Infusion therapy

Infusion therapy is a method of parenterally providing the body with water, electrolytes, nutrients and drugs.

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Infusion therapy: goals and objectives

The goal of infusion therapy is to maintain the body's functions (transport, metabolic, thermoregulatory, excretory, etc.), determined by the VEO.

The objectives of infusion therapy are:

• ensuring the normal volume of water spaces and sectors (rehydration, dehydration), restoration and maintenance of normal plasma volume (volume reconstruction, hemodilution);
• restoration and maintenance of VEO;
• restoration of normal blood properties (fluidity, coagulability, oxygenation, etc.);
• detoxification, including forced diuresis;
• prolonged and uniform administration of drugs;
• implementation of parenteral nutrition (PP);
• normalization of immunity.

Types of infusion therapy

There are several known types of infusion therapy: intraosseous (limited, possibility of osteomyelitis); intravenous (main); intra-arterial (auxiliary, for delivering drugs to the site of inflammation).

Venous access options:

• vein puncture - used for short-term infusions (from several hours to a day);
• venesection - when there is a need for continuous administration of drugs for several (37) days;
• catheterization of large veins (femoral, jugular, subclavian, portal) - with proper care and asepsis provides infusion therapy lasting from 1 week to several months. Plastic catheters, disposable, 3 sizes (by external diameter 0, 6, 1 and 1.4 mm) and length from 16 to 24 cm.

Intermittent (jet) and continuous (drip) administration of solutions can be considered methods of infusion therapy.

For jet injection of drugs, syringes (Luer or Record) made of glass or plastic are used; preference is given to disposable syringes (reduces the likelihood of children becoming infected with viral infections, in particular HIV and viral hepatitis).

Currently, drip infusion therapy systems are made of inert plastics and are intended for single use. The rate of administration of solutions is measured in drops per 1 min. It should be borne in mind that the number of drops in 1 ml of solution depends on the size of the dropper in the system and the surface tension created by the solution itself. Thus, 1 ml of water contains on average 20 drops, 1 ml of fat emulsion - up to 30, 1 ml of alcohol - up to 60 drops.

Volumetric peristaltic and syringe pumps provide high precision and uniformity of solution administration. The pumps have a mechanical or electronic speed controller, which is measured in milliliters per hour (ml/h).

Solutions for infusion therapy

Solutions for infusion therapy include several groups: volume-replacing (volemic); basic, essential; corrective; preparations for parenteral nutrition.

Volume-substituting drugs are divided into: artificial plasma substitutes (40 and 60% dextran solutions, starch solutions, hemodez, etc.); natural (autogenous) plasma substitutes (native, fresh frozen - FFP or dry plasma, 5, 10 and 20% solutions of human albumin, cryoprecipitate, protein, etc.); blood itself, red blood cell mass or a suspension of washed red blood cells.

These drugs are used to replace the volume of circulating plasma (VCP), the deficiency of red blood cells or other plasma components, to absorb toxins, to ensure the rheological function of the blood, and to obtain an osmotic diuretic effect.

The main feature of the action of drugs in this group is that the greater their molecular weight, the longer they circulate in the vascular bed.

Hydroxyethyl starch is produced as a 6 or 10% solution in physiological saline (HAES-steril, infucol, stabizol, etc.), has a high molecular weight (200-400 kD) and therefore circulates in the vascular bed for a long time (up to 8 days). It is used as an anti-shock drug.

Polyglucin (dextran 60) contains a 6% dextran solution with a molecular weight of about 60,000 D. Prepared in 0.9% sodium chloride solution. The half-life (T|/2) is 24 hours, and remains in circulation for up to 7 days. Rarely used in children. Anti-shock drug.

Rheopolyglucin (dextran 40) contains 10% dextran solution with a molecular weight of 40,000 D and 0.9% sodium chloride solution or 5% glucose solution (indicated on the bottle). T1/2 - 6-12 hours, duration of action - up to 24 hours. Note that 1 g of dry (10 ml of solution) dextran 40 binds 20-25 ml of fluid entering the vessel from the interstitial sector. Anti-shock drug, the best rheoprotector.

