Burns: resuscitation and intensive care in the early stages. Treatment of burns in children
Experimental and clinical researches quite convincingly showed that the rate and volume of fluid loss (plasma loss) increase with an increase in the area of the burn, which does not depend on the depth of the burn and does not manifest itself only in the case of skin hyperemia (burn I degree).
For all other lesions, the following trend is observed. The maximum plasma loss occurs in the first 8 hours from the moment of the burn. Then it gradually decreases and becomes minimal by the middle or end of 2 days.
Batehelor (1963) found that the increase in fluid loss can reach 60% of the body surface and, therefore, after this limit, there is no need to increase the volume of transfusions.
In transfusion treatment, the rate of administration and the volume of fluid administered should be individual for each patient.
Infusion-transfusion treatment should be carried out so that the rate of administration of various fluids corresponds to the changing rate of wound loss. Various formulas have been proposed that make it possible to take into account the amount of injected volumes of liquids (daily volume) with distribution over various time intervals - in the first 24 hours and then in the next 2 days.
The use of various formulas is the program of action of various infusions during the shock period. Determination of the volume of fluids administered at different time intervals is carried out upon admission of the patient to the hospital.
The decrease or increase in the volume of fluids and the rate of their administration in a given period of time can be modified in accordance with the received clinical and laboratory information about the condition of the victim. The large number of existing formulas for calculating the volume of injected fluid introduces certain difficulties. However, there are a number of provisions developed by clinicians, which boil down to the following:
1. The injected volume of fluids should not exceed 10% of the patient's body weight.
2. On the 2nd and, if necessary, the 3rd day, half the volumes used in the first 24 hours are transfused (ie, no more than 5% of the victim's body weight).
3. In the first 8 hours from the moment of receiving a burn (denoted as the period of maximum fluid loss), 1/2 or even 2/3 of the volume of fluid scheduled for 1 day is injected intravenously. Nai greater value for calculating formulas, it has not only the area of the burn (erythema, i.e., I degree is not taken into account), but also the mass of the victim. For example, a child's volume of infusions will be several times less than that of an adult. It is regrettable that in most formulas, age gradations (the elderly and especially the elderly) do not take into account the volumes of fluids required for administration, as well as the localization of the injury (burns). respiratory tract).
Such formulas are inaccurate and cannot be a guideline for infusion-transfusion treatment in all cases.
The most common and acceptable formulas are: Evans formula, Gwenn formula - Brock Medical Center, formula, or budget, Moore.
Evans formula: the number of milliliters of fluid needed for administration is 2 ml multiplied by the percentage of burn and the victim's body weight plus 2000 ml of 5% glucose solution. For example: with a burn area of 30% and a body weight of 60 kg, it is necessary to transfuse 5600 ml of liquid, of which half are colloids (plasma, dextrans, polyvinylpyrrolidone - only 2 l) and the other half - electrolyte solutions (only about 4 l).
There are two explanations for this formula. One of them indicates that for burns of more than 50%, the calculated value of fluids should not exceed this figure, and the other - the volume of transfused fluid in patients over 50 years of age should be 1 1/2-2 times less than suggested in the formula.
Broquet's formula which is a modification of the Evans formula, is calculated in the same way, with the difference that 1/4 of the amount of liquid calculated according to this formula is colloids (in the Evans formula - 1 part of colloids and an equal part of electrolytes plus 2000 ml of 5% glucose solution) and 3D electrolytes plus 2000 ml 5% glucose solution. The size of the burn more than 50% of the body surface, as in the Evans formula, is not taken into account. The elderly and the elderly are transfused with no more than 3/4 or 1/2 of the determined volume of liquids.
According to Moore's formula, during shock, the volume of fluids during the first 48 hours is 10% of the patient's body weight and is distributed as follows: 1/2 of the volume - in the first 12 hours, 1/4 - in the next 12 hours and 1/4 in the next 24 hours In addition, during the 1st day, 2500 ml of 5% glucose solution is poured to cover losses with sweating.
