IVK in premature babies. Premature babies Blood pressure norms in premature babies

Heart rate (HR) is one of the main characteristics of human health. The norm of heart rate in children by age has its own differences. This is due to the internal characteristics of the growing organism and the influence of external factors on it.

The rate of heart rate changes with the age of the child

Heart rate norms in children of different ages

A child's heart grows rapidly in the first year of life. At this time, the pulse is the highest. As you grow older, the heart system is formed, the vessels are strengthened, which leads to the stabilization of the heart rate and a decrease in this indicator.

Table "Age rate of heart rate in children"

Age	Boundary indicators	Mean
In a newborn (from the first day to 30 days of life)	110–170	138
In an infant (from 1 to 6 months)	107–165	135
6 months to 1 year	104–163	132
For 1-year-olds and up to 2 years	92–155	123
From 2 to 4 years	90–141	116
From 4 to 6 years	88–127	108
From 6 to 8 years old	77–117	97
8 to 10 years old	69–108	88
10 to 12 years old	62–102	82
From 12 to 14 years old	54–97	77

Starting from the age of 15, in adolescents, the number of heartbeats is fixed within 75 beats per minute (limit values \u200b\u200b- 62-81 beats per 60 seconds), which is a normal indicator for an adult.

Deviations from the norm for no apparent reason, especially at rest, may be the result of disturbances in the work of the heart, blood vessels or other vital organs. In order to avoid serious complications, it is better to see a doctor.

Pulse rate in premature babies

Some organs and systems in babies born prematurely are not completely formed. In this case, the baby's body needs more time to adapt to environmental conditions. The child is more sensitive to external stimuli, which greatly increases the frequency of contractions of the heart muscle and blood pressure. That is why in premature babies, a pulse of 180 beats per minute is not considered a pathology, but is their age norm.

High heart rate in premature babies is normal

Normal heart rate in child athletes

The heart rate of a child who is constantly involved in sports in a calm state is lower than that of his peers. This is a normal phenomenon, which indicates the good work of the heart muscle and its health. The maximum heart rate in such children during training should not exceed the indicator, which is calculated by the formula - 220 beats minus age. The obtained values are present only during the first 10 minutes after physical exertion, and then return to normal. If the high pulse has not stabilized, we are talking about cardiac pathologies.

An increase in heart rate in children during exercise is normal.

The difference in heart rate between boys and girls

Pulse in children preschool age does not depend on gender. As they grow older (puberty), the development of the autonomic regulation of the heart in girls and boys is slightly different, as a result, the pulse of the beautiful half of humanity is 10–15 beats higher.

Girls have a slightly higher heart rate than boys.

Causes of heart rate deviation from the norm

Heartbeat, like pressure, can change during the day under the influence of external factors:

heavy physical exercise;
stressful situations;
weather conditions (heat, high humidity).

Stressful situations can increase a child's heart rate

Changes in the environment enhance the work of the heart, and increase its usual rhythm by almost 3 times. This condition is considered normal if short time values return to normal, and the baby's well-being does not suffer.

If palpitations are observed in children at rest, the cause may be:

inflammatory processes in the respiratory organs;
pathologies of the cardiovascular system;
negative deviations in the endocrine system;
diseases caused by a bacterial or viral infection;
problems in blood formation (anemia).

Exhaustion of the body and severe overwork can also cause increased contraction of the heart muscle, which negatively affects blood pressure and the functioning of vital systems in general.

How to measure heart rate correctly

Measuring heart rate in children does not require special skills.

The main thing is to know the places on the body where the pulsation occurs best:

in newborn babies and children under one year old - a large fontanel, chest;
at one year old babies, older children, adolescents and adults - the neck (carotid artery), temple, wrist (above the wrist joint), elbow or groin.

To measure the heart rate, you will need a stopwatch (electronic clock). At the site of the pulsation, you need to place the index and middle fingers, note the time (60 seconds) during which to count the number of strokes.

When measuring heart rate, put your index and middle fingers on the place of the pulsation

When measuring heart rate, it is important to remember that any external factors can affect its performance. In sleep, the pulse is usually below the limit values, after squats it is 2–2.5 times higher than normal, and at temperature, the heart rate can go off scale.

In order for the measurement to show reliable results, you should follow some recommendations:

It is necessary to measure the heart rate when the baby is at rest (sitting or lying down), preferably in the morning.
The procedure is carried out for 3-4 days at the same time. This will provide more accurate data.
The results obtained after physical exertion or an emotional outburst should be checked by re-measurement when the baby is in a calm state.