Hemodez includes 6% solution of polyvinyl alcohol (polyvinyl pyrrolidone), 0.64% sodium chloride, 0.23% sodium bicarbonate, 0.15% potassium chloride. The molecular weight is 8000-12 000 D. T1/2 is 2-4 hours, the duration of action is up to 12 hours. Sorbent, has moderate detoxifying, osmotic and diuretic properties.

In recent years, the so-called dextran syndrome has been identified, caused in some patients by a special sensitivity of the epithelial cells of the lungs, kidneys and vascular endothelium to dextrans. In addition, it is known that with prolonged use of artificial plasma substitutes (especially hemodesis), macrophage blockade may develop. Therefore, the use of such drugs for infusion therapy requires caution and strict indications.

Albumin (5 or 10% solution) is an almost ideal volume-replacing agent, especially in infusion therapy for shock. In addition, it is the most powerful natural sorbent for hydrophobic toxins, transporting them to liver cells, in whose microsomes the actual detoxification occurs. Plasma, blood and their components are currently used for strict indications, mainly for replacement purposes.

Basic solutions are used to administer medicinal and nutritious substances. Glucose solutions of 5 and 10% have osmolarity of 278 and 555 mosm/l, respectively; pH 3.5-5.5. It should be remembered that the osmolarity of solutions is provided by sugar, the metabolization of which into glycogen with the participation of insulin leads to a rapid decrease in the osmolarity of the administered fluid and, as a consequence, the threat of developing hypoosmolal syndrome.

Ringer's, Ringer-Locke's, Hartman's, lactasol, acesol, disol, trisol and other solutions are the closest in composition to the liquid part of human plasma and are adapted for treating children, contain sodium, potassium, calcium, chlorine and lactate ions. Ringer-Locke's solution also contains 5% glucose. Osmolarity 261-329 mosm/l; pH 6.0-7.0. Isoosmolar.

Corrective solutions are used in case of ion imbalance and hypovolemic shock.

Physiological 0.85% sodium chloride solution is not physiological due to excessive chlorine content and is almost never used in young children. Sour. Isoosmolar.

Hypertonic solutions of sodium chloride (5.6 and 10%) in pure form are rarely used - in case of severe sodium deficiency (< 120 mmol/l) or severe intestinal paresis. A solution of 7.5% potassium chloride is used only for infusion correction of hypokalemia as an additive to a glucose solution in a final concentration of no more than 1%. It cannot be administered in pure form (risk of cardiac arrest!).

Sodium bicarbonate solutions (4.2 and 8.4%) are used to correct acidosis. They are added to Ringer's solution, physiological sodium chloride solution, and less often to glucose solution.

Infusion therapy program

When drawing up an infusion therapy program, a certain sequence of actions is necessary.

1. To establish a diagnosis of VEO disorders, paying attention to volemia, the state of the cardiovascular, urinary systems, central nervous system (CNS), to determine the degree and characteristics of the deficiency or excess of water and ions.
2. Taking into account the diagnosis, determine:
   1. the purpose and objectives of infusion therapy (detoxification, rehydration, treatment of shock; maintaining water balance, restoring microcirculation, diuresis, administration of drugs, etc.);
   2. methods (jet, drip);
   3. access to the vascular bed (puncture, catheterization);
3. infusion therapy equipment (IV drip, syringe pump, etc.).
4. Make a prospective calculation of current pathological losses for a certain period of time (4, 6, 12, 24 hours) taking into account the qualitative and quantitative assessment of the severity of shortness of breath, hyperthermia, vomiting, diarrhea, etc.
5. To determine the deficit or excess of extracellular water and electrolytes that developed over the previous similar period of time.
6. Calculate the child's physiological need for water and electrolytes.
7. Summarize the volumes of physiological requirements (PR), existing deficit, predicted losses of water and electrolytes (primarily potassium and sodium ions).
8. Determine that portion of the calculated volume of water and electrolytes that can be administered to the child in a certain period of time, taking into account the identified aggravating circumstances (cardiac, respiratory or renal failure, cerebral edema, etc.), as well as the ratio of enteral and parenteral routes of administration.
9. Correlate the calculated need for water and electrolytes with their amount in the solutions intended for infusion therapy.
10. Select a starting solution (depending on the leading syndrome) and a base solution, which is most often a 10% glucose solution.
11. Determine the need to administer special-purpose drugs based on the established syndrome diagnosis: blood, plasma, plasma substitutes, rheoprotectors, etc.
12. Decide on the number of jet and drip infusions with the determination of the drug, the volume, duration and frequency of administration, compatibility with other drugs, etc.
13. Detail the infusion therapy program, writing out (on resuscitation cards) the order of administration, taking into account the time, speed and sequence of drug administration.

