Using peak flow meters to diagnose asthma

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Peak expiratory flow is a test that measures a person's maximum expiratory rate, to check lung function, and is commonly used in the diagnosis of asthma.

1. Peak flowmeter

Peak flowmeter is a handheld device that measures peak expiratory flow. This is a simple hand-held instrument with a bellows on one end and a scale on the other. A small plastic arrow moves as air is blown into the tube, measuring the air flow rate.
Peak expiratory flow is an important criterion in the diagnosis and monitoring of asthma. In addition, peak expiratory flow rate is also used when the patient has an acute asthma attack to assess the severity of the asthma attack. Peak flow is not measured in patients with severe respiratory distress or in critical situations.

2. Peak flow meter in asthma diagnosis

Peak expiratory flow test is a simple, common and can be done at home test that helps diagnose and monitor lung related problems including:
Asthma Obstructive lung disease Chronic dysfunction after lung transplant

The technique of performing peak expiratory flow measurement by peak flow meter includes 6 steps:
Step 1: Check the instrument before measuring, move the indicator button to zero on the ruler. Step 2: Stand up straight, can sit but must be straight, measure the same posture at all times. Step 3: The patient takes a deep breath in, put the tip of the peak flowmeter into the mouth so that the peak flowmeter is horizontal, perpendicular to the body, between the teeth, close the lips, do not let the tongue cover the blowing hole of the patient. peak flowmeter. Step 4: Blow really hard and fast, with maximum effort, in just 1 blow. Step 5: Take the peak flow meter out of the mouth, read and write the measured reading according to the stopper. Repeat 2 times like this, choose the highest index out of 3 measurements. Step 6: Spray bronchodilators 2-4 times, bronchodilators act as fast as ventolin. Then, wait 15-20 minutes each time and then repeat steps 3 to 5.

Peak expiratory flow readings are most valuable if checked at the same time each day. For an accurate assessment, the patient needs to be measured at least twice a day for 2 to 3 weeks. The best time to measure is in the morning and again in the evening.
To compare results between measurements, the patient needs to use the same peak flow meter and the same measurement method. Based on the results of peak expiratory flow after bronchodilator administration, compare % to theoretical value or % to patient's best value:
Mild > 80% Moderate 60%-80% Severe < 60% or less than 2 hours bronchodilator response In the diagnosis of asthma:
If the result is increased by 20% or more from pre-medication or the peak expiratory flow rate changes by or more than 20%. Patients will be trialed with beta 2 agonists and inhaled corticosteroids with results in reducing clinical symptoms such as relief of dyspnea, reduced lung murmurs, and improved peak expiratory flow.

Peak flowmeter is an instrument used to measure peak expiratory flow. The patient's best peak flow value is important in the diagnosis of asthma, and is used for comparison to help assess the severity of asthma in patients with bronchial asthma.
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