Heart rate control allows you to monitor the state of the child's body and helps to identify negative deviations in the work of vital systems in time. The main thing is to measure the pulse correctly and not to panic in case of deviations from fixed indicators, but to consult a doctor.

The rate of heart rate in children of different ages is very different. In babies of the first year of life, this indicator is the highest, but closer to adolescence, the pulse stabilizes, since the cardiovascular system has already been formed. Heart rate is influenced by both external (emotional stress, physical activity, weather conditions) and internal (pathologies of the cardiovascular system) factors. Therefore, it is important to constantly monitor the child’s pulse in order to keep this indicator normal.

From the article you will learn what is the norm of pressure in children. What should it be in different periods child development, whether it depends on gender. When the change blood pressure(abbreviated blood pressure) in children is the norm, and when to seek help. How to correctly measure the pressure of a child.

Article publication date: 07/18/2017

Article last updated: 06/02/2019

Blood pressure is an indicator that depends on the age of a person. The lowest values are recorded in newborns (in the first 4 weeks), when blood pressure is in the range of 60–80 to 40–50 mm Hg. Art.

As the work of blood vessels and the heart changes, associated with the transition to a pulmonary type of breathing, blood pressure also increases - during the first year it can reach a value of 90 to 70 mm Hg. Art., but more often lies in the lower limits.

Normal children's pressure from 1-2 to 8-9 years is about 100 per 70 mm Hg. Art. Then it gradually grows and by the age of 15 enters the "adult" boundaries.

Children also have fairly large pressure fluctuations, often up to 20–25 mm Hg. Art., which is associated with increased activity of the child.

Problems with blood pressure under the age of 18 are dealt with by neonatologists, district pediatricians and pediatric cardiologists.

Normal blood pressure in children

Immediately after birth, the child registers the most low level Blood pressure, which grows as quickly as possible (on average, up to 2 units per day) during the first weeks. In the future, the growth rate slows down.

In pediatric practice, unlike the adult population, there is no single normal level of pressure - indicators that are registered in 90-94% of children are taken beyond the boundaries.

A table by the age of the child, including physiological fluctuations:

Age limits	Level, mm Hg Art.
Age limits	systolic	diastolic
First 2 weeks - neonatal period	60–96	40–50
2 to 4 weeks - neonatal period	80–112	40–74
From 1 to 12 months - the infant stage	90–112	50–74
1 to 3 years - early childhood	100–112	60–74
3 to 6 years old - preschool	100–116	60–76
6 to 9 years old - early school stage	100–122	60–78
9 to 12 - middle school age	110–126	70–82
From 12 to 15-17 - senior school period	110–136	70–86

Also, normal blood pressure in children of different ages can be obtained using the formulas for calculating:

The physiological limits of fluctuations in the formulaic calculation system are up to 30 units in the direction of increase.

Speaking about the norm, it should be noted that it is always individual, especially in relation to childhood. Many factors will affect the level of pressure of the child:

Place of residence (in a mountainous or tropical climate, a natural decrease in blood pressure is observed).
The amount of salt in food (for children during the period breastfeeding mother's salt preferences).
Time of birth (in children born prematurely, blood pressure is lower).
activity (than more active child- the higher its pressure in the younger period, and with regular sports loads, older children develop a physiological decrease in blood pressure).
Compliance with measurement technique.
Growth (the higher the child, the higher the pressure).

In order to facilitate the use of tables with age and gender standards, pediatrics has a rule:

consider acceptable blood pressure for the first 10 years, figures up to 110 per 70 mm Hg. Art.;
after 10 years - up to 120 per 80 mm Hg. Art.

When this norm of blood pressure in children is violated, this is a reason to use formulas and tables to make sure that there is no pathology.

Sex differences

Not always present, but it must be taken into account that, depending on the sex of the child, there may be differences in blood pressure:

from birth to the end of the first year, the level of pressure in girls and boys is the same;
then, in girls, it gradually increases, reaching a maximum difference by 3–4 years;
at the age of five years, the indicators are compared;
from five to ten years, the pressure level of girls is again higher than that of boys;
after 10 years of age, boys lead, this championship is maintained until the age of 17.

Why does blood pressure drop in children?

Low blood pressure may be physiological. This is due to the features of the function nervous system when its parasympathetic part is more active. In this variant, against the background of a decrease in blood pressure, there are no disturbances in the general well-being of the child.

