Violations of fvd i iii degree. Changes in fvd with obstructive type of day

Date: 29.06.2020

Respiratory function assessment (RPF) is the simplest test that characterizes the functionality and reserves of the respiratory system. A research method that allows you to assess the function of external respiration is called spirometry. This technique is currently widely used in medicine as a valuable method for diagnosing ventilation disorders, their nature, degree and level, which depend on the nature of the curve obtained during the study (spirogram).

Respiratory function assessment does not allow for a definitive diagnosis. However, spirometry greatly facilitates the task of making a diagnosis, differential diagnosis of various diseases, etc. Spirometry allows:

to identify the nature of ventilation disorders that led to certain symptoms (shortness of breath, cough);
to assess the severity of chronic obstructive pulmonary disease (COPD), bronchial asthma;
carry out, using certain tests, differential diagnosis between bronchial asthma and COPD;
monitor ventilation disorders and evaluate their dynamics, treatment efficacy, assess the prognosis of the disease;
to assess the risk of surgery in patients with ventilation disorders;
to identify the presence of contraindications to certain physical activity in patients with ventilation disorders;
check for ventilation disorders in patients at risk (smokers, professional contact with dust and irritating chemicals, etc.) who are not presenting complaints at the moment (screening).

The examination is carried out after half an hour's rest (for example, in bed or in a comfortable chair). The room must be well ventilated.

The survey does not require complex preparation. The day before spirometry, it is necessary to exclude smoking, drinking alcohol, and wearing tight clothing. Do not overeat before the test, do not eat less than a few hours before spirometry. It is advisable to exclude the use of short-acting bronchodilators 4-5 hours before the study. If this is not possible, it is necessary to inform the medical personnel conducting the analysis of the time of the last inhalation.

In the course of the study, tidal volumes are assessed. Instructions on how to properly carry out breathing maneuvers are given by the nurse immediately prior to the test.

Contraindications

The technique has no clear contraindications, except for a general serious condition or disturbances of consciousness, which do not allow spirometry to be performed. Since it is necessary to make certain, sometimes significant efforts to implement a forced respiratory maneuver, spirometry should not be performed in the first few weeks after myocardial infarction and operations on the thoracic and abdominal cavity, ophthalmic surgical interventions. Determine the function of external respiration should also be delayed in case of pneumothorax, pulmonary hemorrhage.

If you suspect that the examined person has tuberculosis, all safety standards must be observed.

According to the results of the study, a computer program automatically creates a graph - a spirogram.

The conclusion on the obtained spirogram may be as follows:

norm;
obstructive disorders;
restrictive disorders;
mixed ventilation disorders.

What verdict the doctor of functional diagnostics will make depends on the correspondence / inconsistency of the indicators obtained during the study with normal values. FVD indicators, their normal range, values of indicators by degrees of ventilation disturbances are presented in the table ^

Indicator	Rate,%	Conventionally norm,%	Mild violations,%	Moderate degree of violations,%	Severe degree of violations,%
Forced vital capacity (FVC)	≥ 80	-	60-80	50-60	< 50
Forced expiratory volume in the first second (FEV1)	≥ 80	-	60-80	50-60	< 50
Modified Tiffno index (FEV1 / FVC)	≥ 70 (absolute value for this patient)	-	55-70 (absolute value for a given patient)	40-55 (absolute value for a given patient)	< 40 (абсолютная величина для данного пациента)
Average volumetric expiratory flow rate at the level of 25-75% of FVC (SOS25-75)	Over 80	70-80	60-70	40-60	Less than 40
Maximum volumetric flow rate at 25% of FVC (MOS25)	Over 80	70-80	60-70	40-60	Less than 40
Maximum volumetric flow rate at 50% of FVC (MOS50)	Over 80	70-80	60-70	40-60	Less than 40
Maximum volumetric flow rate at 75% of FVC (MOS75)	Over 80%	70-80	60-70	40-60	Less than 40

All data are presented as a percentage of the norm (the exception is the modified Tiffno index, which is an absolute value that is the same for all categories of citizens), determined depending on gender, age, weight and height. The most important is the percentage compliance with the normative indicators, and not their absolute values.

Despite the fact that in any study the program automatically calculates each of these indicators, the most informative are the first 3: FVC, FEV 1 and the modified Tiffno index. Depending on the ratio of these indicators, the type of ventilation disturbances is determined.

FVC is the largest volume of air that can be inhaled after the maximum exhalation or exhaled after the largest inhalation. FEV1 is the part of FVC, which is determined in the first second of the breathing maneuver.

Determining the type of violation

With a decrease in FVC alone, restrictive disorders are determined, that is, disorders that limit the maximum mobility of the lungs during breathing. Restrictive ventilation disorders can be caused by both pulmonary diseases (sclerotic processes in the lung parenchyma of various etiologies, atelectasis, accumulation of gas or fluid in the pleural cavities, etc.), and chest pathology (ankylosing spondylitis, scoliosis), leading to limitation of its mobility.

With a decrease in FEV1 below normal values and the ratio of FEV1 / FVC< 70% определяют обструктивные нарушения - патологические состояния, приводящие к сужению просвета дыхательных путей (бронхиальная астма, ХОБЛ, сдавление бронха опухолью или увеличенным лимфатическим узлом, облитерирующий бронхиолит и др.).

