Oxygen reserves in the body are very limited, and they last for 5-6 minutes. The body is supplied with oxygen through the process of breathing. Depending on the function performed, there are 2 main parts of the lung: conductive part to supply air into the alveoli and remove it out and respiratory part, where gas exchange occurs between air and blood. The conducting part includes the larynx, trachea, bronchi, i.e., the bronchial tree, and the respiratory part itself includes the acini, consisting of afferent bronchioles, alveolar ducts and alveoli. External respiration refers to the exchange of gases between atmospheric air and blood of the capillaries of the lungs. It is carried out through simple diffusion of gases through the alveolar-capillary membrane due to the difference in oxygen pressure in the inhaled (atmospheric) air and venous blood, flowing through the pulmonary artery into the lungs from the right ventricle (Table 2).
Table 2
Partial pressure of gases in inspired and alveolar air, arterial and venous blood (mmHg)
|
Indicator |
Inhaled air |
Alveolar air |
Arterial blood |
Venous blood |
|
RO 2 | ||||
|
RSO 2 | ||||
|
RN 2 | ||||
|
RN 2 ABOUT | ||||
|
Total pressure |
The difference in oxygen pressure in the alveolar air and venous blood flowing through the pulmonary capillaries is 50 mm Hg. Art. This ensures the transfer of oxygen into the blood through the alveolar-capillary membrane. The difference in carbon dioxide pressure causes its transition from venous blood to alveolar air. The effectiveness of the function of the external respiration system is determined by three processes: ventilation of the alveolar space, adequate ventilation of the lungs by capillary blood flow (perfusion), and diffusion of gases through the alveolar-capillary membrane. Compared to adults, children, especially the first year of life, have pronounced differences external respiration. This is explained by the fact that in the postnatal period there is further development respiratory sections of the lungs (acini), where gas exchange occurs. In addition, children have numerous anastomoses between the bronchial and pulmonary arteries and capillaries, which is one of the reasons for blood shunting, bypassing the alveolar spaces.
Currently, external respiration function is assessed using the following groups of indicators.
Pulmonary ventilation- frequency (f), depth (Vt), minute volume of respiration (V), rhythm, volume of alveolar ventilation, distribution of inhaled air.
Lung volumes- vital lung capacity (VC, Vc), total lung capacity, inspiratory reserve volume (IRV), expiratory reserve volume (ERV), functional residual capacity (FRC), residual volume (RR).
Mechanics of breathing- maximum ventilation of the lungs (MVL, Vmax), or breathing limit, respiratory reserve, forced vital capacity (FEV) and its relation to vital capacity (Tiffno index), bronchial resistance, volumetric flow rate of inhalation and exhalation during quiet and forced breathing.
Pulmonary gas exchange- the amount of oxygen consumption and carbon dioxide release per minute, the composition of alveolar air, the oxygen utilization rate.
Gas composition arterial blood - partial pressure of oxygen (PO 2) and carbon dioxide (PCO 2), the content of oxyhemoglobin in the blood and the arteriovenous difference in hemoglobin and oxyhemoglobin.
The depth of breathing, or tidal volume (DO, or Vt, in ml), in children, both in absolute and relative numbers, is significantly less than in an adult (Table 3).
Table 3
Tidal volume in children depending on age
|
Age |
Tidal volume in children, ml |
|||
|
According to N. A. Shalkova |
||||
|
Abs. number |
Per 1 kg body weight |
Abs. number |
Per 1 kg body weight |
|
|
Newborn | ||||
|
Adults | ||||
This is due to two reasons. One of them, naturally, is the small mass of the lungs in children, which increases with age, and during the first 5 years mainly due to the formation of alveoli. Another, no less important reason explaining the shallow breathing of children early age, are the structural features of the chest (the anterior-posterior size is approximately equal to the lateral size, the ribs extend from the spine almost at a right angle, which limits the excursion of the chest and changes in lung volume). The latter changes mainly due to the movement of the diaphragm. An increase in tidal volume at rest may indicate respiratory failure, and a decrease in tidal volume may indicate a restrictive form of respiratory failure or chest rigidity. At the same time, the need for oxygen in children is much higher than in adults, which depends on a more intense metabolism. Thus, in children of the first year of life, the need for oxygen per 1 kg of body weight is approximately 7.5-8 ml/min, by 2 years it increases slightly (8.5 ml/min), by 6 years it reaches its maximum value (9 .2 ml/min), and then gradually decreases (at 7 years - 7.9 ml/min, 9 years - 6.8 ml/min, 10 years - 6.3 ml/min, 14 years - 5.2 ml /min). In an adult, it is only 4.5 ml/min per 1 kg of body weight. The shallow nature of breathing and its irregularity are compensated by a higher breathing frequency (f). So, in a newborn - 40-60 breaths per minute, in a one-year-old - 30-35, in a 5-year-old - 25, in a 10-year-old - 20, in an adult - 16-18 breaths per minute. The respiratory rate reflects the compensatory capabilities of the body, but in combination with a small tidal volume, tachypnea indicates respiratory failure. Due to the higher respiratory rate, per 1 kg of body weight, the minute volume of breathing is significantly higher in children, especially young children, than in adults. In children under 3 years of age, the minute volume of breathing is almost 1.5 times greater than that of an 11-year-old child, and more than 2 times that of an adult (Table 4).
Table 4
Minute volume of breathing in children
|
Indicators |
Newborn cash |
3 months |
6 months |
1 year |
3 years |
6 years |
11 years old |
14 years old |
Adults |
|
MOD, cm | |||||||||
|
MOD per 1 kg of body weight |
Observations of healthy people and children with pneumonia have shown that at low temperatures (0...5 ° C) there is a decrease in breathing while maintaining its depth, which is apparently the most economical and effective breathing for providing the body with oxygen. It is interesting to note that a warm hygienic bath causes a 2-fold increase in pulmonary ventilation, and this increase occurs mainly due to an increase in the depth of breathing. Hence, the proposal of A. A. Kisel (an outstanding Soviet pediatrician), which he made back in the 20s of the last century and which became widespread in pediatrics, to widely use the treatment of pneumonia with cold fresh air, becomes quite understandable.
Vital capacity of the lungs(VC, Vc), i.e., the amount of air (in milliliters) maximally exhaled after maximal inhalation (determined by a spirometer), is significantly lower in children than in adults (Table 5).
Table 5
Vital capacity of the lungs
|
Age |
Vital capacity, ml |
Volumes, ml |
||
|
respiratory |
reserve exhalation |
reserve breath |
||
|
4 years | ||||
|
6 years | ||||
|
Adult | ||||
If we compare the values of the vital capacity of the lungs with the volume of breathing in a quiet position, it turns out that children in a quiet position use only about 12.5% of vital capacity.
Inspiratory reserve volume(ROVD, IRV) - the maximum volume of air (in milliliters) that can be additionally inhaled after a quiet breath.
For its assessment, the ratio of ROVD to VC (Vc) is of great importance. In children aged 6 to 15 years, ROVD/VC ranges from 55 to 59%. A decrease in this indicator is observed with restrictive (limiting) lesions, especially with a decrease in elasticity lung tissue.
