and adult
Child: 20-34
Adult: 25-50
What is considered significant difference in FeNO
For FeNO>50: 20% change is significant
For FeNO<50: 10 point change is signifciant
What is the intepretation of an elevated FeNO?
- eosinophilic airway inflammation
- predsicts steroid responsiveness
- may suggest persistent allergen exposure
- can support the diagnosis of asthma, but there are also non-eoinophilic types of asthma
- can be used to monitor airway inflammation in asthma
Patient with asthma, ongoing symptoms, but low FeNO?
Unlikely eosinophilic airway inflammation or persistent allergen exposure, unlikely to benefit from increased ICS dose, look for other causes of symptoms
Asthma patient, no ongoing symptoms, low FeNO, manangement?
Consider weaning ICS and repeating FeNO in about 1 month
Asthma patient, ongoing symptoms, high FeNO?
- eosinophilic airway inflammation or persistent allergen exposure
- inadequate ICS–non-adherence, poor technique or need an increase in dose
- risk for exacerbation
Causes for low FeNO?
1) Adequately treated with steroids - no symptoms
2) Technical faults - constant expiratory flow is not maintained - will have symptoms
3) Smoking can cause lower FENO levels - can have symptoms
4) Non eosinophilic asthma(steroid resistant) - will have symptoms
Why shouldn’t you use PEF in children
- PEFR should NOT be used to diagnose asthma since it is very effort dependent and only reflects obstruction in large central airways
- Numbers can be artificially high with tongue thrusts or spitting. Or they may be artificially low due to not enough effort or poor technique
Onset of action for ipratropium and main side effect?
- Onset of action at 20 minutes, with peak at 60 minutes
- S/E: dry mouth
Spiriva (tiotropium): drug category, receptor and duration of action?
- Anticholinergic
- Muscarinic receptor - M1, M2, M3 (it’s a muscarinic receptor antagonist)
- Duration: 24 hours (this is why there is a long withhold time of up to 48 hours prior to bronchodilator testing)
- Peak onset of action: 1-3 hours
- Typical dose: 2 puff of 1.25 micrograms, given once daily
How is salmeterol different than formoterol?
- Salmeterol:
- slower onset of action (10-30 minutes) versus 5 minutes for formoterol
- shorter duration of action (9 hours) versus 12 hours
- partial agonist of the B2 adrenergic receptor so flatter dose response curve and less bronchoprotection against methacholine (recall that bronchoprotection and bronchodilation are similar, but slightly different effects of LABA)
