Parenteral nutrition

In practice, parenteral nutrition is used a number of terms: complete parenteral nutrition, partial, additional. Some authors believe that parenteral nutrition should be adequate and can be combined with natural or probing.

[1], [2], [3],

What is parenteral nutrition?

With lack of food, the defenses of the body are depleted, the function of the epithelial barrier of the skin and mucous membranes, the function of T-cells, the synthesis of immunoglobulins, the bactericidal function of the leukocytes deteriorates, which increases the risk of infectious diseases, sepsis. Hypoalbuminemia adversely affects the healing of wounds and increases the risk of edema (lung and brain), pressure sores.

With a deficiency of essential fatty acids (linoleic, linolenic, arachidonic), a peculiar syndrome develops, which is manifested by a delay in the growth of the child, skin flaking, and a decrease in resistance to infections. This syndrome can occur even with a short (5-7 days) parenteral nutrition of children without including fat emulsions.

In nutritional solutions for parenteral nutrition, the same basic ingredients (and in the same proportions) as in the usual meal: amino acids, carbohydrates, fats, electrolytes, microelements, vitamins should be present.

The success of the treatment of patients largely depends on the balance of the nutrients introduced, careful calculation of all components. With sepsis, severe diarrhea, toxicosis, a hypermetabolism condition is observed, in which the digestibility of fats increases and carbohydrates decrease. In these cases, the introduction of a large number of carbohydrates can cause a deepening of stress with an increase in the number of catecholamines, an increase in the need for oxygen and an excess of carbon dioxide. Accumulation of the latter contributes to the development of hypercapnia and related shortness of breath, respiratory failure (DV).

In the appointment of parenteral nutrition take into account the phase of the stress reaction:

1. adrenergic (in the first 1-3 days);
2. corticoid, reverse development (on the 4th-6th day);
3. transition to the anabolic phase of metabolism (on the 6-10th day);
4. the phase of accumulation of fat and protein (from 1 week to several months or years after the development of shock, stress reaction).

In the I phase, the body creates an emergency protection for survival, which is accompanied by an increase in the tone of the sympathetic-adrenal system with the participation of a large number of hormones (pituitary, adrenal, etc.), the need for energy that is satisfied due to the breakdown of its own proteins, fats, glycogen, disturbed by VEO (there is a delay in water and sodium in the body and the release of increased amounts of potassium, calcium, magnesium and phosphorus in the urine).

In the second phase of the stress reaction, the level of counterinsulant hormones, catecholamines, glucocorticoids decreases, diuresis increases, nitrogen losses decrease, catabolism decreases, which is clinically reflected in lower body temperature, appetite, better hemodynamics and microcirculation.

In the III phase, protein synthesis begins, hypokalemia is characteristic. Here, an adequate intake of food of the patient is important, regardless of its variants (enteral or parenteral), as well as additional administration of potassium and phosphorus salts.

In the IV phase, MT accumulation is possible only with increased consumption of plastics material with food. To utilize 1 g of protein (amino acids), 25-30 kcal of energy is required. Consequently, the heavier the stress, the more energy materials the patient needs, but with the mandatory consideration of the period of recovery from the stress reaction and the tolerability of parenteral nutrition.

Indications and contraindications for parenteral nutrition

Indications for parenteral nutrition:

• intestinal insufficiency, including persistent diarrhea;
• mechanical intestinal obstruction;
• syndrome of the "small intestine";
• severe pancreatitis (pancreatic necrosis);
• external fistula of the small intestine;
• preoperative preparation as part of infusion-transfusion therapy.

Contraindications to parenteral nutrition:

• intolerance of individual nutrients (including anaphylaxis);
• shock;
• hyperhydration.

Preparations for parenteral nutrition

The drugs used for parenteral nutrition include glucose and fatty emulsions. Solutions of crystalline amino acids used in parenteral nutrition also serve as energy substrates, but their main purpose is plastic, since various proteins of the organism are synthesized from amino acids. For amino acids to fulfill this goal, it is necessary to supply the body with adequate energy due to glucose and fat - non-protein energy substrates. With a lack of so-called non-protein calories, amino acids are included in the process of neoglucogenesis and become only an energy substrate.