Expiratory reserve volume(ROvyd, ERV) - the maximum volume of air (in milliliters) that can be exhaled after a quiet inhalation. Just as for the inspiratory reserve volume, its relationship to vital capacity (Vc) is important for assessing ERV. In children aged 6 to 15 years, ROV/VC is 24-29% (increases with age).
Vital capacity of the lungs decreases with diffuse lesions of the lungs, accompanied by a decrease in the elastic extensibility of the lung tissue, with an increase in bronchial resistance or a decrease in the respiratory surface.
Forced vital capacity(FVC, FEV), or forced expiratory volume (FEV, l/s), is the amount of air that can be exhaled during forced exhalation after maximum inspiration.
Tiffno index(FEV in percent) - the ratio of FEV to vital capacity (FEV%), normally for 1 s FEV is at least 70% of the actual vital capacity.
Maximum ventilation(MVL, Vmax), or breathing limit, is the maximum amount of air (in milliliters) that can be ventilated in 1 minute. Usually this indicator is examined within 10 s, as signs of hyperventilation may occur (dizziness, vomiting, fainting). MVL in children is significantly less than in adults (Table 6).
Table 6
Maximum ventilation in children
|
Age, years |
Average data, l/min |
Age, years |
Average data, l/min |
Thus, a 6-year-old child’s breathing limit is almost 2 times less than that of an adult. If the breathing limit is known, then it is not difficult to calculate the value of the respiratory reserve (the minute volume of breathing is subtracted from the limit). A smaller vital capacity and rapid breathing significantly reduce the respiratory reserve (Table 7).
Table 7
Breathing reserve in children
|
Age, years |
Breathing reserve, l/min |
Age, years |
Breathing reserve, l/min |
The effectiveness of external respiration is judged by the difference in oxygen and carbon dioxide content in the inhaled and exhaled air. Thus, this difference in children of the first year of life is only 2-2.5%, while in adults it reaches 4-4.5%. The exhaled air of young children contains less carbon dioxide - 2.5%, in adults - 4%. Thus, young children absorb less oxygen and emit less carbon dioxide per breath, although gas exchange in children is more significant than in adults (calculated per 1 kg of body weight).
Of great importance in judging the compensatory capabilities of the external respiration system is the oxygen utilization factor (OCF 2) - the amount of absorbed oxygen (PO 2) from 1 liter of ventilated air.
KIO 2 =PO 2 (ml/min) / MOD (l/min).
In children under 5 years of age, ERI 2 is 31-33 ml/l, and at the age of 6-15 years - 40 ml/l, in adults - 40 ml/l. KIO 2 depends on the conditions of oxygen diffusion, the volume of alveolar ventilation, on the coordination of pulmonary ventilation and blood circulation in the pulmonary circle.
Oxygen is transported from the lungs to the tissues by blood, mainly in the form of a chemical compound with hemoglobin - oxyhemoglobin and, to a lesser extent, in a dissolved state. One gram of hemoglobin binds 1.34 ml of oxygen, therefore, the volume of bound oxygen depends on the amount of hemoglobin. Since newborns have a higher hemoglobin content during the first days of life than adults, the oxygen-binding capacity of their blood is higher. This allows the newborn to survive a critical period - the period of formation of pulmonary respiration. This is also facilitated by the higher content of fetal hemoglobin (HbF), which has a greater affinity for oxygen than adult hemoglobin (HbA). After pulmonary respiration is established, the HbF content in the child’s blood quickly decreases. However, with hypoxia and anemia, the amount of HbF may increase again. This is like a compensatory device that protects the body (especially vital organs) from hypoxia.
The ability to bind oxygen by hemoglobin is also determined by temperature, blood pH and carbon dioxide content. With increasing temperature, decreasing pH and increasing PCO 2, the binding curve shifts to the right.
The solubility of oxygen in 100 ml of blood at PO 2 equal to 100 mm Hg. Art., is only 0.3 ml. The solubility of oxygen in the blood increases significantly with increasing pressure. Increasing the oxygen pressure to 3 atm ensures the dissolution of 6% oxygen, which is sufficient to maintain tissue respiration at rest without the participation of oxyhemoglobin. This technique (oxybarotherapy) is currently used in the clinic.
Capillary blood oxygen diffuses into tissues also due to the oxygen pressure gradient in the blood and cells (in arterial blood the oxygen pressure is 90 mm Hg, in the mitochondria of cells it is only 1 mm Hg).
The features of tissue respiration have been studied much less well than other stages of respiration. However, it can be assumed that the intensity of tissue respiration in children is higher than in adults. This is indirectly confirmed by the higher activity of blood enzymes in newborns compared to adults. One of the significant features of metabolism in young children is an increase in the proportion of the anaerobic phase of metabolism compared to that in adults.
The partial pressure of carbon dioxide in tissues is higher than in blood plasma, due to the continuity of the processes of oxidation and release of carbon dioxide, therefore H 2 CO 3 easily enters the blood from tissues. In the blood, H 2 CO 3 is found in the form of free carbonic acid bound to erythrocyte proteins and in the form of bicarbonates. At a blood pH of 7.4, the ratio of free carbonic acid and bound in the form of sodium bicarbonate (NaHCO 3) is always 1:20. The reaction of binding carbon dioxide in the blood with the formation of H 2 CO 3, bicarbonate and, conversely, the release of carbon dioxide from compounds in the capillaries of the lungs is catalyzed by the enzyme carbonic anhydrase, the action of which is determined by the pH of the environment. In an acidic environment (i.e., in cells, venous blood), carbonic anhydrase promotes the binding of carbon dioxide, and in an alkaline environment (in the lungs), on the contrary, it decomposes and releases it from compounds.
The activity of carbonic anhydrase in premature newborns is 10%, and in full-term newborns it is 30% of the activity in adults. Her activity slowly increases and only by the end of the first year of life reaches the norms of an adult. This explains the fact that with various diseases (especially pulmonary diseases), children more often experience hypercapnia (accumulation of carbon dioxide in the blood).
Thus, the breathing process in children has a number of features. They are largely determined by the anatomical structure of the respiratory organs. In addition, young children have lower breathing efficiency. All of the above anatomical and functional features of the respiratory system create the prerequisites for easier breathing disorders, which leads to respiratory failure in children.
There are several stages in the development of the respiratory system:
Stage 1 – up to 16 weeks intrauterine development the formation of bronchial glands occurs.
From the 16th week - the recanalization stage - cellular elements begin to produce mucus and fluid and, as a result, the cells are completely displaced, the bronchi acquire lumen, and the lungs become hollow.
Stage 3 - alveolar - begins from 22 - 24 weeks and continues until the birth of the child. During this period, the formation of the acini, alveoli, and the synthesis of surfactant occurs.
By the time of birth, there are about 70 million alveoli in the fetal lungs. From 22-24 weeks, differentiation of alveolocytes, the cells lining the inner surface of the alveoli, begins.
There are 2 types of alveolocytes: type 1 (95%), type 2 – 5%.
Surfactant is a substance that prevents the alveoli from collapsing due to changes in surface tension.
It lines the alveoli from the inside thin layer, during inspiration, the volume of the alveoli increases, surface tension increases, which leads to respiratory resistance.
