Function of external respiration state index from to. Spirometry - goals, indications and contraindications, indicators of the condition of the lungs, how the procedure is carried out, norms, interpretation of the results, where to do it, price. Spirometry and spirography. Will the FVD show in a child

Preparation for functional diagnostics

Memo for the patient in preparation for spirography

(examination of the function of external respiration)

When preparing for the study, you must follow simple rules:

- if you smoke, do not smoke during the day before the study (if this failed, strictly - do not smoke for 2 hours before the study);

- do not drink alcohol during the day before the study;

- exclude a heavy meal 2 hours before the study, your breakfast should be light;

- exclude physical activity (including physical education and climbing stairs) during2 hours before the study;

- put on clothing that does not restrict movement before the examination, come to the examination in advance, relax in front of the office;

- be sure to tell the specialist conducting the study about your medication (name, dose, time of the last dose on the day of the study). Be careful, this information is very important!

- you need to know the exact data of height and weight;

- carry a handkerchief;

Before the study, it is strictly forbidden to take the following medications:

• for 6 hours - salbutamol, ventolin, berotek, salamol, asthmapent, berodual, terbutaline (brikanil), alupent, atrovent, traventol, truvent, or their analogues;
• for 12 hours - teopek, teodur, teotard, monofillin-retard;
• within 24 hours - intal, sodium cromoglycate, ditek, servent, formoterol, volmax;
• for 96 hours - hormonal preparations - becotide, ingakort, budesonide-forte, flexotide.
• During the study of the function of external respiration, you will breathe into an individual mouthpiece, the device will measure the speed and volume of air flow during inhalation and exhalation. It is possible that some samples will be repeated several times to select the result. During the study, to assess the reaction of your body, it may be necessary to take or inhale the drug and then repeat the study.
• The examination is safe, it usually takes 15-30 minutes if you correctly perform the breathing movements recommended by the specialist conducting the examination. You can discuss the results of the study with your doctor.

Before an EEG study, it is necessary:
- wash your hair the day before the examination
- do not use styling products on the day of the examination
- feed infants before the study.

Before conducting an EEG video study, the patient must comply with the following conditions:
The study is conducted by appointment only.
Have with you:
- referral or medical history,
- a diaper or sheet.
For younger children, a bottle of formula, tea, juice, water, toys, books.
Preparation for the study:
The time of night sleep on the eve of the study and the time of awakening on the day of the study are discussed in advance with the doctor who conducts EEG video monitoring. The child must be delivered to the study in an awake state,
because when examining, it is very important to record how the child falls asleep. Clothing should be comfortable, soft with long sleeves
long pants (it is impossible to hide during the examination). If the examination is carried out at lunchtime before the examination, it is advisable to feed the child.

Before conducting a ABPM study, the patient must comply with the following conditions:

The wearable SMAD recorder is installed for a day. Blood pressure measurements are taken automatically during the daytime every 15 minutes,
during hours of night sleep - every 30 minutes. inefficient measurement of blood pressure or when a measurement result is obtained that differs sharply from the previous measurement, the device
measures blood pressure after 3 minutes. If repeated measurements are repeated frequently, it is necessary to check the position of the cuff on the arm

When conducting research:

- any change of activity, especially physical activity (any, even insignificant, namely: running, walking, climbing - descending the stairs);



- any complaints about a change in well-being.
Keeping such a diary allows the doctor to clarify the causes of episodic rises or decreases in blood pressure and correctly interpret the results of the study.
3. The patient needs to control the position of the cuff and, if necessary, correct it so that the lower edge is 1-2 fingers higher than the elbow bend. All manipulations with the cuff should be carried out after a successful measurement of blood pressure. 4. During the study, it is prohibited:





- carrying out other diagnostic procedures (X-ray, ultrasound, gamma scintigraphy, computed and magnetic resonance imaging)

- remove the batteries from the monitor; - mechanically damage or wet the device (do not take a shower or bath on the day of the study). 5. The patient (child) recognizes the beginning of the measurement by squeezing the shoulder due to an increase in pressure in the cuff. At this moment, if the patient was walking or running, it is necessary to stop, lower the arm with the cuff along the body, relax the muscles of the arm as much as possible, do not move your fingers and do not talk. If the patient is sitting or lying down, the hand should be left in the same position in which it was at the time the device was turned on and not move. 6. In case of excessive clamping of the hand and the occurrence of unpleasant disturbances in it (swelling, discoloration), it is necessary after measurement:
- raise the arm with the cuff up to restore blood circulation;
- contact the medical staff, or the department where the device was installed.

Before conducting a SCM ECG study, the patient must comply with the following conditions:

Wearable SCM ECG recorder is installed for a day, constantly recording ECG
throughout the duration of the study.

When conducting research:
1. The daily routine, the mode of physical activity should be as normal as possible.
2. The patient must necessarily keep a diary of self-observation, in which it is necessary to mark in time:
- any change in activity, especially physical activity (any, even insignificant, namely: running, walking, climbing - descending the stairs);
- psycho-emotional stress;
- the main meals and medications (with the name and dose of the drug);
- sleep (time to fall asleep and time to wake up);
- any complaints about a change in well-being, especially pain or discomfort in the region of the heart, interruptions in the heart rhythm.
Keeping such a diary allows the doctor to correctly interpret the results of the study.
3. During the study, it is prohibited:
- to be near and use microwave ovens;
- use radiotelephones and cell phones;
- pass through the metal detector arch and electromagnetic arches in stores;
- use electric transport (trams, trolleybuses, electric trains);
- work with a computer (including a laptop);
- carrying out other diagnostic procedures (X-ray, ultrasound, gamma scintigraphy, computed and magnetic resonance imaging)
- independently disconnect the connectors of the device;
- remove the batteries from the monitor;
- mechanically damage or wet the device (do not take a shower or bath on the day of the study);
- do not touch wires and electrodes unnecessarily. In the event that the wires are disconnected from the electrodes or the electrodes from the body, it is necessary to restore the integrity of the system, because. ECG recording may stop or become unreadable.

Reminder for the patient in preparation for endoscopic examination of the intestine

(fibrocolonoscopy, sigmoidoscopy)

Bowel preparation is one of the most important factors in the success of an endoscopic examination, which results in an accurate diagnosis.

For high-quality bowel preparation, 2 conditions must be met:

2-3 days strict adherence to a slag-free diet, on the day of preparation for the study: switching to clear liquids and equivalent products (clear broth, green tea, clear juices without pulp, jelly without berries and grains, still water)

Direct bowel cleansing with FORTRANS preparations, "FLIT-Phospho-soda", (following the instructions for use)

If during the use of drugs, during bowel cleansing, pains in the abdomen of a cramping nature appear - call an ambulance!

Three days before the study:

It is impossible: Meat, black bread, fresh fruits and vegetables, greens, beans and peas, mushrooms, berries, seeds, nuts, jam with stones, incl. small (currant and raspberry), grapes, kiwi.

Do not take vaseline oil, activated charcoal and preparations containing iron!

You can: Broth, boiled meat, fish, chicken, cheese, white bread, butter, biscuits (without poppy seeds)

If you suffer from constipation, you should take a laxative at least a week before the test (consult your doctor about the drug).

Remember! If the endoscopist is not satisfied with your bowel preparation, the examination will be rescheduled.

