Once a child is diagnosed with diabetes, parents often go to the library for information on the subject and are faced with the possibility of complications. After a period of worry, parents are hit with the next blow when they learn about diabetes-related morbidity and mortality statistics.
Relatively recently, the hepatitis alphabet, which already included hepatitis viruses A, B, C, D, E, G, was replenished with two new DNA-containing viruses, TT and SEN. We know that hepatitis A and hepatitis E do not cause chronic hepatitis and that hepatitis G and TT viruses are most likely “innocent spectators” that are transmitted vertically and do not affect the liver.
When treating chronic functional constipation in children, it is necessary to take into account important factors in the child's medical history; establish a good relationship between the health care professional and the child-family to ensure that the proposed treatment is carried out properly; a lot of patience on both sides, with repeated assurances that the situation will gradually improve, and courage in cases of possible relapses, constitute the best way to treat children suffering from constipation.
The results of a ten-year study have indisputably proven that frequent self-monitoring and maintaining blood glucose levels within normal limits leads to a significant reduction in the risk of late complications caused by diabetes and a decrease in their severity.
In the practice of pediatric orthopedists and traumatologists, the question is often raised about the need to confirm or exclude disorders of the formation of the hip joints (hip dysplasia, congenital hip dislocation) in infants. The article shows an analysis of a survey of 448 children with clinical signs of disorders of the formation of the hip joints.
Most nurses and doctors don't like gloves, and for good reason. Wearing gloves, the sensitivity of your fingertips is lost, the skin on your hands becomes dry and flaky, and the instrument tends to slip out of your hands. But gloves have been and remain the most reliable means of protection against infection.
It is believed that every fifth adult on earth suffers from lumbar osteochondrosis; this disease occurs in both young and old age.
(to help medical workers in medical institutions)
The guidelines cover the issues of monitoring medical workers who have had contact with the blood of a patient infected with HIV. Actions are proposed to prevent occupational HIV infection. A logbook and an official investigation report for contact with the blood of an HIV-infected patient have been developed. The procedure for informing higher authorities about the results of medical observation of health workers who came into contact with the blood of an HIV-infected patient has been determined. Designed for medical workers medical and preventive institutions.
Chlamydia of the genitals is the most common sexually transmitted disease. All over the world, there is an increase in chlamydia among young women who have just entered the period of sexual activity.
Currently, there is an increase in certain nosological forms infectious diseases, first of all, viral infections. One of the directions for improving treatment methods is the use of interferons, as important nonspecific factors of antiviral resistance. These include cycloferon, a low molecular weight synthetic inducer of endogenous interferon.
Quantity microbial cells, present on the skin and mucous membranes of the macroorganism in contact with external environment, exceeds the number of cells of all its organs and tissues combined. The weight of the microflora of the human body is on average 2.5-3 kg. The importance of microbial flora for a healthy person was first noticed in 1914 by I.I. Mechnikov, who suggested that the cause of many diseases are various metabolites and toxins produced by various microorganisms that inhabit the organs and systems of the human body. The problem of dysbacteriosis in recent years causes a lot of discussions with an extreme range of judgments.
In recent years, throughout the world and in our country, there has been an increase in the incidence of sexually transmitted infections among the adult population and, which is of particular concern, among children and adolescents. The incidence of chlamydia and trichomoniasis is increasing. According to WHO, trichomoniasis ranks first in frequency among sexually transmitted infections. Every year, 170 million people worldwide become ill with trichomoniasis.
Intestinal dysbiosis and secondary immunodeficiency state are increasingly encountered in the clinical practice of doctors of all specialties. This is due to changing living conditions, the harmful effects of preformed environment on the human body.
The lecture “Viral hepatitis in children” presents data on viral hepatitis A, B, C, D, E, F, G in children. All clinical forms are given viral hepatitis, differential diagnosis, treatment and prevention that currently exist. The material is presented from a modern perspective and is intended for senior students of all faculties of medical universities, interns, pediatricians, infectious disease specialists and doctors of other specialties who are interested in this infection.
By volume, parenteral nutrition is divided into complete and partial.
Total parenteral nutrition
Total parenteral nutrition (TPN) consists of intravenous administration of all nutritional components (nitrogen, water, electrolytes, vitamins) in quantities and ratios that most closely correspond to the body's needs at the moment. Such nutrition is usually needed during complete and prolonged fasting.
The purpose of PPP is to correct disorders of all types of metabolism.
Indications for total parenteral nutrition
As mentioned above, TPN is indicated for patients who cannot, should not, or do not want to feed enterally. These include the following categories of patients:
1. Patients who are unable to eat or digest food normally. When diagnosing malnutrition, the presence of muscle wasting, hypoalbuminemia, protein-free edema, a decrease in the thickness of the skin fold and a significant decrease in body weight is taken into account in the patient. But isolated weight loss should not be considered a sign of malnutrition, since the presence of edema or previous obesity may mask the actual degree of endogenous nitrogen depletion.
2. Patients with an initially satisfactory nutritional status who are temporarily (for one reason or another) unable to eat and, in order to avoid excessive malnutrition, require TPN. This is especially important in pathological conditions accompanied by increased catabolism and tissue depletion (postoperative, post-traumatic, septic patients).
3. Patients suffering from Crohn's disease, intestinal fistulas and pancreatitis. Normal nutrition in such patients aggravates the symptoms of the disease and worsens the general condition of the patients. Transferring them to PPP accelerates the healing of fistulas and reduces the volume of inflammatory infiltrates.
4. Patients with a prolonged coma, when feeding through a tube is impossible (including after brain surgery).
5. Patients with severe hypermetabolism or significant protein losses, for example in patients with injuries, burns (even in cases where normal nutrition is possible).
6. To provide nutritional support to patients receiving therapy for malignant tumors, especially when malnutrition is due to decreased food intake. Often the consequences of chemotherapy and radiation treatment are anorexia and inflammation of the mucous membranes of the gastrointestinal tract, which limits the possibilities of enteral nutrition.
7. It is possible to perform PPP in debilitated patients before upcoming surgical treatment.
8. Patients with mental anorexia. TPN in such patients is necessary, since theoretically justified tube feeding under anesthesia is fraught with dangers associated not only with complications of anesthesia, but also with the possibility of pulmonary complications due to food or gastric contents entering the respiratory tract.
Partial parenteral nutrition
Partial parenteral nutrition is most often an addition to enteral nutrition (natural or tube), if the latter does not fully cover the nutritional deficiency that occurs due to reasons such as 1) a significant increase in energy costs: 2) a low-calorie diet; 3) inadequate absorption of food, etc.
Indications for partial parenteral nutrition
Partial parenteral nutrition is indicated in cases where enteral nutrition does not provide the desired effect due to impaired intestinal motility or insufficient absorption of nutrients in the digestive tract, as well as if the level of catabolism exceeds the energy capabilities of normal nutrition.