During exhalation, the volume of the alveoli decreases (more than 20-50 times), surfactant prevents their collapse. Since 2 enzymes are involved in the production of surfactant, they are activated by different dates gestation (at the latest from 35-36 weeks), it is clear that the shorter the child’s gestational age, the more pronounced the surfactant deficiency and the higher the likelihood of developing bronchopulmonary pathology.
Surfactant deficiency also develops in mothers with preeclampsia, during complicated pregnancy, caesarean section. The immaturity of the surfactant system is manifested by the development respiratory distress– syndrome.
Surfactant deficiency leads to collapse of the alveoli and the formation of atelectasis, as a result of which the function of gas exchange is disrupted, the pressure in the pulmonary circulation increases, which leads to the persistence of the fetal circulation and the functioning of the open ductus arteriosus and oval window.
As a result, hypoxia and acidosis develop, vascular permeability increases and the liquid part of the blood with proteins sweats into the alveoli. Proteins are deposited on the wall of the alveoli in the form of half rings - hyaline membranes. This leads to disruption of gas diffusion and the development of severe respiratory failure, which is manifested by shortness of breath, cyanosis, tachycardia, and the participation of auxiliary muscles in the act of breathing.
The clinical picture develops within 3 hours from the moment of birth and changes increase within 2-3 days.
By the time a child is born, the respiratory system reaches morphological maturity and can perform the function of breathing.
In a newborn, the respiratory tract is filled with a liquid that has low viscosity and a small amount of protein, which ensures its rapid absorption after the birth of the child through the lymphatic and blood vessels. In the early neonatal period, the child adapts to extrauterine existence.
After 1 inhalation, a short inspiratory pause occurs, lasting 1-2 seconds, after which exhalation occurs, accompanied by a loud cry of the child. In this case, the first respiratory movement in a newborn is carried out as a gasping (inspiratory “flash”) - this is a deep breath with difficult exhalation. Such breathing persists in healthy full-term infants until the first 3 hours of life. U healthy newborn With the child's first exhalation, most of the alveoli expand, and at the same time, vasodilation occurs. Complete expansion of the alveoli occurs within the first 2-4 days after birth.
The mechanism of the first breath. The main trigger point is hypoxia, which occurs as a result of clamping of the umbilical cord. After ligation of the umbilical cord, oxygen tension in the blood drops, carbon dioxide pressure increases and pH decreases. In addition, for a newborn child great influence has an environmental temperature that is lower than in the womb. Contraction of the diaphragm creates negative pressure in the chest cavity, which allows air to enter the airways more easily.
A newborn baby has well-expressed protective reflexes - coughing and sneezing. Already in the first days after the birth of a child, the Hering-Breuer reflex functions, which, at threshold stretching of the pulmonary alveoli, leads to the transition of inhalation to exhalation. In an adult, this reflex occurs only when very strong stretching lungs.
Anatomically, the upper, middle and lower respiratory tract are distinguished. The nose is relatively small at the time of birth, the nasal passages are narrow, there is no lower nasal passage, turbinate, which are formed by the age of 4. Submucosal tissue is poorly developed (matures by 8-9 years), cavernous or cavernous tissue is underdeveloped up to 2 years (as a result, young children do not experience nosebleeds). The nasal mucosa is delicate, relatively dry, rich in blood vessels. Due to the narrowness of the nasal passages and the abundant blood supply to their mucous membrane, even minor inflammation causes difficulty breathing through the nose in young children. Breathing through the mouth is impossible in children in the first six months of life, since the large tongue pushes the epiglottis backward. The exit from the nose - the choanae - is especially narrow in young children, which is often the cause of long-term disruption of nasal breathing in them.
The paranasal sinuses in young children are very poorly developed or completely absent. As the facial bones increase in size ( upper jaw) and teeth erupt, the length and width of the nasal passages increase, the volume paranasal sinuses nose These features explain the rarity of diseases such as sinusitis, frontal sinusitis, ethmoiditis, in early childhood. A wide nasolacrimal duct with underdeveloped valves contributes to the transfer of inflammation from the nose to the mucous membrane of the eyes.
The pharynx is narrow and small. The lymphopharyngeal ring (Waldeyer-Pirogov) is poorly developed. It consists of 6 tonsils:
2 palatines (between the anterior and posterior palatines)
2 tubes (near the Eustachian tubes)
1 throat (in the upper part of the nasopharynx)
1 lingual (in the area of the root of the tongue).
The palatine tonsils are not visible in newborns; by the end of the 1st year of life they begin to protrude from behind the palatine arches. By the age of 4-10 years, the tonsils are well developed and their hypertrophy can easily occur. During puberty, the tonsils begin to undergo reverse development. The Eustachian tubes in young children are wide, short, straight, located horizontally and when the child is in a horizontal position pathological process from the nasopharynx easily spreads to the middle ear, causing the development of otitis media. With age they become narrow, long, and tortuous.
The larynx has a funnel shape. The glottis is narrow and located high (at level 4 cervical vertebra, and in adults – at the level of the 7th cervical vertebra). Elastic tissue is poorly developed. The larynx is relatively longer and narrower than in adults; its cartilages are very pliable. With age, the larynx acquires a cylindrical shape, becomes wide and descends 1-2 vertebrae lower. False vocal cords and mucous membrane are delicate, rich in blood and lymphatic vessels, elastic tissue is poorly developed. The glottis in children is narrow. Young children's vocal cords are shorter than those of older children, which is why they have a high-pitched voice. From the age of 12, boys' vocal cords become longer than girls'.
The bifurcation of the trachea lies higher than in an adult. The cartilaginous frame of the trachea is soft and easily narrows the lumen. Elastic tissue is poorly developed, the mucous membrane of the trachea is tender and richly supplied with blood vessels. The growth of the trachea occurs in parallel with the growth of the body, most intensively in the 1st year of life and during puberty.
The bronchi are richly supplied with blood, muscle and elastic fibers in young children are underdeveloped, and the lumen of the bronchi is narrow. Their mucous membrane is richly vascularized.
The right bronchus is like a continuation of the trachea; it is shorter and wider than the left. This explains the frequent entry of a foreign body into the right main bronchus.
The bronchial tree is poorly developed.
There are bronchi of the 1st order - main, 2nd order - lobar (3 on the right, 2 on the left), 3rd order - segmental (10 on the right, 9 on the left). The bronchi are narrow, their cartilage is soft. Muscle and elastic fibers in children of the 1st year of life are not yet sufficiently developed, the blood supply is good. The bronchial mucosa is lined with ciliated epithelium, which provides mucociliary clearance, which plays a major role in protecting the lungs from various pathogens from the upper respiratory tract and has an immune function (secretory immunoglobulin A). The tenderness of the bronchial mucosa and the narrowness of their lumen explain the frequent occurrence of bronchiolitis with the syndrome of complete or partial obstruction and pulmonary atelectasis in young children.