Pathological decrease in blood pressure has its negative manifestations:

Weakness.
Decreased activity.
Appetite problems.
Dizziness.
Different intensity of pain in the head.
Tendency to collapse and faint.
Vegetative disorders.

The reason for this condition is a violation of the pressure regulation system, which is aggravated by external factors:

pathology of the course of pregnancy (somatic diseases in the mother, infections, the action of harmful agents, etc.);
premature birth;
increased intracranial cerebrospinal fluid pressure;
chronic infectious and inflammatory foci;
personal characteristics (emotional instability, hysteria);
psycho-emotional stress;
unfavorable socio-economic conditions;
insufficient level of physical activity;
violation of the mode of activity and rest;
a period of high instability of hormone levels (11–14 years).

Increased intracranial pressure

Why is the pressure rising?

Under certain conditions, an increase in pressure is a physiological norm. This is how it happens:

in any stressful situation, when the emotional background is increased;
during and immediately after intense physical activity;
in cases of trauma.

A feature of this state is the temporary nature of the change in pressure.

In the case of pathological primary arterial hypertension in children, a moderate level of pressure increase (“mild hypertension”) is noted. High blood pressure numbers indicate a secondary genesis of pathology.

There are often no symptoms of pressure changes. This is an accidental finding during a routine inspection.

If high blood pressure figures are detected, it is necessary to prescribe the child an additional examination to clarify the cause:

Cause group	Specific diseases
Damage to the kidney tissue	Glomerulonephritis - inflammatory changes in the glomeruli of the kidneys Glomerulosclerosis - transformation of kidney tissue into connective tissue Nephropathy of any origin Hydronephrosis - an increase in the pyelocaliceal system of the kidney with compression of the glomeruli and a gradual "shutdown" of the organ Underdevelopment of kidney tissue (hypoplasia) Benign and malignant neoplasms Alport's syndrome - a combined pathology of the kidneys, hearing and vision
Vascular changes	Malformations - shunting of blood between the arterial and venous system Developmental disorders of the aorta (coarctation, stenosis or underdevelopment of the abdominal part, open duct between the aorta and the pulmonary trunk) Vasculitis - inflammatory process in the wall of autoimmune vessels Narrowing of the renal arteries Takayasu's disease - vasculitis involving the aorta and large arteries
Endocrine diseases	Hyperthyroidism Increased function of the adrenal cortex (hyperaldosteronism)
Damage to the nervous system	Tumor processes Infectious and inflammatory diseases Day-Riley disease is a pathology of the nervous system with vegetative manifestations
Medicinal action	Non-steroidal anti-inflammatory drugs Synthetic hormones of the adrenal cortex Appetite suppressants Tablet contraceptives Steroid drugs Amphetamine phencyclidine
Other reasons	Nicotine Alcohol Lead or mercury poisoning (heavy metals)

Features of the measurement technique

Measurement of pressure in children has its own characteristics, if they are violated, there is a high risk of misinterpretation of the result.

Primary requirements:

The width of the tonometer cuff is at least 40% of the circumference of the arm.
The cuff should cover the arm by 80-100%.
Take measurements on both hands.
Multiplicity - at least two times.
Control of blood pressure, in case of its change, is carried out at home in the morning and evening for one week.
Do not measure immediately after feeding, active play or crying baby.
The study should be done only in the supine or sitting position, after 20–30 minutes of rest.

Indications for daily measurement

In children, due to their increased activity and excitability, often to establish a diagnosis pathological change Blood pressure is measured during the day to avoid errors in diagnosis.

Indications for monitoring blood pressure at home for 24 hours.

Few parents are prepared for the birth of their child. ahead of time. Most often, the birth of a premature baby becomes a difficult test for the whole family. This is because everyone is waiting for the birth of a plump, rosy-cheeked toddler, expecting to return from the maternity hospital in a maximum of 5 days, and in general, as a rule, they make optimistic plans for the future. Great amount information for expectant and young parents, including the Internet, television, printed publications, is dedicated to a normal pregnancy, childbirth without complications and caring for a healthy newborn. When something starts to go wrong, parents find themselves in an information vacuum, which sometimes exacerbates an already difficult situation.