Do not hesitate to ask, the doctor and the nurse will give you detailed, understandable recommendations on how to behave during the procedure so that it goes the least unpleasantly, as soon as possible and successfully. Listen carefully and follow the advice of the examining physician.

Location of the study: GAUZ NSO "GKP No. 1", Lermontov St., 38, aab. No. 117

Bring sheets and towels with you.

Preparation for laboratory research

Blood analysis: A necessary condition is blood sampling on an empty stomach. For 1-2 days, exclude fatty, fried foods from the diet. Blood should not be donated after x-rays, massage, physiotherapy. The results of the studies are affected by the intake of medications, if you are taking medications, you should definitely notify the doctor about this.

blood glucoseIN ADDITION TO ALL OF THE FOLLOWING, IT IS IMPOSSIBLE TO: BRUSH YOUR TEETH, CHEW CHEWING GUM, DRINK TEA OR COFFEE (THE IS NOT SWEET). THIS ANALYSIS MAY BE AFFECTED BY ANY TABLETS YOU TAKE.

General urine analysis: BEFORE COLLECTING URINE IN THE INTENDED DISHES, IT IS NECESSARY TO TAKE THE EXTERNAL GENITAL ORGANS TOILET AND DRY THEM WITH A CLEAN TOWEL. DO NOT USE DIRTY DISHES. AND 24 HOURS AFTER DRINKING ALCOHOL. YOU NEED TO COLLECT THE FIRST MORNING PORTION (Previous urination SHOULD BE NO LATE THAN 4-6 HOURS). FOR ANALYSIS, 50-100 ML OF URINE IS ENOUGH.

Urinalysis according to Nechiporenko.: Before taking urine, perform hygiene of the external genital organs, as well as before a general urine test, after which an average portion of early urine is collected in a clean 100 ml container.

3. Analysis is taken on an empty stomach, while cardiovascular and antihypertensive drugs are not canceled !!!

4. On the day of the test for the sugar curve, the patient comes to office No. 15 at 8 o'clock in the morning, having with him a referral from the attending physician with the result of a blood test for glucose and 75 g of glucose in powder (buy at the pharmacy the day before). Have an individual glass for dissolving glucose with you.

5. A glucose solution is prepared by a laboratory assistant.

6. Blood is taken from the patient on an empty stomach, then they are given a glucose solution to drink (no more than 5-10 minutes).

7. After 2 hours after exercise, the blood is taken again.

GLUCOSE TAKING AND 2 HOURS AFTER MEAL:

When determining glucose on an empty stomach and 2 hours after a meal, the subject donates blood on an empty stomach from 8 to 10 am, and the next day donates blood 2 hours after a meal (cereal or bun and a glass of tea) from 8 to 10 am.

Memo for the patient in preparation for the biochemical study of urine (calcium, phosphorus, Rehberg's test, uric acid)

• Urine collection begins at 7 a.m., while the night portion is poured into the toilet, and the remaining portions during the day (from 7 a.m. to 7 a.m. the next day) are collected in clean dishes with a capacity of 1.5 - 2 liters.
• Urine is stored at a temperature from +4 C to +8 C.
• Before delivery to the laboratory, the urine is thoroughly mixed and the volume is measured to the nearest 10 ml. (infants with an accuracy of 1 ml.), Cast 50 - 100 ml. for delivery to the laboratory.
• Urine is delivered to the laboratory at st. Lermontov No. 40, 2nd floor, interdistrict centralized biochemical laboratory, in the accompanying form, the patient indicates the time of collection and the total volume of urine.
  

Preparing for an MRI of the abdomen:

• .during the day it is necessary to refuse food products that increase gas formation (carbonated drinks, sour-milk products, black bread, fruits, vegetables);
• .when performing MRI of the spleen, liver, pancreas, a carbohydrate-free diet is sometimes recommended 2-3 days before the procedure;
• .on the day of the diagnosis, it is advisable to eat light food, refuse coffee and tea;
• .after the last meal, at least 6-8 hours should pass;
• .should refrain from drinking 4-6 hours before the examination;
• .with increased gas formation, it is recommended to take a tablet of Espumizan or activated charcoal;
• .you must have with you all the necessary medical documentation relating to the organ under study (ultrasound, CT, x-ray data, postoperative extracts).
• Memo for the patient in preparation for X-ray examination of the urinary tract, lumbar spine, barium enema
• 1. 2 days before the study, exclude from the diet foods that cause bloating (legumes, fresh fruits, vegetables, black bread, milk)
• 2. On the eve of the study, take 30 g in the morning. (2 tablespoons) castor oil.
• 3. On the day of the study, 3 hours before the study, make a cleansing enema.
• 4. For barium enema, bring a sheet and toilet paper with you.

Preparation before the ultrasound.

Ultrasound of the abdominal organs:

2-3 days before the examination, it is recommended to switch to a slag-free diet, exclude from the diet products that increase gas formation in the intestines (raw vegetables rich in vegetable fiber, whole milk, black bread, legumes, carbonated drinks, as well as high-calorie confectionery products - pastries, cakes ). The last meal in 2000 the day before, children up to a year three hours before meals.

It is advisable to take enzyme preparations and enterosorbents during this period of time (for example, festal, mezim-forte, activated carbon or espumizan 1 tablet 3 times a day), which will help reduce the manifestations of flatulence.

Ultrasound of the abdominal organs must be performed on an empty stomach. If you plan to conduct the study outside of the morning, a light breakfast is allowed at least 6 hours before the study.

Gynecological ultrasound:

The examination with a transabdominal (through the abdomen) sensor is performed with a full bladder, therefore it is necessary not to urinate before the examination for 3-4 hours and drink 1 liter of non-carbonated liquid 1 hour before the procedure.

For transvaginal ultrasound, special preparation is not required; this study is used, among other things, to determine pregnancy in the early stages.

Ultrasound of the bladder and prostate in men:

The study is performed with a full bladder, so you must not urinate before the study for 1-2 hours and drink 1 liter of non-carbonated liquid 1 hour before the procedure. Before transrectal prostate examination (TRUS), a cleansing enema should be given.

Ultrasound of the mammary glands:

It is desirable to conduct a study of the mammary glands from the 5th to the 10th day of the menstrual cycle (optimally 5-7 days). The first day of the cycle is counted from the start of menstruation.

Breathing is the main property of any living being. As a result of respiratory movements, the body is saturated with oxygen and gets rid of carbon dioxide, which is formed during metabolism (metabolism). There are two stages in respiration:

• external (gas exchange between the environment and the lungs);
• internal or tissue (the process of transferring gases by red blood cells and the use of oxygen by body cells).

One of the directions for diagnosing specific and nonspecific (chronic bronchitis, asthma, emphysema) pulmonological diseases is the study of the function of external respiration.

What is FVD

FVD in official medicine is a whole complex of studies of the state of the lungs and bronchi. The main methods are spirography, body plethysmography, pneumotachometry, peak flowmetry.

How is the study of FVD

Pulmonologists prescribe a study of respiratory function to calculate the volume of the lungs, the speed of work and identify the pathology of the respiratory system in order to diagnose, monitor the development of the disease and the effectiveness of treatment. Ecologists, biologists and physicians study the features of external respiration of people for a comparative analysis of the influence of environmental conditions on the body. IHPV is necessary to determine the suitability of a person to work in special conditions, for example, under water, or to determine the degree of loss of temporary disability.