Lung tissue is less airy, elastic tissue is underdeveloped. In the right lung there are 3 lobes, in the left 2. Then the lobar bronchi are divided into segmental ones. A segment is an independently functioning unit of the lung, with its apex directed towards the root of the lung, and has an independent artery and nerve. Each segment has independent ventilation, a terminal artery and intersegmental septa made of elastic connective tissue. The segmental structure of the lungs is already well expressed in newborns. There are 10 segments in the right lung, and 9 in the left lung. The upper left and right lobes are divided into three segments - 1st, 2nd and 3rd, middle right lobe- into two segments - 4th and 5th. In the left light medium The lobe corresponds to the lingular lobe, also consisting of two segments - the 4th and 5th. The lower lobe of the right lung is divided into five segments - 6, 7, 8, 9 and 10th, the left lung - into four segments - 6, 7, 8 and 9th. The acini are underdeveloped, the alveoli begin to form from 4 to 6 weeks of life and their number quickly increases within 1 year, increasing up to 8 years.
The oxygen requirement in children is much higher than in adults. Thus, in children of the 1st year of life, the need for oxygen per 1 kg of body weight is about 8 ml/min, in adults - 4.5 ml/min. The shallow nature of breathing in children is compensated by a high breathing frequency, the participation of most of the lungs in breathing
In the fetus and newborn, hemoglobin F predominates, which has an increased affinity for oxygen, and therefore the dissociation curve of oxyhemoglobin is shifted to the left and up. Meanwhile, in a newborn, like in a fetus, red blood cells contain extremely little 2,3-diphosphoglycerate (2,3-DPG), which also causes less saturation of hemoglobin with oxygen than in an adult. At the same time, in the fetus and newborn, oxygen is more easily transferred to the tissues.
U healthy children depending on age is determined different character breathing:
a) vesicular - exhalation is one third of inhalation.
b) puerile breathing - enhanced vesicular
V) hard breathing- exhalation is more than half of inhalation or equal to it.
G) bronchial breathing- exhalation is longer than inhalation.
It is also necessary to note the sonority of breathing (normal, increased, weakened). In children of the first 6 months. breathing is weakened. After 6 months up to 6 years of age, breathing is puerile, and from 6 years of age - vesicular or intensely vesicular (one third of inhalation and two thirds of exhalation are heard), it is heard evenly over the entire surface.
Frequency breathing movements(NPV)
|
Frequency per minute |
|
|
Premature |
|
|
Newborn |
|
Stange test - holding your breath while inhaling (6-16 years old - from 16 to 35 seconds).
Gench's test - holding your breath while exhaling (N - 21-39 seconds).
ANATOMICAL AND PHYSIOLOGICAL FEATURES OF THE RESPIRATORY SYSTEM
The formation of the tracheopulmonary system begins at the 3-4th week of embryonic development. Already by the 5-6th week of embryo development, second-order branches appear and the formation of three lobes of the right lung and two lobes of the left lung is predetermined. During this period, the trunk of the pulmonary artery is formed, growing into the lungs along the primary bronchi.
In the embryo, at the 6-8th week of development, the main arterial and venous collectors of the lungs are formed. Within 3 months, the bronchial tree grows, segmental and subsegmental bronchi appear.
During the 11-12th week of development, areas of lung tissue are already present. They, together with the segmental bronchi, arteries and veins, form the embryonic segments of the lungs.
Between the 4th and 6th months, rapid growth of the pulmonary vascular system is observed.
In fetuses at 7 months, the lung tissue acquires the features of a porous canal structure; the future air spaces are filled with fluid, which is secreted by the cells lining the bronchi.
At 8–9 months of the intrauterine period, further development of the functional units of the lungs occurs.
The birth of a child requires the immediate functioning of the lungs; during this period, with the onset of breathing, significant changes occur in the airways, especially the respiratory part of the lungs. The formation of the respiratory surface in individual parts of the lungs occurs unevenly. To straighten the respiratory apparatus of the lungs great importance have the condition and readiness of the surfactant film lining the lung surface. Violation of the surface tension of the surfactant system leads to serious illnesses young child.
In the first months of life, the child maintains the ratio of the length and width of the airways, like a fetus, when the trachea and bronchi are shorter and wider than in adults, and the small bronchi are narrower.
The pleura covering the lungs in a newborn baby is thicker, looser, contains villi and outgrowths, especially in the interlobar grooves. Pathological foci appear in these areas. The lungs are prepared for the birth of a child to perform the respiratory function, but individual components are in the development stage, the formation and maturation of the alveoli is rapidly proceeding, the small lumen of the muscular arteries is being restructured and the barrier function is being eliminated.
After three months of age, period II is distinguished.
I – period of intensive growth pulmonary lobes(from 3 months to 3 years).
II – final differentiation of the entire bronchopulmonary system (from 3 to 7 years).
Intensive growth of the trachea and bronchi occurs in the 1st-2nd year of life, which slows down in subsequent years, and small bronchi grow intensively, and the branching angles of the bronchi also increase. The diameter of the alveoli increases, and the respiratory surface of the lungs doubles with age. In children under 8 months, the diameter of the alveoli is 0.06 mm, in 2 years – 0.12 mm, in 6 years – 0.2 mm, in 12 years – 0.25 mm.
In the first years of life, growth and differentiation of lung tissue elements and blood vessels occur. The ratio of share volumes of individual segments is equalized. Already at 6–7 years of age, the lungs are a mature organ and are indistinguishable from the lungs of adults.
FEATURES OF THE RESPIRATORY TRACT
The respiratory tract is divided into the upper, which includes the nose, paranasal sinuses, pharynx, eustachian tubes, and lower, which include the larynx, trachea, and bronchi.
The main function of breathing is to conduct air into the lungs, cleanse it of dust particles, and protect the lungs from the harmful effects of bacteria, viruses, and foreign particles. In addition, the airways warm and humidify the inhaled air.
The lungs are represented by small sacs that contain air. They connect with each other. The main function of the lungs is to absorb oxygen from the atmospheric air and release gases, primarily carbon dioxide, into the atmosphere.
Breathing mechanism. When you inhale, the diaphragm and chest muscles contract. Exhalation in older age occurs passively under the influence of elastic traction of the lungs. With bronchial obstruction, emphysema, and also in newborns, active inhalation occurs.
Normally, breathing is established at a frequency at which the volume of breathing is performed due to the minimum energy expenditure of the respiratory muscles. In newborn children, the respiratory rate is 30–40, in adults – 16–20 per minute.
The main carrier of oxygen is hemoglobin. In the pulmonary capillaries, oxygen binds to hemoglobin to form oxyhemoglobin. In newborns, fetal hemoglobin predominates. On the first day of life, it is contained in the body about 70%, by the end of the 2nd week - 50%. Fetal hemoglobin has the ability to easily bind oxygen and difficult to release it to tissues. This helps the child in the presence of oxygen starvation.
Transport of carbon dioxide occurs in dissolved form; blood oxygen saturation affects the carbon dioxide content.
The respiratory function is closely related to pulmonary circulation. This is a complex process.
During breathing, autoregulation is noted. When the lung is stretched during inhalation, the inhalation center is inhibited, while exhalation is stimulated during exhalation. Deep breathing or forced inflation of the lungs leads to a reflex expansion of the bronchi and increases the tone of the respiratory muscles. When the lungs collapse and are compressed, the bronchi become narrowed.