For the first time in Russia, a resource has been created that is completely devoted to the problem of premature birth and prematurity. This resource was created by parents for parents who are expecting or have already given birth to a child prematurely. From our own experience, we have experienced a lack of information during the period of maintaining a pregnancy, nursing a baby in a maternity hospital and a perinatal center. We felt an acute shortage of funds for specialized care, which is so necessary for the full physical and mental maturation of the child outside the womb. Behind him is more than one month spent at the incubator, then at the crib in endless expectation, fear and hopes for recovery. As the baby grew, more and more information was needed about the care, development, education of a child born prematurely, which would be adapted to our situation and which is very difficult to find. Such experience gives us reason to believe that the information posted on our website will help young mothers and fathers be more prepared for the birth of their dearest baby, which means it is easier and more peaceful to survive this difficult period in life. Knowledge and experience will make you more confident and help you focus on the most important thing - the health and development of your baby.

As materials for creating the site, we used medical and pedagogical literature, reference books, practical guides, opinions of specialists in the field of obstetrics, gynecology and neonatology, child psychology and pedagogy, materials from foreign resources, as well as the invaluable experience of parents whom we met and became close friends thanks to our children.

We draw your attention to the fact that the materials presented here are not a “recipe” for you and your child, but are only intended to help you deal with the situation, dispel some doubts and orient yourself in your actions. Mention of any medicines, equipment, trademarks, institutions, etc. is not an advertisement and cannot be used without the consent of experts.

We hope that we will be useful to you from the moment your baby is born and we will grow with you. If you have any questions, wishes or suggestions, This e-mail address is being protected from spambots. You need JavaScript enabled to view it !

Sincerely yours,

Since 1961, according to WHO recommendations, all newborns weighing less than 2500 g have been designated as "low birth weight" newborns. Currently, this position is not shared by many researchers, since it eliminated the concepts of "prematurity" and "prenatal development" in assessing the condition of the child. Many researchers divide newborns with low body weight into three groups:

newborns whose intrauterine growth rate was normal until birth (body weight corresponds to gestational age);
children born at term or overdue, but having a body weight that is insufficient for a given gestational age, due to a slowdown in intrauterine growth;
premature, who, in addition, noted a slowdown in fetal growth, i.e., their body weight is insufficient due to both prematurity and impaired intrauterine development.

Cause of premature babies

In most observations, the phenomena of intrauterine growth retardation in primigravidas were due to the morphofunctional features of the placenta and the development of placental insufficiency. A comparative analysis of qualitative indicators and quantitative characteristics showed that at birth at 28-32 weeks, half, and at birth at 33-36 weeks - only one third of the placenta had anomalies in the shape and attachment of the umbilical cord. In those cases when the pregnancy proceeded with the threat of termination in the first trimester, changes in the placenta were more pronounced. Thus, the index of the resorption surface of the placenta decreased to 3.1 m 2 at a gestational age of 28-32 weeks and to 5.7 m 2 at a period of 33-36 weeks.

When using general survey methods of morphological studies in the placenta in women who gave birth prematurely, a number of changes were revealed, which include massive fibrinoid deposits in the decidual plate and intervillous space with the presence of single X-cells, areas of calcification, an increase in the number of altered terminal villi (sclerosed, edematous, fibrinoid-altered), narrowing of the intervillous space. All these changes characterized dystrophic processes and were more often found in the placentas of women who gave birth before 32 weeks. At the same time it was determined a large number of unchanged terminal villi with syncytial "nodules" of proliferative type, with dilated, full-blooded and subepithelial located capillaries. These villi determined compensatory-adaptive reactions in the placenta. These features were more often detected in the placentas of women who gave birth later than 33 weeks of gestation. Stereometric analysis of the placenta confirmed the predominance of dystrophic processes in the placenta during childbirth up to 32 weeks and compensatory and adaptive changes during childbirth at a later date. In women who had acute respiratory viral diseases during pregnancy, histological examination of the placentas, in addition to these changes, showed severe disorders of the uteroplacental circulation in the form of extensive hemorrhages in the decidua, intervillous space and stroma of the villi.

When analyzing the morphometric data of the placenta and comparing them with data on the state of premature babies at birth and in the early neonatal period, it was found that the body weight of newborns, the weight and morphometric parameters of the placenta, depending on the gestational age, are reduced in cases where children were born with signs of intrauterine growth retardation. development. The condition of children born with signs of malnutrition was assessed on the Apgar scale, as a rule, below 5 points. In the morphological analysis of the placenta, dystrophic processes more pronounced in intensity and prevalence were observed in those women whose children were born with signs of malnutrition and before 32 weeks of pregnancy. These data were confirmed by a stereometric analysis of the structural elements of the terminal villi, where a decrease in the relative areas of the intervillous space was observed. If, during histological examination, compensatory changes in the placentas prevailed over dystrophic ones, then the physical data of the children were normal and corresponded to the gestational age.

