Peak flowmetry. Algorithm for what it is, the norm in adults, children, a table for bronchial asthma, COPD, chronic bronchitis, pneumonia

Peak flowmetry is one of the methods by which diagnostics of respiratory diseases. The algorithm of the procedure is not complicated, it is easily mastered by patients. The technique allows you to assess the condition of the lungs and the effectiveness of the therapy.

What is peak flowmetry?

Peak flowmetry is performed to adjust treatment and prevent exacerbation of bronchial asthma. This standardized peak flow chart helps the clinician and the person with asthma recognize the nature of the disease and identify outbreaks at an early stage.

Peak flowmetry (the research algorithm must be studied before starting the procedure) is a diagnostic method by which the maximum expiratory air velocity is measured.

Peak flow monitoring helps determine the degree of airway obstruction (narrowing).

Because of the wide range of "normal" values ​​and the high degree of variability, peak flow is not always the recommended test for asthma. However, people with asthma can benefit from regular monitoring of peak flow and the doctor can evaluate the effectiveness of the therapy.

With regular monitoring of peak flow, the results are recorded on a peak flow chart. For daily monitoring of the condition, a portable peak flow meter, peak flow meter is used. It is important to use the same machine every time.

What is it for?

Peak flowmetry (the algorithm is the same for all devices) reflects the flow of air masses leaving the lungs in 1 min. with the maximum speed, which is measured in ml / min.

This is called PEF, the peak expiratory flow rate, which is measured in two ways:

• Short-term monitoring, for 2-8 weeks:
• helps in the diagnosis, including cases of occupational asthma, or the exclusion of asthma;
• to determine the causes of the disease;
• to monitor the effectiveness of treatment or change the dosage.
• Long term monitoring:
• for people with asthma who have frequent flare-ups (exacerbations);
• moderate or severe asthma;
• to control bronchial hyperactivity;
• helps to determine the moment for a change in therapeutic action;
• to identify the progression of the disease or addiction during prolonged therapy with the same type of drugs.

To determine "personal results", the patient must measure the maximum flow rate:

• twice a day for 2-3 weeks;
• in the morning, after waking up, in the afternoon or early evening;
• the procedure should be carried out 15-20 minutes after the application of an inhaled fast-acting beta2-agonist.

Albuterol is a common beta2 agonist. This medicine relaxes the muscles surrounding the airways, helping them to expand.

Benefits of PSV diagnostics

The peak flow meter is a diagnostic tool that is used to monitor lung function. It measures the rate at which air is expelled from the lungs. When several measurements are taken over several weeks or months, it can be determined whether the lungs are stable or worsening.

The use of a peak meter for moderate to severe asthma is an important part of treatment. Changes in the respiratory system should be monitored daily and the doctor should be informed when the narrowing of the airways occurs.

Regular use of a peak flow meter can help control asthma by detecting airway constriction before the onset of disease-specific symptoms. This allows time to adjust medications or take other therapeutic measures before symptoms worsen.

Peak flowmetry (the algorithm for adults and children is the same) is performed for children with suspected asthma, starting at the age of 5.

Indications

A peak flow meter can be used to assess other lung problems, such as:

• Emphysema. It is a chronic lung disease in which small vesicles in the lungs (alveoli) are affected.
• Chronical bronchitis. Prolonged inflammation of the bronchi, accompanied by sputum and chronic cough.

Contraindications to the procedure

There are no contraindications to taking measurements of peak daily expiration.

Design and types of peak flow meters

Mechanical models are commercially available, where readings are indicated with an arrow. There are also electronic models, on the display of which the readings are shown in numbers. The principle of the device is approximately the same. There is a mouthpiece on one side, a scale with clearly marked zones is indicated on the device itself. There is a plate inside the device that moves the slider when you exhale.

Firms engaged in the manufacture and supply of peak flow meters:

• Omron. The small size of the device allows you to take it with you for a walk, on a trip. Replaceable mouthpieces are available for both adults and children. The device is marked with a European scale for measurement, there is a convenient folding handle. It is easy to use and easy to care for.
• Personal Best Full Range. The device is suitable for the treatment and prevention of chronic bronchitis, asthma. It is used both at home and in clinics and laboratories. The mouthpiece has a device that prevents accidental air ingress, is easy to handle due to the ergonomic handle.
• Vitalograph. A portable device that determines the function of external respiration. It can be used to measure the maximum value of the air jet output using the three-zone asthma control system.
• Philips Respironics Personal Best. The device is easy to use. It has a foldable handle, with which it is convenient to observe the indications during the procedure. The set includes a protective cover required for transportation. Lightweight, easy to clean, even dishwasher safe. The device provides the ability to calibrate values ​​for a specific patient, taking into account his age, health status.