List of diseases for which partial parenteral nutrition is indicated:
Gastric ulcer and duodenal ulcer;
Pathology of the organs of the hepatobiliary system with functional liver failure;
Various forms of colitis;
Acute intestinal infections (dysentery, typhoid fever);
Pronounced catabolism in early period after major extraperitoneal operations;
Purulent-septic complications of injuries;
Sepsis;
Hyperthermia;
Chronic inflammatory processes(lung abscesses, osteomyelitis, etc.);
Oncological diseases;
Severe endo- and exotoxicosis;
Severe diseases of the blood system;
Acute and chronic renal failure.
For quotation: Kotaev A.Yu. Principles of parenteral nutrition // RMZh. 2003. No. 28. S. 1604
MMA named after I.M. Sechenov
P Nutrition is an important component of the treatment of many diseases and traumatic injuries.
Artificial nutrition (enteral or parenteral) is indicated for patients who have not received food for 7-10 days, as well as in cases where independent nutrition is not enough to maintain normal nutritional status.
Parenteral nutrition is used when natural nutrition is impossible or insufficient.
The purpose of parenteral nutrition is to provide the body with plastic materials, energy resources, electrolytes, microelements and vitamins.
The need for parenteral nutrition is associated with the catabolic orientation of metabolism during traumatic injuries, diseases internal organs, heavy infectious processes and in the postoperative period. The severity of the catabolic reaction is directly proportional to the severity of the lesion or disease.
With any injury, hemodynamic and respiratory disorders may occur, leading to hypoxia, disruption of water-electrolyte balance, acid-base status, hemostasis and rheological properties of blood. At the same time, during stress, the basal metabolism is stimulated through the pituitary gland, adrenal cortex, and thyroid gland, energy consumption increases, and the breakdown of carbohydrates and proteins increases.
Glucose reserves in the form of glycogen (in muscles and liver) during fasting are quickly depleted (after 12-14 hours), then their own protein is broken down into amino acids, which are converted into glucose in the liver. This process (gluconeogenesis) is uneconomical (56 g of glucose is produced from 100 g of protein) and leads to rapid protein loss.
Large protein losses negatively affect reparative processes, immunity and create conditions for the development of complications. Malnutrition in surgical patients leads to an increase in postoperative complications 6 times, and mortality - 11 times (G.P. Buzby and J.L. Mullen, 1980).
Nutritional status assessment Many methods have been proposed for assessing nutritional status. Some of them are shown in Table 1.
Anamnesis (lack of appetite, nausea, vomiting, weight loss) and examination of the patient (muscle atrophy, loss of subcutaneous fat layer, hypoproteinemic edema, symptoms of vitamin deficiency and deficiency of other nutrients) are important for assessing nutrition.
Choosing the optimal method of nutritional support Artificial nutritional support for patients can be provided in the form of parenteral and/or enteral nutrition.
There are total parenteral nutrition, in which the provision of nutrients is carried out only by intravenous infusions (usually used central veins) and additional parenteral nutrition through peripheral veins (prescribed for a short period as an addition to enteral nutrition).
Algorithm rational choice nutritional support is presented in Figure 1.
Indications for parenteral nutrition Indications for parenteral nutrition can be conditionally combined into 3 groups: primary therapy, which assumes the influence of nutrition on the disease that caused the nutritional imbalance; maintenance therapy, which provides nutritional support but does not influence the cause of the disease; indications that are under study (J.E. Fischer, 1997).
Primary therapy:
Proven effectiveness ()
Maintenance therapy:
Proven effectiveness (Randomized prospective studies were conducted.)
After identifying indications for parenteral nutrition, it is necessary to calculate the necessary components for adequate correction of energy costs, selecting optimal solutions for infusion based on determining the need for protein, fats, carbohydrates, vitamins, microelements and water.
Calculation of energy needs Energy costs depend on the severity and nature of the disease or injury (Table 2).
For a more accurate calculation of energy costs, basal metabolic rate is used.
Basal metabolism represents the minimum energy requirements under conditions of complete physical and emotional rest, comfortable temperature and 12-14 hour fasting.
The basal metabolic rate is determined using Harris-Benedict equations (Harris-Benedict):
for men: OO = 66 + (13.7xW) + (5xP) - (6.8xW)
for women: OO = 655 + (9.6xW) + (1.8xP) - (4.7xW)
BT = basal metabolic rate in kcal, BT = body weight in kg, P = height in cm, B = age in years.
Normally, true energy expenditure (IRE) exceeds basal metabolism and is estimated using the formula:
IRE = ООхАхТхП, Where
A - activity factor:
T - temperature factor (body temperature):
P - damage factor:
On average, proteins account for 15-17%, carbohydrates - 50-55% and fats - 30-35% of the energy released (depending on specific metabolic conditions and diet).
Calculation of protein needs Nitrogen balance is used as an indicator of protein metabolism (the difference between the amount of nitrogen entering the body with proteins and lost in various ways) (Table 3).
The determination of nitrogen loss by the urea content in daily urine is also used (urea in grams x 0.58).
The loss of nitrogen corresponds to the loss of protein and leads to a decrease in body weight (1 g nitrogen = 6.25, protein = 25 g muscle mass)
The main purpose of introducing proteins is to maintain a balance between protein intake and consumption in the body. At the same time, if enough non-protein calories are not supplied at the same time, protein oxidation increases. Therefore, the following ratio between non-protein calories and nitrogen should be observed: the number of non-protein calories/nitrogen in grams = 100-200 kcal/g.
The nitrogenous component in the parenteral nutrition diet can be represented by protein hydrolysates and amino acid mixtures obtained by synthesis. The use of undigested protein preparations (plasma, protein, albumin) for parenteral nutrition is ineffective due to too long period half-life of exogenous protein.
Protein hydrolysates used for parenteral nutrition are solutions of amino acids and simple peptides obtained by hydrolytic breakdown of heterogeneous proteins of animal or plant origin. Protein hydrolysates are less efficiently utilized by the body (compared to amino acid mixtures) due to the presence of high molecular weight peptide fractions in them. It is more justified to use amino acid mixtures, from which specific organ proteins are then synthesized.
Amino acid mixtures for parenteral nutrition must meet the following requirements: contain an adequate and balanced amount of essential and essential amino acids; be biologically adequate, i.e. so that the body can transform amino acids into its own proteins; don't call adverse reactions after they enter the vascular bed.
Contraindications to the administration of protein hydrolysates and amino acid mixtures:
1. dysfunction of the liver and kidneys - liver and kidney failure (special amino acid mixtures);
2. any forms of dehydration;
3. states of shock;
4. conditions accompanied by hypoxemia;
5. acute hemodynamic disorders;
6. thromboembolic complications;
7. severe heart failure.