Indications for FVD

The main indications are diseases of the respiratory system:

• bronchial asthma, bronchitis;
• infectious and inflammatory processes in the lungs, alveolitis;
• silicosis, pneumoconiosis and other respiratory pathologies.

Silicosis is an occupational disease that develops with regular contact with dust containing silicon dioxide. Pneumoconiosis develops in miners when coal dust is inhaled.

Who is contraindicated for IHFD

• in acute infectious or febrile conditions;
• children under 4 years old, since at this age they can rarely adequately understand the instructions of doctors;
• with stable angina, heart attack, recent stroke, uncontrolled hypertension;
• after a recent operation;
• heart failure, causing a sharp non-specific respiratory failure during exercise or at rest;
• aortic aneurysm;
• with mental illness.

More difficult classical spirography determines latent bronchospasm. Therefore, to identify the obstructive type of respiratory pathology, a test is performed using Salbutamol, Ventolin or Berodual (this is called a bronchodilator test). The study is carried out before and after inhalation of a bronchodilator. The presence of a difference in spirometry readings makes it possible to assume a hidden spasm of bronchial vessels, to identify violations at the initial stages of the development of the pathological process.

If the test with Salbutamol shows negative results, this means that the bronchi do not respond to bronchodilators, the test and the obstruction has become irreversible.

Before spirography with bronchodilator Salbutamol, 6 hours before the examination, you can not use other drugs of similar action. This can deceive a specialist in respiratory function, which will lead to incorrect interpretation of the results, ineffective treatment of the disease.

Examination of respiratory function with a bronchodilator is safe, it can be performed in children. Contraindications are basically the same as with conventional spirometry. A bronchodilator should not cause an allergic attack.

Vital capacity of the lungs

VC (vital capacity) indicates how much air can enter the lungs after the deepest breath. If this indicator is below the norm, then there is a decrease in the respiratory surface of the pulmonary vesicles - the alveoli.

FVC - functional vital capacity of the lungs, the maximum amount of air to exhale after a maximum breath. It characterizes the extensibility of lung tissue, bronchi. The indicators should be less than the VC, since part of the air during such an exhalation remains in the lungs. If FVC is less than VC per liter or more, pathology of small bronchial vessels is assumed. Due to the rapid collapse of the bronchi, the air does not have time to leave the lungs.

Indicators

The main indicators in a healthy person:

Forced expiratory volume

FEV1 - determination during forced expiration of the volume of air in 1 second. The indicators decrease in chronic bronchitis, bronchial asthma - obstructive disorders, in which the exit of air from the bronchial tree is difficult.

Tiffno index

Shows the percentage of FEV1 parameters to FVC. Normally, U is from 75 to 85%. The value of the Tiffno index decreases due to FEV1 with age or obstruction. This indicator becomes more than normal when the elasticity of the lung tissue changes.

Minute ventilation rate

MVL shows the average amplitude of maximum respiratory movements, multiplied by their number in 1 minute. Normally, this figure is from 250 liters.

Pneumotachometry

A simple, accessible and informative method for diagnosing the functional state of the pulmonary system, airway patency. The essence of the study is to measure the speed of air passing through the respiratory tract during inhalation and exhalation using a pneumotachometer. The device is equipped with a special tube with a replaceable mouthpiece.

Indications

It is prescribed for bronchial asthma, atopic bronchitis, pneumosclerosis and chronic obstructive pathology, to select the most optimal therapy.

Contraindications

Pneumotachometry is prohibited for such indications:

• recent stroke, heart attack;
• high blood pressure;
• acute inflammatory processes in the respiratory organs;
• aneurysms, respiratory failure, epilepsy;
• pregnancy.

Study preparation

The patient needs:

• stop drinking alcohol and cigarettes on the eve of the study;
• for the day to give up heavy physical exertion, try not to get into stressful situations;
• 4-5 hours to stop taking bronchodilators;
• prepare loose clothing that will not hamper breathing movements;
• On the day of pneumotachometry, refuse breakfast.

For a more accurate determination of the state of the respiratory system, anthropometric measurements are carried out before the study.

Where is pneumotachometry performed?

The procedure is carried out in the office of a hospital or clinic. The patient sitting on the couch is clamped with a special clip, the tube of the device with a sterile mouthpiece is given. The patient is offered to make several calm respiratory movements, then several maximum breaths. The doctor fixes, then deciphers the readings of the device, determines the tactics of treatment.

Indicators

Normal research indicators for pneumotachometry:

With a chronic violation, a decrease in speed indicators occurs. This means that there is a narrowing of the distal, small bronchi.

Peakflowmetry

An examination method that determines the rate of exhalation and the degree of narrowing of the branches of the bronchial tree. This test is given to patients to do at home.

Indications

It is prescribed for patients with chronic respiratory pathologies, bronchial asthma, bronchitis with difficulty breathing, asthma attacks. The test is carried out in the morning and in the evening during the time determined by the doctor. During peak flowmetry, peak expiratory flow rate (PEV) is recorded - the highest air velocity in the respiratory tract during maximum exhalation. With the help of this test, you can predict, track the dynamics of the disease, adjust treatment, and control medication.

Thanks to peak flowmetry, it is possible to determine the relationship between bronchospasm and signs of the disease, select more effective inhalers, and prevent the onset of seizures.

Types of peak flowmeters

Peak flow meters are available in two versions - for hospitals and home use. Home appliances are small, compact, easy to fit in pockets or handbags, and last at least two years. They have a graduation in the form of color zones - green, red, yellow. There are models for different age categories of patients, or universal ones. Children differ from adults in the scale of divisions. For children, the scale is from 35 to 350 l / min. For adult devices, the scale is 50-850 l / min.

Technique for using the device

Using the device is quite simple - you need to wrap your lips around the mouthpiece and blow harder. The test should be carried out in a standing position, in the morning and in the evening, with a difference of 10 or 12 hours, on an empty stomach, half an hour after the end of active physical work or exercise.

results

The green part of the scale (from 80 to 100%) indicates the normal functioning of the respiratory system, the correct treatment.

The yellow scale (from 50% to 80%) requires careful attention to your health and the need to consult a doctor for advice.

The red scale (less than 50%) indicates that the patient's condition is dangerous, the treatment does not give positive results, an urgent examination or hospitalization is needed.

Peak flow diary

Keeping a diary is mandatory, because according to these results, the doctor can control the course of the disease, replace drugs with more effective ones, and give appropriate recommendations.

Bodyplethysmography

A research technique that allows you to fully explore the work of the respiratory system, more accurately establish a diagnosis, and select a qualitative therapeutic treatment. The device, body plethysmograph, is a camera for a person, a pneumotograph, a computer, on the display of which the researcher reads data - residual volume, total and functional residual lung capacity.

With the help of pneumotachometry, peak flowmetry, spirographic research methods, an effective diagnosis of pulmonary diseases is achieved, treatment is prescribed and corrected, and forecasts for the development of the disease and recovery of patients are made.

The study of the function of external respiration allows you to respond in a timely manner to changes in the state of health, prevent complications and maintain the health and vitality of patients.

Keywords: respiratory function, spirography, obstruction, restrictive changes, bronchial resistance

The role of the study of the function of external respiration (RF) in pulmonology is difficult to overestimate, and the only reliable criterion for chronic obstructive pulmonary diseases are respiratory disorders detected by spirometry.