Carbohydrates for parenteral nutrition

The most common nutrient for parenteral nutrition is glucose. Its energy value is about 4 kcal / g. The share of glucose in parenteral nutrition should be 50-55% of the actual energy expenditure.

The rational speed of delivery of glucose in parenteral nutrition without the risk of glucosuria is 5 mg / (kg x min) [0.25-0.3 g / (kg x h)], with a maximum rate of 0.5 g / kg h). The dose of insulin, the addition of which is necessary for the infusion of glucose, is shown in Table. 14-6.

The daily amount of glucose administered should not exceed 5-6 g / kg x day). For example, with a body weight of 70 kg, it is recommended to administer 350 grams of glucose per day, which corresponds to 1750 ml of a 20% solution. In this case 350 g of glucose provide delivery of 1,400 kcal.

[4], [5], [6], [7], [8], [9]

Fat emulsions for parenteral nutrition

Fat emulsions for parenteral nutrition contain the most energy-intensive nutrient - fats (energy density 9.3 kcal / g). Fatty emulsions in 10% solution contain about 1 kcal / ml, in 20% solution - about 2 kcal / ml. The dose of fatty emulsions is up to 2 g / kg x day). The rate of administration is up to 100 ml / h for a 10% solution and 50 ml / h for a 20% solution.

Example: an adult with a body weight of 70 kg is prescribed 140 g, or 1400 ml of a 10% solution of fat emulsion per day, which should provide 1260 kcal. Such volume at the recommended speed is poured for 14 hours. In case of application of 20% solution, the volume is reduced by half.

Historically, three generations of fat emulsions are distinguished.

• First generation. Fatty emulsions based on long-chain triglycerides (intralipid, lipofundin 5, etc.). The first of these, intralipid, was created by Arvid Vretlind in 1957.
• The second generation. Fat emulsions based on a mixture of triglycerides with a long and medium chain (MCG and LCT). The ratio MCT / LCT = 1/1.
• The third generation. Structured lipids.

Among the lipids in recent years, preparations containing co-3 fatty acids - eicosapentic (EPA) and deco-pentenoic (DPA), contained in fish oil (omega) have become widely spread. The pharmacological action of co-3 fatty acids is determined by the substitution in the phospholipid structure of the arachidonic acid cell membrane on EPA / DPA, resulting in a decrease in the formation of pro-inflammatory metabolites of arachidonic acid - thromboxanes, leukotrienes, prostaglandins. Omega-3-fatty acids stimulate the formation of eicosanoids with anti-inflammatory effect, reduce the release of mononuclear cytokines (IL-1, IL-2, IL-6, TNF) and prostaglandins (PGE2), reduce the incidence of wound infection and the length of stay in hospital.

[10], [11], [12], [13], [14], [15], [16], [17], [18]

Amino acids for parenteral nutrition

The main purpose of amino acids for parenteral nutrition is to provide the body with nitrogen for plastic processes, but with energy deficiency, they also become an energy substrate. Therefore, it is necessary to observe a rational ratio of non-protein calories to nitrogen - 150/1.

WHO requirements for amino acid solutions for parenteral nutrition:

• absolute transparency of solutions;
• the content of all 20 amino acids;
• ratio of essential amino acids to replaceable 1: 1;
• the ratio of essential amino acids (d) to nitrogen (d) is closer to 3;
• the leucine / isoleucine ratio is about 1.6.

[19], [20], [21], [22], [23], [24]

Amino acids for parenteral nutrition with branched chain

The inclusion of crystalline amino acids, essential amino acids with a branched chain (valine, leucine, isoleucine-VLI), creates distinct therapeutic effects, especially manifested in hepatic insufficiency. Unlike aromatic branched amino acids prevent the formation of ammonia. The VLI group serves as a source of ketone bodies - an important energy resource for patients in critical conditions (sepsis, multiple organ failure). The increase in the concentration of branched amino acids in modern solutions of crystalline amino acids is justified by their ability to oxidize directly in muscle tissue. They serve as an additional and effective energy substrate for conditions in which the absorption of glucose and fatty acids is slow.

With stress, arginine becomes an indispensable amino acid. Also serves as a substrate for the formation of nitric oxide, positively affects the secretion of polypeptide hormones (insulin, glucagon, growth hormone, prolactin). Additional inclusion of arginine in food reduces the hypothyrophy of the thymus, increases the level of T-lymphocytes, improves wound healing. In addition, arginine dilates the peripheral vessels, reduces systemic pressure, promotes the release of sodium and enhances myocardial perfusion.