With a joint decrease in FVC and FEV1, a mixed type of ventilation disorders is determined. In this case, the Tiffno index can correspond to normal values.

Based on the results of spirometry, it is impossible to give an unambiguous conclusion. Deciphering the results obtained should be carried out by a specialist, be sure to correlate them with the clinical picture of the disease.

Pharmacological tests

In some cases, the clinical picture of the disease does not allow to unambiguously determine what the patient has: COPD or bronchial asthma. Both of these diseases are characterized by the presence of bronchial obstruction, but narrowing of the bronchi in bronchial asthma is reversible (except for advanced cases in patients who have not received treatment for a long time), and in COPD it is only partially reversible. The reversibility test with a bronchodilator is based on this principle.

The study of FVD is carried out before and after inhalation of 400 μg of salbutamol (Salomol, Ventolin). An increase in FEV1 by 12% of the initial values (about 200 ml in absolute terms) indicates a good reversibility of the narrowing of the lumen of the bronchial tree and testifies in favor of bronchial asthma. An increase of less than 12% is more typical for COPD.

Less widespread was the test with inhaled glucocorticosteroids (ICS), prescribed as a trial therapy for an average of 1.5-2 months. Respiratory function is assessed before and after the appointment of ICS. An increase in FEV1 by 12% compared with the baseline indicates the reversibility of bronchial narrowing and a greater likelihood of bronchial asthma in a patient.

With a combination of complaints characteristic of bronchial asthma with normal spirometry indicators, tests are performed to detect bronchial hyperreactivity (provocative tests). During them, the initial values of FEV1 are determined, then inhalation of substances that provoke bronchospasm (methacholine, histamine) or an exercise test is carried out. The decrease in FEV1 by 20% from the initial values is evidence in favor of bronchial asthma.

1. Decreased expiratory power.

2. Decrease in PSV.

3. Decreased FEV1.

4. Decrease in the Tiffno index (Tiffno index = (FEV1 / VC) x 100%, the norm is 70-80%).

5. Decrease in MVL (due MVL = VC X 35).

Restrictive type of DN

Causes of occurrence:

1) pulmonary fibrosis (pneumoconiosis, scleroderma);

2) pulmonary emphysema;

3) pleural adhesions;

4) exudative pleurisy, hydrothorax;

5) pneumothorax;

6) alveolitis, pneumonia, lung tumors;

7) removal of a portion of the lungs.

FVD changes in restrictive DN type

1. Decreased VC.

2. Decrease in MVL.

Mixed (obstructive-restrictive) type of DN

It is characterized by the presence in the patient of signs of obstructive and restrictive types in DN.

Acute DN

The term acute DN is understood.

1. Sudden occurrence of DN.

2. The gradual development of DN to a critical state requiring intensive therapy or resuscitation.

Stages of acute DN

Stage I- initial.

Characteristic:

Forced position of the patient - orthopnea;

Severe cyanosis of the skin and mucous membranes;

Agitation, anxiety, sometimes delirium, hallucinations;

Rapid breathing up to 40 in 1 minute;

Participation of auxiliary respiratory muscles in the act of breathing;

Tachycardia up to 120 in 1 minute;

Moderate arterial hypoxemia (Ra O 2 - 60-70 mm Hg) and normocapnia (Ra CO 2 - 35-45 mm Hg).

Stage II- deep hypoxia.

Characteristic:

The condition of the patients is extremely serious;

Shallow breathing, patients convulsively gasp for air;

Position - orthopnea;

Alternating periods of arousal with periods of drowsiness;

Respiratory rate exceeds 40 in 1 minute;

Heart rate above 120 per minute;

Hypoxia (R a O 2 - 50-60 mm Hg) and hypercapnia (R a CO 2 - 50-70 mm Hg) are detected in the blood.

Stage III- hypercapnic coma.

Characteristic:

Consciousness is absent;

Severe diffuse cyanosis;

Cold clammy sweat;

The pupils are dilated (mydriasis);

Breathing is shallow, rare, often arrhythmic - like Cheyne-Stokes;

In the blood, sharp hypoxia (P a O 2 - 40-55 mm Hg) and severe hypercapnia (P a CO 2 - 80-90 mm Hg) are detected.

Stages of chronic respiratory failure

Stages	I (compensated)	II (pronounced subcompensated)	III (decompensated)
Dyspnea	Under prof. load	With daily stress	At rest
Cyanosis	Not	Appears under load	Diffuse constant
Involvement of accessory muscles in the act of breathing	Do not participate	Participation in the load is noticeable	Participate in peace
BH (in 1 min.)	mb. norm	More than 20 alone	More than 20 alone
Heart rate (in 1 min.)	norm	Over 90	Over 90
Ventilation disturbances	Decrease in performance up to 80-50%	Decrease in performance up to 50-30%	Decrease in indicators below 30%

LECTURE: Symptomatology and diagnosis of bronchitis and pulmonary emphysema

Acute bronchitis- This is an inflammatory process in the trachea, bronchi and (or) bronchioles, characterized by an acute course and diffuse reversible damage mainly to their mucous membrane.

Etiology of acute bronchitis

1. Infectious factors - influenza viruses, parainfluenza, adenoviruses, mycoplasmas (ie, causative agents of acute respiratory diseases).