We are treating burn shock, using the Moore or Brock formula. In the first 8 hours after receiving a burn, we pour 1/2 of the amount of liquids intended for infusion within 24 hours, the remaining half - in the next 16 hours. On the 2-3rd day, we pour half the amount of liquids introduced on the 1st day. In this case, the following ratios are observed: colloids electrolytes +5% glucose solution=1:2; with severe burn shock - 1: 1.5.
Let's stop at basic infusion-transfusion environments.
Electrolyte solutions play an important role in the treatment of burn shock. Their ratio with the input colloids ranges from 3:1 or 2:1.
Isotonic sodium chloride solution is not sufficiently effective in replenishing the volume of circulating blood. Further, with the infusion of large volumes (1-2 liters), it can cause intracellular disorders. Ringer's solution - Locke contains a sufficient amount of electrolytes. However, its effectiveness in the treatment of burn shock is also low. He also quickly leaves the vascular bed. Currently, in the treatment of burn shock, balanced electrolyte solutions with sodium lactate (Hartmann's solution, lactasol) are more often used. Infusions of these solutions are not only effective for hypovolemia, but also improve the acid-base balance. The inclusion of sodium lactate in them as an energy substrate is realized in the Krebs cycle.
Our numerous observations on the use of lactasol have shown the success of its use in mild and moderate burn shock or in pure form, or in combination with small doses of colloids (polyglucin and reopoliglyukin in the elderly). Lactasol, used for the treatment of burn shock at a dosage of 2-4 liters, improved the rheological properties of blood, microcirculation and, to a certain extent, served as a prophylactic against disseminated intravascular coagulation. Thus, balanced electrolyte solutions, especially with the addition of lactate and sodium bicarbonate, are currently recognized as the best of the crystalloids in the treatment of burn shock.
Dextran preparations(polyglucin and reopoliglyukin). In one of the sections, a detailed description of the dextran preparations used in the treatment of burn shock has already been given. In this section, we will briefly touch on the mechanism of their action and the amount of fluid used in the treatment. In principle, dry or native plasma should be the main transfusion substitution medium. However, a number of shortcomings (danger of transmission of the hepatitis virus, limited shelf life, especially of native plasma, the content of a significant amount of preservative, high cost) forced the search for other medicines. Currently, the domestic drug rheo-polyglucin (rheomacrodex), a low molecular weight drug that leaves the vascular bed relatively quickly, is widely used, prescribed as a means of combating microcirculation disorders (improves blood flow in small vessels and capillaries at a dosage of 400-800 ml). The drug is more effective in combination with polyglucin, which has a pronounced hemodynamic effect.
Polyglucin (medium molecular weight dextran) is the best plasma replacement solution: it circulates in the vascular bed for a long time, maintaining the volume of circulating blood, improving minute volume, causing a diuretic effect. The use of polyglucin is indicated for severe hemodynamic disorders, as well as in cases where small amounts of fluid are needed to normalize blood circulation (burns of the respiratory tract, shock in the elderly and the elderly). The volume of injected polyglucin can vary between 400-1600 ml, and in combination with rheopolyglucin within 800-2000 ml.
Whole blood and its preparations. The use of whole blood in burn shock has not lost its significance. The rationale for its use is based on the fact that in the blood of a person burned during shock, destruction of erythrocytes is observed, the magnitude of which depends on the area of a deep burn. There is no doubt that we established [Murazyan R. I., 1973] the fact that transfusion of blood of short periods of storage in dosages up to 1 liter against the background of transfusion of 4-6 liters of other liquids (electrolyte solutions, dextrans) does not aggravate hemoconcentration. Blood with a shelf life of 1-3 days improves oxygen transport to body tissues.
Blood has a positive effect on metabolic processes, reduces the permeability of blood vessels and cell membranes.
However, as advocates of whole blood transfusion, in last years we apply it only on the 2nd-3rd day of the shock period. This circumstance is dictated by the fact that the transfused blood, despite the short shelf life, is subject, like the blood of the patient, to significant destructive processes. The destruction of erythrocytes most intensively occurs in the first 24-36 hours, as a result of which microcirculation may worsen and aggregation of blood cells may occur. When transfusing fresh blood at a dose of 250-1000 ml after the specified period, in combination with infusions of rheopolyglucin, the danger is negligible.