Pharmaconutrients (nutraceuticals) are nutrients that have curative effects.

Glutamine is the most important substrate for cells of the small intestine, pancreas, alveolar epithelium of the lungs and leukocytes. In the composition of glutamine, about 3% of nitrogen is transported in the blood; Glutamine is used directly for the synthesis of other amino acids and protein; also serves as a donor of nitrogen for the synthesis of urea (liver) and ammoniogenesis (kidney), antioxidant glutathione, purines and pyrimidines involved in the synthesis of DNA and RNA. The small intestine is the main organ that consumes glutamine; with stress, the use of glutamine guts increases, which increases its deficiency. Glutamine, being the main source of energy for the cells of the digestive organs (enterocytes, colonocytes), is deposited in skeletal muscles. Reduction of the level of free glutamine of muscles to 20-50% of the norm is considered a sign of damage. After surgical interventions and other critical conditions, the intramuscular concentration of glutamine is reduced by a factor of 2 and its deficit persists to 20-30 days.

The introduction of glutamine protects the mucous membrane from the development of stress stomach ulcers. The inclusion of glutamine in nutritional support significantly reduces the level of bacterial translocation by preventing mucosal atrophy and stimulating effects on immune function.

The most widely used dipeptide is alanine-glutamine (dipeptin). In 20 g dipeptivene contains 13.5 g of glutamine. The drug is administered intravenously together with commercial solutions of crystalline amino acids for parenteral nutrition. The average daily dose is 1.5-2.0 ml / kg, which corresponds to 100-150 ml of dipeptivene per day for a patient with a body weight of 70 kg. The drug is recommended to enter at least 5 days.

According to modern studies, infusion of alanine-glutamine to patients receiving parenteral nutrition, allows:

• improve nitrogen balance and protein metabolism;
• support intracellular glutamine pool;
• Correct the catabolic reaction;
• improve immune function;
• protect the liver. Multicenter studies have noted:
• restoration of bowel function;
• decrease in the frequency of infectious complications;
• decreased mortality;
• decreased duration of hospitalization;
• reduction of treatment costs for parenteral administration of glutamine dipeptides.

[25], [26], [27], [28], [29], [30],

Parenteral nutrition

Modern parenteral nutrition technology is based on two principles: infusion from various capacities ("bottle") and "all in one" technology, developed in 1974 by K. Solassol. The technology "all in one" is represented by two options: "two in one - two in one" and "three in one - three in one".

Method of infusion from different capacities

The technique assumes intravenous introduction of glucose, solutions of crystalline amino acids and fat emulsions separately. The technique of simultaneous transfusion of solutions of crystalline amino acids and fatty emulsions in the regime of synchronous infusion (drop by drop) from different vials into a single vein through a Y-shaped adapter is used.

Two-in-One Method

For parenteral nutrition, preparations containing a solution of glucose with electrolytes and a solution of crystalline amino acids are used, usually produced in the form of two-chamber bags (nutriflex). The contents of the package are mixed before use. This technique allows to observe the conditions of sterility during infusion and allows simultaneous introduction of components of parenteral nutrition, previously balanced in the content of components.

Three-in-one methodology

When using the technique, all three components (carbohydrates, fats, amino acids) are introduced from one bag (cab). Bags "three in one" are designed with an additional port for the introduction of vitamins and trace elements. With the help of this technique, a completely balanced nutrient composition is introduced, reducing the risk of bacterial contamination.

Parenteral nutrition in children

In newborns, the level of metabolism in the MT recalculation is 3 times higher than that of adults, while about 25% of energy is spent on growth. At the same time, energy reserves are substantially limited in children in comparison with adults. For example, in a premature baby with a body weight of 1 kg at birth, fat reserves are only 10 g and therefore are quickly disposed of in the process of metabolism in the absence of nutritional elements. Stock of glycogen in young children is utilized for 12-16 hours, the elder - for 24 hours.

At stress up to 80% of energy is formed from fat. The reserve is the formation of glucose from amino acids - glycoeogenesis, in which carbohydrates come from the proteins of the child's body, primarily from the muscle protein. Decay of the protein provides stress hormones: GCS, catecholamines, glucagon, somatotropic and thyrotropic hormones, cAMP, and hunger. These same hormones have counterinsular properties, so in an acute phase of stress glucose utilization worsens by 50-70%.

