CSU - Peak Flow Meter

this is the notorious Peak-Flow meter station that was examined on our senior batch;
this summary was done with the kind contribution of Joe Wee, he had the notes for the peak flow CSU session.

introduction

Peak Flow Meter measures the PEAK Expiratory Flow RATE (PEF) in litres / min.
indications for peak flow meter are;

• recognition of early signs of a worsening asthma
• assess severity of asthma
• to differentiate between COPD and restrictive Lung disease
• self-monitoring of patients - they would know when to seek immediate medical help.
• indication of when to alter medications depending on the course of asthma.
• assess diurinal pattern
• 
  

methodology

1. GIEP. be clear to explain the procedure.
2. ask several questions regarding the patient's asthmatic history*
3. ask patient to stand upright
4. ensure that the peak flow meter reading is at 0 reading before beginning
5. place mouth piece onto the peak flow meter.
6. instruct patient to breath in deeply
7. instruct patient to place and cover the whole circumferance of the mouth-piece (so there is no air leakage), and exhale as hard and fast as they can. (also tell them NOT to cough)
8. record number
9. repeat 3 times
10. take the largest value of the 3.

*questions that could be asked are;

• how long have you been an asthmatic?
• have you done this before? 
• do you know what medication they're using? inhalers what colour? (Blue -> B-agonist, Brown ->Corticosteroids)
• are they free of any URTIs?

interpretations

you may be given a graph like this, for a first-timer patient for PEF examination.

using this graph, you may be able to roughly determine whether the person has the adequate PEF for his/her age and height. (which also suggests that the 3 factors affecting the person's PEF is AGE, SEX, and HEIGHT)

for e.g., if i am a 160cm tall 20yearold male, my PEF should exceed 570litres / min following this graph. etc etc.

in Monitering the known asthmatic case, this kind of chart may be used.

notice that the peak flow number isn't filled in. 

the ranges are decided by the proportion of personal best Peak Flow, therefore

80-100% of best PEF = green zone - no action

50-80% of best PEF = yellow zone - asthma worsening, start medication

less than 50% of PEF = red zone. - asthma control failing- contact doctor.