Thermoregulation of the newborn

Thermoregulation of the newborn 0 4.1


Thermoregulation of the newborn

At first glance, the newborn baby is just the same as you and me: breathing in the same way, he hears and sees, and sneezes and coughs ... But any doctor will tell you that the crumbs organism differs significantly from the adult: it has its own, inherent only he, illness, and his own principles of work - physiological characteristics. Know these features is very important for parents, because they depend on them, many nuances of caring for the baby. We will tell you about the special "arrangement" of the newborn in this rubric.

Ekaterina Komar Neonatologist, Research Institute of Obstetrics and Pediatrics, Rostov-na-Donu

Man, like all mammals, is distinguished by the constancy of the temperature regime: the temperature of his body does not depend on the temperature of the environment. Constancy is achieved through a complex mechanism of thermoregulation, which ensures heat exchange between the body and the environment. 

How does it work

Thermoregulation of the human body is a multi-stage process, controlled by the central nervous system, the main controlling link is the hypothalamus - a structure located in the very center of the brain. The hypothalamus receives information from peripheral nerve endings about body temperature and sends commands to various systems that perform certain processes that maintain the constancy of the internal temperature. Heat exchange of the organism with the environment is carried out due to two differently directed mechanisms - heat production and heat transfer.

Heat production. In newborn children, it occurs mainly through oxidative processes in the so-called brown adipose tissue, which is found only in the fetus and the newborn baby. A feature of this process is that it occurs with maximum heat production at minimum energy expenditure. This function of fatty tissue has a stimulating effect of thyroid hormones, under the influence of which oxidative processes occur in the brown adipose tissue.

Brown fat begins to form in the fetus from the 26th week of pregnancy and by the time it is completed, it amounts to 3 to 8% of the total body weight of the child, according to various sources. Brown fat is a completely unique tissue, the only function of which is to protect a newborn child from hypothermia. It is located in the neck, between the shoulder blades, behind the breastbone and around some internal organs. The second most important for the newborn mechanism of heat production is muscle tremor. With a decrease in body temperature, involuntary muscle contractions occur, which contribute to an increase in oxidative processes in the muscle tissue, which is accompanied by an increase in body temperature. When hypothermia, newborns wake up and begin to cry, this is accompanied by an increase in motor activity, which increases the process of heat production in muscles and increases body temperature. But this mechanism is significantly inferior in importance to the role of brown adipose tissue. This is the fundamental difference between the heat production of an adult organism and the organism of a newborn child. In adults, brown fat is absent, and the main mechanism of heat production is muscle contraction - both voluntary and involuntary.

Heat transfer. The implementation of heat alone could not meet the requirements of maintaining the internal temperature of the body at a constant level. It is necessary that between the body and the environment is constantly carried out heat exchange - for this, there are mechanisms of heat transfer. These include sweating and regulation of the tone of blood vessels. When the temperature of the surrounding environment rises, the human body begins to exercise increased production of sweat, which, evaporating from the surface of the body, causes its cooling. In newborns, the number of sweat glands is even higher than in adults, but because of immaturity, they do not cope with the tasks assigned to them: sweating in newborns is very small. The second important point in the regulation of heat transfer is the change in the tone of the vessels, depending on the temperature of the environment or body temperature. When it increases, the skin vessels expand, thereby increasing the heat transfer. When the temperature of the body or air decreases, the tone of the vessels rises, which causes a narrowing of the vessels and a decrease in the heat release. But even in this mechanism there are important differences between the body of an adult and a newborn baby: adults have a well developed subcutaneous fatty tissue, in neonates, as a rule, it is not sufficiently developed. Therefore, even with narrowing of the vessels of the skin, heat losses can continue.

Thus, the features of thermoregulation of a newborn child include: a tendency to overheat due to limited sweating, a tendency to subcooling due to insufficient development of the subcutaneous fat layer, immaturity of the mechanisms of thermoregulation. 

In addition, the body of a newborn is significantly higher in water content compared to its content in the adult body. The skin of the newborn has a very thin layer of epidermis, so the heat loss of the naked child by evaporation of moisture from the skin surface can be significant. 

Normally, the body temperature of a newborn baby is from 36.4 ° to 37.2 ° C. To measure the temperature is best in the armpit. For this purpose, both mercury and electronic thermometers can be used. The previously used method of thermometry in the rectum has no advantages over thermometry in the armpit: first, one can injure the rectal mucosa; secondly, it causes a reflex reaction (slowing of the heart rate, spasm of the blood vessels). In addition, the temperature in the rectum is always 0.5 ° C higher than the skin temperature.