When pathological conditions and hunger in children quickly develop a loss of MT, dystrophy; for their prevention, timely application of parenteral nutrition is necessary. It should also be remembered that in the first months of life the brain of the child is intensively developing, the nerve cells continue to divide. Malnutrition can lead to a decrease not only in the growth rates, but also in the level of the child's mental development, which is not compensated in the future.

For parenteral nutrition, 3 main groups of ingredients are used, including proteins, fats and carbohydrates.

Protein (amino acid) mixtures: protein hydrolysates - Aminosol (Sweden, USA), Amigen (USA, Italy), Izovac (France), Aminon (Germany), hydrolysine-2 (Russia), and solutions of amino acids - Polyamine (Russia), Levamin-70 (Finland), Vamin (USA, Italy), Moriamin (Japan), Friamin (USA), etc.

Fat emulsions: Intralipid-20% (Sweden), Lipofundin-C 20% (Finland), Lipofundin-S (Germany), Lipozin (USA) and others.

Carbohydrates: Glucose is usually used - solutions of various concentrations (from 5 to 50%); fructose in the form of 10 and 20% solutions (less irritate the intima of the veins than glucose); invertosis, galactose (maltose is rarely used); Alcohols (sorbitol, xylitol) are added to fat emulsions to create osmolarity and as an additional energy substrate.

It is usually believed that parenteral nutrition should be continued until normal function of the digestive tract is restored. More often parenteral nutrition is necessary for a very short time (2-3 weeks to 3 months), but with chronic bowel diseases, chronic diarrhea, malabsorption syndrome, short loop syndrome and other diseases, it can be more prolonged.

Parenteral nutrition in children can cover the basic needs of the body (with a stable phase of intestinal inflammation, in the preoperative period, with prolonged parenteral nutrition, in the unconscious state of the patient), moderately elevated needs (for sepsis, cachexia, gastrointestinal diseases, pancreatitis, cancer patients), as well as increased needs (with severe diarrhea after stabilization of HEO, burns of II-III degree - more than 40%, sepsis, severe injuries, especially the skull and brain).

Parenteral nutrition is usually performed by catheterization of the patient's veins. Catheterization (venepuncture) in peripheral veins is performed only at the expected duration of parenteral nutrition less than 2 weeks.

Calculation of parenteral nutrition

The energy requirement of children aged 6 months and older is calculated by the formula: 95 - (3 x age, years) and is measured in kcal / kg * day).

In children of the first 6 months of life, the daily requirement is 100 kcal / kg or (according to other formulas): up to 6 months - 100-125 kcal / kg * day), in children older than 6 months and up to 16 years of age, it is calculated on the basis of: 1000 + (100 n), where n is the number of years.

When calculating energy needs, you can focus on the average performance with minimal (core) and optimal metabolism.

If the body temperature rises on the HS, this minimum need needs to be increased by 10-12%, with moderate motor activity by 15-25%, with pronounced motor activity or convulsions - by 25-75%.

The need for water is determined on the basis of the amount of energy needed: in infants, from the ratio of 1.5 ml / kcal, in older children - 1.0-1.25 ml / kcal.

With respect to the MT, the daily requirement for water in newborns over 7 days and in infants is 100-150 ml / kg, with MT from 10 to 20 kg -50 ml / kg + 500 ml, more than 20 kg -20 ml / kg + 1000 ml. In newborns at the age of the first 7 days of life, the volume of fluid can be calculated by the formula: 10-20 ml / kg x L, where n is the age, days.

For premature and small children born with MT less than 1000 g, this figure is 80 ml / kg or more.

It is also possible to calculate the demand for water according to the Aberg-Din nomogram, adding the volume of pathological losses. In case of MT deficiency, we develop due to acute fluid loss (vomiting, diarrhea, perspiration), first of all, this deficiency should be eliminated according to the standard scheme and only then proceed with parenteral nutrition.