The medulla oblongata contains the respiratory center, from where commands are sent to the respiratory muscles. The bronchi lengthen when you inhale, and shorten and narrow when you exhale.
The relationship between the functions of breathing and blood circulation manifests itself from the moment the lungs expand during the first breath of a newborn, when both the alveoli and blood vessels expand.
With respiratory diseases in children, respiratory dysfunction and respiratory failure may occur.
STRUCTURE FEATURES OF THE NOSE
In young children, the nasal passages are short, the nose is flattened due to an underdeveloped facial skeleton. The nasal passages are narrower, the conchae are thickened. The nasal passages are fully formed only by the age of 4 years. The nasal cavity is relatively small in size. The mucous membrane is very loose and well supplied with blood vessels. The inflammatory process leads to the development of edema and, as a result, a reduction in the lumen of the nasal passages. Mucus often stagnates in the nasal passages. It can dry out, forming crusts.
When the nasal passages close, shortness of breath may occur; during this period, the child cannot suckle, becomes anxious, abandons the breast, and remains hungry. Children, due to difficulty in nasal breathing, begin to breathe through their mouths, their warming of incoming air is disrupted and their susceptibility to colds increases.
If nasal breathing is impaired, there is a lack of discrimination of odors. This leads to a disturbance of appetite, as well as a disturbance in the understanding of the external environment. Breathing through the nose is physiological, breathing through the mouth is a sign of nasal disease.
Accessory cavities nose The paranasal cavities, or sinuses as they are called, are confined spaces filled with air. The maxillary (maxillary) sinuses are formed by the age of 7. Ethmoidal - by the age of 12, the frontal is fully formed by the age of 19.
Features of the nasolacrimal canal. The nasolacrimal duct is shorter than in adults, its valves are not sufficiently developed, and the outlet is located close to the corner of the eyelids. Due to these features, the infection quickly spreads from the nose to the conjunctival sac.
FEATURES OF THE PHARYN
The pharynx in young children is relatively wide, the palatine tonsils are poorly developed, which explains rare diseases sore throat in the first year of life. The tonsils are fully developed by the age of 4–5 years. By the end of the first year of life, almond tissue hyperplasias. But its barrier function at this age is very low. Overgrown almond tissue can be susceptible to infection, which is why diseases such as tonsillitis and adenoiditis occur.
The Eustachian tubes open into the nasopharynx and connect it to the middle ear. If an infection enters the middle ear from the nasopharynx, middle ear inflammation occurs.
FEATURES OF THE LARYNX
The larynx in children is funnel-shaped and is a continuation of the pharynx. In children, it is located higher than in adults, and has a narrowing in the area of the cricoid cartilage, where the subglottic space is located. The glottis is formed by the vocal cords. They are short and thin, which is responsible for the child’s high, sonorous voice. The diameter of the larynx in a newborn in the subglottic space is 4 mm, at 5–7 years old – 6–7 mm, by 14 years old – 1 cm. Features of the larynx in children are: its narrow lumen, many nerve receptors, easily occurring swelling of the submucosal layer, which can lead to severe breathing problems.
The thyroid cartilages form a more acute angle in boys over 3 years of age; from the age of 10, a typical male larynx is formed.
FEATURES OF THE TRACHEA
The trachea is a continuation of the larynx. It is wide and short, and the tracheal frame consists of 14–16 cartilaginous rings, which are connected by a fibrous membrane instead of an elastic end plate in adults. The presence of a large number of muscle fibers in the membrane contributes to changes in its lumen.
Anatomically, the trachea of a newborn is located at the level of the IV cervical vertebra, and in an adult – at the level of the VI–VII cervical vertebra. In children, it gradually descends, as does its bifurcation, which is located in a newborn at the level of the third thoracic vertebra, in children 12 years old - at the level of the V-VI thoracic vertebra.
During physiological breathing, the lumen of the trachea changes. During coughing, it decreases by 1/3 of its transverse and longitudinal dimensions. The mucous membrane of the trachea is rich in glands that secrete a secretion that covers the surface of the trachea with a layer 5 microns thick.
The ciliated epithelium promotes the movement of mucus at a speed of 10–15 mm/min from the inside to the outside.
The characteristics of the trachea in children contribute to the development of its inflammation - tracheitis, which is accompanied by a rough, low-pitched cough, reminiscent of a cough “like in a barrel”.
FEATURES OF THE BRONCHIAL TREE
The bronchi in children are formed at birth. Their mucous membrane is richly supplied with blood vessels, covered with a layer of mucus, which moves at a speed of 0.25-1 cm/min. A feature of the bronchi in children is that elastic and muscle fibers are poorly developed.
The bronchial tree branches to bronchi of the 21st order. With age, the number of branches and their distribution remain constant. The size of the bronchi changes rapidly in the first year of life and during puberty. They are based on cartilaginous semirings in early childhood. Bronchial cartilage is very elastic, pliable, soft and easily displaced. The right bronchus is wider than the left and is a continuation of the trachea, so foreign bodies are more often found in it.
After the birth of a child, a columnar epithelium with a flickering apparatus. With hyperemia of the bronchi and their swelling, their lumen sharply decreases (up to its complete closure).
Underdevelopment of the respiratory muscles contributes to a weak cough impulse in small child, which can lead to blockage of small bronchi with mucus, and this, in turn, leads to infection of the lung tissue and disruption of the cleansing drainage function of the bronchi.
With age, as the bronchi grow, wide lumens of the bronchi appear, and the bronchial glands produce less viscous secretions, acute diseases of the bronchopulmonary system are less common compared to younger children.
FEATURES OF THE LUNG
The lungs in children, as in adults, are divided into lobes, and lobes into segments. The lungs have a lobular structure, the segments in the lungs are separated from each other by narrow grooves and partitions of connective tissue. The main structural unit is the alveoli. Their number in a newborn is 3 times less than in an adult. Alveoli begin to develop from 4-6 weeks of age, their formation occurs up to 8 years. After 8 years, the lungs in children increase due to their linear size, and the respiratory surface of the lungs increases in parallel.
The following periods can be distinguished in the development of the lungs:
1) from birth to 2 years, when intensive growth of the alveoli occurs;
2) from 2 to 5 years, when elastic tissue intensively develops, bronchi with peribronchial inclusions of lung tissue are formed;
3) from 5 to 7 years the functional abilities of the lungs are finally formed;
4) from 7 to 12 years, when a further increase in lung mass occurs due to the maturation of lung tissue.
Anatomically, the right lung consists of three lobes (upper, middle and lower). By 2 years sizes individual shares correspond to each other, like those of an adult.
In addition to the lobar, segmental division is distinguished in the lungs: in the right lung there are 10 segments, in the left - 9.
The main function of the lungs is breathing. It is believed that 10,000 liters of air pass through the lungs daily. Oxygen absorbed from the inhaled air ensures the functioning of many organs and systems; the lungs take part in all types of metabolism.
The respiratory function of the lungs is carried out with the help of a biologically active substance - surfactant, which also has a bactericidal effect, preventing fluid from entering the pulmonary alveoli.
The lungs remove waste gases from the body.