Objective measurement of respiratory function as monitoring in bronchial asthma is similar to the corresponding measurements in other chronic diseases, for example, measuring blood pressure in ar-teri-al hypertension, determining the level of glucose -zy in diabetes mellitus.

The main objectives of the study of respiratory function can be formulated as follows:

1. Diagnosis of violations of respiratory function and an objective assessment of the severity of respiratory failure (RD).
2. Differential diagnosis of obstructive and restrictive disorders of pulmonary ventilation.
3. Substantiation of pathogenetic therapy of DN.
4. Evaluation of the effectiveness of the ongoing treatment.

All indicators characterizing the state of the function of external respiration can be conditionally divided into four groups.

The first group includes indicators characterizing lung volumes and capacities. Lung volumes include: tidal volume, inspiratory reserve volume and residual volume (the amount of air remaining in the lungs after maximum deep exhalation). Lung capacities include: total capacity (the amount of air in the lungs after maximum inspiration), inspiratory capacity (the amount of air corresponding to the tidal volume and inspiratory reserve volume), vital capacity (consisting of tidal volume, inspiratory reserve volume -ha and expiration), functional residual capacity (the amount of air remaining in the lungs after a quiet exhalation - residual air and expiratory reserve volume).

The second group includes indicators characterizing lung ventilation: respiratory rate, tidal volume, minute respiratory volume, minute alveolar ventilation, maximum lung ventilation, respiratory reserve or respiratory reserve ratio.

The third group includes indicators characterizing the state of bronchial patency: forced vital capacity of the lungs (tests of Tiffno and Votchal) and the maximum volumetric respiratory rate during inhalation and exhalation (pneumotachometry).

The fourth group includes indicators characterizing the efficiency of pulmonary respiration or gas exchange. These indicators include: the composition of the alveolar air, the absorption of oxygen and the release of carbon dioxide, the gas composition of arterial and venous blood.

The volume of the study of the respiratory function is determined by many factors, including the severity of the patient's condition and the possibility (and expediency!) The most common methods for the study of respiratory function are spirography (Fig. 1) and spiro-metry.

Rice. one. Spirogram of the expiratory maneuver (according to Roitberg G.E. and Strutynsky A.V.)

Evaluation of respiratory function indicators

Quantitative assessment of spirographic indicators is carried out by comparing them with the standards obtained during the examination of healthy people. Significant individual differences in healthy people force, as a rule, to use not the general average of one or another indicator, but to take into account the sex, age, height and weight of the subjects. For most of the spiro-graphical indicators, due values ​​have been developed, for some, a range of individual differences in healthy people has been determined. The proper value in each specific case is taken as 100%, and the one obtained during the examination is expressed as a percentage of the due.

The use of proper values ​​reduces, but does not completely eliminate individual differences in healthy people, which for most indicators are within 80-120% of due, and for some - in an even wider range. Even small deviations from the results of the previous examination of the patient can indicate the magnitude and direction of the changes that have occurred. Their correct assessment can only be given taking into account the reproducibility of the indicator. It should be noted that when evaluating the final result of the study, it is physiologically more justified to use the largest value, rather than the average of several measurements, regardless of the number of repetitions. Below, the criteria for evaluating individual spirographic displays.

Minute respiratory volume (MOD)

With a calm and even breathing of the patient, the TO is measured, which is calculated as an average value after registering at least six respiratory cycles. In the course of the study, the respiratory rate (RR) habitual for the patient at rest, the depth of breathing and their qualitative ratio, the so-called breathing pattern, can be assessed. Taking into account the respiratory rate and respiratory volume, the minute respiratory volume (MOD) can be calculated as the product of BH by DO.

It is well known that one of the main clinical manifestations of pulmonary insufficiency is the increase and superficial nature of breathing. However, according to the instrumental study, these signs have a very limited diagnostic value.

The volume of respiration in healthy people fluctuates over a very wide range - in conditions of basal metabolism in men from 250 to 800, in women from 250 to 600, and in conditions of relative rest, respectively, from 300 to 1200 and from 250 to 800 ml, which practically deprives these indicators of diagnostic value. So, with chronic pneumonia, respiratory rate of more than 24 per minute is usually observed only in 6-8% of patients, OD less than 300 ml - in 1-3%.

The detection of hyperventilation at rest was previously given great diagnostic value. With its presence, the idea of ​​\u200b\u200bpulmonary insufficiency was almost eliminated. Indeed, in patients with frequent and shallow breathing and an increase in dead space due to uneven distribution of air in the lungs, the ventilation efficiency deteriorates. The proportion of the volume of respiration involved in the ventilation of the alveoli decreases to 1/3 against 2/3-4/5 in the norm. To ensure a normal level of alveolar ventilation, it is necessary to increase the MOD, which has to be observed in all cases, even with hypoventilation of the alveoli.

In some pathological conditions, hyperventilation occurs as a compensatory reaction in response to disturbances in other parts of the respiratory system. Therefore, the idea of ​​hyperventilation at rest as a valuable diagnostic indicator is correct, provided that the influence of the emotional factor on ventilation is excluded. This can be achieved only with strict observance of the conditions of the main exchange. The conditions of relative rest do not give any guarantees in this regard.

With relative rest, patients show a tendency to a greater increase in MOD than in healthy people. So, in chronic pneumonia, more than 200% of the MOD is observed in 35-40% of cases, while in healthy people - in 15-25% of the MOD below the norm, but not less than 90% is observed extremely rarely - only in 2-5% of all cases. teas. This proves the low value of this indicator.

Test VC, FVC (forced VC)

This most valuable stage in the study of the function of external respiration is the measurement of flows and volumes during forced ventilation maneuvers. Performing the test can provoke a coughing fit, and in some patients even an attack of labored breathing.

The vital capacity of the lungs in healthy people ranges from 2.5 to 7.5 liters, such a variation in values ​​​​requires the mandatory use of proper values. Of the many proposed formulas for calculating proper VC, the following can be recommended:

• due VC BTPS = due basal metabolic rate * 3.0 (for men);
• due VC BTPS = due basal metabolic rate * 2.6 (for women).

The limits of the norm are in the range of 80-120% due. In patients with initial pathology, VC below normal is recorded in 25% of cases. In the second stage of chronic pneumonia, this figure almost doubles and amounts to 45-65%. Thus, VC has a high diagnostic value.

The inspiratory reserve volume is normally 50 (35-65)% VC while sitting, 65 (50-80)% VC lying down. Expiratory reserve volume - sitting 30 (10-50)%, lying down - 15 (5-25)% VC. In case of pathology, there is usually a decrease in ROvd, ROvyd in % VC.

Forced VC in healthy people actually reproduces VC and, thus, is its repetition. Differences in VC and FVC in men are 200 (-600:::+300) ml, in women - 130 (-600:::+300) ml. In the event that FVC is greater than VC, which, although not often, can be observed both in normal conditions and in pathology, according to general rules, it should be taken into account as the largest value of VC. Values ​​that go beyond the reproducibility limit of VC acquire diagnostic value. In the case of obstruction of the FVC, the VC is significantly lower, and in the presence of restriction, the VC will decrease first of all.

Maximum voluntary ventilation (MVL)

This is the most stressful part of the spirographic study. This indicator characterizes the limiting capabilities of the breathing apparatus, depending both on the mechanical properties of the lungs and on the ability to perform the test well in connection with the general physical fitness of the subject.