The first minutes of life

Until the birth, the fetus remains in a constant temperature environment: the temperature in the uterus is maintained at 38 ° C throughout the period of intrauterine development. Therefore, the mechanisms of thermoregulation remain unoccupied. After birth, the child enters the environment, the temperature of which differs sharply from the one to which he is accustomed. In addition, the baby is born with moist skin. Evaporation of moisture from the skin surface causes rapid and significant cooling. That's why newly born children first dry dry and place under a heat source.

To make the baby feel comfortable ...Thermoregulation of the newborn

Taking into account all the mentioned features of thermoregulation, it is necessary to organize the care of the newborn in the optimal way.

Remembering that the child can be easily overheated as well as supercooled, it is necessary to maintain the optimal temperature of the air in the room in which the newborn is. The temperature regime in the room largely depends on the age of the child. In the early neonatal period, the air temperature should be about 25 ° C. In the first month of a child's life, the temperature optimum for him becomes 24 ° C, for children over 1 month - 23 ° C. This temperature regime is the most comfortable for kids, it prevents both overheating and overcooling. However, important is how the child is dressed. If the baby, staying in a room with a temperature of 24 ° C, is simultaneously dressed in a pair of raspashonok, wrapped in a warm diaper and a blanket, then it can overheat.

The main signs of overheating are anxiety, rejection of the breast, loud screaming, redness of the skin. When overheating, the temperature of the child's body can rise to 38-39 ° C. In this case, the child must be undressed to a thin raspashonki, water with water (30 ml of boiled water at room temperature), calm and after 10-15 minutes measure the temperature again. If symptoms persist, it is necessary to show the child to the pediatrician.

When supercooling, the pallor of the skin is noted, cyanotic staining of the nasolabial triangle, lethargy or anxiety of the baby. Cool to the touch of the foot and palm of the child is not an unconditional sign of hypothermia: there can be a subjective feeling of their low temperature, because, on the one hand, they are much cooler than the rest of the child's body, and on the other - can sweat more and, consequently, cool down.

If the child is cold, supercooled, it must be warmed, put on to the chest, ensure close contact with the mother. However, cases of hypothermia of newborn babies are much less common than cases of overheating: parents mostly seek to dress the child as warmly as possible and maintain an excessively high temperature in the children's room.

One of the most important moments in the organization of caring for the baby in the first year of his life is walking in the fresh air. Begin to go out with a child on the street from the 10 days of his life. For the first time you should walk 10-15 minutes and choose for this glorious windless days. In winter it is possible - to start walking, if the air temperature is not lower - 10 ° С. On the second day, the walk can be doubled and gradually brought up to 2 hours. It is undesirable to go for a walk on days when humidity is high, it's raining. But these restrictions apply only to the first month of the child's life - with an older baby you can walk in any weather.

The longer a child will be in the open air in summer, the better. But here there are some rules: you should not walk with your child in the open sun, preferring shady places. There is a danger of overheating of the baby if it is in a stroller: in the closed space it is significantly restricted the air circulation, and the temperature in the stroller can be several degrees higher than outside. Therefore, you can not leave the stroller with the baby in the open sun for a long time. It is quite permissible and useful dosage of sunbathing throughout the walk, but they must be done in a lacy shadow and not at the hottest time of the day.

Thermoregulation of a child is one of the most important components of the constancy of the internal environment of the body. Being immature by the time of birth, gradually it is being improved. But in order for this growing up to be successful, it is necessary to train all the mechanisms of thermoregulation. Observing the recommendations for caring for the child, for organizing the temperature in the room, enough time spending with him in the fresh air, you "tune" this complex mechanism, helping the kid resist disease, grow strong and healthy.

How to dress a kid for a walk?

In the spring and autumn, dressing the child for a walk, be guided by your feelings - wear the baby as it seems comfortable to you personally. Walking for a long time, check to see if the baby's clothes are too warm: if the child has a wet neck and neck, then it's hot for him.

Worrying about whether you are not too cool, you have dressed your child, do not focus on the temperature of his spout. On a walk, it is always to the touch much colder than the rest of the body. It is more informative to try to touch the palms of the baby: if they are cool, it is better to wrap the baby warmer.