An electron microscopic examination of the placenta revealed changes in all cellular structures of the villous chorion: syncytiotrophoblast, stroma of the villi and capillaries. The microvilli covering the syncytiotrophoblast were absent in places or unevenly located on the altered terminal villi. The ultrastructure of sclerosed villi was characterized by an increase in the number of collagen fibers in the stroma running in different directions, while edematous villi were characterized by a decrease in the number of cellular components with large electron-optically transparent formations. various shapes and numerous barriers. The amount of collagen fibers around the capillary confirmed the presence of vascular sclerosis. At the same time, endothelial cells lining the inner surface of the capillary were changed. Their nuclei were elongated, the nuclear chromatin was located compactly along the periphery, sometimes with destruction of the cytoplasm. All these changes in the cellular elements of the terminal villus confirmed the presence of a dystrophic process in the placenta. An electron microscopic examination of the placenta also showed an increase in subepithelial vessels and hyperplastic capillaries, changes in the density of microvilli, and the appearance in syncytium of grouped nuclei of syncytiotrophoblast with swollen mitochondrial rists.

As a result of the study of the enzymatic activity of ATPase and 5 "-nucleotidase in placentas during preterm birth, the dependence of the reaction product on changes in various structures of the terminal villus was established. Thus, high enzymatic activity was observed on microvilli secreting pinocytic vesicles, nuclei of syncytium, cytotrophoblast and endothelial cells , i.e., unchanged terminal villi, where more often the processes were of a compensatory nature.So, where destruction was detected during ultrastructural examination of the placenta, the enzymatic activity of ATPase and 5 "-nucleotidase was reduced. This was especially true of edematous, sclerosed and fibrinoid-altered villi. Electron microscopic examination made it possible to once again determine the predominance of dystrophic or compensatory processes in the placentas in women who gave birth prematurely. The results of ultrastructural and ultracytochemical studies confirmed that the changes occurring in the placenta indicate the development of placental insufficiency.

Thus, morphofunctional studies of placenta in preterm birth, carried out using morphometric and electron microscopic methods, made it possible to detect the phenomena of placental insufficiency. In cases of predominance of compensatory-adaptive processes in the placentas over dystrophic ones, the pregnancy proceeded favorably and premature babies were born with physical parameters corresponding to gestational age. With pronounced dystrophic changes in the placentas, the development of placental insufficiency led to intrauterine growth retardation of the fetus, a complicated course of the neonatal period in premature babies and was one of the indications for early termination of pregnancy.

The main signs of a premature baby

A baby born before 38 weeks of gestation is considered premature. Children weighing more than 2500 g at birth are diagnosed with prematurity, according to the international nomenclature (Geneva, 1957), if they were born earlier than 37 weeks.

Classification of prematurity based on gestational age at birth

I degree - 35-37 weeks of pregnancy.
II degree - 32-34 weeks of pregnancy.
III degree - 29-31 weeks of pregnancy.
IV degree - less than 29 weeks of pregnancy.

For physical development premature babies are characterized by a higher rate of weight gain and body length in the first year of life (with the exception of the first month). By 2-3 months, they double the initial body weight, by 3-5 - triple, by the year - increase by 4-7 times. At the same time, extremely immature children are significantly behind in terms of absolute indicators of height and body weight (“miniature” children), 1-3 “corridor” of centile tables. In subsequent years of life, very premature babies may retain a kind of harmonic "delay" of physical development. The assessment of physical development is carried out according to the scale of G.M. Dementieva, E.V. Short and according to the method of E.A. Usacheva, taking into account gestational age.

The neuropsychic development of premature babies in the first 1.5 years is usually slowed down, the degree of this delay depends on the severity of prematurity, this is a kind of "norm" for immature children. In the absence of damage to the nervous system, even extremely immature children by the age of 2-3 years do not differ from full-term ones in terms of the level of psychomotor development, although many of them retain emotional lability, fatigue, and rapid exhaustion of nervous processes.