Calculation of infusion therapy

Prospective calculation of infusion therapy and current pathological losses (CPL) of water based on precise measurements of actual losses (by weighing diapers, collecting urine and feces, vomit, etc.) for the previous 6, 12 and 24 hours allows determining their volume for the upcoming period of time. The calculation can also be done approximately according to existing standards.

Deficiency or excess of water in the body is easy to take into account if the dynamics of infusion therapy over the past time (12-24 hours) is known. More often, the deficit (excess) of the extracellular volume (ECV) is determined based on a clinical assessment of the degree of dehydration (hyperhydration) and the deficit (excess) of MT observed at the same time. At the first degree of dehydration, it is 20-50 ml/kg, at the second - 50-90 ml/kg, at the third - 90-120 ml/kg.

For infusion therapy for the purpose of rehydration, only the MT deficit that has developed over the last 1-2 days is taken into account.

Calculation of infusion therapy in children with normo- and hypotrophy is based on the actual MT. However, in children with hypertrophy (obesity), the amount of total water in the body is 15-20% less than in thin children, and the same loss of MT in them corresponds to a higher degree of dehydration.

For example: a "fat" child aged 7 months has a BM of 10 kg, over the past 24 hours he has lost 500 g, which is 5% of the BM deficit and corresponds to the first degree of dehydration. However, if we take into account that 20% of his BM is represented by additional fat, then the "fat-free" BM is 8 kg, and the BM deficit due to dehydration is 6.2%, which already corresponds to its second degree.

It is acceptable to use the caloric method of calculating infusion therapy of water requirements or in terms of the child's body surface: for children under 1 year - 150 ml/100 kcal, over 1 year - 100 ml/100 kcal or for children under 1 year - 1500 ml per 1 m ² of body surface, over 1 year - 2000 ml per 1 m ². The child's body surface can be determined using nomograms, knowing the indicators of his height and MT.

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Volume of infusion therapy

The total volume of infusion therapy for the current day is calculated using the formulas:

• to maintain water balance: OB = FP, where FP is the physiological need for water, OB is the volume of fluid;
• in case of dehydration: OC = DVO + TPP (in the first 6, 12 and 24 hours of active rehydration), where DVO is the deficit of extracellular fluid volume, TPP is the current (predicted) pathological water loss; after the elimination of DVO (usually from the 2nd day of treatment), the formula takes the form: OC = FP + TPP;
• for detoxification: OD = FP + OVD, where OVD is the volume of age-related daily diuresis;
• in case of acute renal failure and oliguria: OD = FD + OP, where FD is the actual diuresis over the previous day, OP is the volume of perspiration per day;
• with grade I AHF: coolant = 2/3 AF; II degree: coolant = 1/3 AF; III degree: coolant=0.

General rules for drawing up an infusion therapy algorithm:

1. Colloidal preparations contain sodium salt and are classified as saline solutions, so their volume should be taken into account when determining the volume of saline solutions. In total, colloidal preparations should not exceed 1/3 of the OJ.
2. In young children, the ratio of glucose and salt solutions is 2:1 or 1:1; in older children, it changes towards the predominance of saline solutions (1:1 or 1:2).
3. All solutions should be divided into portions, the volume of which usually does not exceed 10-15 ml/kg for glucose and 7-10 ml/kg for saline and colloidal solutions.

The choice of the starting solution is determined by the diagnosis of VEO disorders, volemia and the tasks of the initial stage of infusion therapy. Thus, in case of shock, it is necessary to administer mainly volemic drugs in the first 2 hours, in case of hypernatremia - glucose solutions, etc.

Some principles of infusion therapy

Infusion therapy for the purpose of dehydration is divided into 4 stages:

1. anti-shock measures (1-3 hours);
2. replenishment of DVO (4-24 hours, in case of severe dehydration up to 2-3 days);
3. maintaining VEO in conditions of ongoing pathological fluid loss (2-4 days or more);
4. PP (complete or partial) or enteral therapeutic nutrition.

Anhydremic shock occurs with rapid (hours-days) development of grade II-III dehydration. In shock, central hemodynamic parameters should be restored within 2-4 hours by administering fluid in a volume approximately equal to 3-5% of BM. In the first minutes, solutions can be administered by jet stream or quickly by drip, but the average rate should not exceed 15 ml/(kg*h). With decentralization of blood circulation, infusion begins with the introduction of sodium bicarbonate solutions. Then 5% albumin solution or plasma substitutes (rheopolyglucin, hydroxyethyl starch) are administered, followed by or simultaneously with saline solutions. In the absence of significant microcirculation disorders, balanced saline solution can be used instead of albumin. Considering the presence of mandatory hypoosmolal syndrome in anhydremic shock, the introduction of electrolyte-free solutions (glucose solutions) into infusion therapy is possible only after satisfactory central hemodynamic parameters are restored!

The duration of the 2nd stage is usually 4-24 hours (depending on the type of dehydration and the adaptive capabilities of the child's body). Fluid is administered intravenously and (or) orally (OJ = DVO + TPP) at a rate of 4-6 ml / (kg h). At stage I dehydration, it is preferable to administer all the fluid orally.

In hypertonic dehydration, 5% glucose solution and hypotonic NaCl solutions (0.45%) are administered in a 1:1 ratio. In other types of dehydration (isotonic, hypotonic), 10% glucose solution and physiological concentration of NaCl (0.9%) in balanced salt solutions are used in the same ratios. To restore diuresis, potassium chloride solutions are used: 2-3 mmol / (kg / day), as well as calcium and magnesium: 0.2-0.5 mmol / (kg / day). Solutions of salts of the last two ions are best administered intravenously by drops, without mixing in one bottle.

Attention! Potassium ion deficiency is eliminated slowly (over several days, sometimes weeks). Potassium ions are added to glucose solutions and injected into a vein at a concentration of 40 mmol/l (4 ml of 7.5% KCl solution per 100 ml of glucose). Rapid, and especially jet, injection of potassium solutions into a vein is prohibited!

This stage ends with an increase in the child’s BW, which is no more than 5-7% compared to the initial (before treatment).

The 3rd stage lasts more than 1 day and depends on the persistence or continuation of pathological water losses (with stool, vomit, etc.). The formula for calculation: OB = FP + TPP. During this period, the child's MT should stabilize and increase by no more than 20 g / day. Infusion therapy should be carried out evenly throughout the day. The infusion rate usually does not exceed 3-5 ml / (kg h).

Detoxification with the help of infusion therapy is carried out only with preserved renal function and includes:

1. dilution of the concentration of toxins in the blood and ECF;
2. increase in glomerular filtration rate and diuresis;
3. improving blood circulation in the reticuloendothelial system (RES), including the liver.

Hemodilution (dilution) of blood is ensured by the use of colloidal and saline solutions in the mode of normo or moderate hypervolemic hemodilution (NC 0.30 l/l, BCC > 10% of the norm).

Diuresis in a child under conditions of postoperative, infectious, traumatic or other stress should not be less than the age norm. When stimulating urination with diuretics and introducing fluid, diuresis can increase by 2 times (more - rarely), while it is possible to increase disturbances in the ionogram. The child's MT should not change (which is especially important in children with damage to the central nervous system, diabetic system). The infusion rate is on average 10 ml / kg * h), but can be higher when introducing small volumes in a short time.

If detoxification with infusion therapy is insufficient, the volume of fluid and diuretics should not be increased, but rather methods of efferent detoxification and extracorporeal blood purification should be included in the treatment complex.

Treatment of hyperhydration is carried out taking into account its degrees: I - increase in MT up to 5%, II - within 5-10% and III - more than 10%. The following methods are used:

• limitation (not cancellation) of water and salt intake;
• restoration of circulating blood volume (albumin, plasma substitutes);
• use of diuretics (mannitol, lasix);
• performing hemodialysis, hemodiafiltration, ultrafiltration or low-flow ultrafiltration, peritoneal dialysis in acute renal failure.