A feature of the lungs in children is the immaturity of the alveoli; they have a small volume. This is compensated by increased breathing: than younger child, the more shallow his breathing. The respiratory rate in a newborn is 60, in a teenager it is already 16–18 respiratory movements per minute. Lung development is completed by age 20.
The most various diseases may interfere with the vital respiratory function of children. Due to the characteristics of aeration, drainage function and evacuation of secretions from the lungs inflammatory process often localized in the lower lobe. This occurs when infants are lying down due to insufficient drainage function. Paravisceral pneumonia most often occurs in the second segment of the upper lobe, as well as in the basal-posterior segment of the lower lobe. The middle lobe of the right lung may often be affected.
Greatest diagnostic value have the following studies: x-ray, bronchology, determination of blood gas composition, blood pH, study of external respiration function, study of bronchial secretions, computed tomography.
By the frequency of breathing and its relationship with the pulse, the presence or absence of respiratory failure is judged (see Table 14).
Table 14 Age dynamics of respiratory rate (Fomin V.F., 2003)
source: Directory of Children's Diseases.
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The respiratory system of a newborn, like all other systems of a newly born baby, is still imperfect. The lower nasal passage is not developed, the glottis is much narrower than in adults, the pharynx is underdeveloped, the bronchi are narrower, and the trachea has a too narrow lumen. All respiratory organs of newborns have yet to be fully formed, and until this happens, parents should be extremely careful.
During the prenatal period, the lungs are in a collapsed state. At the moment of birth, the child makes the first breathing movement, which we learn about thanks to the first exhalation - a cry. Breathing becomes possible thanks to a special substance - surfactant, which covers the walls of the alveoli already in the prenatal period. Surfactant prevents the collapse of alveoli and the development of respiratory disorders during the newborn period.
Upper respiratory tract infant have a number of features: the nose is wide and short, the lower nasal passage is not developed, the mucous membrane is delicate, easily wounded. The baby may have difficulty breathing due to blockage of the nasal passages during the inflammatory process, this forces him to breathe through the mouth.
Another anatomical and physiological feature of the respiratory organs of a newborn is the underdevelopment of the frontal and main grooves; they begin to mature only after the 1st year of life.
The baby's throat is narrow, the lymph glands that form a ring in it are underdeveloped, and the tonsils are small. In this regard, children in the first year of life do not have sore throats.
The newborn's respiratory organ, the larynx, has a funnel shape. The vocal cords are short and the glottis is narrower than in adults. The mucous membrane of the larynx is delicate, well supplied with blood vessels and lymphoid tissue. Due to these features, babies often develop laryngeal stenosis. Children have a ringing voice due to short vocal cords. At the age of 3, the size and shape of the larynx in boys and girls are the same. Gender differences are formed during puberty and are associated with the fact that in boys the angle of intersection of the thyroid cartilage becomes sharper and the vocal cords lengthen.
The trachea has an almost funnel-shaped shape and a narrow lumen; its cartilages are very pliable and easily move. The number of mucous glands is small. This anatomical and physiological feature of the respiratory system of newborns contributes to the development of inflammatory processes in it and the occurrence of stenosis.
The bronchi are narrow, the cartilage in them is soft. The peculiarity is that one bronchus - the right one - occupies vertical position, being a continuation of the trachea, the left one departs at an angle from the trachea. Foreign bodies often enter the right bronchus. There are few mucous glands in the mucous membrane of the organ, but it is richly supplied with blood. All these features of the respiratory organs of young children contribute to the easy occurrence of inflammatory processes and stenotic complications.
A child's lungs are constantly developing. During the newborn period, they are less airy, abundantly supplied with blood vessels, and their elastic tissue is underdeveloped. After birth, the number of alveoli in the respiratory system of a newborn child increases and continues to increase until the age of 8 years.
During the first months of life, breathing is variable, and an increase in its rhythm may be observed. In infancy, breathing is shallow, which is associated with the horizontal position of the ribs, weak contraction of the diaphragm, relatively large sizes liver. All this contributes.
The respiratory rate decreases with age: in a newborn it is 75-48 per minute, in the first year of life it is 45-35. The ratio between breathing and heart contractions in newborns is 1:3, later - 1:3.5-4.
Breath counting in children is carried out with a hand placed on the chest or stomach, in restless children - by eye.
In infants in the first months of life, breathing is counted through a stethoscope placed on the baby's nose. Breathing disorders in children may occur:
The anatomical, physiological and functional characteristics of the respiratory system in newborns explain the significant incidence of diseases, especially pneumonia, and their more severe course in infancy.
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In children it occurs in the 3-4th week of gestation. The respiratory organs are formed from the rudiments of the foregut of the embryo: first - the trachea, bronchi, acini (functional units of the lungs), in parallel with which the cartilaginous frame of the trachea and bronchi is formed, then the circulatory and nervous systems of the lungs. By birth, the vessels of the lungs have already been formed, the airways are quite developed, but filled with fluid, the secretion of the cells of the respiratory tract. After birth, with a cry and the baby's first breath, this fluid is absorbed and coughed up.
The surfactant system is of particular importance. Surfactant is a surfactant that is synthesized at the end of pregnancy and helps the lungs expand during the first breath. With the onset of breathing, the inhaled air is immediately purified from dust and microbial agents through the nose due to biologically active substances, mucus, and bactericidal substances. secretory immunoglobulin A.
With age, a child's respiratory tract adapts to the conditions in which he must live. The nose of a newborn is relatively small, its cavities are poorly developed, the nasal passages are narrow, and the lower nasal passage is not yet formed. The cartilaginous skeleton of the nose is very soft. The mucous membrane of the nasal cavity is richly vascularized with blood and lymphatic vessels. Around the age of four, the lower nasal passage is formed. The cavernous (cavernous) tissue of the child’s nose gradually develops. Therefore, nosebleeds are very rare in children under one year of age. It is almost impossible for them to breathe through the mouth, since the oral cavity is occupied by a relatively large tongue, pushing the epiglottis posteriorly. Therefore, in acute rhinitis, when breathing through the nose is sharply difficult, the pathological process quickly descends into the bronchi and lungs.
The development of the paranasal sinuses also occurs after one year, so in children of the first year of life their inflammatory changes are rare. Thus, than smaller child, the more his nose is adapted to warming, humidifying and purifying the air.
The pharynx of a newborn baby is small and narrow. The pharyngeal ring of the tonsils is in the development stage. Therefore, the palatine tonsils do not extend beyond the edges of the arches of the palate. At the beginning of the second year of life lymphoid tissue develops intensively, and the palatine tonsils begin to extend beyond the edges of the arches. By the age of four, the tonsils are well developed; under unfavorable conditions (infections of the ENT organs), their hypertrophy may appear.
The physiological role of the tonsils and the entire pharyngeal ring is the filtration and sedimentation of microorganisms entering from the environment. In case of prolonged contact with a microbial agent, sudden cooling of the child protective function tonsils weaken, they become infected, and acute or chronic inflammation develops with a corresponding clinical picture.
Enlargement of the nasopharyngeal tonsils is most often associated with chronic inflammation, against the background of which respiratory failure, allergization and intoxication of the body are noted. Hypertrophy palatine tonsils leads to disturbances in the neurological status of children, they become inattentive and perform poorly at school. With hypertrophy of the tonsils in children, a pseudocompensatory malocclusion is formed.
