Peak flow meter

My son, like many allergy sufferers, is at risk of developing bronchial asthma, so he got acquainted with the peak flow meter when he was 4 years old.

Peak flow measurement, along with breath nitric oxide measurement, is considered the main method for managing asthma, according to the scientific committee of the GINA (Global Strategy for the Treatment and Prevention of Asthma).

The international GINA program has been operating since 1993, with leading asthma specialists from around the world taking part in its activities.

What is peak flow meter

The task of peak flow meter is to determine the maximum expiratory flow rate. Determine the speed using a special device – peak flow meter. Measured in liters per minute (l / min.).

Who needs this research

Peak flow meter is prescribed for patients with bronchial asthma, chronic bronchitis and other diseases that require constant monitoring of the state of the airway patency. Since allergy sufferers with sensitive mucous membranes of the nose and bronchi are often predisposed to bronchial asthma, peak flow meter will also be useful for them.

Indications for peak flow meter

• Diagnostics of bronchial asthma, when it is not possible to make the function of external respiration.
• Assessment of the severity of asthma in the course of the disease.
• In the case when it is necessary to distinguish bronchial asthma from chronic obstructive pulmonary disease (COPD).
• Control of bronchial asthma.
• Forecast of exacerbation of the disease.
• Determine the feasibility of changing the treatment strategy.
• Assess the patient’s response to new drugs.
• Prevent addiction to drugs.

What age is peak flow meter prescribed

The test can be done at any age, but young children (under 4-5 years of age) are unlikely to be able to perform the test correctly. Toddlers may be blowing out air with their cheeks or loosely wrap their lips around the mouthpiece of the peak flow meter.
My son, a fan of inflating balloons, mastered peak flow at age 4.

Peak flow meter device

The peak flow meter is a device invented in England in 1957 that measures the expiratory flow rate.

Types of peak flow meters

• Mechanical (Omron, Philips, Personal Best);
• Electronic (eMini Wright).

Advantages of mechanical peak flow meters

• The price is lower;
• Simple to use;
• They rarely break;
• No batteries needed.

Advantages of electronic peak flow meters

• Measured more accurately;
• You can set individual indicators;
• You can save, view and compare results;
• There is additional functionality;
• Compact.

Which peak flow meter to choose

According to their purpose, peak flow meters are divided into two groups.

1. For children – from 35 to 350 l / min (height up to 135 cm).
2. For adults – from 60 to 800 l / min (height above 135 cm).

It is best to choose a peak flow meter that has colored sliders or color-coded zones.
The mouthpiece of the device can be round or oval with a protective cap. Rounded mouthpieces are better for kids.

We have a mechanical peak flow meter from OMRON, which we only use to monitor the bronchi during flowering. It seems to me that for daily use, an electronic device would be better suited.

Peak Flow Meter Care

The peak flow meter is an individual device, so after use it must be wiped off with an alcohol wipe or left for 10 minutes in a disinfectant solution (see the article How to clean inhalers) or use replaceable mouthpieces.

Before using the peak flow meter device

Ask your pulmonologist or allergist-pulmonologist for detailed test instructions. Specify how long peak flow measurement can be performed in your case.

• Usually it is 1-2 weeks – when there is no exacerbation of the disease and the patient does not take medicine;
• If the asthmatic is receiving inhalation therapy, then testing should be done before inhalation (the doctor may suggest other options).

Peak flow diary

Be sure to keep a peak flow diary, where you will record all the indicators obtained, indicate medications and factors that could affect the state of the bronchi (weather, emotional or physical stress).
It is better to keep entries in a notebook in a cage or in a special diary that can be downloaded on the Internet.

How to use a peak flow meter

• The starting position for the test is standing;
• measurements should be taken in the morning and evening, twice a day;
• it is better to do the test on an empty stomach in the morning, in the evening 2 hours after eating (consult your doctor);
  keep the peak flow meter horizontal;
• before the test, set the indicator of the device to 0 (or below the minimum digit);
• take in as deep a breath as possible;
• tightly wrap your lips around the mouthpiece (tip);
• exhale as strongly and sharply as possible through the peak flow meter (as if blowing out a candle from a distance);
  write down the result;
• repeat measurements 2 more times, remembering to set the indicator to zero;
• select the maximum (highest) result and record it in the peak flow diary.

Peak flow meter range

According to GINA 2018

Peak flow meter zones are marked with colored markers, by analogy with a traffic light: green, yellow, red.

Green zone (80-100% of the norm) – everything is fine. Everything’s under control. Normal lung condition.

Yellow zone (50 – 80% of the norm) – attention. Deterioration warning. Analyze the indicators of the diary and be sure to consult a doctor – you need to find the cause of the deterioration.

Red zone (less than 50% of the norm) – danger! It is necessary to urgently consult a doctor or call an ambulance.

It is interesting that the patency of the bronchi changes during the day.
Fluctuations in patency in healthy children should not change by more than 15% of the norm.
20% of the norm – in children with bronchial asthma, in remission.

Peak flow meter chart

Test results will vary based on age, gender, weight and height. You cannot expect the same results for a young athlete and an elderly couch resident.

The generally accepted table for evaluating peak flowmetry data compares indicators only by height, which is not entirely true.
Therefore, do not chase the results on the table, remember that the results depend on many factors.

For example, some children can inflate a balloon at 2 years old, while others find it difficult to cope with this task at 7 years old.
It is important to understand which numbers are optimal for your baby.

Table of approximate norms of peak flow in children, depending on height

height (м)	rate (L / min)	height (м)	rate (L / min)
0.85	87	1.30	212
0.90	95	1.35	233
0.95	104	1.40	254
1.00	115	1.45	276
1.05	127	1.50	299
1.10	141	1.55	323
1.15	157	1.60	346
1.20	174	1.65	370
1.25	192	1.70	393

Explanations for the table

First, you need to find out what expiratory indicators will be the norm for your child. The rate is determined at a time when the child is healthy, there are no exacerbations of the disease.

Let’s say your child has an expiratory flow rate (PSV) of 200 L / min. This means that indicators of at least 160 l / min will be a green zone for him (up to 80% of his norm).

If the expiratory flow is in the range of 100 to 160 l / min. – this is the yellow zone (below 80% of the norm).

Indicators less than 100 l / min. (less than 50% of the norm) – this is the red zone. We urgently need to see a doctor.

Peak flow meter rate for adults

If the rates for children is recommended by GINA, then official data on peak flow rates for adults could not be found. Therefore, use numbers for guidance. My healthy and athletic husband couldn’t blow the norm for his age and height. So don’t panic and look for your result.

Men

Age height	15	20	25	30	35	40	45	50	55	60	65	70
160 sm	518	568	598	612	613	606	592	578	565	555	544	534
168 sm	530	580	610	623	623	617	603	589	577	566	556	546
175 sm	540	590	622	636	635	627	615	601	588	578	568	558
183 sm	552	601	632	645	646	638	626	612	600	589	578	568
190 sm	562	612	643	656	656	649	673	623	611	599	589	579

Men

Age height	15	20	25	30	35	40	45	50	55	60	65	70
145 sm	438	445	450	452	452	449	444	436	426	415	400	385
152 sm	450	456	461	463	463	460	456	448	437	425	410	396
160 sm	461	467	471	474	473	470	467	458	449	437	422	407
168 sm	471	478	482	485	484	482	478	470	460	448	434	418
175 sm	481	488	493	496	496	493	488	480	471	458	445	428