2. Physical factors - hot air and hypothermia, ionizing radiation.

3. Chemical factors - vapors of acids, alkalis, toxic substances (sulfur dioxide, nitrogen oxides).

4. Exposure to dust particles .

Predisposing factors:

Smoking;

Alcoholism;

Cardiovascular disease (left ventricular failure);

Nasal breathing disorders;

Focuses of chronic infection in the nasopharynx;

Severe diseases that reduce the body's immunological reactivity.

Phases of development of acute bronchitis

1. Reactive-hyperemic or neuro-reflex:

Hyperemia and edema of the mucous membrane;

Damage to the epithelium;

Suppression of mucociliary clearance;

Increased mucus production.

2. Infectious phase:

Fixation on the mucous membrane of a bacterial infection;

Development of purulent inflammation.

Classification of acute bronchitis

I. Etiological factor.

1. Acute infectious bronchitis.

2. Acute non-infectious bronchitis.

II. The nature of the inflammation.

1. Catarrhal.

2. Purulent.

3. Purulent-necrotic.

III. Localization of the lesion.

1. Proximal.

2. Distal.

3. Acute bronchiolitis.

IV. Functional features.

1. Non-obstructive.

2. Obstructive.

V. Current.

1. Acute - up to 2 weeks.

2. Protracted - up to 4 weeks.

3. Recurrent - occurs 3 or more times during the year.

Clinic of acute bronchitis

Complaints

1. Cough.

2. Separation of sputum.

3. Expiratory dyspnea (with bronchial obstruction syndrome).

4. Fever.

5. Signs of intoxication.

Inspection

1. Signs of fever: facial flushing, glittering eyes, sweating.

2. Diffuse cyanosis (with broncho-obstructive syndrome).

3. The ribcage is not changed.

Percussion and palpation of the chest

Pathological changes are not detected.

Lung auscultation

1. Hard breathing.

2. Exhalation phase lengthening (with bronchial obstruction syndrome).

3. Dry wheezing.

Instrumental methods for the diagnosis of acute bronchitis

1. X-ray examination of the lungs: strengthening of the pulmonary pattern in the basal zones; expansion of the roots of the lungs.

2. Study of the function of external respiration.

The broncho-obstructive syndrome is characterized by:

Decrease in the value of the Tiffeneau index;

Decreased peak expiratory flow (PSV);

Moderate decrease in maximum ventilation (MVV).

Laboratory signs of acute bronchitis

1. Complete blood count: neutrophilic leukocytosis with a shift in the nuclear formula of neutrophils to the left; acceleration of ESR.

2. Biochemical blood test: increased levels of C-reactive protein, seromucoid, fibrinogen, glycoproteins, sialic acids.

3. Microscopic examination of sputum: a large number of leukocytes with a predominance of neutrophils; epithelium of the bronchi.

Chronic obstructive pulmonary disease (COPD) is a disease characterized by chronic diffuse inflammation of the bronchi, manifested by cough with sputum and shortness of breath, leading to a progressive impairment of pulmonary ventilation and obstructive gas exchange.

Epidemiological definition of COPD (WHO)

Patients with COPD should be considered those persons who have a cough with sputum production lasts at least 3 months a year for 2 years in a row, provided that these patients have excluded other diseases that can cause the same symptoms (chronic pneumonia, bronchiectasis, tuberculosis, etc. other).

Etiology of COPD

COPD risk factors

Stages of COPD formation

Stage I- the threat of the disease.

Exogenous and endogenous risk factors: smoking tobacco; long-term exposure to dust and other pollutants (irritants); frequent acute respiratory infections (more than 3 times a year); violation of nasal breathing; genetic predisposition, etc.

II stage- pre-illness.

Changes in the bronchial mucosa are characteristic: restructuring of the secretory apparatus; replacement of the ciliated epithelium with goblet cells; hyperplasia of the mucous glands; mucociliary insufficiency.

Clinical manifestations: smoker's cough; protracted and recurrent course of acute bronchitis.

Stage III- clinically established COPD.

Stage IV- complications: pulmonary emphysema; bronchiectasis; hemoptysis; respiratory failure; chronic cor pulmonale.

COPD pathogenesis

Revealing bronchial hyperreactivity

With normal values of FVD held FVD with physical activity(6-minute running protocol) - the appearance of signs of obstruction (decrease in IT, FEV1 by 15% or more) indicates the development of pathological bronchospasm in response to physical activity, i.e., bronchial hyperreactivity.

FVD with drug test (inhalation of a bronchodilator) held in the presence of signs of obstruction on the initial FVD to reveal its reversibility. An increase in FEV1, IT by 12% or more will testify in favor of the reversibility of bronchial obstruction (bronchospasm).

Peak flowmetry

Methodology of carrying out. Patient's peak flow meter over 5 years old exhales. According to the readings of the slider on the scale of the device, PSV is measured - the peak expiratory flow rate in l / min, which has a correlation with FEV1. The PSV indicators are compared with the normative data - up to 11 years old, the indicators depend only on gender and height, from 15 years old - on gender, height and age.