Plasma transfusions, even among adherents of whole-roof transfusions, do not meet with objections. Until 1960, plasma (native and dry) was the main transfusion medium in the treatment of burn shock. The doubts that have arisen about the advisability of its use are caused, we repeat, by the possibility of transmitting serum hepatitis, the high cost and the limited possibility of obtaining it in large quantities.
Plasma contains specific antibodies, which can lead to its transfusion in large quantities, as well as during blood transfusion, to the destruction of erythrocytes. During the period of burn shock, the optimal dose of transfused plasma, according to various authors, should be 2-4 liters [Vilyavin GD, Shumov OV, 1963; Monsaigon, 1959; Muir, 1974, etc.].
In recent years, albumin solutions have attracted more and more attention in the treatment of burn shock. However, it must be remembered that albumin, as a finely dispersed protein, quickly leaves the vascular bed and is found in the lost wound fluid. Because of this, it is necessary to administer large doses of 5% albumin solution, using it like plasma for a long time, for many hours. Albumin creates an appropriate oncotic pressure, its concentrated solutions because of this, contribute to the release of fluids from the tissues into the vascular bed (dehydration effect). Albumin solutions are involved in the transport medicinal substances, water, vitamins, they also have a detoxifying effect. Complications are rare, but in patients with cardiovascular decompensation, transfusions of large amounts of albumin solutions can lead to a worsening of the condition. The use of albumin solutions in the required dosages (200-400 ml or more) is not always possible.
Anticoagulants. Until now, there is no consensus on the advisability of using anticoagulants due to the fact that along with thrombus formation and hypercoagulation in the shock period, various bleeding(gastric, hemorrhages in other internal organs). Our many years of experience and numerous studies have shown that the degree of hypercoagulability is directly dependent on the size of the burn injury. The more extensive and deeper the burn, the more often thromboembolic complications are observed. Activation of the blood coagulation system dictates the need for the use of heparin in prophylactic doses, and in case of detection of thromboembolic complications, its use in therapeutic doses.
Intravascular coagulation is caused by many factors, of which the most significant role is played by microcirculation disorders, an increase in the number of platelets, and the detection of a large amount of tissue thromboplastin. To the above should be added an increasing increase in fibrinogen. The effectiveness of heparin is due to the fact that it reduces the degree of hypercoagulability, improves blood circulation in the capillaries, tissue gas exchange, being a proven tool in the fight against pulmonary vascular complications. When using anticoagulants, it is necessary to laboratory research blood coagulation system. A severe degree of hypercoagulability justifies the use of fibrinolysin.
Antihistamines. It is known that histamine and its products are found in large quantities in the body of the victim, being released from burned tissues. They increase the permeability of the vascular wall and capillaries, contribute to the defeat of their intima. Based on this, intensive antihistamine therapy is indicated. Used drugs such as pipolfen, diprazine, calcistin, diphenhydramine, suprastin. They reduce, according to Koslowski (1969), the permeability of capillaries, also providing a sedative effect.
Hormonal preparations. A number of experimenters and clinicians argue that the use of adrenal cortex hormones can help prevent the development of collapse in burned patients. However, many combustiologists consider the beneficial effect of these hormones in shock to be unproven and, therefore, protest against their introduction. Buterfield (1957), Muir (1974) repeatedly emphasized the lack of evidence of insufficient adrenocortical activity in burn shock.
Rudovsky et al. (1980) write that with the early development of collapse in victims, they use cortisone extremely rarely and in moderate doses. Cortisone is widely used for burns of the respiratory tract in the first days of the disease, which helps to relieve swelling of the tracheobronchial tree.
Other medicines. IN clinical practice in the treatment of extensive burns, cardiac and narcotic drugs are widely used. Considering the possibility of developing pneumonia in the coming days after the post-shock period, as well as to improve the activity of the cardiovascular system, it is advisable to use camphor preparations (intravenous sulfocamphocaine, etc.). With severe tachycardia, intravenous administration of korglucon is indicated. It is possible to use digitalis preparations, especially in patients over 50 years of age. However, it must be remembered that digitalis preparations are contraindicated in violation of cardiac conduction and ventricular extrasystole.