Calculation of carbohydrates Carbohydrates are the most accessible sources of energy for the patient's body. Their energy value is 4 kcal/g.
For parenteral nutrition, glucose, fructose, sorbitol, and glycerol are used. Minimum daily requirement tissue in glucose is about 180 g.
It is optimal to administer a 30% glucose solution with the addition of insulin (1 unit of insulin per 3-4 g of dry matter of glucose). In elderly patients, in the first 2 days after surgery, it is advisable to reduce the glucose concentration to 10-20%.
The administration of glucose reduces gluconeogenesis, so glucose is included in parenteral nutrition not only as an energy carrier, but also to obtain a protein-saving effect.
Excessive glucose administration, however, can cause osmotic diuresis, with loss of water, electrolytes and the development of hyperosmolar coma. An overdose of glucose leads to increased liponeogenesis, in which the body synthesizes triglycerides from glucose. This process occurs mainly in the liver and adipose tissue and is accompanied by very high production of CO 2, which leads to a sharp increase in minute tidal volume and, accordingly, respiratory rate. In addition, fatty infiltration of the liver may occur if hepatocytes are unable to remove the resulting triglycerides into the blood. Therefore, the glucose dose for adults should not exceed 6 g/kg body weight per day.
Fat calculation Fats are the most beneficial source of energy (energy value is 9.3 kcal/g).
Fats account for 30-35% of daily calorie intake, most of which are triglycerides (esters consisting of glycerol and fatty acids). They are a source of not only energy, but also essential fatty acids, linoleic and a-linolenic acids - precursors of prostaglandins. Linoleic acid takes part in the construction of cell membranes.
The optimal dose of fat in clinical settings is 1-2 g/kg body weight per day.
The need for fats during parenteral nutrition is provided by fat emulsions.
The administration of fat emulsions in isolated form is impractical (ketoacidosis occurs), therefore they are used simultaneous administration a solution of glucose and fat emulsion with a calorie ratio of 50:50 (normally 70:30; for polytrauma, burns - 60:40).
The most widely used drugs in our country are Intralipid and Lipofundin. The advantage of Intralipid is that at 20% concentration it is isotonic with plasma and can be administered even into peripheral veins.
Contraindications for the administration of fat emulsions are basically the same as for the administration of protein solutions. It is not advisable to administer fat emulsions to patients with disorders fat metabolism, with diabetes mellitus, thromboembolism, acute myocardial infarction, pregnancy.
Water calculation The need for water during parenteral nutrition is calculated based on the amount of losses (urine, feces, vomit, breath, discharge through drains, discharge from fistulas, etc.) and tissue hydration. Clinically, this is assessed by the amount of urine and its relative density, skin elasticity, tongue moisture, presence of thirst and changes in body weight.
Normally, water requirements exceed diuresis by 1000 ml. In this case, the endogenous formation of water is not taken into account. Loss of proteins, electrolytes and glucosuria significantly increase the body's need for exogenous water.
For parenteral nutrition, it is recommended to administer 30-40 ml of water per 1 kg of body weight for adults. It is believed that the digital number of kilocalories administered should correspond to the digital value of the volume of fluid transfused (in milliliters).
Calculation of electrolytes Electrolytes are integral components of total parenteral nutrition. Potassium, magnesium and phosphorus are essential for optimal nitrogen retention in the body and tissue formation; sodium and chlorine - to maintain osmolality and acid-base balance; calcium - to prevent bone demineralization (Table 4).
To cover the body's need for electrolytes, the following infusion media are used: isotonic solution sodium chloride, balanced solutions of electrolytes (lactosol, acesol, trisol, etc.), a solution of 0.3% potassium chloride, solutions of chloride, calcium gluconate and lactate, magnesium lactate and sulfate.
Calculation of vitamins and microelements Parenteral nutrition involves the use of vitamin complexes and microelements. An amount of vitamins and microelements sufficient to meet daily requirements should be added to the basic solution for parenteral nutrition (Tables 5 and 6). The use of vitamins in the diet is justified with full amino acid supply, otherwise they are not absorbed and are excreted mainly in the urine. Should not be entered excess quantities fat-soluble vitamins (A, D) due to the risk of hypercalcemia and other toxic effects.
For parenteral nutrition, special mixtures of vitamins and microelements are used.
In recent years they have been producing combination drugs, containing amino acids, minerals and glucose.
Conditions for the effectiveness of parenteral nutrition Before administering parenteral nutrition, the patient’s condition must be stabilized and hypoxia eliminated, since complete absorption of the components of parenteral nutrition occurs only under aerobic conditions. Therefore, in the first hours after major operations, trauma, burns, in terminal conditions and shock, only glucose solutions can be used to centralize the blood circulation.
The rate of administration of drugs should correspond to the rate of their optimal absorption (Table 7).
When calculating the daily calorie content of parenteral nutrition, the contribution of protein should not be taken into account, because otherwise the lack of energy will lead to the burning of amino acids and the synthesis processes will not be fully realized.
The introduction of parenteral nutrition should begin with a solution of glucose with insulin (1 unit per 4-5 g of dry matter of glucose). After infusion of 200-300 ml of glucose solution, an amino acid preparation or protein hydrolysate is added. Subsequently, the amino acid mixture or protein hydrolysate is administered along with glucose, electrolytes and vitamins. It is advisable to administer amino acids, protein hydrolysates and 30% glucose at a rate of no more than 40 drops per minute. Fat emulsions are allowed to be poured together with solutions of amino acids and hydrolysates. It is not recommended to administer them simultaneously with electrolytes, since the latter contribute to the enlargement of fat particles and increase the risk of fat embolism. The rate of administration of the fat emulsion should initially not exceed 10 drops per minute. If there is no reaction, the speed can be increased to 20-30 drops per minute. For every 500 ml of fat emulsion, 5000 units of heparin are administered.
For timely correction of parenteral nutrition, clinical and laboratory methods nutritional effectiveness assessments.
Features of artificial nutrition in some conditions Kidney failure For patients with renal failure, the volume of fluid administered, the amount of nitrogen and electrolytes are of particular importance. In acute renal failure, if dialysis is not treated, total parenteral nutrition is carried out with concentrated solutions (70% glucose, 20% fat emulsion, 10% amino acid solution), which reduces the volume of fluid and provides a sufficient amount of energy. The nitrogen content in the nutritional mixture is reduced (when calculating the daily protein requirement, the norm is 0.7 g/kg), and the content of potassium, calcium, magnesium and phosphorus is also reduced.
During dialysis treatment, the amount of protein can be increased to 1.0-1.5 g/kg/day.
Liver failure
With liver failure, all types of metabolism are affected, and primarily protein metabolism. Impaired urea synthesis leads to the accumulation of ammonia and other toxic nitrogenous compounds in the blood. Artificial nutrition should meet the body's needs for proteins and other nutrients, but not be accompanied by the appearance or intensification of encephalopathy.