Average proper values of psv (l / min) in children and adolescents

Height (cm)	PSV (l / min)	Height (cm)	PSV (l / min)

Normal numbers of the examinedmust be at least 80% of the average("green corridor")

Compare morning and evening PSV data - variability between them should not exceed 20%(Fig. -1), the change per day is more than 20% - daily fluctuations (Fig. -2).

Find out the difference between the morning reading and the evening before - if it is more than 20% - a sign of bronchial hyperreactivity (" morning failure" - rice. -3).

Peak flowmetry indicators are used to monitor the adequacy of therapy - an increase in fluctuations between morning and evening values requires an increase in therapy.

hitting the PSV indicators in the "yellow corridor" - 60-80% of the average values - indicates the possible development of an attack.
hitting the PSV indicators in the "red corridor" - less than 60% of the average values indicates an asthma attack, requires urgent treatment.

Sputum examination

Quantity per day

General appearance (serous, mucous, purulent, bloody)

Microscopic examination:

Charcot-Leiden crystals (decay products of eosinophils) - for bronchial asthma.
Kurshman's spirals (mucous casts of the bronchi) - with bronchial asthma.
Elastic fibers - for tuberculosis, breakdown of lung tissue (abscess).
Dietrich plugs - purulent plugs - with bronchiectasis.
Koch lenses - formations in the form of rice grains - tuberculosis with disintegration of lung tissue.
Tumor cells.
Hemosiderophages are a sign of pulmonary hemosiderosis, pulmonary infarction.

Sputum bacteriological examination- sowing on tuberculosis pathogens, pathogenic flora

Pleural fluid examination

Inflammatory nature - exudate

Specific gravity over 1015
Protein amount - more than 2-3%
Rivalta's positive reaction (normally negative)
Neutrophils are a sign of acute bacterial inflammation
Lymphocytes - with tuberculosis

Non-inflammatory nature - transudate

Protein less than 30 g / l
Leukocytes are less than 2000 per 1 cubic mm, mononuclear cells predominate.

Cardiology

Apex projection hearts in a newborn, it is located in the 4th intercostal space,

from 1.5 years - in the 5th intercostal space.

Apical impulse - l calcification:

Up to 1.5 years in IV, then in V intercostal space (horizontal line).

Vertical line up to 2 years - 1-2 cm outward from the left SCR.

2-7 years - 1 cm outward from the SCR.

7-12 years old - on the left SCR.

Over 12 years old - 0.5 cm medially from the SCR.

Square- 1 x 1, for older children 2 x 2 cm.

Left border of OST coincides with the apical impulse.

Borders of relative cardiac dullness and transverse dimension of the heart

	Child's age
				Over 12 years old
	Right parasternal line	Inward from the right parasternal line	In the middle between the right parasternal and right sternal lines	In the middle between the right parasternal and right sternal lines, closer to the last, hereinafter - the right sternal line
		II intercostal space
	2 cm outward from the left midclavicular line	1 cm outward from the left midclavicular line	On the left midclavicular line	Medially 0.5-1 cm from the left midclavicular line
Transverse dimension

The sound of tones depends on age:

In the first 2-3 days of life at the 1st point of auscultation (at the apex) II> I, then I = II, and from 2-3 months of life at the topItone>II.

Based on the heart(2nd and 3rd points of auscultation) at 1 year of life I> II, then I = II, from 3 years oldII> I.

Fine from 2 years of age to 12 yearsIItone over the pulmonary artery (left) is strongerIItones above the aorta (right) ("strengtheningIItones over l / a ")... From the age of 12, the sound of these tones has been compared.

Normally, there may be a III tone (quiet, short, after the II tone) - only lying down, at the 5th point of auscultation, disappears in a standing position.

Normal tones are sonorous- the ratio of I and II tones corresponds to age characteristics (from 2-3 months of life at the apex of I> II tone).

Normal tones are clear - unsplit, compact. But maybe physiological degradationIItones- due to non-simultaneous closure of the valves of the aorta and pulmonary artery or non-simultaneous contraction of the ventricles (later LV diastole due to greater blood volume). Listened to based on the heart, impermanent.

Pulse rhythm - healthy children 2-11 years old may have respiratory arrhythmia(on inhalation, increased heart rate, on exhalation, decrease, while holding the breath, the pulse becomes rhythmic).

Inorganic noises

Functional- with diseases of other organs and systems, and the heart is healthy.

Heard over the pulmonary artery(less often at the apex) due to blood swirling with a change in blood viscosity, high impact ejection:
- VSD, anemia, fever, thyrotoxicosis, chronic tonsillitis.

Physiological= innocent = incidental = murmurs of heart formation - in healthy children, caused by AFO CVS - more often in children of preschool and preschool age, audible over the pulmonary artery(up to 7 years of age, increased development of the trabecular network on the inner surface of the endocardium, higher blood flow velocity, wider vessel diameter, uneven growth of valves and chords).