The use of narcotic drugs, especially neuroleptic drugs, is advisable for extensive and deep burns. According to recent data, the use of antibiotics is not mandatory. With extremely extensive and deep burns, and especially burns of the respiratory tract, their use is possible as a prophylactic agent to combat infectious complications.
Indications for infusion-transfusion treatment in burn shock. As you know, patients are admitted to the hospital after 1-2 hours from the moment of receiving a burn. Infusion-transfusion therapy should therefore begin immediately. Leape (1971) in the experiment, Arts, Moncrief (1969) and others in the clinic convincingly showed that the best effect from the use of infusion-transfusion treatment is observed if it is started no later than 1 hour after the burn. This opinion is not objected to by most clinicians. Of course, it is important before starting treatment, if possible, to identify the size and depth of the burn injury, the age, body weight of the patient, the diseases preceding the injury, and finally, to exclude the burn of the respiratory tract.
The first practical action upon admission of the patient is venipuncture or vascular catheterization, since all subsequently administered drugs require intravenous administration.
According to a certain area and severity of the burn, the volume of fluid required for administration on the 1st, 2nd and 3rd days is set, followed by correction of the information received accordingly.
It is most acceptable to use Broca's formula for this purpose: 2 ml X body weight X lesion area + + 2000 ml 5% glucose solution. The ratio of the volume of crystalloids to colloids is 3:1. On the second or third day, half the amounts of liquids administered on the 1st day are used.
For elderly patients with burns of the respiratory tract, the volume of fluids should be reduced by 1/2-1/3, using a ratio of crystalloids to colloids of 2: 1 or 1: 1. It must be remembered that the volume of fluids administered on the first day should not exceed 10% of the victim's body weight. Based on this, the volume of infusion therapy with a lesion area of 50% or more should be the same.
In the first 8 hours from the moment of receiving a burn injury, it is necessary to transfuse up to 1/2-2/3 of the daily volume of liquids, with a ratio of crystalloids to colloids 1: 1 or 1: 2.
During the period of burn shock, it is recommended to administer colloids: polyglucin and reopoliglyukin, hemodez, albumin solution, plasma, fresh whole blood or erythrocyte-containing media of short shelf life. The latter should be transfused only on the 2-3rd day. Electrolyte solutions are also used.
The effectiveness of the ongoing infusion treatment is determined primarily by clinical symptoms - the absence of arousal, adynamia, dyspeptic symptoms, pulmonary symptoms, as well as hematocrit and hemoglobin values every 4-8 hours; central venous pressure and blood pressure(hourly), acid-base status (preferably every 8-12 hours), hourly measurement of the amount of urine.
Once calculated, the volume of liquid is subject to clarification, modification based on the received hourly information. So, for example, depending on the state of the central venous pressure and other indicators, the amount and composition of the fluid used may vary. An increase in central venous pressure, indicating the development of right ventricular failure, forces a decrease in the volume of intravenous fluid administered through the use of colloids, and an increase in cardiovascular therapy. At the same time, a decrease in central venous pressure indicates hypovolemia and dictates the need to increase the volume and rate of fluid administration.
Infusion treatment is not indicated for patients who have a burn of less than 15% of the body surface, in the elderly - less than 10%. The exception is burn victims, who have a more intense loss of fluid, and therefore, with a burn of more than 5-6% of the body surface, the transfusion of electrolyte solutions to these patients brings undoubted benefits. In general, patients with lesions less than 10-15% should be advised plentiful drink(electrolyte solutions, mineral waters, alkaline water), older people, even with a lesion area of less than 10% of the body surface, require the introduction of neuroplegics and cardiovascular agents. The total amount of liquids administered orally in the first 12 hours is calculated by the formula: 4 ml, multiplied by the percentage of burn and body weight in kg. In the next 2 days, the same amounts are administered.
All ongoing treatment and clinical and laboratory data for an accurate analysis of its effectiveness are recorded in a shock sheet, the columns of which are filled in by the medical staff as information becomes available.
Murazyan R.I. Panchenkov N.R. Emergency care for burns, 1983
30. Burns in children. Classification. Calculation of the burn surface. Clinic depending on the severity of the burn. Emergency care for acute burn injury.