Fat emulsions (intralipid, lipofundin) in most children, except for prematurity, are administered intravenously, starting from 1-2 g / kg-day) and increasing the dose for the next 2-5 days to 4 g / kg) (with appropriate tolerability). In preterm infants, the first dose is 0.5 g / kg-day), in term infants and in infants - 1 g / kg-day). When deducing the children of the first half of life with severe hypotrophy from the state of intestinal toxicosis, the initial dose of lipids is determined at the rate of 0.5 g / kg-day), and in the next 2-3 weeks it does not exceed 2 g / kg-day). The rate of lipid administration is 0.1 g / kg-h), or 0.5 ml / (kg-h).

With the help of fats 40-60% of energy is supplied to the child's body, and 9 kcal per gram of lipids is released when fat is disposed of. In emulsions, this value is 10 kcal due to the utilization of xylitol, sorbitol added in the mixture as an emulsion stabilizer, and substances that ensure the osmolarity of the mixture. In 1 ml of 20% lipofundin contains 200 mg of fat and 2 kcal (in 1 liter of 20% of the mixture contains 2000 kcal).

Lipid solutions should not be confused with anything when injected into a vein; they do not add heparin, although it is desirable to administer it (intravenously, in a jet along with the introduction of fat emulsions) at usual therapeutic doses.

According to Rosenfeld's figurative expression, "fats burn in the flame of carbohydrates," therefore, when carrying out parenteral nutrition according to the Scandinavian scheme, it is necessary to combine the introduction of fats with the transfusion of solutions of carbohydrates. Carbohydrates (glucose solution, less often fructose) in this system should provide the same amount of energy as fats (50:50%). Utilization of 1 g of glucose gives 4.1 kcal of heat. In glucose solutions, insulin can be administered at a rate of 1 unit per 4-5 g of glucose, but this is not required for prolonged parenteral nutrition. With a rapid increase in the concentration of glucose in intravenously administered solutions, hyperglycaemia with coma may develop; to avoid this, you need to increase it gradually by 2.5-5.0% every 6-12 hours of infusion.

The Dadric scheme requires continuity when introducing glucose solutions: even a one-hour break can cause hypoglycemia or hypoglycemic coma. The concentration of glucose is also reduced slowly, in parallel with a decrease in the volume of parenteral nutrition, i.e., in 5-7 days.

Thus, the use of high-concentration glucose solutions poses a certain risk, so it is important to observe safety rules and monitor the patient's condition through clinical and laboratory analysis.

Glucose solutions can be administered in a mixture with amino acid solutions, with the final glucose content in the solution decreasing and the likelihood of developing phlebitis. With Scandinavian parenteral nutrition, these solutions are administered continuously for 16-22 hours every day, with the Dadric scheme - 24 hours a day, without interruptions, drip or with syringe pumps. In the solutions of glucose, add the necessary amount of electrolytes (calcium and magnesium do not mix), vitamin mixtures (vitafusine, multivitamin, intravit).

Amino acid solutions (levamin, moriprom, aminin, etc.) are intravenously administered by protein: 2-2.5 g / kg-day) in infants and 1-1.5 g / kg-day) in older children . With partial parenteral nutrition, the total amount of protein can reach 4 g / kg-day).

The exact account of the protein necessary for the cessation of catabolism, it is better to conduct by the volume of its losses with urine, i.e., on the amino nitrogen of urea:

The amount of residual nitrogen in the daily urine, g / l х 6.25.

In 1 ml of 7% of a mixture of amino acids (levamin, etc.) contains 70 mg of protein, in 10% of the mixture (polyamine) - 100 mg. The rate of administration is maintained at a level of 1-1.5 ml / (kg-h).

The optimal ratio of proteins, fats and carbohydrates for children is 1: 1: 4.

The program of parenteral nutrition per day is calculated by the formula:

Amount of amino acid solution, ml = Required amount of protein (1 -4 g / kg) x MT, kg x K, where the K coefficient is 10 at 10% solution concentration and 15 at 7% concentration.

The need for a fat emulsion is determined taking into account the energy value: 1 ml of 20% emulsion gives 2 kcal, 1 ml of 10% solution - 1 kcal.

The concentration of glucose solution is chosen taking into account the amount of kilocalories released during its utilization: for example, in 1 ml of a 5% solution of glucose contains 0.2 kcal, 10% of solution -0.4 kcal, 15% -0.6 kcal, 20% - 0, 8 kcal, 25% - 1 D) kcal, 30% - 1.2 kcal, 40% - 1.6 kcal and 50% - 2.0 kcal.