Total parenteral nutrition with reduced nitrogen content is used; when calculating the daily protein requirement, the norm is 0.7 g/kg of weight. With ascites, in addition, the volume of the nutritional mixture is limited and the sodium content is reduced.
Disorders of protein metabolism in liver failure lead to amino acid imbalance (increased concentrations of aromatic acids phenylalanine and tyrosine, as well as decreased concentrations of branched amino acids isoleucine, leucine and valine) (J.E. Fischer et al., 1976). These disorders cause encephalopathy and, along with protein restriction, are the main cause of high catabolism in such patients.
With a decrease in liver function and shunting of portal blood, the balanced amino acid composition in the plasma is disrupted (especially amino acids - precursors of central monoamine neurotransmitters), which is accompanied by a decrease in the level of neurotransmitters in the central nervous system and is one of the causes of encephalopathy.
Correction of amino acid imbalance is achieved by introducing an adapted amino acid mixture, in which the fraction of aromatic amino acids is reduced and the fraction of branched amino acids is increased. Because these amino acid solutions contain all essential amino acids and a wide range of non-essential amino acids, they can also be used for parenteral nutrition in liver failure.
Parenteral nutrition for liver failure is recommended in the following doses: adapted amino acids - up to 1.5 g/kg body weight per day, glucose - up to 6 g/kg body weight per day and fats - up to 1.5 g/kg body weight per day .
Heart and respiratory failure.
In case of heart failure, sodium intake is limited and the volume of the nutritional mixture is reduced. Patients with respiratory failure are prescribed nutritional mixtures with a low glucose content and a high fat content. Replacing the energy source from carbohydrates to fats reduces CO 2 production and the risk of hypercapnia. Fat has a lower respiratory quotient than carbohydrates (0.7 and 1.0, respectively). Patients with hypercapnia should receive 40% of their energy in the form of fat emulsion.
Complications of parenteral nutrition With parenteral nutrition, as with other types infusion therapy, allergic and post-transfusion reactions are possible.
In addition, there are several other types of complications of parenteral nutrition:
1. Technical (5%):
- air embolism;
- artery damage;
- damage to the brachial plexus;
- arteriovenous fistula;
- perforation of the heart;
- catheter embolism;
- catheter displacement;
- pneumothorax;
- thrombosis of the subclavian vein;
- damage to the thoracic duct;
- damage to veins.
2. Infectious (5%):
- infection at the venipuncture site;
- “tunnel” infection;
- catheter-associated sepsis.
3. Metabolic (5%):
- azotemia;
- excessive fluid administration;
- hyperglycemia;
- hyperchloremic metabolic acidosis;
- hypercalcemia;
- hyperkalemia;
- hypermagnesemia;
- hyperosmolar coma;
- hyperphosphatemia;
- hypervitaminosis A;
- hypervitaminosis D;
- hypoglycemia;
- hypocalcemia;
- hypomagnesemia;
- hyponatremia;
- hypophosphatemia.
4. Liver dysfunction.
5. Gallstone disease.
6. Metabolic disorders of bone tissue.
7. Micronutrient deficiency.
8. Respiratory failure.
Parenteral nutrition (from the Greek para - about + enteron - intestine) is the provision of the body with nutritional ingredients (nutrients) bypassing the gastrointestinal tract. Parenteral nutrition can be complete, when all nutrients are introduced into the vascular bed (the patient does not even drink water), partial (incomplete), when only basic nutrients are used (for example, proteins and carbohydrates), and auxiliary, when oral nutrition is insufficient and requires addition.
Pathophysiology of fasting. In the adult body, the main factor determining the normal balance of metabolic processes is the relationship between food intake and energy expenditure.
If a person is deprived of food, the blood glucose level first decreases and, as a consequence, the secretion of the anabolic hormone insulin. At the same time, the secretion of the catabolic hormone glucagon, which stimulates glycogenolysis in the liver, increases. Thus, glycogen stores in the liver are depleted.
Starting from the second day of fasting, glucagon activates hormone-sensitive lipase, due to which more fatty acids are released, the oxidation of which increases the level ketone bodies. If the level of their formation exceeds the rate of utilization, metabolic acidosis develops.
As fasting continues, tissue proteins become energy sources. The labile proteins of the gastrointestinal tract and circulating blood are the first to be mobilized, then the proteins of the internal organs and muscles are broken down, and the last are the proteins of the nervous system.
Thus, fasting in a certain sense can be considered as a state in which the body “devours itself” to satisfy its energy needs.
The main goals of parenteral nutrition are:
Indications for parenteral nutrition. Indications for parenteral nutrition in a hospital include:
a) the patient cannot eat through the mouth (after injuries and interventions in the area of the facial skull, on the digestive tract);
b) the patient should not eat through the mouth.
Cases of the advisability of enteral nutrition arise in the postoperative period in patients with intestinal obstruction, pancreatic necrosis, after surgical interventions on the gastrointestinal tract, as well as with inflammatory diseases intestines (Crohn's disease, ulcerative colitis, ileus);
This happens with injuries of the skull and brain, severe burns, a state of persistent catabolism after extensive operations and injuries, purulent-destructive processes with the generalization of a highly invasive infection. Parenteral nutrition is recommended for the dystrophic form of congestive heart failure, rehabilitation of deeply asthenized patients, for severe infectious diseases with extreme catabolism, for neurological patients with widespread lesions of the nervous system - from strokes to demyelinating diseases;
Achieving the described goals is possible only if the following conditions are met: adequate fluid load, a sufficient mass of quickly digestible energy-giving nutrients, ensuring the absorption of a sufficient amount of potassium ions and conditional protein in the form of amino acids in an amount of at least 0.5 g/kg body weight.
Before starting parenteral nutrition, the following measures must be taken:
Calculation of the need for parenteral nutrition. This requires an assessment of the patient's nutrition. To determine the patient’s initial nutritional level, the mass-height index (MHI) is used: MHI = BW (kg)/ m 2 (height).
Normally, MRI is 21-25 kg/m2; less than 20 kg/m2 means a clear decrease in nutrition; 17 kg/m2 – significant reduction in nutrition; less than 16 kg/m2 - extreme exhaustion.
Another indicative indicator of nutritional status is the ratio of actual body weight (FBM) to ideal body weight (BMI), expressed as a %: BMI = Height (cm) - 100.
A decrease in the FMI/BMI ratio to 80% means a mild degree of protein-energy malnutrition; a decrease within 70-80% - moderate deficiency; a decrease to 70% or less—severe degree of protein-energy malnutrition.