In a number of patients, especially in the presence of vegetative dystonia, the implementation of this maneuver is accompanied by dizziness, blackness in the eyes, and sometimes fainting, and in patients with severe bronchial syndrome expiratory dyspnea may be significantly increased, so the test should be considered as potentially dangerous for the patient. At the same time, the information content of the method is low.

The indicator of air movement speed (PSVV) is the ratio of MVL / ZHEL. PSLV is usually expressed in l / min. With its help, it is possible to differentiate restrictive violations of ventilation from a violation of bronchial patency. In patients with bronchial asthma, it can be reduced to 8-10, with a restrictive process - increased to 40 or more.

Forced expiratory volume (FEV), Tiffno index

This test has become the gold standard for diagnosing bronchial asthma and chronic obstructive pulmonary disease.

The use of a forced exhalation test made it possible to control tracheo-obronchial patency using functional diagnostic methods. The result of forced exhalation is determined by a complex of anatomical and physiological properties of the lungs. A significant role is played by the resistance to the flow of exhaled air in the large bronchi and trachea. The determining factor is the elastic and transmural pressure, which causes compression of the bronchi (Benson M. K., 1975 op. cit.). Normally, at least 70% of the forcedly exhaled air falls on the first second of exhalation.

The main spirographic indicator of obstructive syndrome is the slowing down of forced exhalation due to an increase in airway resistance and a decrease in FEV1 and the Tiffno index. A more reliable sign of broncho-obstructive syndrome is a decrease in the Tiffno index (FEV1 \ VC), since the absolute value of FEV1 can decrease not only with bronchial obstruction, but also with restrictive disorders due to a proportional decrease in all pulmonary volumes. mov and capacities, including FEV1 and FZhEL. With normal lung function, the FEV1/FVC ratio is over 80%.

Any values ​​below those given may suggest bronchial obstruction. Spiro-graphy indicators lose their value at FEV1 values ​​less than 1 liter. This method of studying bronchial patency does not take into account a decrease in the volume of forced exhalation due to expiratory collapse of the bronchi during exhalation with effort. A significant drawback of the test is the need for a maximum breath preceding a forced exhalation, which can temporarily prevent bronchospasm in healthy individuals (Nadel V. A., Tierney D. F., 1961 J, op. cit.), and in a patient with bronchial asthma induce bronchoconstriction (Orehek J. et al., 1975, op. cit.). The method is unacceptable for the purposes of the examination, since it entirely depends on the desire of the patient. In addition, forced exhalation often causes cough in patients, which is why patients with severe cough, regardless of their will, do not perform the test properly.

Volumetric air flow measurement

Already in the early stages of the development of an obstructive syndrome, the calculated indicator of the average volumetric velocity decreases at the level of 25-75% of the FVC. It is the most sensitive spirographic indicator, indicating an increase in airway resistance earlier than others. According to some researchers, a quantitative analysis of the expiratory part of the flow-volume loop also makes it possible to form an idea of ​​the predominant narrowing of large or small bronchi (Fig. 2).

Rice. 2. Curves of inspiratory and expiratory volumetric velocity (flow-volume loop) in a healthy person and a patient with obstructive syndrome (according to Roitberg G.E. and Strutynsky A.V.)

It is believed that the obstruction of large bronchi is characterized by a decrease in the volumetric rate of forced expiratory flow, mainly in the initial part of the loop, and therefore such indicators as peak volumetric velocity (PIC) and maximum volumetric flow rate at 25% of FVC (MOS 25% or MEF25). At the same time, the volume flow rate of air in the middle and end of expiration (MOS 50% and MOS 75%) also decreases, but to a lesser extent than POSvyd and MOS 25%. On the contrary, with obstruction of small bronchi, a predominantly vein decrease in MOS of 50% is detected, while PVR is normal or slightly reduced, and MOS of 25% is moderately reduced.

However, it should be emphasized that these provisions are currently quite controversial and cannot be recommended for use in clinical practice. MOS 50% and MOS 25% are less force dependent than MOS 75% and more accurately characterize small bronchial obstruction. At the same time, when obstruction is combined with restriction, leading to a decrease in FVC and a slight increase in speed towards the end of expiration, one should very carefully draw a conclusion about the level of obstruction.

In any case, there are more reasons to believe that the uneven decrease in the volumetric air flow rate during forced expiration reflects the degree of bronchial obstruction rather than its localization. The early stages of bronchial constriction are accompanied by a slowdown in the expiratory air flow at the end and middle of exhalation (decrease in MOS 25%, MOS 75%, SOS 25-75% with little changed values ​​of MOS 25%, FEV1 / FVC and POS), while with severe bronchial obstruction, a relatively proportional decrease in all speed indicators, including the Tiffno index, POS and MOS25%, is observed.

Measurement of peak volumetric air flow during forced exhalation (PEF) using a peak flowmeter

Peak flowmetry is a simple and affordable method for measuring peak volumetric airflow rate during forced expiratory flow (PEF). PEF monitoring is an important clinical test used in the doctor's office, emergency room, hospital, and home. This study allows you to assess the severity of the disease, the degree of daily fluctuations in lung function, which will make it possible to judge the hyperreactivity of the respiratory tract; it also helps evaluate the effectiveness of therapy, identify clinically asymptomatic impaired pulmonary ventilation and take action before the situation becomes more serious.

In most cases, FEV correlates well with FEV1 and FEV1 / FVC, the value of which in patients with broncho-obstructive syndrome varies within a day within a fairly wide range. Monitoring is carried out with the help of modern portable and relatively inexpensive individual peak fluometers, which allow you to fairly accurately determine POSvyd during forced exhalation. PSV variability is assessed using home 2-3-week monitoring of PSV with measurement in the morning, immediately after waking up and before bedtime.

The lability of the bronchial tree is assessed by the difference between the minimum morning and maximum evening PSV values ​​in% of the average daily PSV value; or the lability index with the measurement of only morning PSV - the minimum value of PSV in the morning before taking a bronchodilator for one to two weeks in% of the best lately (Min% Max).

The daily spread of PSV values ​​by more than 20% is a diagnostic sign of the daily variability of the bronchial tree. The morning decrease in PSV is considered morning failure.The presence of even one morning failure during the measurement of PSV indicates the daily variability of bronchial conduction.

PSV may underestimate the degree and nature of bronchial obstruction. In this situation, spirography is performed with a broncho-li-ti test.

When performing peak flowmetry, broncho-obstructive syndrome can be assumed if:

PSV increases by more than 15% 15-20 minutes after inhalation (a fast-acting 2-agonist, or

PSV varies during the day by more than 20% in a patient receiving bronchiolitis (> 10% in a patient not receiving them), or PSV decreases by more than 15% after 6 minutes of continuous running or other physical load.

With a well-controlled broncho-obs-tructive syndrome, in contrast to an uncontrolled one, fluctuations in PSV do not exceed 20%.

Measurement of lung volumes

The parameters discussed above, measured using spirography, are highly informative in assessing obstructive pulmonary ventilation disorders. Restrictive disorders can be reliably diagnosed if they are not combined with a violation of bronchial patency, i.e. in the absence of mixed disorders of pulmonary ventilation. Meanwhile, in the practice of a doctor, it is mixed disorders that most often occur (for example, with bronchial asthma or chronic obstructive bronchitis, complicated by emphysema and pneumosclerosis). In these cases, violations of pulmonary ventilation can be diagnosed by analyzing the value of lung volumes, in particular the structure of the total lung capacity (TLC or TLC).