Classification:
1. superficial burn of the epidermis - hyperemia, swelling and severe soreness of the skin. Edema and hyperemia do not disappear from finger pressure.
2. defeat of the epidermis and the surface layer of the dermis - hyperemia, blisters filled with transparent contents.
3. a) damage to the epidermis and dermis at various levels - blisters with liquid jelly-like contents.
b) damage to the epidermis and dermis at all levels - blisters with hemorrhagic contents.
4. damage to all layers of the skin and deeper layers - charring, extensive defects, tissues and deeper damage to the fascia and muscles, tendons and bones.
Calculation of the burn surface
1. palm method - palm of the victim = 1% of the area
2. method "9" according to Wallace - for emergency care
3. Land-Browder table
4. Blokhin's scheme
Clinic, depending on the severity of the burn (the area of the burnt surface, the degree of burn and the age of the patient)
Emergency care for acute burn injury. Indications for hospitalization: I - n\r, 10%, II -\u003e 5% - 5-7 years,\u003e 10% -\u003e 7 years, III-IV - all.
1. warming the patient
2. drinking - salt-alkaline solution (1 liter of water + 1 g of soda + 3 g of salt), alkaline mineral waters.
3. catheterization: nasal, intravenous, m\n, with II-III degree - gastric tube
4. hourly registration: respiratory rate, heart rate, blood pressure, the amount of injected and withdrawn fluid, KLA, OAM, KOS, electrolytes.
5. anti-shock therapy (all children with area> 10%, children under 3 years -> 5%)
6. anesthesia: I-II degree - analgin, diphenhydramine, older than 1 year 1% promedol - 0.1 ml / year, 25% droperidol - 0.1-0.2 ml / kg
7. infusion therapy - 1) during the first 48 hours - 1/3 V - 8, 16, 24 hours, 2) composition: 1/3 - proteins (albumin), colloidal solutions (rheopolyglucin), HSR (r -R Ringer-Lock), 3) glucose-novocaine mixture - 0.25% solution of novocaine and 5% glucose solution in equal proportion in an amount of 100 to 200 ml.
8. diuretics in III-IV degree: with thirst - 10, 15, 20% mannitol (1 g / kg / day), with vomiting - 10% urea (1 g / kg / day)
9. GCS - hydrocortisone - 10 mg / kg / day, prednisolone - 3 mg / kg / day
11. cardiac glycosides according to indications
12. aseptic dressings (furatsilin)
Calculation of liquid (ml) per 1% of the surface for 48 hours: 0-5 months. - 15-20, 6-12 months - 25, 1-3 years - 30-40, 3-8 years - 50-60, 8 and more - 80-100. Calculation of 4% solution of soda per day: 4 x m / t (kg). Calculation of glucose-novocaine mixture per day. (0.25% novocaine: 5% glu \u003d 1: 1) - 0-1 years - 10-30, 1-3 - 30-100, 3-10 - 100-150, 10 and more years - 150-200
21. Burn disease, phases of the course. Principles of treatment of burn disease. Methods of treatment of burn wounds.
Burn shock phase. In children, it usually does not exceed several hours, but it can last 24-48 hours. There are short-term (erectile) and long-term (torpid) phases. In the erectile phase of burn shock, the victims are usually excited, moaning, complaining of sharp pain. Sometimes there is a state of euphoria. Blood pressure is normal or slightly elevated, pulse is rapid. In the torpid phase of burn shock, inhibition phenomena come to the fore. The victims are adynamic, indifferent to the environment, they do not complain. There is thirst, sometimes vomiting. Body temperature is lowered. The skin is pale, facial features are pointed. The pulse is frequent, weak filling. The amount of urine excreted is reduced. A decrease in circulating blood volume leads to a decrease in blood pressure and hypoxia. One of the formidable signs of increasing circulatory disorders is oliguria, and in some cases anuria. Functional depletion of the cerebral cortex can be profound and lead to the death of the patient.