Many devices are equipped with special covers to protect them from damage.

Algorithm and recommendations for taking measurements

Peak flowmetry is performed 1 or more times a day at the same time of day, or when there are early signs of asthma.

Algorithm of the procedure:

• Ensure that the slide pointer on the Peak Air Meter is reset to 0 before each use.
• Hold the PFM by the handle.
• Stand up or sit up straight.
• Take a deep breath and place the mouthpiece in your mouth, wrapping your lips and teeth tightly around it

  

• Exhale the air sharply.
• Pay attention to the number on the scale where the pointer stopped.
• Reset pointer to 0.
• Repeat the procedures 3 times, pause 2-3 minutes between sessions.
• If saliva or water gets into the meter, the reading may be affected.
• Record the highest of the 3 readings on the graph and record it in your diary.
• Do not average all numbers together. The highest number will be the best personal indicator of maximum flow.
• Peak flows should be measured at the same time every day.
• After the session, the apparatus should be cleaned and rinsed.
• If a new meter is used, a new personal value must be found on the device.

In adults

For adults, devices are available with a graduation from 60 to 850 l / min. It is not recommended to touch the scale with your hands during measurement.

In children

For children 8–9 years old, devices with a scale not exceeding the norm of 350 l / min are produced. When purchasing a peak flow meter for a child over 9 years old, its height and weight should be taken into account. If the height of the child is over 1 m 40 cm, it is necessary to buy models intended for adults.

Peak flowmetry rates in adults, children (table)

The peak flow meter displays the result as a unit of volume per unit of time. In particular, the unit of measure for the peak flow meter is liters per minute. Normal peak flow meter readings depend on the parameters: height, age, and gender of the person. For measuring the expiratory force in children, only age is taken into account.

Normal peak air flow for men:

Age	Growth
1 m 65 cm	1 m 70 cm	1 m 80 cm	1 m 90 cm
20	602	649	693	740
25	590	636	679	725
30	577	622	664	710
35	565	609	651	695
40	552	596	636	680
45	540	583	622	665
50	527	569	607	649
55	515	556	593	634
60	502	542	578	618
65	490	529	564	603
70	477	515	550	587

The figures shown in the table should not be considered rigorous. There is such a thing as an individual norm, which is determined over several days with good health.

Normal peak air flow for women:

Age	Growth
1 m 55 cm	1 m 60 cm	1 m 70 cm	1 m 85 cm
20	423	460	496	529
25	418	454	490	523
30	413	448	483	516
35	408	442	476	509
40	402	436	470	502
45	397	430	464	495
50	391	424	457	488
55	386	418	451	482
60	380	412	445	475
65	375	406	439	467
70	369	400	432	461

When measuring peak output, it is best to plot the reading. This will give a clearer picture of the development of the disease. Do not forget about the accompanying factors that influenced the force of exhalation.

PSV indicators in children under 15 years of age:

Growth	90	100	109	115	120	131	138	145	150	161	168	170
l / min	100	119	139	171	210	251	280	126	160	399	430	475

Normal peak meter readings are between 80-100% of baseline, indicating stable lung function. When the reading is between 50% and 80% of the baseline, it indicates a deterioration in lung function. Indications below 50% of the baseline indicate a medical emergency.

Peak flow zones

Peak flux is interpreted in traffic light-like color zones.

• Green Zone: 80 to 100 percent of normal consumption. This is the ideal zone, it means that the condition is under control, the drug should be taken according to the prescribed regimen.
• Yellow zone: 50 to 80 percent of normal consumption. If the pointer is between the 2 yellow marks, it indicates that the condition is getting worse.
• Red zone: less than 50 percent of the normal level. This indicates that the airway is narrowed and medical attention should be sought immediately.