Signs of inorganic noise	Signs of organic noise
Systolic only	May be systolic, diastolic, systolic and diastolic The presence of a dystolic murmur immediately indicates its organic genesis.
Not associated with tones	Usually associated with tones
Not more than 1 / 3-1 / 2 systole	Prolonged - more than half of the systole
More often above the l / a, less often at the top	Heard at any point, more than two - organic genesis
Do not irradiate	The presence of irradiation is a sign of organic matter
Quiet or moderately loud	If loud, rude - organic genesis
Weaken or disappear with a deep breath	Do not change with a deep breath
They disappear or decrease under load	After loading do not change or increase
Better audible in the wedge position (lying), weaken or disappear when moving to the ortho position	When moving to the orthoposition, the
On PCG - low-amplitude, low-frequency	On PCG - high-amplitude, high- and medium-frequency
There are no pronounced changes on the ECG	ECG - signs of department hypertrophy
According to Echo-KG, there are no signs of organic damage to the heart (normal cavity sizes and myocardial thickness, high ejection fraction (EF above 65%), unchanged valves, free pericardial space)	Echo-KG - signs of endocarditis, valvulitis, congenital heart disease, or acquired heart defects

Noises on the background of MARS- borderline noises.

MARS - violations of the formation of the heart, which are not accompanied by changes in systemic hemodynamics, the size of the heart, its contractility. These are additional chords, anomalies in the location of the chords, mitral valve prolapse.

Fickle clicks or noise of a blowing or musical tone are not carried out, standing up can be heard better.

No complaints, signs of hemodynamic disturbance, normal heart boundaries.

The level of stigmatization (short, curved little fingers ...), posture disorders, organ of vision, and manifestations of HMS are increased.

Pericardial friction noise

Does not match tones. It intensifies when pressed with a stethoscope, when holding the breath while taking a deep breath, when leaning forward.

At the beginning, it is heard in a local place - it does not coincide with the places of auscultation of the valves, then it spreads to the entire region of the heart.

Does not radiate beyond the heart ("dies where he was born").

Stages of circulatory insufficiency (NK)

Age criteria for pulse rate, bradycardia and tachycardia(V.K. Tatochenko, 1997)

Bradycardia			Tachycardia
	Moderate	Significant		Moderate	Significant

Blood pressure assessment

Normal blood pressure- 10-89 percentile of the blood pressure distribution curve.

High normal(upper limit of normal) - 90-94 percentile.

Arterial hypertension- equal or higher than the 95th percentile of the blood pressure distribution curve for the corresponding sex, age and height.

Arterial hypotension- below the 3rd percentile.

Low normal blood pressure(lower limit of the norm) - 4-10 percentile.

If the measurement result falls into the zone below the 10th and above the 90th centile, the child should be taken under special observation with regular repeated measurements of blood pressure. In cases where the child's blood pressure is repeatedly in the zone below the 3rd or above the 95th centile, an examination is indicated. in a specialized pediatric cardiology clinic to establish the causes of arterial hypotension or hypertension.

Inhalation and exhalation for a person is not just a physiological process. Remember how we breathe in different life circumstances.

Fear, anger, pain - the breath is choked and constrained. Happiness - there are not enough emotions for the manifestation of joy - we breathe deeply.

Another example with the question: how long will a person live without food, sleep, water? And without air? Probably, you shouldn't go on talking about the importance of breathing in a person's life.

Breathing - at a glance

The ancient Indian teaching of yoga states: "A person's life is the time periods between inhalation and exhalation, for these movements, saturating all cells with air, ensure his very existence."

A man who breathes half and lives also half. This, of course, is about unhealthy or improper breathing.

How can you breathe incorrectly, the reader will argue, if everything happens without the participation of consciousness, so to speak "on the machine." The smart guy will continue - breathing is controlled by unconditioned reflexes.

The truth lies in the psychological trauma and all kinds of diseases that we accumulate throughout our lives. It is they who make the muscles tense (overextended) or, conversely, lazy. Therefore, over time, the optimal mode of the respiratory cycle is lost.

It seems to us that ancient man did not think about the correctness of this process, nature itself did it for him.

The process of filling human organs with oxygen is divided into three components:

Clavicular (superior). Inhalation occurs at the expense of the upper intercostal muscles and collarbones. Try to be sure this mechanical movement does not fully unfold the ribcage. Little oxygen gets in, breathing becomes frequent, incomplete, dizziness occurs and the person begins to choke.
Secondary or breast. With this type, the intercostal muscles and the ribs themselves are included. The ribcage expands as much as possible, allowing it to be completely filled with air. This type is typical under stressful circumstances or with mental stress. Remember the situation: you are agitated, but as soon as you take a deep breath, everything disappears somewhere. This is the result of proper breathing.
Abdominal diaphragmatic breathing. This type of breathing, from the point of view of anatomy, is the most optimal, but, of course, not entirely comfortable and familiar. You can always use it when you need to relieve mental stress. Relax your abdominal muscles, lower the diaphragm to the lowest position, then return it back to its original position. Pay attention, there was a calmness in the head, the thoughts brightened.

Important! By moving the diaphragm, you not only improve your breathing, but also massage the abdominal organs, improving metabolic processes and food digestion. Due to the movement of the diaphragm, the blood supply to the digestive organs and venous outflow are activated.

This is how important it is for a person not only to breathe correctly, but also at the same time to have healthy organs that ensure this process. Constant monitoring of the condition of the larynx, trachea, bronchi, lungs contributes to the solution of these problems.

Examination of the function of external respiration

FVD in medicine, what is it? To test the functions of external respiration, a whole arsenal of techniques and procedures is used, the main task of which is to objectively assess the state of the lungs and bronchi, as well as to open them at an early stage of the development of pathology.