Phase of acute toxemia. In this phase, the phenomena of intoxication, violation of protein metabolism, which is associated with ongoing plasma loss and tissue protein breakdown, come to the fore. Infection of the burnt surface and absorption of toxins, degenerative changes in parenchymal organs and dehydration lead to a worsening of the burn disease. The toxic state is manifested by pallor, high fever, impaired cardiovascular activity. In connection with the thickening of the blood, erythrocytosis, an increase in the content of hemoglobin, are initially observed, and then true anemia occurs.
septicemia phase. In some cases, it is clinically difficult to distinguish it from the previous phase of intoxication. With extensive deep burns, when the defect formed at the site of the burn is a huge festering wound, and the body's resistance falls, the picture of sepsis comes to the fore in these cases, the fever becomes hectic in nature, anemia and hypoproteinemia increase, reactive processes stop, granulations become lethargic, pale, bleeding. Often there are bedsores, and sometimes metastatic purulent foci. On the part of the blood, changes of a septic nature are noted.
The convalescence phase is characterized by the normalization of the general condition, wound healing. With deep burns, sometimes long-term non-healing ulcers remain, and as a result of scarring, tightening disfiguring scars and contractures can form.
Principles of treatment of burn disease. see question 20.
Methods of treatment of burn wounds. Methods of local treatment of burns can be divided into 3 groups: 1) treatment under a bandage; 2) treatment open way and 3) coagulation method. Bandage treatment is the main treatment for burns in children. Primary surgical treatment is performed under general anesthesia, it consists in a careful, minimally traumatic and gentle cleansing of the burn surface, blisters and surrounding skin by washing and wiping with antiseptic solutions. The burn area is freed from contamination and hanging flaps of the epidermis, carefully removing dirt and extraneous layers with a gauze ball moistened with novocaine solution. Unopened blisters are lubricated with alcohol or a 3-5% solution of potassium permanganate, after which they are cut with scissors at the base and, without cutting off the epidermis completely, the contents are evacuated. After the toilet, a bandage is applied to the burn surface. It can be wet, moistened in a solution of furatsilin, ethacrine lactate, novocaine with antibiotics or impregnated with Vishnevsky ointment, synthomycin emulsion, propolis ointment, solcoseryl, etc. It is very effective for II-IIIA degree burns to close the burn surface of artificial skin (after primary surgical treatment).
The open method according to Povolotsky (treatment of the burn surface without dressings) is rarely used in children. Although this method frees patients from painful dressings, eliminates to a large extent the unpleasant odor emitted by large bandages soaked in pus, the wound heals slowly, its surface is covered with thick crusts, under which purulent discharge accumulates. In recent years, the treatment of burn wound surfaces under conditions of local or general gnotobiological isolation, the use of abacterial principles, as well as chambers with a laminar flow of sterile air, have become widespread.
The coagulating method for conducting an open method according to Nikolsky - Bethman is used to treat the burn surface of the face, neck and perineum, mainly with II degree of damage. The treatment is carried out under general anesthesia with a gauze cloth moistened with a warm 0.25-0.5% solution of ammonia (ammonia), the burnt surface is cleaned. In case of a burn on the head, the hair is shaved off, then the burned surface is smeared with a 5% freshly prepared aqueous solution of tannin, after which the surface of the burn is smeared with a 10% solution of silver nitrate (lapis) with another cotton swab. The surface quickly turns black, through a short time becomes dry and crusty. After treatment, the patient is placed under the frame with light bulbs and covered with a blanket. The temperature under the frame is monitored; the patient should be warmed at a temperature of 24-25 ° C, but not higher in order to avoid overheating. wound healing, skin grafting is performed. Autoplasty is performed in the early stages, as soon as the wound begins to granulate well and the general condition of the patient becomes satisfactory. The objective indicators that determine the time of transplantation are the content of hemoglobin in the blood of at least 50%, protein in the blood serum of at least 7% and the good condition of the wound - its cytogram. If the patient has a sufficient surface of the skin that can be used for transplantation, a flap is taken with a dermatome, passed through a Brown perforator and, having closed the burned surface, strengthened along the edges of the wound with rare sutures.