One of the most useful biochemical indicators in assessing nutritional status and the effectiveness of nutritional therapy is considered to be creatinine, 98% of which is found in skeletal muscles, mainly in the form of creatinine phosphate. To calculate muscle mass, the creatinine index (CI) is used - the ratio of daily creatinine excretion (g) to height (cm).
Normally IR = 10.5. With a weak degree of protein-energy deficiency, IC = 9.5-8.4.
Determination of energy needs. The minimum energy expenditure of the body under conditions of relatively complete physical and emotional rest (awake, fasting) is defined as basal metabolic rate (BM).
OO = 66.5 + (13.75 x M) + (5 x P) - (6.7 x V) , where M is body weight (kg), P is height (cm), B is age (years).
It is also possible to use a simplified and, accordingly, less accurate formula OO = 25 Ё M.
Calculation of the patient's actual energy requirement (DNE) (kcal/day) is carried out according to the formula
DPE = OO x FA x FU x TF x DMT , where FA is the activity factor: bed rest - 1.1; semi-bed - 1.2; walking - 1.3;
FU factor injury: after small operations- 1.1; large operations - 1.3; peritonitis - 1.4; sepsis - 1.5; multiple injuries - 1.6; traumatic brain injury - 1.7;
TF - temperature factor: 38.0°C - 1.1; 39.0°C - 1.2; 40.0°C - 1.3; 41.0°C - 1.4.
The body receives energy mainly from carbohydrates and fats. The oxidation of 1 g of fat releases about 9 kcal (38 kJ), while 1 g of carbohydrate provides about 4 kcal (17 kJ) and 1 g of protein or amino acids provides about 5 kcal (23 kJ).
IN The recommended values for the main components of parenteral nutrition are given. Recommendations for doses of amino acids, glucose, lipids and energy load do not depend on the type of nutrition: total parenteral nutrition, enteral or mixed.
Carbohydrates. In modern parenteral nutrition, glucose is used mainly, although, according to some authors, fructose, sorbitol and xylitol can be used. Considering a number of undesirable effects of glucose in high concentrations (more than 20%) on the acid-base state (acidosis) and myocardium (inhibition of its function), the use of glucose solutions in concentrations above 20-25% is not recommended. The maximum rate of glucose utilization during intravenous administration is 0.75 g/kg per 1 hour. Exceeding the noted rate of drug administration leads to osmotic diuresis.
Sorbitol is phosphorylated in the liver to fructose-6-phosphate. Insulin has no effect on either sorbitol or fructose, making them insulin-independent energy sources. When they are used, hyperglycemic acidosis does not occur, which occurs in cases where drugs containing glucose are used for parenteral nutrition.
The daily requirement for glucose ranges from 2 g/kg (no less, otherwise glucose begins to be synthesized from amino acids) to 6 g/kg. Insulin is indicated at the rate of 1 unit per 4-6 g of glucose.
Using more concentrated solutions glucose (20-40%) is possible for patients requiring infusion volume limitation.
Amino acids and proteins. Determination of daily protein requirements. Laboratory parameters reflecting protein metabolism include the content of serum albumin, transferrin, prealbumin and retinol-related proteins. The decrease in serum concentrations of these proteins occurs as a result of increased catabolism and decreased protein synthesis. Labile proteins with a short half-life—prealbumin—contain the most information.
Approximately, the following figures for the daily protein requirement are given: the minimum amount is 0.54 g/kg/day, the recommended amount is 0.8 g/kg/day; with increased catabolism (catabolic status) - 1.2 -1.6 g/kg/day.
About adequacy daily intake Protein is judged by the value of nitrogen balance (NA), which determines the difference between consumption and loss of nitrogen and is calculated using the following formula:
AB (g) = (amount of protein consumed/ 6.25) - (AM + 4) , where AM is the nitrogen content in urine collected over 24 hours.
The coefficient 6.25 reflects the conversion of nitrogen content into protein content (6.25 g of protein contains 1 g of nitrogen). Amendment 4 takes into account nitrogen excreted not in urine. In case of diarrhea, blood loss or increased rejection of necrotic tissue, extrarenal nitrogen losses are assumed to be 6 g/day.
Knowing the amount of decomposed protein, it is also possible to estimate the daily energy requirement, taking into account that the oxidation of 1 g of protein requires from 150 to 180 kcal.
The modern standard is to use only solutions of crystalline amino acids as the protein component. Protein hydrolysates are currently completely excluded from clinical parenteral nutrition practice.
The total dose of administered amino acids is up to 2 g/kg per day, the rate of administration is up to 0.1 g/kg per hour.
There are no generally accepted requirements (including WHO) for amino acid solutions, but most recommendations for amino acid solutions for parenteral nutrition include the following:
Essential amino acids include isoleucine, phenylalanine, leucine, threonine, lysine, tryptophan, methionine, valine. However, the amino acids listed above are essential only for a healthy and adult body. It should be taken into account that 6 amino acids - alanine, glycine, serine, proline, glutamic and aspartic acids - are synthesized in the body from carbohydrates. Four amino acids (arginine, histidine, tyrosine and cysteine) are synthesized in insufficient quantities.
Amino acids introduced into the body intravenously enter one of two possible metabolic pathways: the anabolic pathway, in which amino acids are linked by peptide bonds into final products - specific proteins, and the metabolic pathway, in which transamination of amino acids occurs.
The amino acid L-arginine promotes the optimal conversion of ammonia to urea, while binding toxic ammonium ions that are formed during protein catabolism in the liver. L-malic acid is necessary for the regeneration of L-arginine in this process and as an energy source for the synthesis of urea.
The presence of non-essential amino acids L-ornithine-aspartate, L-alanine and L-proline in the preparations reduces the body's need for glycine.
Ornithine stimulates glucose-induced insulin production and carbamoyl phosphate synthetase activity, which increases glucose utilization by peripheral tissues, urea synthesis and, in combination with asparagine, reduces ammonia levels.
In addition to “pure” solutions of amino acids, there are solutions with energy and electrolyte additives.
Among the energy components, in addition to glucose, sorbitol or xylitol can be added, the use of which is not recommended by all authors. Sorbitol is a better solvent for amino acids than glucose, since it does not contain aldehyde and ketone groups and, thus, does not bind to amino groups into complexes that reduce the effect of amino acids.
Thus, Vamin EF contains glucose, aminosol, polyamine and chymix - sorbitol, infezol 40 - xylitol.
A number of standard solutions of amino acids contain Na +, K +, Mg + cations and the Cl - anion.
Sodium ion is the main cation of the extracellular fluid and, together with the chloride anion, is the most important element to maintain homeostasis. Potassium ion is the main cation of intracellular fluid. It was found that a positive nitrogen balance in the body with total parenteral nutrition can only be achieved by supplementing infusion solution potassium ions.
Magnesium ion is important for maintaining the integrity of mitochondria and for excitation of impulses in the membranes of nerve cells, myocardium and skeletal muscles, as well as for the transfer of high-energy phosphates during the synthesis of adenosine triphosphate. In patients on long-term parenteral nutrition, hypomagnesemia is often accompanied by hypokalemia.
Electrolytes contain the following solutions of amino acids: aminosol, infezol 40 and 100, aminoplasmal E.
The addition of standard solutions of amino acids with B complex vitamins (riboflavin, nicotinamide, panthenol and pyridoxine) is due to their limited reserves in the body and the need for daily administration, especially with long-term total parenteral nutrition.
Specialized solutions of amino acids. In various pathological conditions there are features in the manifestation of metabolic disorders. Accordingly, the quantitative and qualitative need for amino acids changes, up to the occurrence of selective deficiency of individual amino acids. In this regard, for pathogenetically directed metabolic treatment and parenteral nutrition, special solutions of amino acids (amino acid mixtures of targeted action) have been developed and are widely used in clinical practice.
A distinctive feature of amino acid solutions for patients with liver failure (aminosteryl N-hepa, aminoplasmal hepa (is a decrease in the content of aromatic (phenylalanine, tyrosine) amino acids and methionine with a simultaneous increase in the content of arginine to 6-10 g/l and branched essential amino acids (valine, leucine , isoleucine) - up to 43.2 g/l.
The amount of arginine is increased to ensure the function of the urea cycle and thereby activate ammonia detoxification in the liver and prevent hyperammonemia. The exclusion of aromatic amino acids from mixtures is due to the fact that in case of liver failure, the concentration of aromatic amino acids and methionine in the plasma increases. At the same time, the concentration of branched amino acids decreases. An increase in the transport of aromatic amino acids into the brain enhances the synthesis of pathological mediators, causing symptoms hepatic encephalopathy. The introduction of drugs with a high content of branched-chain essential amino acids reduces these manifestations. Since these amino acid solutions contain all essential and a wide range of non-essential amino acids, they have a corrective effect on metabolic processes and are used for parenteral nutrition.
For parenteral nutrition and treatment of patients with acute and chronic renal failure, special solutions of amino acids are used: aminosteril KE nephro carbohydrate-free, nephrotect, neframin, with a certain ratio of amino acids. The ratio of essential and non-essential amino acids in such solutions is 60:40. In addition, drugs in this group contain eight essential amino acids and histidine (5 g/l), which makes it possible to reduce azotemia when administered. Due to the interaction of a specially selected spectrum of amino acids with nitrogenous residues, the production of new non-essential amino acids and protein synthesis occur. As a result, uremia decreases. The concentration of amino acids in such solutions is within 57%. There are no carbohydrates and electrolytes or the amount of electrolytes in the solution is minimal.
Fat emulsions. Another source of energy supply is fat emulsions.
Fat emulsions are usually used in long-term nutritional support programs, especially in cases where parenteral nutrition lasts more than 5 days and there is a need to cover the deficiency of essential fatty acids.
Essential fatty acids are structural components of all cell membranes and contribute to the restoration of their structures, permeability and osmotic resistance. In addition, unsaturated fatty acids, as precursors of prostaglandins, thromboxanes and leukotrienes, play an important role in restoring the metabolic and gas exchange functions of the lungs, ensure the transport of fat-soluble vitamins, and are modulators of immune processes.
In addition to the nutritional effect, fat emulsions also perform the following functions:
There are several types of fat emulsions currently available.
The clinical effects of using a physical mixture of medium- and long-chain triglycerides do not differ from fat emulsions based on long-chain triglycerides. A meta-analysis by D. Heyland et al (2003) showed the absence of any advantages of a physical mixture of triglycerides over conventional fat emulsions.
Conventional fat emulsions containing long-chain triglycerides with 16-20 carbon atoms should be considered the safest and given preference as a basic fat emulsion, which, depending on the patient’s condition, can be supplemented with an emulsion based on fish oil.
The daily dose of fat emulsions is up to 2 g/kg per day, for liver failure, encephalopathy - up to 1.5 g/kg per day. The rate of administration is up to 0.15 g/kg/hour.
Fat emulsions are contraindicated in cases of lipid metabolism disorders, disorders in the hemostasis system, pregnancy, acute myocardial infarction, various embolisms, unstable diabetic metabolism, shock.
Complications of parenteral nutrition. Among the complications of total parenteral nutrition are mechanical, metabolic, purulent-septic complications and allergic reactions.
Mechanical complications are technical complications of central venous catheterization (pneumothorax, subclavian vein/artery perforation, thoracic lymphatic duct injury, hemothorax, hydrothorax, paravasal hematoma), various types embolism, thrombosis and thrombophlebitis.
Metabolic complications include:
Purulent-septic complications involve infection at the site of drug administration and generalization of infection.
Thus, parenteral nutrition can be considered as pharmacotherapy for metabolic disorders and the only way to meet the energy-plastic needs of the body in the post-aggression period, which require specially selected compositions of nutrients.
V. G. Moskvichev, Candidate of Medical Sciences
R. Yu. Volokhova
MGMSU, Moscow
Drugs used in parenteral nutrition include glucose and fat emulsions. Solutions of crystalline amino acids used in parenteral nutrition also serve as an energy substrate, but their main purpose is plastic, since various proteins of the body are synthesized from amino acids. In order for amino acids to fulfill this purpose, the body must be supplied with adequate energy from 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.
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 actual energy expenditure.
The rational rate of glucose delivery during parenteral nutrition without the risk of glucosuria is considered to be 5 mg/(kg x min), the maximum rate is 0.5 g/kg x h). The dose of insulin, the addition of which is necessary for glucose infusion, is indicated in Table. 14-6.
The daily amount of administered glucose should not exceed 5-6 g/kg x day). For example, with a body weight of 70 kg, it is recommended to administer 350 g of glucose per day, which corresponds to 1750 ml of a 20% solution. In this case, 350 g of glucose provides the delivery of 1400 kcal.
Fat emulsions for parenteral nutrition contain the most energy-intensive nutrient - fats (energy density 9.3 kcal/g). Fat emulsions in a 10% solution contain about 1 kcal/ml, in a 20% solution - about 2 kcal/ml. The dose of fat 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 weighing 70 kg is prescribed 140 g, or 1400 ml of a 10% fat emulsion solution per day, which should provide 1260 kcal. This volume at the recommended speed is poured over 14 hours. If a 20% solution is used, the volume is halved.
Historically, three generations of fat emulsions have been distinguished.
Among lipids, in recent years, preparations containing co-3-fatty acids - eicosapentoic acid (EPA) and decosopentoenic acid (DPA), contained in fish oil (omegaven) have become widespread. Pharmacological action co-3-fatty acids are determined by substitution in the phospholipid structure of the cell membrane arachidonic acid 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, which have an anti-inflammatory effect, reduce the release of cytokines (IL-1, IL-2, IL-6, TNF) and prostaglandins (PGE2) by mononuclear cells, reduce the incidence of wound infection and the length of stay of patients in the hospital.
The main purpose of amino acids for parenteral nutrition is to provide the body with nitrogen for plastic processes, however, with energy deficiency, they also become an energy substrate. Therefore, it is necessary to maintain a rational ratio of non-protein calories to nitrogen - 150/1.
WHO requirements for amino acid solutions for parenteral nutrition:
The inclusion of crystalline amino acids, essential branched chain amino acids (valine, leucine, isoleucine-VLI) into the solution creates distinct medicinal effects, especially manifested when liver failure. Unlike aromatic amino acids, 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 in conditions where the absorption of glucose and fatty acids is slow.
Arginine becomes an essential amino acid under stress. It also serves as a substrate for the formation of nitric oxide and has a positive effect on the secretion of polypeptide hormones (insulin, glucagon, growth hormone, prolactin). Additional inclusion of arginine in food reduces thymus hypotrophy, increases the level of T-lymphocytes, and improves wound healing. In addition, arginine dilates peripheral vessels, reduces systemic pressure, promotes sodium excretion and enhances myocardial perfusion.
Pharmaconutrients (nutraceuticals) are nutrients that have therapeutic effects.
Glutamine is an essential substrate for cells of the small intestine, pancreas, alveolar epithelium lungs and leukocytes. As part of glutamine, about V3 of total nitrogen is transported in the blood; glutamine is used directly for the synthesis of other amino acids and protein; also serves as a nitrogen donor for the synthesis of urea (liver) and ammoniogenesis (kidneys), the antioxidant glutathione, purines and pyrimidines involved in the synthesis of DNA and RNA. Small intestine- the main organ that consumes glutamine; Under stress, the use of glutamine by the gut increases, which increases its deficiency. Glutamine, being the main source of energy for cells of the digestive organs (enterocytes, colonocytes), is deposited in skeletal muscles. A decrease in the level of free muscle glutamine to 20-50% of normal is considered a sign of damage. After surgical interventions and in other critical conditions, the intramuscular concentration of glutamine decreases by 2 times and its deficiency persists for up to 20-30 days.
The introduction of glutamine protects the mucous membrane from the development of stress ulcers of the stomach. The inclusion of glutamine in nutritional support significantly reduces the level of bacterial translocation by preventing mucosal atrophy and stimulating the immune function.
The most widely used dipeptide is alanine-glutamine (dipeptide). 20 g of dipeptivene contains 13.5 g of glutamine. The drug is administered intravenously along with commercial solutions of crystalline amino acids for parenteral nutrition. Average daily dose is 1.5-2.0 ml/kg, which corresponds to 100-150 ml of dipeptivene per day for a patient weighing 70 kg. The drug is recommended to be administered for at least 5 days.
According to modern research, infusion of alanine-glutamine in patients receiving parenteral nutrition allows:
Modern parenteral nutrition technology is based on two principles: infusion from various containers (“bottle”) and “all in one” technology, developed in 1974 by K. Solassol. The all-in-one technology is presented in two options: “two in one” and “three in one”.
The technique involves intravenous administration of glucose, solutions of crystalline amino acids and fat emulsions separately. In this case, they use the technique of simultaneous transfusion of solutions of crystalline amino acids and fat emulsions in a synchronous infusion mode (drop by drop) from different bottles into one vein through a Y-shaped adapter.
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 you to maintain sterile conditions during infusion and makes it possible to simultaneously administer parenteral nutrition components, pre-balanced in component content.
When using the technique, all three components (carbohydrates, fats, amino acids) are introduced from one bag (kabiven). Three-in-one bags are designed with an additional port for the administration of vitamins and microelements. This technique ensures the introduction of a completely balanced composition of nutrients and reduces the risk of bacterial contamination.
In newborns, the metabolic rate in terms of body weight is 3 times higher than in adults, while approximately 25% of energy is spent on growth. At the same time, children have significantly limited energy reserves compared to 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 utilized in the metabolic process when there is a lack of nutritional elements. Glycogen reserve in children younger age disposed of in 12-16 hours, older ones - in 24 hours.
Under stress, up to 80% of energy comes from fat. The reserve is the formation of glucose from amino acids - gluconeogenesis, in which carbohydrates come from proteins in the child’s body, primarily from muscle protein. Protein breakdown is ensured by stress hormones: GCS, catecholamines, glucocorticosteroids, somatotropic and thyroid-stimulating hormones, cAMP, and also hunger. These same hormones have counter-insular properties, so in the acute phase of stress, glucose utilization deteriorates by 50-70%.
In pathological conditions and hunger, children quickly develop weight loss and dystrophy; To prevent them, timely use of parenteral nutrition is necessary. It should also be remembered that in the first months of life, the child’s brain develops intensively, and nerve cells continue to divide. Malnutrition can lead to a decrease not only in the growth rate, but also in the level of mental development of the child, which is not compensated for in the future.
For parenteral nutrition, 3 main groups of ingredients are used, including proteins, fats and carbohydrates.
Protein (amino acid) mixtures: protein hydrolysates - “Aminozol” (Sweden, USA), “Amigen” (USA, Italy), “Izovac” (France), “Aminon” (Germany), hydrolysin-2 (Russia), as well as amino acid solutions - “Polyamine” (Russia), “Levamin-70” (Finland), “Vamin” (USA, Italy), “Moriamin” (Japan), “Friamin” (USA), etc.
Fat emulsions: “Intralipid-20%” (Sweden), “Lipofundin-S 20%” (Finland), “Lipofundin-S” (Germany), “Lipozin” (USA), etc.
Carbohydrates: glucose is usually used - solutions of varying concentrations (from 5 to 50%); fructose in the form of 10 and 20% solutions (less irritating to the intima of veins than glucose); invertose, galactose (maltose is rarely used); alcohols (sorbitol, xylitol) are added to fat emulsions to create osmolarity and as an additional energy substrate.
It is generally accepted that parenteral nutrition should be continued until recovery is achieved. normal function Gastrointestinal tract. More often, parenteral nutrition is necessary for a very short period of time (from 2-3 weeks to 3 months), but in case of chronic intestinal diseases, chronic diarrhea, malabsorption syndrome, short loop syndrome and other diseases, it may be longer.
Parenteral nutrition in children can cover the basic needs of the body (with a stable phase of intestinal inflammation, in the preoperative period, with long-term parenteral nutrition, with the patient unconscious), moderately increased needs (with sepsis, cachexia, gastrointestinal diseases, pancreatitis, in cancer patients), as well as increased needs (in case of severe diarrhea after stabilization of VEO, II-III degree burns - more than 40%, sepsis, severe injuries, especially of the skull and brain).