Registration of results in the diary

Keeping a self-control diary is essential for successful asthma management. The maximum values ​​are marked on the graph in the corresponding column - in the evening or in the morning of a certain date. The set with the device is supplied with diaries: daily and weekly. The first is filled every 2 hours, and the second - 3 times a day or daily for 7 days.

In the diary, one should note in the comments the circumstances that influenced the changes in the volume of air:

• contact with an allergen;
• physical exercise;
• cold;
• newly taken medications.

If the measurements allow for 20% or more changes in peak flow measurements taken after waking in the morning, then compared to daily readings obtained after using an asthma medication, this may indicate a developing disease. In this case, the shape of the graphic image is close to a straight line.

A more zigzagged graph indicates a worsening condition.

Consistently high peak flow rates indicate that a person can cope with asthma. If peak flow rates vary greatly over the course of the day, this is a sign that the disease is poorly controlled. The lowest peak flow rates are usually in the morning, between 4 and 8 am. The highest rates appear at noon and in the late afternoon, between 4 and 6 pm.

Peak flowmetry indicators for bronchial asthma, COPD, chronic bronchitis, pneumonia

There are several reasons for incorrect peak meter readings. Any lung condition that decreases air flow will result in an incorrect reading. Asthma, chronic obstructive pulmonary disease, and emphysema are some of the conditions that affect peak flow meter readings. It always decreases with obstructive diseases.

Indicators for various types of diseases:

• PSV in bronchial asthma> 8о% of the due, and daily fluctuations <20-30%.
• PSV in severe bronchial asthma <60% of the due, and daily fluctuations> 30%.
• PSV in chronic bronchitis is about 80%.
• PSV with COPD is less than 70-80% of the due.
• Community-acquired pneumonia, PSV <50% of the due.

What is the correct assessment of the results obtained?

Peak flowmetry (the algorithm of the procedure does not depend on the patient's age) is one of the methods of self-control, but the first measurements are best done under the supervision of a doctor.

The functions of the lungs of a person who is regularly involved in sports, and the performance of an organ in a patient differ from each other, but the parameters of a person may be the same. In this case, you should focus on the best personal measurements that were recorded in the process of asthma treatment, and not on the average numbers in the table,

If the disease is in remission, the best indicators will be daily measurements set for 1-3 weeks during the period of relief of symptoms.

The border of the green zone is determined as follows: the best indicator is multiplied by 0.8. If that was 500 l / min, then multiplying this figure by 0.8, you get 400 l / min. Another value above this figure will refer to the green zone, which indicates the normal functioning of the bronchi.

How to determine the border of the yellow zone: the personal indicator should be multiplied by 0.6. For example, the best personal figure is 500 l / min, hence the lower limit = 600 * 0.6 = 300 l / min. Thus, the yellow zone is between 400 l / min and 300 l / min.

The red zone is defined by a figure less than the lower limit of the yellow zone, 300 l / min.

Peak flowmetry price

The diagnostic procedure for determining the speed of exhaled air can be carried out in a laboratory setting. The sessions are conducted by pulmonologists, while giving consultations on the disease.

Procedure cost:

• Electronic flowmetry - from 100 to 600 rubles.
• Electronic flowmetry with a preliminary intake of a bronchodilator - from 500 to 750 rubles.

Patients with asthma, chronic obstructive airways disease should purchase an apparatus for performing procedures at home. The expiratory flow rate in this case will be clearly visible in dynamics. Many firms produce devices in two versions, with a full, 60-180 l / min, and low, 30-390 l / min, range.

Cost of devices:

• Omron PFM-20 - 1,000 RUB 590
• RESPIRONICS, Philips firm - 1 thousand. RUB 290
• VITALOGRAPH, made in Ireland, - 816 rubles.
• Peak flow meter for adults PERSONAL BEST - 1,000 RUB 470
• Personal Best peak flow meter for adults and children (Philips Respironics) - 1,000 800 RUB
• Personal Best peak flow meter for adults and children (Philips Respironics) - 900 rubles.

A diary for recording daily readings can be purchased separately. Cost - from 30 to 50 rubles.

Peak flowmetry is a painstaking business and requires attention. But the mastered algorithm of the procedure will help to control the state of health, observe a certain therapy regimen, and notice the impending danger in time.

Peak flowmetry video

What you need to know about peak flowmetry: