RU79420U1 - INCUBATOR FOR PREMATURE CHILDREN EXTREMELY LOW BODY WEIGHT - Google Patents

Description

The utility model relates to medicine, obstetrics, perinatology, neonatology, pediatrics and can be used in neonatology for nursing premature infants with extremely low body weight (extremely premature newborns) with a body weight of 500 g and gestational age from 23 to 34 weeks.

There are a lot of methods for nursing small children using a variety of devices. In the 20-60s In the 20th century, the so-called cots-heating pads and other devices providing warming in a dry-air environment were used for nursing prematurely. Currently, for this purpose, incubators (couves) of open and closed types are used, that is, devices that provide humidity and temperature comfort in the air (Shabalov NP Neonatology / M. Medpress-inform, 2004, T.1 pg. 299-351). These devices have the same principle of operation. This is an apparatus with the possibility of manual and / or automatic adjustment, supporting the required temperature, humidity and oxygen concentration in the air chamber of the incubator. The length of time a newborn stays in an incubator is determined by its degree of maturity and adaptive abilities, that is, the ability to retain heat, the stability of vital functions, etc. Examples of such devices are the most popular models, such as IDN - 03 (Yekaterinburg), AMEDA Pulsar (AMECARE), Caleo (DRAGER), etc.

Despite the significant number of devices on the medical equipment market for nursing premature infants, the problem of nursing extremely premature infants remains unresolved. Most babies weighing less than 1000 g. Die or become disabled. According to Nick Rutter (UK) mortality among extremely premature

According to Nick Rutter (Great Britain), mortality among extremely premature infants is ≈30%, and disability -70% (Herald of Medicine No. 2, 1997, pp. 10-11).

An obstacle to the effective nursing of extremely premature infants with the help of traditional means is a certain biological “barrier”, that is, medical problems inherent in extremely premature infants and which are a direct result of their structural and functional immaturity. These problems concern the basic vital systems: respiration, central nervous system, digestive tract and skin integument. (Rogowski J. Cost-effectiveness of care for very low birth weight infants. Pediatrics. 1998 Jul; 102: 35-43).

In particular, lung development with gestational age ≤26 weeks is not complete. The lungs are represented by expanding air spaces on the periphery of the bronchioles (saccules) - prototypes of the alveoli. The differentiation of the cells of the respiratory epithelium begins only at 23-24 weeks of gestation, so the concentration of surfactant in the pneumocytes is extremely low.

A feature of the central nervous system (CNS) of extremely premature newborns is the presence of a pronounced germinal formation of the germinal matrix, which is an extremely fragile vascular formation. In cases of hemodynamic disorders of any origin (a sharp change in ambient temperature, pain, infusion, etc.), the vessels of the germinal matrix are often ruptured, followed by hemorrhage, both into the cavity of the lateral ventricles of the brain and into the cerebral parenchyma (peri- and intraventricular hemorrhages). The terminal sections of the cerebral vessels (arterioles) are underdeveloped and end blindly in the white matter of the brain. With spasms of arterioles arising against the background of hemodynamic disorders (see above), cerebral parenchyma ischemia develops, leading to the formation of cysts in periventricular tissue, i.e. leukomalacia.

Immaturity of the digestive tract (decreased intestinal motility, malabsorption of food) does not allow for effective enteral nutrition. The most natural for an extremely premature baby is parenteral nutrition, which mimics the intrauterine way of feeding.

The skin of extremely premature babies is characterized by extreme immaturity of the epidermis. Therefore, such newborns are very easy to dry, i.e. water loss, and, consequently, hemodynamic disorders. In addition, the skin is easily susceptible to trauma under any tactile effect.

Thus, the existing limit of possibilities for neonatal adaptation does not allow extremely premature newborns to adapt to environmental conditions due to the deep morphological and functional immaturity. For these newborns, which are essentially fruits, only the intrauterine environment is physiological: a state of complete immersion in the amniotic fluid, approaching the composition of the blood plasma, parenteral nutrition and placental and transcutaneous gas exchange (La Pine TR, Jackson JC, Bennett FC Outcome of infants weighing less than 800 grams at birth: 15 years' experience. Pediatrics. 1995 Sep; 96 (3 Pt 1): 479-83).

Known incubator Caleo company Drager. This device has created the conditions for optimizing the vital functions of premature babies. It is a chamber enclosed in a transparent plastic case, which maintains the appropriate temperature, humidity and oxygen concentration necessary for nursing a child. Microprocessor control provides an optimal environment for a controlled influx of heat (air temperature or skin temperature of the patient), the required humidity and oxygen concentration. Provides regulation of the child’s body position. There is a built-in incubator cleaning program. Air Curtain Prevents Heat Loss (Gray R.I. .. Flenady V.J., Cot-nursing versus

incubator care for preterm infants. (Cochrane Review). Cochrane Library, Issue 2, 2003. Oxford update Software Ltd.).

The disadvantages of this device are:

1. The air environment into which the extremely premature fetus after birth enters, which is not physiological for it. Due to the morpho-functional features of the skin of extremely premature newborns in the air, drying occurs, which adversely affects its hemodynamics and gas exchange, as part of the skin microcirculatory bed, which is involved in the consumption of oxygen dissolved in the amniotic fluid, is turned off during drying. In addition, there are large losses of water, manifested in pathological loss of body weight (14% or more). The result of this can be gas exchange disorders and acidosis, which are currently associated with immaturity of the lungs, can also be explained by a violation of the so-called “skin respiration” that occurs in a liquid medium when oxygen is dissolved in the amniotic fluid directly into the microvasculature of the fetus.

2. The gravitational effect has a much greater effect on an extremely premature baby than on a more mature newborn, squeezing his tissues and organs. This factor contributes to the violation of the formation of pulmonary respiration due to increased pressure on the chest, which in turn causes hemodynamic disorders in the form of persistent fetal communications. In addition, excessive premature load on the musculoskeletal system can lead not only to its atrophy, but also to centrifugal effects on the central nervous system, causing violations of its regulatory function.

3. After birth, the baby falls out of total darkness into a brightly deliberated room. The aggressive effect of light on an immature retina may result in subsequent

to her degenerative changes and blindness, i.e. to disability (Crofts B. .. King R., Johnson A. The contribution of low birth weight to severe vision loss in giographically defined population. Br J Ophthalmol 1998; 82: 1: 9-13).

Thus, inadequate, untimely effects of the extrauterine environment, causing the neonatal adaptation mechanisms in a mature newborn, in an extremely premature baby, contribute to the disruption of vital functions, such as respiratory, cardiovascular and nervous. Against the background of life support disorders, severe metabolic complications develop (acidosis, hypoglycemia, electrolyte disorders, etc.), which can lead to the death of the child.

Closest to the claimed device in the group of inventions by the totality of signs, is a DEVICE FOR CAREING DEEPLY MATTED CHILDREN AND CHILDREN WITH CRITICAL BODY WEIGHT (RF Patent 2140248, CL A61G 11/00 of 10.27.1999). The device allows you to partially immerse the child in an oxygenated liquid (electrolyte solution), heated to 37-38 ° C.

The device design includes a case with a transparent cap, a bath, a permeable frame, an oxygen supply device, heating elements, temperature sensors, brackets for fixing systems for intravenous infusions.

This device, adopted as a prototype, allows you to create conditions for the newborn, close to intrauterine. These include partial immersion in a liquid medium.

The disadvantages of the device prototype are:

1. The device involves the use of mechanical ventilation (mechanical ventilation). Prolonged mechanical ventilation of the lungs against the background of deep immaturity of the respiratory tract of the newborn can lead to structural changes in the lungs (broncho-pulmonary dysplasia) with subsequent disability of the child.

2. A newborn is immersed in a solution of electrolytes, which in its composition cannot be considered similar to amniotic fluid, since amniotic fluid is a colloidal solution, approaching in composition to blood plasma, that is, have a higher density. In this regard, the anti-gravity protection of the liquid medium in the bath of the device is not effective enough.

3. The child is not completely immersed in the liquid, which can contribute to the deformation of the skeleton against the background of the difference in gravitational impact: flattening of the skull, deformation of the extremities.

4. Judging by the drawing, the child, sitting on a permeable skeleton, is in a position that involves bending the head, which provokes extension of the lower extremities due to the symmetrical neck-tonic reflex characteristic of newborns (A.B. Palchik. Hypoxic-ischemic encephalopathy of newborns . “Peter”, St. Petersburg, 2000, p. 49). This posture is unnatural and cannot be considered physiological for a premature baby. Violation of the fetal flexion posture is not comfortable for nursing a newborn and may contribute to its distress with subsequent development of neonatal adaptation disorders (Sarman I, Ribbe T. and Tunell R .: Thermally controlled water-filled mattress for warming preterm baby: a physical assessment. Medical & Biological, Engineering & Computing 1993, 31, 639-643).

5. The presence of a permeable frame limits the independent movements of the newborn, which can lead to disruption of the formation of the musculoskeletal system.

6. The placement of the heating elements under the bottom of the bath cannot ensure uniform heating of the stationary fluid.

7. The position of the temperature sensor in the lower layers of the liquid is not enough to assess the temperature in its upper layers.

8. There is no control over the body temperature of the child.

9. The influence of light on an extremely premature baby adversely affects the development of the retina (see above).

10. The movement of a child from a liquid medium to air and the associated tactile and mechanical effects are not physiological for extremely premature newborns. Such aggressive effects can provoke stressful conditions and contribute to the development of complications such as hemodynamic disorders, intraventricular hemorrhages, cerebral ischemia, etc. (see above).

We first developed and proposed an incubator for nursing infants with extremely low body weight.

Figure 1 shows the proposed device, where

1 - camera

2 - perfluorocarbon emulsion (perfluorane)

3 - transparent plastic cap

4 - endotracheal tube

5 - respiratory circuit

6 - umbilical cord

7 - plastic mattress

8 - rectal temperature sensor

9 - pipe

10 - vascular communications

11 - capacity

12 - pump

13 - pipe

14 - pipe

15 - heating element

16 - source of ultraviolet radiation

17 - oxygen cylinder

18 - light-insulating screen

19 - device for ECMO

20 - bracket

This incubator is a waterproof chamber (1) filled with a perfluorocarbon emulsion (perfluorane) (2) to a level that ensures full immersion of the newborn, equipped with an opening cap made of transparent plastic (3). The device additionally includes a container (11) with a pump (12) located in it, as well as a heating element (15) and a source of ultraviolet radiation (UV) (16). In this case, the heating element and the ultraviolet source are built into the tank wall. The tank is connected to the camera by two nozzles. Through one of them, located in the lower parts of the chamber (14), perfluorane enters from the chamber into the container, and through the other, located above (13), it leaves it. The container is also connected via a dispenser to an oxygen cylinder (17). Additionally, the incubator contains a light-insulating screen (18). At the bottom of the chamber is a plastic mattress filled with perfluorane (7).

The perfluorocarbon emulsion has a composition approaching, in its physicochemical properties, to blood plasma and, therefore, to amniotic fluid: perfluorodecalin cis and transformation - 11.05-12.0 g; fast-releasing lipophilic perfluorocarbons,

with a total carbon content in the molecule in the range of C7-C10 - 1.001.95 g, perfluoro-N-4- (methylcyclohexyl) piperidine and its isomers - 3.3-4.3 g; slow-releasing lipophobic perfluorotertic amines with a total carbon content in the molecule in the range of C11-C13 - 2.2-3.2 g; proxanol 268 1 - 4 g, sodium chloride (FS 42-2572-95; GOST 4233-77, chemical grade) - 0.6 g; potassium chloride (GF X, p. 362) - 0.039 g; magnesium chloride (GOST 4209-77 h.h.) - 0.019 g; sodium bicarbonate (GF X, p.430; GOST 4201-89) - 0.065 g; sodium phosphate od unsubstituted (GOST 245-76, analytical grade) - 0.02 g; glucose (FS 42-0004-00) - 0.2 g; water for injection (FS 42-2620-97) - up to 100 ml (Mitsuno T., Ohyanagi H., Naito R. Clinical studies of a perfluorochemical whole bloob substitute (Fluosol-DA) // Ann. Surg. - 1982. - vol.195, N1. - p.60-69., Krylov NL, Moroz VV Experience of the clinical use of perfluorane - a blood substitute based on perfluorocarbons // Physico-chemical and clinical studies of perfluororganic compounds. - Pushchino, 1994. - p. 33-50, Moroz V.V., Krylov N.L., Ivanitsky G.R. et al. Use of perfluorane in the clinic // Anesthesiology and Intensive Care. - 1995. - N 6. - p.12-17 )

The emulsion is constantly circulating through the nozzles (13 and 14) at a speed of 0.5-1 l / h (the emulsion is replaced in the chamber every 3-4 hours). In the process of circulation, the emulsion entering the tank (11) is heated to a temperature of 37.7-38 ° C, saturated with oxygen to a concentration of 21-30%, and is subjected to ultraviolet radiation. The intensity of heating the emulsion is regulated in accordance with the readings of the rectal sensor (8).

The proposed incubator is characterized by a fundamentally new approach to ensuring the respiration of the newborn by extracorporeal membrane oxygenation (ECMO) (19). After birth, the newborn is intubated, the endotracheal tube (4) is connected to the open breathing circuit (5), fixed on the bracket (20), after which the baby is immediately placed in the incubator chamber filled with perfluorocarbon

emulsion (2), heated to 37.7-38 ° C so that the child is completely immersed in the liquid. The volume of perfluorocarbon emulsion depends on the mass of the child and ensures its complete immersion. The child is placed on a plastic mattress, also filled with perftoran, which ensures a uniform density of the environment surrounding the child and prevents squeezing of his tissues. The child’s position on the mattress can effectively prevent trophic disturbances, does not limit his spontaneous motor activity, and allows the infant to be given a comfortable flexor (embryonic) pose. This posture, which is characteristic of the intrauterine state, allows you to create a relaxing effect, a feeling of comfort, safety and peace, has a calming and relaxing effect on the child, which positively affects the development of its central nervous system and musculoskeletal system (Sarman I, Ribbe T. and Tunell R .: Thermally controlled water-filled mattress for warming preterm baby: a physical assessment. Medical & Biological, Engineering & Computing 1993, 31,639-643).

The umbilical cord (6) intersects below the clamp, applied at a distance of 12-15 cm from the umbilical ring. Its distal end is discharged through pipe No. 1 (9) in the incubator wall. The vessels of the umbilical cord are catheterized and, using vascular communications (10), used for parenteral nutrition and extracorporeal membrane oxygenation, as well as for the necessary metabolic correction.

Gas exchange in the newborn’s body is carried out using an extracorporeal membrane oxygenation (ECMO) device (19) using umbilical cord vessels, as well as through “skin respiration”, i.e. transcutaneous intake and elimination of gases. (A.P. Zilber. Respiratory failure. - M. Medicine, 1989, - p. 255-258).

With the maturation of the lungs and / or the appearance of independent breathing, a newborn can spontaneously switch to independent breathing with a gradual departure from the ECMO mode. To ensure independent breathing of the newborn, an open breathing circuit (5) is introduced, which is brought into the airspace under the incubator cap.

The perfluorocarbon emulsion in the incubator chamber is replaced every 3-4 hours by constant circulation using a pump (12). In the process of circulation, the fluid flows through a container containing a heating element (15), and a source of ultraviolet radiation (16), where it is heated and subjected to ultraviolet radiation for the purpose of microbial decontamination.

A child can stay in this device until the maturation and stabilization of its vital functions that can ensure its life in the air (~ 32-34 weeks of gestation).

The advantage of the incubator presented is its advantage over traditionally used analogues, as well as over the prototype device, since this device creates conditions that are closest to those of the fetal life, which allows a premature baby to complete the fetal cycle under conditions close to natural (intrauterine) ), namely:

1. Staying in a liquid medium, approaching in its properties to the amniotic fluid to the amniotic fluid and containing dissolved oxygen, will significantly reduce the gravitational effect, prevent hemodynamic disorders, improve skin gas exchange;

2. The circulation of the liquid will ensure its uniform heating and reduce the risk of infection;

3. Complete immersion of the child in the liquid with preservation of the embryonic pose will ensure the maturation of the musculoskeletal system in conditions close to physiological;

4. A breathing method is provided, similar to transplacental gas transfer, which will contribute to lung maturation without forced ventilation;

5. Parenteral nutrition using the vessels of the umbilical cord of the child is identical to the intake of nutrients transplacentally without the involvement of the immature digestive tract;

6. Limitation of external aggression factors: light effects and tactile influences, creation of conditions for the embryonic pose will contribute to the preservation of the central nervous system and retina;

7. The ultraviolet irradiation of a perfluorocarbon emulsion forms an aseptic state similar to that of the development of the fetal egg.

The use of the presented device will allow:

1. Ensure the intact survival of extremely premature infants and, therefore, significantly reduce their disability.

2. To preserve and develop the adaptive abilities of the child, as well as lay the foundations of his health at a preconceptual level.

3. Reduce the rates of neonatal and infant morbidity and mortality.

Claims (3)

1. An incubator for premature babies of extremely low body weight, containing a chamber with a transparent cap filled with a solution, equipped with a device for supplying oxygen to a solution, a heating element, a temperature sensor, a bed for a newborn, characterized in that the chamber is filled with a perfluorocarbon emulsion to a level that provides complete immersion of the newborn, in addition, a container with a pump located in it is included in the incubator, connected to the chamber by two nozzles, through one of which perfluorocarbon Ulsia from the chamber enters the vessel, and through another leaves it into the chamber, and the heating element and the ultraviolet radiation source are integrated into the vessel connected to the oxygen cylinder, a pipe is made in the front wall of the chamber to provide access to the umbilical cord vessels for parenteral nutrition and extracorporeal membrane oxygenation. 2. The incubator according to claim 1, characterized in that the bed for the newborn is a plastic mattress filled with a perfluorocarbon emulsion. 3. The incubator according to claims 1 and 2, characterized in that it contains a light-tight screen that insulates the camera.