To calculate the REL, it is necessary to determine the functional residual capacity (FRC) and calculate the indicators of the residual lung volume (RCR or RV).

The obstructive syndrome, characterized by airflow limitation at the outlet, is accompanied by a distinct increase in the TEL (more than 30%) and FRC (more than 50%). Moreover, these changes are detected already in the early stages of the development of bronchial obstruction. With restrictive disorders of pulmonary ventilation, the REL is significantly below the norm. At clean restriction (without concomitance with obstruction), the structure of the OEL does not change significantly, or there is a slight decrease in the ratio of OOL / OEL. If restrictive disorders occur against the background of violations of bronchial patency, then, along with a clear decrease in the REL, there is a significant change in its structure, which is characteristic of broncho-obstructive syndrome: an increase in TRL / TEL (more than 35%) and FFU / TEL ( more than 50%). In both variants of restrictive disorders, VC is significantly reduced.

Thus, the analysis of the structure of the OEL makes it possible to differentiate all three variants of ventilation disorders (obstructive, restrictive and mixed), while the analysis of only spirographic parameters does not make it possible to reliably distinguish a mixed variant from an obstructive, accompanying one. given by a decrease in VC (see table).

Table.

Airway resistance measurement

Compared to the tests described earlier, the measurement of airway resistance is not as widely used in clinical practice. However, bronchial resistance is a diagnostically important parameter of pulmonary ventilation. Unlike other methods for studying respiratory function, the measurement of bronchial resistance does not require patient cooperation and can be used in children, as well as for the purpose of examination in patients of any age.

Indicators of aerodynamic resistance of the respiratory tract allow us to distinguish true obstruction from functional disorders (for example, in the case of pro-vis-sa-nia volume-flow loops, normal numbers of resistance and RO indicate autonomic imbalance of bronchial innervation). Maximum inhalation and forced expiration can cause bronchial constriction, as a result of which, sometimes, when prescribing bronchodilators, FEV1 remains the same or even decreases. In these cases, it becomes necessary to measure the resistance of the airways using the whole body plethysmography method (see below).

As you know, the main force that ensures the transfer of air through the airways is the pressure gradient between the oral cavity and the alveoli. The second factor that determines the magnitude of the gas flow through the airways is the aerodynamic resistance (Raw), which in turn depends on the clearance and length of the airways, as well as on the viscosity gas. The value of the volumetric air flow velocity obeys Poiseuille's law:

where V is the volumetric velocity of the laminar air flow;

∆P-pressure gradient in the oral cavity and alveoli;

Raw-aerodynamic resistance of the airways.

Therefore, to calculate the aerodynamic resistance of the airways, it is necessary to simultaneously measure the difference between the pressure in the oral cavity and al-ve-o-lah, as well as the volumetric air flow rate:

There are several methods for determining airway resistance, among them

• whole body plethysmography method;

• airflow blocking method.

Whole body plethysmography method

With plethysmography, the subject sits in a sealed chamber and breathes air from the extra-chamber space through a breathing tube. The breathing tube begins with a mouthpiece and has a shutter that allows you to block the flow of breathing gases. Between the mouthpiece and the damper there is a pressure sensor of the mixture of gases in the oral cavity. Distal to the damper in the breathing tube is a gas mixture flow sensor (pneumatic tachometer).

To determine the resistance of the airways, two maneuvers are performed: first, the subject breathes through an open hose connected to a pneumotachograph, while determining the individual relationship between the volumetric airflow rate (V) and the changing pressure in the plethysmograph chamber (Pcam) . This dependence is registered in the form of the so-called bronchial resistance loop. Wherein:

The slope of the bronchial resistance loop to the Pcam axis (tgα) is inversely proportional to the value of Raw, i.e. the smaller the angle α, the smaller the air flow and the greater the resistance of the airways.

To calculate specific Raw values, it is necessary to establish a relationship between Ralv and Rkam. With the hose flap closed, the patient makes short attempts inhalation and exhalation. Under these conditions, the alveolar pressure is equal to the pressure in the oral cavity. This allows you to register a second dependency between Ralv (or Rrot) and Rcam:

Thus, as a result of performing two breathing maneuvers, the value of the air flow velocity V and the alveolar pressure Ralv necessary for the calculation can be expressed in terms of the pressure in the chamber of the plethysmograph Pcam. Substituting these values ​​into the Raw definition formula, we get:

Air flow shutoff method

This method is used more often, since it is easier to determine bronchial resistance with its help. The technique is based on the same principles as the determination using integral plethysmography.

The value of the air flow rate is measured with calm breathing through a pneumotacho-graphic tube. To determine Ralv, a short-term (no more than 0.1 s) blocking of the air flow is automatically performed using an electromagnetic damper. In this short period of time, Ralv becomes equal to the pressure in the oral cavity (Prot). Knowing the value of the air flow rate (V) immediately before the moment of overlapping of the pneumotachograph tube and the value of Ralv, it is possible to calculate the resistance of the airways:

Normal values ​​of tracheobronchial resistance (Raw) are 2.5-3.0 cm of water. st/l/s.

It should be noted that the method of blocking the air flow allows you to get accurate results, provided that the pressure in the system is equalized very quickly (within 0.1 s) alveoli-bronchi-trachea-oral cavity. Therefore, with severe violations of bronchial patency, when there is a significant unevenness of pulmonary ventilation, the method gives underestimated results.

When using the technique of interrupting the air flow with a valve to determine the alveolar pressure, its value is influenced by the asin-phase resistance of the lungs, which leads to a false increase in alveolar pressure and, consequently, to a false increase in bronchial resistance .

In order to take into account the differences in the indicators obtained by different methods, the airway resistance value measured in the body plethysmograph was traditionally called bronchial resistance. And the value measured by the dynamic component of the transpulmonary pressure is aerodynamic resistance. Principles-pi-al-but these concepts are synonymous, the only difference is that different methods are used to measure them.

In clinical practice, the reciprocal of Raw (1/ Raw airway conductance) is often used. When analyzing the results of plethysmography, the concept is also used specific conductivity of the airways-gaw:

where VGO is the intrathoracic volume of gas.

Normal Gaw values ​​are about 0.25 w.c.

An increase in Raw and a decrease in Gaw indicate the presence of an obstructive syndrome. The upper respiratory tract accounts for about 25%, the trachea, lobar, segmental bronchi for about 60%, and the small airways for about 15% of the total airway resistance.

An increase in airway resistance may be due to:

1. swelling of the mucosa and hypersecretion of mucus (for example, with bronchitis);
2. spasm of smooth muscles (bron-chi-al asthma);
3. narrowing of the larynx due to inflammatory or allergic edema or swelling of the larynx;
4. the presence of a tracheal tumor or dyskinesia of the membranous part of the tracheal mucosa;
5. bronchogenic lung cancer, etc.

It should be noted that the interpretation of the results of the study of respiratory function should be made taking into account the clinical picture and other paraclinical studies.

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Various diagnostic methods are used to assess the functioning of the respiratory system. In this case, it is useful to know spirography - what it is, why it is performed, and what results it can give. There are certain rules for the preparation and implementation of the procedure itself.

FVD - what is it in medicine?