Most frequent illnesses of the upper respiratory tract in children there are acute rhinitis and tonsillitis.
The larynx in a newborn has a funnel-shaped structure, with soft cartilage. The glottis of the larynx is located at the level of the IV cervical vertebra, and in an adult at the level of the VII cervical vertebra. The larynx is relatively narrow, the mucous membrane covering it has well-developed blood and lymphatic vessels. Its elastic tissue is poorly developed. Sex differences in the structure of the larynx appear at puberty. In boys, the larynx sharpens in place of the thyroid cartilages, and by the age of 13 it already looks like the larynx of an adult man. And in girls, by the age of 7-10, the structure of the larynx becomes similar to the structure of an adult woman.
Until 6-7 years of age, the glottis remains narrow. From the age of 12, boys' vocal cords become longer than girls'. Due to the narrow structure of the larynx, good development The submucosal layer in young children is often affected (laryngitis), often accompanied by a narrowing (stenosis) of the glottis, and a picture of croup with difficulty breathing often develops.
The trachea is already formed by the time the baby is born. The upper edge of the se in newborns is located at the level of the IV cervical vertebra (in an adult at the level of the VII cervical vertebra).
The bifurcation of the trachea lies higher than in an adult. The mucous membrane of the trachea is delicate and richly vascularized. Its elastic tissue is poorly developed. The cartilaginous skeleton in children is soft, the lumen of the trachea narrows easily. In children, with age, the trachea gradually grows in length and width, but the overall growth of the body exceeds the growth of the trachea.
During physiological breathing, the lumen of the trachea changes; during coughing, it decreases by approximately 1/3 of its transverse and longitudinal size. There are many secreting glands in the mucous membrane of the trachea. Their secretion covers the surface of the trachea with a layer 5 microns thick; the speed of mucus movement from inside to outside (10-15 mm/min) is ensured by the ciliated epithelium.
Children often experience tracheal diseases such as tracheitis, in combination with damage to the larynx (laryngotracheitis) or bronchi (tracheobronchitis).
The bronchi are formed for the birth of the child. Their mucous membrane is richly supplied with blood vessels, covered with a layer of mucus, which moves from inside to outside at a speed of 0.25 - 1 cm/min. The right bronchus is like a continuation of the trachea, it is wider than the left. In children, unlike adults, the elastic and muscle fibers of the bronchi are poorly developed. Only with age do the length and width of the lumen of the bronchi increase. By the age of 12-13 years, the length and lumen of the main bronchi doubles compared to a newborn. With age, the ability of the bronchi to resist collapse also increases. The most common pathology in children is acute bronchitis, which is observed against the background of acute respiratory diseases. Relatively often, children develop bronchiolitis, which is facilitated by the narrowness of the bronchi. Around the age of one, bronchial asthma may develop. At first it flows against the background acute bronchitis with syndrome of complete or partial obstruction, bronchiolitis. Then the allergic component comes on.
The narrowness of the bronchioles also explains the frequent occurrence of pulmonary atelectasis in young children.
In a newborn baby, the weight of the lungs is small and amounts to approximately 50-60 g, this is 1/50 of its weight. Subsequently, the weight of the lungs increases 20 times. In newborns, the lung tissue is well vascularized, it contains a lot of loose connective tissue, and the elastic lung tissue is less developed. Therefore, emphysema is often observed in children with lung diseases. The acini, which is the functional respiratory unit of the lungs, is also underdeveloped. The alveoli of the lungs begin to develop only from the 4-6th week of a child’s life; their formation occurs up to 8 years. After 8 years, the lungs increase due to the linear size of the alveoli.
In parallel with the increase in the number of alveoli up to 8 years, the respiratory surface of the lungs increases.
In the development of the lungs, 4 periods can be distinguished:
I period - from birth to 2 years; intensive growth of lung alveoli;
II period - from 2 to 5 years; intensive development of elastic tissue, significant growth of bronchi with peribronchial inclusions of lymphoid tissue;
III period - from 5 to 7 years; final maturation of the acinus;
IV period - from 7 to 12 years; further increase in lung mass due to maturation of lung tissue.
The right lung consists of three lobes: upper, middle and lower, and the left lung consists of two: upper and lower. At birth, the upper lobe of the left lung is less developed. By 2 years, the sizes of the individual lobes correspond to each other, as in adults.
In addition to the lobar division, the lungs also have a segmental division corresponding to the division of the bronchi. There are 10 segments in the right lung, and 9 in the left lung.
In children, due to the characteristics of aeration, drainage function and evacuation of secretions from the lungs, the inflammatory process is more often localized in the lower lobe (in the basal-apical segment - the 6th segment). It is here that conditions for poor drainage are created in supine position in infants. Another place of pure localization of inflammation in children is the 2nd segment of the upper lobe and the basal-posterior (10th) segment of the lower lobe. Here so-called paravertebral pneumonia develops. The middle lobe is also often affected. Some segments of the lung: mid-lateral (4th) and mid-inferior (5th) - are located in the area of bronchopulmonary lymph nodes. Therefore, when the latter become inflamed, the bronchi of these segments are compressed, causing a significant shutdown of the respiratory surface and the development of severe lung failure.
The mechanism of the first breath in a newborn is explained by the fact that at the moment of birth the umbilical cord blood circulation stops. The partial pressure of oxygen (pO 2) decreases, the pressure of carbon dioxide (pCO 2) increases, and the acidity of the blood (pH) decreases. An impulse arises from peripheral receptors carotid artery and the aorta to the respiratory center of the central nervous system. Along with this, impulses from skin receptors go to the breathing center, as the conditions of the child’s stay in environment. He gets into more cold air with less humidity. These influences also irritate the respiratory center, and the child takes his first breath. Peripheral regulators of respiration are hema- and baroreceptors of the carotid and aortic formations.
The formation of breathing occurs gradually. In children in the first year of life, respiratory arrhythmia is often recorded. Premature babies often experience apnea (cessation of breathing).
Oxygen reserves in the body are limited, they last for 5-6 minutes. Therefore, a person must maintain this supply by constant breathing. From a functional point of view, there are two parts of the respiratory system: conductive (bronchi, bronchioles, alveoli) and respiratory (acini with afferent bronchioles), where gas exchange takes place between atmospheric air and the blood of the capillaries of the lungs. Diffusion of atmospheric gases occurs through the alveolar-capillary membrane due to the difference in gas pressure (oxygen) in the inhaled air and venous blood flowing through the lungs through the pulmonary artery from the right ventricle of the heart.
The pressure difference between alveolar oxygen and venous blood oxygen is 50 mmHg. Art., which ensures the transition of oxygen from the alveoli through the alveolar-capillary membrane into the blood. At this time, carbon dioxide is transferred from the blood, which is also in the blood under high pressure. Children have significant differences in external respiration compared to adults due to the ongoing development of the respiratory acini of the lungs after birth. In addition, children have numerous anastomoses between the bronchiolar and pulmonary arteries and capillaries, which is the main reason for the shunting (connection) of blood that bypasses the alveoli.