Parenteral nutrition is usually carried out by catheterizing the patient's veins. Catheterization (venipuncture) of peripheral veins is performed only if the expected duration of parenteral nutrition is less than 2 weeks.
The energy requirement of children aged 6 months and older is calculated using the formula: 95 - (3 x age, years) and measured in kcal/kg*day).
In children in 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 over 6 months and up to 16 years old, it is determined at the rate of: 1000 + (100 p), where l is the number of years.
When calculating energy needs, you can focus on average indicators at minimum (basic) and optimal metabolism.
In the case of an increase in body temperature during HS, the indicated minimum requirement should be increased by 10-12%, with moderate physical activity - by 15-25%, with severe motor activity or convulsions - by 25-75%.
The need for water is determined based on the amount of energy required: for infants - from the ratio of 1.5 ml/kcal, for older children - 1.0-1.25 ml/kcal.
In relation to BW, the daily need for water in newborns over 7 days old and in infants is 100-150 ml/kg, with BW from 10 to 20 kg -50 ml/kg + 500 ml, over 20 kg -20 ml/kg + 1000 ml. In newborns aged the first 7 days of life, the volume of fluid can be calculated using the formula: 10-20 ml/kg x l, where n is age, days.
For premature and low birth weight babies born with a body weight of less than 1000 g, this figure is 80 ml/kg or more.
You can also calculate water requirements using the Aber Dean nomogram by adding the volume of pathological losses. In case of MT deficiency, which develops as a result of acute fluid loss (vomiting, diarrhea, perspiration), this deficiency should first be eliminated according to the standard scheme and only then should parenteral nutrition be started.
Fat emulsions (intralipid, lipofundin) in most children, except premature ones, are administered intravenously, starting from 1-2 g/kg-day) and increasing the dose in the next 2-5 days to 4 g/kg-day) (with appropriate tolerance). In premature infants, the 1st dose is 0.5 g/kg-day), in full-term newborns and in infants - 1 g/kg-day). When removing children in the 1st half of life with severe malnutrition from a 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 when fat is utilized, 9 kcal are released per 1 g of lipids. In emulsions, this value is 10 kcal due to the utilization of xylitol, sorbitol, added to the mixture as an emulsion stabilizer, and substances that ensure the osmolarity of the mixture. 1 ml of 20% lipofundin contains 200 mg of fat and 2 kcal (1 liter of 20% mixture contains 2000 kcal).
When injected into a vein, lipid solutions should not be mixed with anything; Heparin is not added to them, although it is desirable to administer it (intravenously, by infusion in parallel with the administration of fat emulsions) in 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 administration of fats with the transfusion of carbohydrate solutions. Carbohydrates (glucose solution, less often fructose) according to this system should provide the same amount of energy as fats (50:50%). Utilization of 1 g of glucose produces 4.1 kcal of heat. Insulin can be added to glucose solutions at the rate of 1 unit per 4-5 g of glucose, but this is not required for long-term parenteral nutrition. At rapid rise concentrations of glucose in intravenously administered solutions may develop hyperglycemia with coma; to avoid this, you need to increase it gradually by 2.5-5.0% every 6-12 hours of infusion.
The Dadrick regimen requires continuity in the administration of glucose solutions: even an hour's break can cause hypoglycemia or hypoglycemic coma. The glucose concentration is also slowly reduced - in parallel with the reduction in the volume of parenteral nutrition, i.e. over 5-7 days.
Thus, the use of high concentration glucose solutions poses a certain danger, which is why it is so important to follow safety rules and monitor the patient’s condition using clinical and laboratory analysis.
Glucose solutions can be administered in mixtures with amino acid solutions, and this will reduce the final glucose content in the solution and reduce the likelihood of developing phlebitis. With the Scandinavian scheme of parenteral nutrition, these solutions are administered continuously for 16-22 hours every day, with the Dadrick scheme - around the clock without breaks, either by drip or using syringe pumps. Add glucose to solutions required quantity electrolytes (calcium and magnesium do not mix), vitamin mixtures (vitafuzin, multivitamin, intravit).
Solutions of amino acids (levamine, moriprom, aminon, etc.) are administered intravenously based on protein: 2-2.5 g/kg-day) in children early age 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).
It is better to accurately account for the protein necessary to stop catabolism by the volume of its loss in the urine, i.e., by urea amino nitrogen:
The amount of residual nitrogen in daily urine, g/l x 6.25.
1 ml of a 7% mixture of amino acids (levamine, etc.) contains 70 mg of protein, and a 10% mixture (polyamine) contains 100 mg. The rate of administration is maintained at 1-1.5 ml/(kg-h).
The optimal ratio of proteins, fats and carbohydrates for children is 1:1:4.
The daily parenteral nutrition program is calculated using the formula:
Amount of amino acid solution, ml = Required amount of protein (1-4 g/kg) x MT, kg x K, where coefficient K is 10 at 10% solution concentration and 15 at 7% concentration.
The need for 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 the glucose solution is chosen taking into account the amount of kilocalories released during its disposal: for example, 1 ml of a 5% glucose solution contains 0.2 kcal, a 10% solution contains 0.4 kcal, 15% contains 0.6 kcal, 20% contains 0. 8 kcal, 25% - 1D) 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 glucose solution will take the following form:
Concentration of glucose solution, % = Number of kilocalories / Volume of water, ml x 25
Calculation example for a total parenteral nutrition program
The remaining volume of water for diluting glucose (900 - 450) is 550 ml. The percentage of glucose solution (300 kcal: 550 ml x 25) is 13.5%. Sodium (3 mmol/kg) and potassium (2 mmol/kg) are also added, or at the rate of 3 and 2 mmol, respectively, for every 115 ml of liquid. Electrolytes are usually diluted throughout the glucose solution (except for calcium and magnesium, which cannot be mixed in the same solution).
With partial parenteral nutrition, the volume of administered solutions is determined by subtracting the total amount of calories and ingredients supplied with food.
Calculation example for a partial parenteral nutrition program
The conditions of the problem are the same. The child's BW is 10 kg, but he receives 300 g of formula per day.
The percentage of glucose solution (200 kcal: 300 ml x 25) is 15%, i.e. this child 300 ml of 15% glucose solution, 100 ml of 20% lipofundin and 200 ml of 7% levamine should be administered.
In the absence of fat emulsions, parenteral nutrition can be performed using the hyperalimentation method (according to Dadrik).
An example of calculating a partial parenteral nutrition program using the Dadrick method
At the same time, the child cannot be allowed to develop deficiency syndrome of essential fatty acids (linoleic and linolenic); their required amount with this option of parenteral nutrition can be provided by plasma transfusion in a dose of 5-10 ml/kg (once every 7-10 days). However, it should be remembered that the administration of plasma to patients is not used for the purpose of replenishing energy and protein.