The gas exchange process that occurs in the tissues of the lungs, between blood and air from the outside, entering the body, medicine calls external respiration.

Research methods that allow diagnosing various pathologies include:

Spirography.
Bodyplethysmography.
Study of the gas composition of exhaled air.

Important! The first four methods of analysis of FVD allow a detailed study of forced, vital, minute, residual and total lung volume, as well as the maximum and peak expiratory flow rate. While the gas composition of the air leaving the lungs is studied using a special medical gas analyzer.

In this regard, the reader may have a false impression that the examination of the FVD and spirometry are one and the same. We emphasize once again that the study of FVD is a whole complex of tests, which includes spirometry.

Indications and contraindications

There are indications for comprehensive testing of upper breathing functions.

These include:

Patients, including children, who manifest: bronchitis, pneumonia, emphysema of the lung tissue, nonspecific lung diseases, tracheitis, rhinitis in various forms, laryngotracheitis, diaphragm damage.
Diagnosis and control and COPD (chronic obstructive pulmonary disease).
Examination of patients involved in hazardous production areas (dust, varnishes, paints, fertilizers, mines, radiation).
Chronic cough, shortness of breath.
Study of the upper breathing in preparation for surgical operations and invasive (taking living tissue) examinations of the lungs.
Examination of chronic smokers and people prone to allergies.
Professional athletes, in order to find out the maximum capabilities of the lungs with increased physical exertion.

At the same time, there are limitations that make it impossible to conduct a survey, due to certain circumstances:

Aneurysm (bulging of the wall) of the aorta.
Bleeding in the lungs or bronchi.
Tuberculosis in any form.
A pneumothorax is when a large amount of air or gas accumulates in the pleural area.
Not earlier than a month after undergoing surgery on the abdominal or chest cavity.
After a stroke and myocardial infarction, the study is possible only after 3 months.
Intellectual retardation or mental disorders.

Video from an expert:

How is the research done?

Despite the fact that the procedure for examining FVD is a completely painless process, in order to obtain the most objective data, it is necessary to carefully approach its preparation.

FVD is done on an empty stomach and always in the morning.
Smokers should refrain from cigarettes four hours before the test.
Physical activity is prohibited on the day of the study.
For asthmatics, exclude inhalation procedures.
The subject should not take any medication that dilates the bronchi.
Do not consume coffee or other caffeinated tonic drinks.
Before the test, loosen clothing and its elements that restrict breathing (shirts, ties, trouser belts).
In addition, if necessary, follow the additional recommendations voiced by the doctor.

Research algorithm:

If there is a suspicion of an obstruction that interferes with the patency of the bronchial tree, an FVD is performed with a sample.

What is this test and how is it done?

Spirometry in the classical version, gives the maximum, but incomplete idea of the functional state of the lungs and bronchi. Thus, in asthma, checking breathing on the apparatus without the use of bronchodilators, such as Ventolin, Berodual and Salbutamol, is not able to detect latent bronchospasm and it will remain unnoticed.

The preliminary results are ready right away, but their deciphering and interpretation by the doctor has yet to be done. This is necessary to determine the strategy and tactics of treating the disease, if any.

Deciphering the results of FVD

After all the test activities have been carried out, the results are entered into the memory of the spirograph, where they are processed using the software and a graphic drawing is built - a spirogram.

The preliminary conclusion drawn by the computer is expressed as follows:

norm;
obstructive disorders;
restrictive disorders;
mixed ventilation disorders.

After decoding the indicators of the function of external respiration, their compliance or non-compliance with regulatory requirements, the doctor makes a final verdict regarding the patient's health.

The studied indicators, the rate of FVD and possible deviations are presented in the generalized table:

Indicators	Rate (%)	Conditional rate (%)	Mild degree of impairment (%)	Average degree of violation (%)	Severe impairment (%)
FVC - forced vital capacity of the lungs	≥ 80	79.5-112.5 (m)	60-80	50-60	< 50
OFV1 / FZHEL - modif. Tiffeneau index (expressed in absolute value)	≥ 70	84.2-109.6 (m)	55-70	40-55	< 40
FEV1 - forced expiratory volume in the first second	≥ 80	80.0-112.2 (m)	60-80	50-60	< 50
MOS25 - maximum volumetric velocity at 25% of FVC	> 80	70-80	60-70	40-60	< 40
MOS50 - maximum volumetric velocity at 50% of FVC	> 80	70-80	60-70	40-60	< 40
SOS25-75 - average volumetric expiratory flow rate at the level of 25-75% of FVC	> 80	70-80	60-70	40-60	< 40
MOS75 - maximum volumetric velocity at 75% of FVC	> 80	70-80	60-70	40-60	< 40

Important! When decoding and interpreting the results of FVD, the doctor pays special attention to the first three indicators, because it is FVC, FEV1 and Tiffno's index that are diagnostically informatively significant. By the ratio between them, the type of ventilation disturbances is determined.

Such a difficult-to-pronounce name was given to the examination method, which allows you to measure the peak volumetric velocity during forced (maximum force) expiration.

Simply put, this method allows you to determine at what speed the patient exhales, making maximum efforts for this. This checks the narrowing of the airways.

Peak flowmetry is especially needed by patients with asthma and COPD. It is she who is able to obtain objective data on the results of the therapeutic measures carried out.