There are a number of indicators of external respiration that characterize its function: 1) pulmonary ventilation; 2) pulmonary volume; 3) breathing mechanics; 4) pulmonary gas exchange; 5) gas composition of arterial blood. The calculation and evaluation of these indicators is carried out in order to determine functional state respiratory organs and reserve capabilities in children of different ages.
This is a medical procedure, and nursing staff must be able to prepare for this test.
It is necessary to find out the timing of the onset of the disease, the main complaints and symptoms, whether the child took any medications and how they affected the dynamics clinical symptoms, what are the complaints today. This information should be obtained from the mother or child's caregiver.
In children, most lung diseases begin with a runny nose. In this case, in the diagnosis it is necessary to clarify the nature of the discharge. The second leading symptom of damage to the respiratory system is cough, the nature of which determines the presence of a particular disease. The third symptom is shortness of breath. In young children with shortness of breath, nodding movements of the head and swelling of the wings of the nose are visible. In older children, one may notice retraction of the compliant areas of the chest, retraction of the abdomen, and a forced position (sitting with support from the hands - in case of bronchial asthma).
The doctor examines the child’s nose, mouth, pharynx and tonsils, differentiates the existing cough. Croup in a child is accompanied by laryngeal stenosis. A distinction is made between true (diphtheria) croup, when the narrowing of the larynx occurs due to diphtheritic films, and false croup(subglottic laryngitis), which occurs as a result of spasm and swelling against the background of acute inflammatory disease larynx. True croup develops gradually, over days, while false croup develops unexpectedly, often at night. The voice with croup can reach aphonia, with sharp breakthroughs of sonorous notes.
Cough with whooping cough in the form of paroxysm (paroxysmal) with reprises (prolonged high inhalation) is accompanied by redness of the face and vomiting.
Bitonal cough (a rough main tone and a musical second tone) is observed with enlargement of the bifurcation lymph nodes and tumors in this place. A painful dry cough is observed with pharyngitis and nasopharyngitis.
It is important to know the dynamics of changes in cough, whether the cough bothered you before, what happened to the child and how the process in the lungs ended, whether the child had contact with a patient with tuberculosis.
When examining a child, the presence of cyanosis is determined, and if it is present, its nature. Pay attention to increased cyanosis, especially around the mouth and eyes, when the child screams or exercises. Children under 2-3 months of age may have foamy discharge from the mouth upon examination.
Pay attention to the shape of the chest and the type of breathing. The abdominal type of breathing remains in boys into adulthood. In girls, from the age of 5-6 years, chest breathing appears.
The number of respiratory movements per minute is counted. It depends on the age of the child. In young children, the number of respirations is counted at rest when they are sleeping.
By the frequency of breathing and its relationship with the pulse, the presence or absence of respiratory failure is judged. By the nature of shortness of breath, one or another damage to the respiratory system is judged. Dyspnea is inspiratory when the passage of air in the upper respiratory tract is difficult (croup, foreign body, cysts and tumors of the trachea, congenital narrowing larynx, trachea, bronchi, retropharyngeal abscess, etc.). When a child inhales, there is retraction of the epigastric region, intercostal spaces, subclavian space, jugular fossa, tension m. sternocleidomastoideus and other accessory muscles.
Shortness of breath can also be expiratory, when the chest is swollen and almost does not participate in breathing, and the stomach, on the contrary, actively participates in the act of breathing. In this case, exhalation is longer than inhalation.
However, there is also mixed shortness of breath - expiratory-inspiratory, when the abdominal and chest muscles take part in the act of breathing.
Shortness of breath may also occur. Shin ( expiratory dyspnea), which occurs as a result of compression lung root enlarged lymph nodes, infiltrates, lower part of the trachea and bronchi; the breath is free.
Dyspnea is common in newborns with respiratory distress syndrome.
Palpation of the child's chest is carried out with both hands to determine its soreness, resistance (firmness), and elasticity. The thickness of the skin fold is also measured in symmetrical areas of the chest to determine inflammation on one side. On the affected side, thickening of the skin fold is noted.
Next they move on to percussion of the chest. Normally, children of all ages receive the same percussion on both sides. At various lesions lungs, the percussion sound changes (dull, boxy, etc.). Topographic percussion is also performed. There are age-related standards for the location of the lungs, which may change due to pathology.
After conducting comparative and topographic percussion perform auscultation. Normally, in children up to 3-6 months, slightly weakened breathing is heard, from 6 months to 5-7 years - puerile breathing, and in children over 10-12 years old it is often transitional - between puerile and vesicular.
With lung pathology, the breathing pattern often changes. Against this background, dry and moist rales and pleural friction noise can be heard. To determine compaction (infiltration) in the lungs, a method for assessing bronchophony is often used, when the voice is heard under symmetrical areas of the lungs. When the lung hardens on the affected side, increased bronchophony is heard. With caverns and bronchiectasis, increased bronchophony may also be observed. A weakening of bronchophony is noted when there is pleural cavity fluids (effusion pleurisy, hydrothorax, hemothorax) and (pneumothorax).
For lung diseases, the most common test is x-ray. In this case, radiography or fluoroscopy is performed. Each of these studies has its own indications. During an X-ray examination of the lungs, attention is paid to the transparency of the lung tissue and the appearance of various dark spots.
TO special research include bronchography - a diagnostic method based on the introduction of a contrast agent into the bronchi.
For mass studies, fluorography is used, a method based on examining the lungs using a special X-ray attachment and outputting it to photographic film.
Other methods are used computed tomography, which allows you to examine in detail the condition of the mediastinal organs, the root of the lungs, to see changes in the bronchi and bronchiectasis. When using nuclear magnetic resonance, a detailed study of the tissues of the trachea and large bronchi is carried out; you can see the vessels and their relationship with the respiratory tract.
An effective diagnostic method is endoscopic examination, including anterior and posterior rhinoscopy (examination of the nose and its passages) using nasal and nasopharyngeal speculum. The lower part of the pharynx is examined using special spatulas (direct laryngoscopy), and the larynx is examined using a laryngeal mirror (laryngoscope).
Bronchoscopy, or tracheobronchoscopy, is a method based on the use of fiber optics. This method is used to identify and remove foreign bodies from the bronchi and trachea, drainage of these formations (suction of mucus) and their biopsy, and administration of medications.
There are also methods for studying external respiration based on graphic recording of respiratory cycles. These records are used to judge the function of external respiration in children over 5 years of age. Then pneumotachometry is performed using a special apparatus, which makes it possible to determine the state of bronchial conductivity. The state of ventilation function in sick children can be determined using the peak flowmetry method.
Among laboratory tests, the method of studying gases (O 2 and CO 2) in the capillary blood of a patient using a micro-Astrup apparatus is used.
Oxygenography is performed using photoelectric measurement of light absorption through the auricle.
Among the stress tests, a test with holding the breath while inhaling (Streny test), a test with physical activity. When squatting (20-30 times) in healthy children, there is no decrease in blood oxygen saturation. An oxygen exhalation test is done when breathing on oxygen is switched on. In this case, the saturation of exhaled air increases by 2-4% within 2-3 minutes.
Examine the patient's sputum laboratory methods: number, content of leukocytes, erythrocytes, squamous epithelial cells, mucus strands.