Anatomical and physiological features of premature babies

Features of the neurological status of preterm infants of the 1st degree (35-38 weeks) without factors aggravating the neurological status do not differ from full-term children. In children with II-IV degree of prematurity, the morphological status depends on the degree of brain maturity. Children with II-III degree of prematurity are characterized by respiratory failure (rhythmic shallow breathing), which persists up to 2-3 months of life. Di 1.5-2 months of life, the syndrome of "heat transfer" is expressed, the marble pattern of the skin, cyanosis, rapid cooling, and edematous syndrome.

Children are lethargic, motor reactions are reduced. Reactions of concentration and initial tracking begin to form with a satisfactory increase in body weight and the absence of somatic diseases, appear from 1.5-2 months of life. Characterized by muscle hypotonia up to 2-4 weeks, then replaced by increased tone in the flexors of the limbs.

Unconditioned reflexes from the group of spinal automatisms (reflexes of support, automatic gait, crawling, etc.) begin to appear from 1-2 months of age. In prematurity III-IV degree, it is difficult to objectively assess the neurological status up to 1.5-2 months, since the leading syndrome is general lethargy, which is also characteristic of CNS depression.

It must be remembered that with improper rehabilitation, even meager clinical manifestations before the age of 3-4 months of life can subsequently progress.

Features of the neurological status in premature babies

Premature babies are identified as a risk group for neuropsychiatric pathology. The pediatrician should pay attention to the clinical manifestations of neuropsychiatric status. In a premature baby, the syndrome of increased neuro-reflex excitability proceeds according to one of three options.

In the first case, the clinical picture in the acute period is similar to that of a full-term baby, subsequently decreases and gradually disappears by 6-12 months. In the second variant, after a year of life, an asthenoneurotic syndrome is formed. In the third variant of the course, minimal manifestations of the syndrome of increased neuro-reflex excitability are transformed into a convulsive syndrome (regardless of age). Such conditions practically do not occur in full-term children with neuro-reflex excitability syndrome.

Thus, minimal clinical changes in the nervous system in a premature baby may have irreversible severe consequences, which requires constant dynamic monitoring by a pediatrician, narrow specialists using instrumental research methods.

Most often, premature babies develop hypertensive hydrocephalic syndrome, which occurs in two ways. Favorable course - at first, hypertensive symptoms disappear, in the future there are no signs of hydrocephalus. Unfavorable course - outcome in cerebral palsy, hydrocephalic and convulsive syndromes.

CNS depression syndrome is typical for children with III-IV degree of prematurity. It indicates not only neurological, but also somatic ill-being, is characteristic of subarachnoid and parenchymal hemorrhages, bilirubin brain damage that occurs with conjugative jaundice in immature premature babies.

Convulsive syndrome can be observed in the first days of life. His clinic is typical. Sometimes in the recovery period, after 4-6 months of life, there are apnea attacks, a sharp reddening or cyanosis of the face, a marbled skin pattern, a Harlequin symptom, increased sweating, regurgitation, nodding movements of the head or bending the body back and forth. These prognostically unfavorable symptoms may first occur against the background of intercurrent diseases, indicating irreversible changes occurring in the central nervous system. All premature babies are characterized by a syndrome of vegetative-visceral dysfunctions, the severity of which depends on the degree of prematurity, the timeliness and volume of rehabilitation measures.

A child born prematurely shows signs of immaturity: body weight less than 2500 g, body length less than 45 cm, a lot of cheese-like lubricant, insufficient development of subcutaneous adipose tissue, fluff on the body (normally it is noted only on the shoulder girdle), short hair on the head , soft ear and nasal cartilages, nails do not go beyond the fingertips, the umbilical ring is located closer to the womb, in boys the testicles are not lowered into the scrotum, in girls the clitoris and labia minora are not covered by large ones, the child's cry is thin (squeaky).

Maturity is assessed using a special scale (WHO, 1976). At the same time, the period of intrauterine development of a newborn can be estimated with an accuracy of 2 weeks. When assessing the degree of maturity, the gestational age at which the birth occurred should be taken into account.

The Apgar score has been proposed for the full-term newborn, but this scale can also be used with success in prematurity. An increased frequency of depression of vital parameters in a premature baby is correlated with low status scores at birth. According to many researchers, with a body weight of up to 1500 g, the condition is assessed on the Apgar scale from 0 to 3 points in about 50%, while with a weight of 3000 g - only in 5-7% of newborns. Of great prognostic value is the assessment of the child's condition on the Apgar scale 5 minutes after birth. If it remains low, then the prognosis is poor.