A peak flow meter is an extremely simple device consisting of a graduated tube. How is it useful for individual use? The patient can independently take measurements and prescribe the dosage of the medications taken.

The device is so simple that even children, not to mention adults, can use it. By the way, some models of these simple devices are produced especially for children.

How is peak flow measurement performed?

The testing algorithm is extremely simple:

How do I interpret the data?

Let us remind the reader that peak flowmetry, as one of the methods for studying the pulmonary respiratory function, measures the peak expiratory flow rate (PSV). For correct interpretation, you need to define three signal zones for yourself: green, yellow and red. They characterize a certain range of PSV, calculated according to the maximum personal results.

Let's give an example for a conditional patient using a real technique:

Green Zone... This range contains values that indicate remission (weakening) of asthma. Anything above 80% PSV characterizes this condition. For example, a patient's personal record - PSV is 500 l / min. We count: 500 * 0.8 = 400 l / min. We get the lower border of the green zone.
Yellow zone... It characterizes the beginning of the active process of bronchial asthma. Here the lower limit will be 60% of the PSV. The calculation method is identical: 500 * 0.6 = 300 l / min.
Red zone... The indicators in this sector indicate an active exacerbation of asthma. As you can imagine, all values below 60% of the PSV are in this hazardous area. In our "virtual" example, this is less than 300 l / min.

A non-invasive (without penetration) method for studying the amount of oxygen in the blood is called pulse oximetry. It is based on a computer spectrophotometric assessment of the amount of hemoglobin in the blood.

In medical practice, two types of pulse oximetry are used:

In terms of measurement accuracy, both methods are identical, but from a practical point of view, the second is the most convenient.

Scope of pulse oximetry:

Vascular and Plastic Surgery... This method is used to saturate (saturate) oxygen and control the patient's pulse.
Anesthesiology and resuscitation... It is used during the movement of the patient to fix cyanosis (blue discoloration of the mucous membrane and skin).
Obstetrics... For fixing the oxyometry of the fetus.
Therapy. The method is extremely important for confirming the effectiveness of treatment and for fixing apnea (breathing pathology that threatens to stop) and respiratory failure.
Pediatrics... It is used as a non-invasive tool for monitoring the condition of a sick child.

Pulse oximetry is prescribed for the following diseases:

complicated course of COPD (chronic obstructive pulmonary disease);
obesity;
cor pulmonale (enlargement and expansion of the right heart);
metabolic syndrome (a complex of metabolic disorders);
hypertension;
hypothyroidism (endocrine system disease).

Indications:

during oxygen therapy;
insufficient breathing activity;
if there is a suspicion of hypoxia;
after prolonged anesthesia;
chronic hypoxemia;
in the postoperative rehabilitation period;
apnea or prerequisites for it.

Important! With blood normally saturated with hemoglobin, the indicator is almost 98%. At a level approaching 90%, hypoxia is noted. Saturation rate should be around 95%.

Blood gas analysis

In humans, the gas composition of the blood is generally stable. Pathologies in the body are evidenced by shifts of this indicator in one direction or the other.

Indications for conducting:

Confirmation of pulmonary pathology in the patient, signs of acid-base balance disorder. This is manifested in the following diseases: COPD, diabetes mellitus, chronic renal failure.
Monitoring the state of health of the patient after carbon monoxide poisoning, with methemoglobinemia - the manifestation in the blood of an increased content of methemoglobin.
Monitoring the patient's condition, which is connected to forced ventilation.
The data is needed by the anesthesiologist before performing surgery, especially on the lungs.
Determination of violations of the acid-base state.
Assessment of the biochemical composition of blood.

The body's response to a change in the gas components of the blood

Acid-base balance pH:

less than 7.5 - there was a supersaturation of the body with carbon dioxide;
more than 7.5 - the volume of alkali is exceeded in the body.

Partial pressure of oxygen PO 2: falling below normal value< 80 мм рт. ст. – у пациента наблюдается развитие гипоксии (удушье), углекислотный дисбаланс.

Partial (partial) pressure level of carbon dioxide PCO2:

The result is below the normal value of 35 mm Hg. Art. - the body feels a lack of carbon dioxide, hyperventilation is not carried out in full.
The indicator is above the norm of 45 mm Hg. Art. - there is an excess of carbon dioxide in the body, the heart rate decreases, the patient is covered with an inexplicable anxious feeling.

Bicarbonate level HCO3:

Below normal< 24 ммоль/л – наблюдается обезвоживание, характеризующее заболевание почек.
The indicator is above the normal value> 26 mmol / l - this is observed with excessive ventilation (hyperventilation), metabolic alkalosis, overdose of steroid substances.

The study of FVD in medicine is the most important tool for obtaining deep generalized data on the state of work of the human respiratory system, the influence of which on the entire process of his life and activity cannot be overestimated.

Diffusion respiratory failure occurs when:

thickening of the alveolar-capillary membrane (edema);
a decrease in the area of the alveolar membrane;
reducing the time of contact of blood with alveolar air;
an increase in the layer of fluid on the surface of the alveoli.