One of the most common options for diagnosing pulmonary diseases is the study of respiratory function (RF). It includes several methods, including spirography. The function of external respiration is the easiest way to detect bronchopulmonary diseases. The procedure is simple and the price is low, so everyone can be checked regularly.

What is spirography and how is it performed?

This assessment method involves determining the volume of air that is inhaled and exhaled, as well as the speed of movement of air masses during breathing. Describing spirography - what kind of procedure it is, it is worth pointing out that it is very informative. For its implementation, specialized devices are needed - spirographs. They can be closed or open circuit. The technical operation of the device is based on registering changes in the filling of a certain container after the patient exhales. There are sensors in the apparatus that monitor the amplitude of the fluctuations of the bellows.

What does spirography show?

During the study, the device records changes in the volume of air and the speed of the flows that pass through it. The interpretation of spirometry begins with a visual assessment of the shape of the obtained curves. After that, the specialist conducts a quantitative analysis of the result, for which the obtained numerical indicators are compared with existing standards. As a result, a spirometric report is issued. Attention deserves spirometry with - it is a bronchodilator drug that helps to draw more accurate conclusions.

Spirography - indications

The meaning of the study is to determine how the volume of the lungs changes during normal and enhanced breathing. Spirography is performed for bronchial asthma and other pathologies. In addition, with the help of such procedures, the effectiveness of the chosen treatment is established. Spirography is prescribed for such symptoms:

• prolonged cough;
• frequent respiratory diseases;
• and feeling of incomplete inspiration;
• acute allergic reactions.

Spirography - contraindications

Not everyone is allowed such a procedure, so it is important to take into account the existing contraindications without fail. FVD spirography is prohibited in the presence of such factors:

• sepsis;
• pneumothorax;
• acute myocardial infarction;
• exacerbation of bronchial asthma;
• tuberculosis;
• increased hemoptysis;
• serious mental disorders;
• other serious health problems.

Spirography - preparation for the study

To get accurate results, you need to properly prepare for the procedure.

How is spirography performed?

The procedure is carried out in a sitting position while maintaining the natural position of the body, head and neck. Since the emphasis is on mouth breathing, but a clip is put on the nose, and the mouthpiece should be pressed as tightly as possible to exclude the possibility of air leakage. The basic instruction on how spirometry is performed includes the following steps:

1. The specialist enters the patient's data into the program, which include height and weight.
2. A person puts a clip on his nose and tightly wraps his lips around the mouthpiece.
3. The procedure begins with calm breathing, and then, at the command of the doctor, a change in rhythm, depth and technique is made. The changes are repeated several times to keep the data as accurate as possible.
4. The duration of the procedure is 15 minutes. Depending on the individual characteristics of the patient, the algorithm for the procedure may vary.

Spirometry with bronchodilator

The procedure provides important information for bronchial asthma, bronchitis and so on. At the same time, there is a risk that latent bronchospasm may go unnoticed, therefore, experts recommend the function of external respiration with a bronchodilator, for example, Berodual or Salbutamol. Such a test is carried out as an addition to the standard complex. This type of study takes into account breathing parameters before and after inhalation of a drug that reduces spasm. If the values ​​differ from those obtained during the standard procedure, then this may indicate a latent bronchospasm.

Spirography - interpretation of the results

When everything is finished, the specialist proceeds to the analysis of the obtained values. Spirometry (deciphering the results) includes the following indicators:

1. BH is determined by the number of breaths and exhalations per minute. The normal amount is 16-17 times.
2. BEFORE refers to the amount of air drawn into the lungs in one breath. The norm is included in a wide range, so for men the range is 300-1200 ml, and for women 250-800 ml.
3. MAUD- the amount of air entering the lungs for a minute. When spirometry is performed, the normal values ​​in the table should fall in the range from 4 to 10 liters.
4. FZhEL indicates the maximum volume of air exhaled during deep forced expiration. Before him, a deep breath is taken. For healthy people, this figure is in the range of 2.5-7.5 liters. VC - the maximum amount of air that is exhaled during a quiet exit, but after a very deep breath.
5. FEV1 implies the maximum amount of exhaled air in one second with a forced exit, which should be after a maximum deep breath. Finding out spirography - what it is, and what results it shows, it should be noted that this value largely depends on the gender and age of the person.
6. IT calculated using the ratio of FEV1 to FVC. The value is expressed as a percentage.
7. MVL is obtained by multiplying the average amplitude of the maximum respiratory excursions by their frequency per minute.
8. PSDV is the ratio of maximum ventilation of the lungs to their vital capacity. The value is expressed as a percentage.

For normal life, the human body needs air.

Saturation of cells with oxygen is the main purpose of the respiratory system.

The volume of air inhaled is important in determining the level of lung function. For this kind of research, there is spirometry.

What it is, for what purpose, how it is carried out and when its appointment is excluded will be discussed later in the article.

The essence of spirometry

The term is formed from two words: spiro- breathing and metria- measurements, measurements.

Spirometry- diagnostic examination of the function of external respiration with the establishment of characteristic speed and volume indicators.

The method is widely used in medicine: it allows you to identify pathologies that cause a low level of gas exchange.

The procedure is painless and harmless. Measurements are based on the frequency of inhalations and exhalations, lung capacity.

The procedure is carried out with a special digital device - a spirometer. Their mechanism is quite simple: an airflow sensor and a computational part that converts information into numerical values.

Readings are calculated automatically. There are computer modifications of the device.

The first examinations were carried out with mechanical (most often water) spirometers. All indicators were calculated manually. The procedure was long and laborious.

If you need constant monitoring, you can use a modern portable spirometer, which is applicable both at home and when traveling.

Consultations of the attending physician and a medical specialist in sales of similar equipment will help to choose the appropriate device. The spirometer is selected taking into account functional requirements and personal preferences.

The most accurate measurements are given by a special camera with sensors - plethysmograph. The results of the study, presented graphically in the form of spirography, help to clearly illustrate the changes in human lung volume during normal and enhanced breathing. What is spirography and how it looks can be clearly seen in the figure:

Through the procedure:

• diagnose pathological abnormalities (foci of impaired gas exchange, the level of bronchial obstruction);
• assess the patient's condition during treatment and the effectiveness of therapy;
• teach various breathing techniques.

Measurements are performed on an outpatient basis with immediate results.

Reasons for an examination

There are a number of indications for the appointment of the procedure. Diagnostics is carried out in order to:

• studies of frequent acute respiratory infections,;
• detection of pathological disorders of the respiratory system with a prolonged cough, respiratory failure, sputum production, pain behind the sternum;
• identifying the causes of deviations in the gas exchange process;
• analysis of the relationship between pulmonary diseases and the function of external respiration, the effectiveness of therapeutic measures in their treatment;
• prevention and early detection of deviations in persons with an increased risk of developing pathologies: smokers and persons whose labor activity is associated with harmful substances;
• monitoring of the course of bronchopulmonary diseases:
  • asthma;
  • etc.;
• study of acute allergic manifestations ();
• calculation of indicators for the establishment of disability and the level of ability to work;
• preparation of patients for operations of the broncho-pulmonary system;
• selection of suitable drugs for bronchial dilatation.

Persons over the age of 40, smokers for 10 years or more, with chronic cough or examination is mandatory.

Preventive medical measures are recommended for workers associated with the regular use of harmful chemicals.

Contraindications for spirometry

Spirometry has no strict contraindications. Mild dizziness, which may occur, passes quickly and does not pose a health hazard.