AT last years it was found that in utero the fetus makes respiratory movements that can be recorded using ultrasound equipment. If these movements are absent or significantly weakened, then newborns often develop hyaline membrane disease. With nephropathy or diabetes in the mother, the frequency of episodes of respiratory movements in the fetus decreases. Intrauterine respiration is a new parameter, which, apparently, will make it possible to more accurately assess the readiness of the fetal body for extrauterine respiration. The mechanism of the first breath is quite complex, and the role of stimuli in this process is not well understood, especially in children born at different gestational dates. Of great importance in the excitation of the respiratory center at the time of birth is asphyxia, which can be observed as a short episode at the time of birth. A decrease in PO2 and pH, an increase in PCO2 stimulate respiratory movements, causing impulses from carotid and aortic chemoreceptors. Such short episodes of asphyxia, which are observed during normal childbirth, are characterized by the absence of metabolic acidosis. Protracted asphyxia is accompanied by the appearance of metabolic and respiratory acidosis and leads to depression of the respiratory center.

Another important stimulus to start breathing is a sharp drop in the temperature of the environment surrounding the baby at birth. Decrease in temperature stimulates the nerve endings in the child's skin, these stimuli are transmitted to the respiratory center. They are an intense breath stimulant. However, excessive cooling of the newborn leads to a deep depression of the child's life. The tactile stimulation created by normal touching of the baby at the time of birth also stimulates the onset of breathing. The end result of the extrauterine activity of the respiratory muscles is the creation of more low pressure than in the atmosphere. Negative intrathoracic pressure promotes the flow of air into the lungs. The diaphragm plays a major role in the normal functioning of the lungs.

Adaptation of the cardiovascular system to extrauterine life occurs simultaneously with the adaptation of the lungs. The expansion of the lungs and adequate oxygenation, which occur in a child with the onset of respiratory movements, cause a decrease in blood pressure in the pulmonary circulation due to the expansion of the pulmonary arterioles. At this time, arterial pressure in the systemic circulation increases significantly due to the shutdown of placental blood flow. Due to the change in the ratio of blood pressure values, conditions are created for the elimination of mixing of venous and arterial blood, the oval window and the arterial, and then the venous duct close. .

To assess the respiratory function at the time of birth and subsequent days, the Silverman scale is increasingly being used, according to which the respiratory function of the newborn is characterized by:

movement chest and retraction of the anterior abdominal wall on inspiration;
retraction of intercostal spaces;
retraction of the sternum;
position mandible and the participation of the wings of the nose in the act of breathing;
the nature of breathing (noisy, with a groan).

Each of these symptoms is scored from 0 to 2 points as its severity increases. The sum of points gives an idea of the respiratory function of the newborn. The lower the score on the Silverman scale, the less pronounced manifestations of pulmonary insufficiency. When nursing premature babies, it is necessary to maintain adequate breathing and normal functioning of the lungs. It is especially important not to disrupt the mechanism of the first breath, so all manipulations to suction mucus from the upper respiratory tract should be carried out with extreme caution.

Maintaining the optimal temperature environment is one of the most important aspects of effective care for a premature baby. The anatomical features of premature babies are such that they predispose to heat loss, and their heat balance is less stable than in children with a larger body weight.

In newborns with low body weight, its surface is relatively large. The large surface of the body causes more extensive contact with the external environment, increasing heat loss. Heat loss per unit mass in a premature baby weighing 1500 g is 5 times greater than in an adult. Another anatomical barrier to heat retention is too thin a layer of subcutaneous adipose tissue, as a result of which heat is quickly transferred from internal organs to the surface of the skin.

The posture of the child is also reflected in the rate of heat loss. With bent limbs, the surface of the body and, accordingly, heat transfer decrease. The tendency to bend the limbs increases with the increase in the period of intrauterine development. The smaller it is, the more heat the newborn loses. These factors significantly affect the ability of the newborn to survive, the rate of recovery after asphyxia, the effectiveness of the treatment of respiratory disorders, as well as the rate of weight gain.

Under the influence of cold, due to the activation of the metabolism in a newborn, the rate of return increases. This phenomenon is observed in both full-term and premature newborns, although the latter have a slightly lower rate of heat transfer. The main metabolic disorders in newborns exposed to cold include hypoxemia, metabolic acidosis, rapid depletion of glycogen stores, and low blood sugar levels. An increase in metabolism leads to an increase in oxygen consumption. If at the same time the oxygen content in the inhaled air is not increased, then the blood PO2 drops. In response to hypothermia, norepinephrine is released, which leads to pulmonary vasoconstriction. In this regard, the efficiency of lung ventilation decreases, which leads to a decrease in the partial pressure of oxygen in arterial blood. In this case, the breakdown of glycogen and its conversion into glucose occur under hypoxic conditions, and with anaerobic glycolysis, the rate of glycogen breakdown is many times higher than with aerobic, resulting in hypoglycemia. In addition, in the process of anaerobic glycolysis, a large amount of lactic acid is formed, which leads to an increase in metabolic acidosis.