Introduction
Large burns in children are accompanied by a huge loss of fluid. Due to the destruction of the skin barrier and capillaries, the fluid is washed out from the surface of the burn and leaves the intravascular space into the institial space. This process is especially intensive in the first 48-72 hours after the burn, when the capillaries begin to restore their work and the liquid begins to seep. Not only water and colloid are lost, but also large reserves of sodium - all those scarce substances that must be replaced in the first days after a burn in order to avoid fatal outcomes of hypovalemia, shock, acidosis and circulatory collapse. Variable changes in normal unburned tissues complicate the problem of fluid loss.
Over the past five decades, there has been constant observation of the fluid loss patterns of children with major burns in order to find a form for fluid replacement - a formula that would incorporate all the changes that are taking place and new information and experience. The changes continue to this day. In this chapter, we will review the characteristics of ideal fluid replacement in burns, present some of the formulas by which losses were once calculated, and finally discuss modifications to fluid therapy in children, as well as special situations that occur in children with burns.
Liquid composition. The fluid should be crystalloid for the first 24 hours as protein will be lost due to circulation during this time. Sodium should be the main ion in whatever fluid you choose - either hypotonic, isotonic or hypertonic.
Fluid replacement rate. Fluid loss occurs rapidly in the first few hours after injury, gradually slowing down after 48 hours. Fluid is lost asymptomatically and should ideally be replaced in the next step. After 48 hours, fluid must be replaced with great care (plus other losses other than burns), since fluid absorption occurs in large volumes and cardiovascular system And renal system have to deal with separation.
Protein versus colloid. Since the vascular membrane and endothelial integrity begin to recover within the second day after the burn, the infusion therapy must contain a colloid to replace the protein losses that have occurred as a result of the burn. In the following days, blood will be needed because anemia develops due to the effect of thermal damage.
Fluid Formula
Numerous formulas have been proposed by inventive researchers over the years, and each formula has its own advantages and disadvantages. The following 6 formulas (Table 1) are chosen to illustrate the evolution of the concept of infusion therapy in children with burns. The first three formulas are now of historical significance, while the remaining three have been used in the present. The application gives more full list formulas.
| Formulas | First 24 hours | Second 24 hours |
|---|---|---|
| Cope & Moore (1947) |
150 ml (75 ml plasma and 75 ml crystalloid) per % of burn area. Speed: 12 for the first 8 hours and 12 for the next hours. Maximum: 10-12% of body weight in liters. |
Half of what was in the first 24 hours. |
| Evans (1952) |
1.0 ml saline % burn surface kg 1.0 ml plasma % burn surface kg. Contents: 2000 ml dextrose (adults). |
|
| Military hospital in Brooke, Reiss (1953) |
1.5 ml Ringer lactate % burn surface kg 0.5 ml plasma % burn surface kg. Contents: 2000 ml dextrose (adults). Speed: 12 for the first 8 hours and 12 for the next 16 hours. Maximum: calculation for 50% of the burn surface. |
Half of what was in the first 24 hours. Contents: 2000 ml dextrose (adults) |
| In 1970, Pruitt revised Brook's formula: |
2.0 ml Ringer lactate % burn area kg. Speed: 12 for the first 8 hours and 12 for the next 16 hours. Maximum: nothing. |
Colloid 0.5 ml % burn area kg. Contents: 2000 ml dextrose (adults) |
| Baxter (1968) |
4 ml Ringer's lactate \% burn surface. Speed: 12 for the first 8 hours and 12 for the next 16 hours. Maximum: nothing |
Plasma is given 20-60% of the calculated plasma volume (Plasma 0.5 \% of the burn surface kg) |
| Carvagal (1975) |
5000 mlm 2 of the burn area 2000 mlm 2 of the total body area Solution: 5% dextrose Ringer's lactate with the addition of albumin. Speed: 12 for the first 8 hours and 12 for the next 16 hours. Maximum: nothing |
One third of what was on the first day plus milk or water by mouth. |
| Bowser & Caldwell (1983) |
2 ml \% of burn area kg Solution: hypertonic lactate Maximum: calculation for 50% of the burn surface. |
Half of what was on the first day. |
Cope & Moore (1947) were the first to start formulating. They were the first to try to compare how much fluid is required per burn surface area and gave convincing evidence of how much fluid should be transfused to the patient in the first 48 hours. Over the years, they found that their patients were fluid overloaded, so they recommended maximum fluid consumption of 10-12% of body weight in liters of fluid.