Forced or strong deep inspiration causes a short-term increase in intracranial and intra-abdominal pressure.

With caution, carry out or refuse the procedure for the following indications:

• recent operations on the abdominal organs or ophthalmic surgical procedures (less than 2 months ago);
• or (depending on the patient's condition, but not earlier than 3 months after them);
• past respiratory tract infections (at least 2 weeks after their curation);
• presence in history;
• arterial or aortic aneurysm;
• severe seizures;
• the presence of pulmonary bleeding;
• epilepsy;
• and other pathologies associated with a violation of pressure;
• increased blood clotting;
• mental disorders;
• pregnancy;
• age restrictions: up to 5 and after 75 years.

Even in the absence of obvious contraindications, it is necessary to consult a specialist before the study.

Spirometry classification

How the procedure is carried out determines its appearance. Spirometry tests are done with the following maneuvers:

• normal calm breathing;
• exhale with effort (forced);
• with maximum ventilation of the lungs;
• with physical activity (before and after it) - dynamic spirometry;
• with the use of special substances - functional and provocative spirometry:
  • With bronchodilators dilating the bronchi. The method helps to identify hidden bronchospasms, correctly diagnose the disease, determines the reversibility of disorders and the effectiveness of therapeutic techniques;
  • With methacholine helping to definitively diagnose asthma, identify predisposition to bronchospasm and hyperreactivity.

Modern spirometers make it possible to determine the level of diffusive capacity of the lungs - the gas exchange of oxygen and carbon dioxide between the respiratory organs and the blood.

An additional examination is bronchospirometry. Allows you to separately fix the indicators in different lobes of the lungs.

Preparatory activities

Preparation for spirography is very important. The reliability of the results obtained is increased if the following rules are observed:

• the study should be done on an empty stomach or at least 2 hours after eating a light meal in the morning;
• one day before the examination, stop smoking (or at least 4 hours in advance), reduce the consumption of caffeinated drinks, do not drink alcohol;
• refuse drugs that can distort the performance;
• loose and comfortable clothing is selected that does not interfere with breathing;
• half an hour before measurements to be at rest, breathe calmly;
• a patient who uses an inhaler takes it to the procedure;
• bring a handkerchief or napkins with you.

Before starting the study, the medical officer must find out the patient's data (height, weight) and enter their device, select the spirometer by size, help the patient to take the desired position and explain the sequence and rules for performing breathing maneuvers.

Performing a procedure

The patient is in a comfortable position, hands on the armrests are relaxed. To ensure only oral breathing, the nose is blocked with a special clip. A tube with a disposable sterile tip (mouthpiece) is inserted into the mouth. At the beginning of the procedure, the patient breathes naturally, evenly.

The DO indicator is determined - the respiratory volume. The patient is then asked to take a normal breath and completely exhale all the air as quickly as possible. This will be the expiratory reserve volume (ERV).

The duration of exhalation with a maximum effort of more than 15 seconds is a reason for diagnosing pathology. Then the maximum breathing capacity is measured.

The deepest breath follows (reserve inspiratory volume is fixed - ROV and vital capacity - VC) and rapid exhalation (FEV and FVC are determined).

The device automatically builds a graph based on measurements. FEV indicators have diagnostic significance.

The shape of the depicted loop allows you to diagnose the type of respiratory failure:

• obstructive;
• restrictive;
• mixed.

The reversibility of obstruction is determined by the data of the test with bronchodilators. It is the readings of the FEV that are of primary comparative importance.

Each test is carried out several times (usually 3 times). After that, the most successful of them are selected.

The device gives the result of the spirogram, according to which the doctor evaluates the specific case and makes a conclusion. The procedure takes about 15 minutes. How many times, with what frequency to carry out diagnostics is determined by the attending pulmonologist according to indications.

Spirometry Data

The result of the survey is evaluated according to the following indicators:

• VC - vital capacity of the lungs, calculated as the difference between the volume of air during full inspiration and full exhalation;
• FVC - forced vital capacity of the lungs. Reflects the maximum volume of exhaled air (FEV) at maximum inspiration. It makes it possible to fix the elasticity of the lung tissue and the excursion of the chest, that is, restrictive violations;
• FEV1 - forced expiratory volume in the first second, usually expressed as a percentage of FEV. The most informative indicator of spirometry. Demonstrates the speed of passage of air in the bronchi. For a final understanding of the pathological process (bronchial obstruction or restriction of the lung parenchyma), the following parameter is calculated;
• Tiffno index - the ratio of FEV1 and FVC parameters in percent. Normally, it is from 70%. Deviations are due to:
  • decrease in FEV1 - disease with obstruction;
  • a decrease in FVC with an unchanged or slightly reduced FEV1 indicator - a change in the elasticity of the lung tissues.

Table 1. Abbreviated designation and characteristics of indicators of spirometric research.

Examination for young patients

From the age of 9, a full examination is possible along with adults. Small patients should be diagnosed in specialized institutions for children.

Creating a relaxed atmosphere is the key to successful spirometry. An employee with a pedagogical approach and the use of a playful form has more authority in the eyes of the child and will be able to carry out the procedure most effectively.

The meaning of the event and its actions are explained to the child. Thematic pictures can be used to allow the child to understand what is required. For example, blow out a candle.

The specialist should pay attention to the correctness of the maneuvers, the correct hermetic girth of the tube with the lips. The protocol reflects the number of successful tests. When forming the conclusion, the age of the patient is taken into account.

Deciphering the result of FVD

There are certain norms of indicators, based on which the doctor draws conclusions.

Deciphering the results of the respiratory function should take into account gender anatomical differences, age-related changes, past diseases, and the type of work activity.

The indicators will be differentiated for a healthy person and a patient. The formulas for calculating the norm are given in the table:

Table 2. Formulas for calculating normal spirometry values

Note. When using a SG spirometer, the due FEV1 decreases by 0.19 liters in men and by 0.14 liters in women. In persons aged 20 years, VC and FEV are approximately 0.2 liters less than at the age of 25 years; in persons over 50 years old, the coefficient when calculating the due MVL is reduced by 2.

For each person, the norm will be individual. Main spirometric parameters: FEV1, VC, FVC, FEV1/FVC. The results are analyzed by the maximum values ​​of FVC and FEV1.

The interpretation of the data obtained should be concise, clear, and complete. The specialist not only determines the deviations of indicators from the normative value, but also evaluates the overall picture, analyzing their entire set in interconnection.

All indicators are presented below:

Table 3 Spirometry indicators

The Tiffno test is informative in assessing pathological abnormalities. To understand the degree of deviation from the norm, it is customary to determine the percentage. Depending on the decrease in the indication, the severity of pathological abnormalities increases.

A 70% FEV1/FVC ratio results in significant false positives, and a reading of 80% also often misinterprets the result in adults but is acceptable in children. For older people (over 70), some experts recommend using a value of 65%.

Carrying out the procedure with a high-quality spirometer will avoid distortion and obtain reliable readings.

Correct interpretation of the results of respiratory function helps to diagnose diseases in the early stages, prevent the development of severe forms, and determine the effectiveness of drugs in the treatment of respiratory disorders.

Correctly performed spirometry, taking into account all the individual characteristics of the patient, provides comprehensive information about the state of the respiratory system. Painlessness, simplicity of the procedure, immediate result, absence of side effects are the undeniable advantages of this type of diagnostics.

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