These disorders occur the sooner the more premature the child is, since his glycogen stores are insignificant, and are especially reduced in newborns with insufficient oxygenation with atelectasis due to lung immaturity and other respiratory disorders. For these newborns, maintaining a warm environment is vital. Body temperature drops immediately after birth. To a certain extent, this is a physiological process, since stimulation of the skin receptors is necessary to stimulate the first breath. In a normal delivery room, the temperature of a full-term newborn decreases by 0.1 ° C in the rectum and 0.3 ° C on the skin per minute. In a premature baby, these losses are even more significant, especially if respiratory distress is observed at the same time.

A significant amount of heat is lost when the amniotic fluid evaporates from the baby's body. In order to reduce these losses, a premature baby should be taken in warm diapers, wiped and placed on a table heated from above by a heat source, or in an incubator heated to 32-35 ° C. Maintaining a thermal regime in the first days of life is a top priority when nursing premature babies.

Premature newborns do not tolerate stressful situations that arise in connection with the onset of extrauterine life. Their lungs are not mature enough to carry out gas exchange, the digestive tract cannot absorb 20-40% of the fat contained in milk. Their resistance to infection is low, and an increase in the rate of heat loss disrupts thermoregulation. Increased fragility of capillaries predisposes to hemorrhage, especially in the ventricles of the brain and the cervical spinal cord. The most common diseases to which premature newborns are predisposed are hyaline membrane disease, intracranial hemorrhage, infection, and asphyxia.

Complications in premature babies

The most severe complication of the postnatal period of life in a premature baby is hyaline membrane disease, or respiratory distress syndrome. Most often, this disease is observed in children with a birth weight of 1000-1500 g or less. In most cases, newborns have surfactant in their lungs to help them breathe efficiently. A small amount of it is produced with the participation of methyltransferase from 22-24 weeks of intrauterine life. After birth, the production of surfactant l in this way stops under the influence of hypoxia. Surfactant synthesis by a more stable system involving phosphocholine transferase begins at 34-35 weeks of intrauterine life; this system is more resistant to acidosis and hypoxia. At birth and soon after premature baby can breathe without difficulties, but due to the fact that the surfactant is consumed, and the new system synthesizes it in small quantities, normal functional residual lung capacity is not established. The alveoli, which expand during inhalation, collapse during exhalation. Each subsequent breath requires incredible effort from the child.

As the child weakens, atelectasis increases, which entails the development of hypoxia and hypercapnia. Since the anaerobic pathway of glycolysis predominates, metabolic acidosis occurs. Hypoxia and acidosis increase vasospasm, resulting in a decrease in blood flow to the lungs. Hypoxia and acidosis lead to capillary damage and alveolar necrosis. In the alveoli and terminal respiratory bronchioles, hyaline membranes are formed from the products of cell necrosis, which by themselves, without causing atelectasis, significantly reduce the elasticity of the lungs. These processes further disrupt the production of surfactant. Insufficient expansion of the lungs and the preservation of high resistance of the pulmonary vessels lead to an increase in blood pressure in the pulmonary circulation, as a result of which the intrauterine type of blood circulation (foramen ovale, arterial duct) is preserved. The action of these extrapulmonary shunts is expressed in the removal of blood from the lungs, and: the child's condition progressively worsens. With the threat of preterm labor and at the time of childbirth, it is necessary to prevent hyaline membrane disease in a child (maintenance temperature regime, sufficient oxygenation, the fight against acidosis). Modern methods intensive care can significantly reduce mortality in this disease. In the neonatal period, premature babies show signs of intrauterine growth retardation. Such conditions are most typical for children born to mothers with extragenital pathology and toxicosis in the second half of pregnancy. At the same time, as our studies have shown), children with malnutrition are often born even in primigravida without any other complications during pregnancy. Hypotrophy is detected more often in preterm birth at 28-32 weeks of gestation (67%). At birth at 33-36 weeks, the frequency of birth of children with signs of intrauterine growth retardation is only 30%.