In hypotonic hyperhydration, preliminary administration of small volumes of concentrated solutions (20-40%) of glucose, sodium chloride or bicarbonate, and albumin (in the presence of hypoproteinemia) may be useful. Osmotic diuretics are better. In the presence of acute renal failure, emergency dialysis is indicated.

In case of hypertonic hyperhydration, diuretics (lasix) are effective against the background of careful intravenous administration of 5% glucose solution.

In case of isotonic hyperhydration, fluid and table salt intake are restricted, and diuresis is stimulated with Lasix.

During infusion therapy it is necessary:

1. Continuously evaluate its effectiveness based on changes in the state of central hemodynamics (pulse) and microcirculation (color of skin, nails, lips), kidney function (diuresis), respiratory system (RR) and central nervous system (consciousness, behavior), as well as changes in clinical signs of dehydration or hyperhydration.
2. Instrumental and laboratory monitoring of the patient’s functional state is mandatory:

• heart rate, respiratory rate, diuresis, volumes lost due to vomiting, diarrhea, shortness of breath, etc. are measured hourly, and blood pressure is measured as indicated;
• 3-4 times (sometimes more often) during the day, body temperature, blood pressure, and central venous pressure are recorded;
• Before the start of infusion therapy, after its initial stage and then daily, the NaCl indicators, the content of total protein, urea, calcium, glucose, osmolarity, ionogram, parameters of acid-base balance and vascular ecology, prothrombin level, blood clotting time (BCT), and relative urine density (RUD) are determined.

3. The volume of infusion and its algorithm are subject to mandatory correction depending on the results of infusion therapy. If the patient's condition worsens, infusion therapy is stopped.
4. When correcting significant shifts in the VEO, the sodium level in the child's blood plasma should not increase or decrease faster than by 1 mmol/lh (20 mmol/l per day), and the osmolarity index should not increase or decrease by 1 mosm/lh (20 mosm/l per day).
5. When treating dehydration or hyperhydration, the child's body weight should not change by more than 5% of the initial weight per day.

The drip container should not contain more than % of the daily calculated amount of OJ at one time.

When performing infusion therapy, errors are possible: tactical (incorrect calculation of the OJ, OI and determination of the components of IT; incorrectly composed infusion therapy program; errors in determining the rate of IT, in measuring the parameters of blood pressure, central venous pressure, etc.; defective analyses; unsystematic and incorrect control of IT or its absence) or technical (incorrect choice of access; use of low-quality drugs; defects in the care of systems for transfusing solutions; incorrect mixing of solutions).

Complications of infusion therapy

1. local hematomas and tissue necrosis, damage to adjacent organs and tissues (during puncture, catheterization), phlebitis and venous thrombosis (due to high osmolarity of solutions, their low temperature, low pH), embolism;
2. water intoxication, salt fever, edema, dilution acidosis, hypo and hyperosmolar syndrome;
3. reactions to infusion therapy: hyperthermia, anaphylactic shock, chills, circulatory disorders;
4. overdose of medications (potassium, calcium, etc.);
5. complications associated with blood transfusion, transfusion reactions (30 min - 2 h), hemolytic reactions (10-15 min or more), massive blood transfusion syndrome (more than 50% of the BCC per day);
6. overload of the circulatory system due to excess of administered solutions, high speed of their administration (swelling of the jugular veins, bradycardia, expansion of the borders of the heart, cyanosis, possible cardiac arrest, pulmonary edema);
7. pulmonary edema due to a decrease in colloid osmotic pressure in the plasma and an increase in hydrostatic pressure in the capillary (hemodilution with water over 15% of the BCC).

The introduction of such a procedure as infusion therapy into widespread medical practice has significantly reduced the mortality rate of children, but at the same time has given rise to a number of problems that are often associated with inaccurate diagnosis of VEO disorders and, accordingly, incorrect determination of indications, calculation of volume and preparation of the IT algorithm. Correct implementation of IT can significantly reduce the number of such errors.

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