Types of respiratory rhythm disorders
The most common form of breathing disorder is shortness of breath. Distinguish between inspiratory dyspnea, characterized by difficulty breathing, and expiratory dyspnea with difficulty breathing out. A mixed form of shortness of breath is also known. It can also be constant or paroxysmal. In the origin of shortness of breath, not only diseases of the respiratory organs E, but also the heart, kidneys, and the hematopoietic system often play a role.
The second group of breathing rhythm disorders is periodic breathing, i.e. group rhythm, often alternating with stops or with intercalated deep breaths. Periodic respiration is subdivided into basic types and variations.

The main types of periodic breathing:

Wave-like.
Incomplete Cheyne-Stokes rhythm.
Cheyne-Stokes rhythm.
Biota rhythm.

The options are:

Tonus fluctuations.
Deep intercalated breaths.
Alternating.
Complex allorhythmias.

The following groups of terminal types of periodic respiration are distinguished.

Big breath of Kussmaul.
Apneastic breathing.
Gasping breath.

There is one more group of disturbances in the rhythm of respiratory movements - dissociated breathing.

These include:

paradoxical movements of the diaphragm;
asymmetry of the right and left half of the chest;
Peyner respiratory center block.

Dyspnea
Shortness of breath is understood as a violation of the frequency and depth of breathing, accompanied by a feeling of lack of air.
Dyspnea is a reaction of the external respiration system, which provides an increased supply of oxygen to the body and the elimination of excess carbon dioxide (considered as protective and adaptive). Dyspnea is most effective in the form of an increase in the depth of breathing in combination with its increased frequency. Subjective sensations do not always accompany shortness of breath, so one should focus on objective indicators.

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There are three degrees of deficiency:

I degree - occurs only with physical stress;
II degree - at rest, deviations of pulmonary volumes are found;
III degree - characterized by dyspnea at rest and is combined with excessive ventilation, arterial hypoxemia and the accumulation of under-oxidized metabolic products.

Respiratory failure and shortness of breath as its manifestation is a consequence of impaired ventilation and corresponding insufficient oxygenation of blood in the lungs (with limited alveolar ventilation, airway stenosis, circulatory disorders in the lungs).
Perfusion disorders occur with abnormal vascular and intracardiac shunts, vascular diseases.
Other factors also cause shortness of breath - a decrease in cerebral blood flow, general anemia, toxic and mental influences.
One of the conditions for the formation of shortness of breath is the preservation of a sufficiently high reflex excitability of the respiratory center. The absence of shortness of breath with deep anesthesia is considered as a manifestation of inhibition created in the respiratory center in connection with a decrease in lability.
The leading links in the pathogenesis of shortness of breath: arterial hypoxemia, metabolic acidosis, functional and organic lesions of the central nervous system, increased metabolism, impaired blood transport, difficulty and limitation of chest movements.

Non-respiratory functions of the lungs
The basis of non-respiratory functions of the lungs are metabolic processes specific to respiratory organs. The metabolic functions of the lungs consist in their participation in the synthesis, deposition, activation and destruction of various biologically active substances (BAS). The ability of the lung tissue to regulate the level of a number of biologically active substances in the blood is called the “endogenous pulmonary filter” or “pulmonary barrier”.

Compared to the liver, the lungs are more active in relation to the metabolism of biologically active substances, since:

their volumetric blood flow is 4 times greater than hepatic;
only through the lungs (with the exception of the heart) all blood passes, which facilitates the metabolism of biologically active substances;
in pathology with redistribution of blood flow ("centralization of blood circulation"), for example, in shock, the lungs can play a decisive role in the exchange of biologically active substances.

Up to 40 types of cells have been found in the lung tissue, of which the most attention are attracted by cells with endocrine activity. They are called Feiter and Kulchitsky cells, neuroendocrine cells or APUD-system cells (apudocytes). The metabolic function of the lungs is closely related to the gas transport.
So, with impaired pulmonary ventilation (more often hypoventilation), impaired systemic hemodynamics and blood circulation in the lungs, there is an increased metabolic load.

The study of the metabolic function of the lungs with their various pathologies made it possible to distinguish three types of metabolic changes:

Type 1 is characterized by an increase in the level of biologically active substances in the tissue, accompanied by an increase in the activity of enzymes of their catabolism (in acute stress situations - the initial stage of hypoxic hypoxia, the early phase of acute inflammation, etc.);
Type 2 is characterized by an increase in the content of biologically active substances, combined with a decrease in the activity of catabolic enzymes in the tissue (with repeated exposure to hypoxic hypoxia, prolonged inflammatory bronchopulmonary process);
Type 3 (found less often) is characterized by a deficiency of biologically active substances in the lungs, combined with suppression of the activity of catabolic enzymes (in pathologically altered lung tissue with long periods of bronchiectasis).

The metabolic function of the lungs has a significant effect on the hemostatic system, which, as you know, takes part not only in maintaining the liquid state of the blood in the vessels and in the process of thrombus formation, but also affects the hemorheological parameters (viscosity, aggregation ability of blood cells, fluidity), hemodynamics, etc. vascular permeability.
The most typical form of pathology that occurs with the activation of the coagulation system is the so-called "shock lung" syndrome, characterized by disseminated intravascular coagulation of blood. The shock lung syndrome is basically modeled by the administration of adrenaline to animals, which ensures pulmonary tissue edema, the formation of hemorrhagic foci, as well as the activation of the kallikrein-kinin blood system.