In this case, the formula for determining the percentage concentration of the glucose solution takes the following form:

Concentration of glucose solution,% = Quantity of kilocalories / Volume water, ml x 25

An example of calculating a complete parenteral nutrition program

• MT of the child - 10 kg,
• volume of energy (60 kcal x 10 kg) - 600 kcal,
• volume of water (600 kcal x 1.5 ml) - 90 0ml,
• volume of protein (2 x 10 kg x 15) - 300 ml,
• volume of fat (300 kcal: 2 kcal / ml) - 150 ml of 20% lipofundin.

The remaining volume of water for dilution of glucose (900 - 450) - 550 ml. The percentage of glucose solution (300 kcal: 550 ml x 25) - 13.5%. Add sodium (3 mmol / kg) and potassium (2 mmol / kg), or 3 and 2 mmol each for each 115 ml of the liquid. Electrolytes are usually diluted in the entire volume of the glucose solution (except calcium and magnesium, which can not be mixed in a single solution).

With partial parenteral nutrition, the volume of solutions administered is determined by subtracting the total number of calories and ingredients coming from food.

Example of calculating the program of partial parenteral nutrition

The conditions of the problem are the same. MT of the child is 10 kg, but he receives 300 grams of milk formula per day.

• The volume of food is 300 ml,
• the remaining volume of energy (1/3 of 600 kcal) is 400 kcal,
• the remaining volume of water (2/9 from 900 ml) is 600 ml,
• volume of protein (2/3 from 300 ml) - 200 ml of 7% levamine,
• volume of fat (1/3 of 150 ml) - 100 ml of 20% lipofundine (200 kcal),
• volume of water for dilution of glucose (600 ml - 300 ml) - 300 ml.

The percentage of glucose solution (200 kcal: 300 ml x 25) is 15%, i.e. This child should be administered 300 ml of 15% glucose solution, 100 ml of 20% lipofundin and 200 ml of 7% levamine.

In the absence of fat emulsions, parenteral nutrition can be performed by the method of hyperalimentation (according to Dadric).

Example of calculating the partial parenteral nutrition program according to the Dadrik method

• The volume of food is 300 ml, the volume of water is 600 ml,
• volume of protein (1/3 of 300 ml) - 200 ml of a solution of 7% levamine,
• volume of glucose: 400 kcal: 400 ml (600-200 ml) x 25, which corresponds to 25% glucose solution, which should be used in the amount of 400 ml.

At the same time, the deficiency of essential fatty acids (linoleic and linolenic) can not be tolerated in the child; their required amount can be provided by plasma transfusion in a dose of 5-10 ml / kg (once every 7-10 days) in this variant of parenteral nutrition. However, it should be remembered that the introduction of plasma to patients is not used to replenish energy and protein.

[31], [32], [33]

Complications of parenteral nutrition

• infectious (phlebitis, angiogenic sepsis);
• metabolic (hyperglycemia, hyperchloremia, acidosis, hyperosmolar syndrome);
• fatty embolism of the pulmonary and cerebral arterial system;
• infection with the development of phlebitis (this is facilitated by hyperosmolarity of solutions), embolism and sepsis;
• acidosis with the development of hyperventilation;
• osmotic diuresis (hyperglycemia) with dehydration;
• hyper or hypoglycemic coma;
• violation of the balance of electrolytes and microelements.

When parenteral nutrition is necessary to ensure that the concentration of glucose in the blood plasma was in the range of 4-11 mmol / l (the blood sample is taken from the finger, and not from the vein into which the glucose solution is injected). The loss of glucose in urine should not exceed 5% of the amount administered during the day.

With the introduction of lipids, a visual assessment can be used: the transparency of the plasma in a patient 30 minutes after the administration (jet-slow) '/ 12 daily dose of fat emulsion.

It is necessary to determine daily the level of urea, creatinine, albumin, osmolality, electrolytes in blood plasma and urine, CBS, bilirubin concentration, and monitor the dynamics of the child's MT and monitor its diuresis.

Prolonged parenteral nutrition (weeks, months) there is a need to provide patients with trace elements (Fe, Zn, Cu, Se), essential lipids, vitamins.

[34], [35], [36], [37], [38]