24/02/2026
Investigation for Asthma
1. spirometry value of FEV/VC ratio indicates obstruction (relative accurate test for those who can perform it usually from age 6 up.
2. Measure of peak expiratory flow before and after SABA has a characteristic improvement of 15% in FEV and PEFR
3. Bronchial provocation test: airway reactivity is tested in respiratory laboratory to inhale histamine, methacholine or hypertonic saline
4. Fractional exhaled nitric oxide test
5. An exercise challenge can also be helpful
6. Allergy testing may be appropriate
7. Chest Xray not routinely but can be done if complications are suspected
Lets talk about Large volume spacers: π£οΈ
Metered dose inhalers are easy to use and convenient (MDI). But deliver less dose of the drug than when a spacer is used. The patient breaths in from the mouth piece taking at least 1 to 2 breaths over a 2-6second length.
Reasons for suboptimal asthma control.
A. Poor adherence
B. Ineffective use of inhaler device. Poor technique
C. Procrastination to introduce optimal therapy
D. Failure to prescribe preventative medication such as inhaled corticosteroids
E. Relying on inappropriate alternative techniques
F: Patient fears (corticosteroids, overdosing, developing tolerance, embarrassment and peer group condemnations)
G. Doctor reluctance to use corticosteroids, recommend obtaining a minimum peak flow, and obtaining a spacer.
H. Medical factors: obesity, rhinosinisitis, GORD, sleep apnea, vocal cord dysfunction, smoking and COPD
Disclaimer: the following information is not for self diagnosis but for education and individual cases should be discussed with your family doctor. π©π»ββοΈ