Evans (1952) developed his formula using the data of Cope and Moore, based on the composition of the liquid of burn blisters. In addition, he gave the daily amount of fluids and limited the maximum fluid given per burn, which was calculated based on 50% of the burn surface.
Reiss (1953) working at the Military Burns Hospital in Brook, using the Evans formula in the first 48 hours, half. Subsequently, the burn department at Brook (Pruitt, 1970) eliminated the administration of colloidal solutions in the first 24 hours, using only Ringer's lactate solution.
Baxter (1968) suggested fluid therapy using large amounts of Ringer's lactate alone, measuring diuresis and assessing clinical status in the first 24 hours. He added colloid during the first day. Experience has shown that this formula can be used in many cases. Problems arise when a child is overloaded with liquid, too much liquid is given to a severely burned patient.
Carvagal (1975) believes that the introduction of fluids should be based solely on the calculation of the body surface. His formula, which uses one solution, requires 2 calculations: one - the percentage of the surface of the burns - the burn content; and another calculation is based on total body surface area - physiological need. He recommends the early use of colloid (albumin) and believes that the formula has particular advantages for burn patients of all ages and with varying degrees of burns. When using this formula, it is important to accurately estimate body surface area.
Bowser & Caldwell (1983) advocates the use of hypertonic saline for resuscitation, especially in children with burns. They believe that this mode avoids fluid overload and restores lost sodium ions. Maintaining normal serum osmolarity and the ratio of normal intracellular fluid to extracellular fluid is considered an advantage. The use of hypertonic fluid for resuscitation of children requires constant monitoring of the patient in order to avoid hypernatremia, hypertensive syndromes and possible syndromes of the central nervous system. No colloids were applied in the first 48 hours.
Physiologically, children are not small adults, they respond differently to a burn and therefore require a different infusion rate and other components of infusion therapy. Such rules, if not followed in children with burns, lead to devastating consequences that are not easily remedied. When compiling an infusion therapy regimen, the following factors should be considered.
Fluid intake in children is directly proportional to body surface area, not body weight. daily requirement in the liquid in children is estimated up to 1750 mlm 2.
Newborns and young children are more sensitive to fluid loss for several reasons:
- Newborns have a larger body surface compared to body weight than adults.
- Children have a higher heat exchange rate than adults, again due to the proportion of body surface area rather than weight.
- Newborns and small children react to a burn with a higher temperature than adults, and thereby increase heat exchange even more.
The surface of the body in children changes until they are 16 years old, then their proportions are already perceived on a par with an adult. Using the table of adult burn patients to estimate the size of a burn in children leads to serious discrepancies with the amount of fluids needed.
Children are characterized by increased diuresis compared to adults in order to get rid of metabolic products.
Infants under 1 year of age require less sodium in intravenous solutions.
Children have less prodromal signs of circulatory collapse due to excessive fluid administration and therefore require closer monitoring.
Children have less glycogen stores, which are then quickly depleted after a burn and lead to severe hypoglycemia.
In some situations, significant quantitative and qualitative changes are required in the plans and calculations of infusion resuscitation.
Extensive burns (80% or more).
Extensive burns usually require more fluid than calculated using any formula and therefore closer control.
The accompanying destruction of red blood cells presents a hemochromogenic burden on the kidneys as well as an increase in serum potassium. Manitol and alkalinization are needed to protect the body from acute tubular necrosis. The presence of excess serum potassium may require changes in fluid composition.
Dextrans should not be used as part of the resuscitation fluid because large volumes of fluids are required and extensive burns tend to spread intravascular coagulation.
Electrical damage by high voltage current.
Such injuries cause more deep damage tissues and muscles than superficial ones, and thus require more fluids than the formula based on body surface area suggests.
Deep muscle damage releases myoglobin and hemochromagens, posing a risk of kidney damage requiring administration of mannitol and alkalinization at normal doses.
High serum potassium usually requires changes in the components of the fluids used for resuscitation.
Lung damage.
The presence of airway damage usually requires an increase in volumes of fluids.
Despite the increase in fluid volumes, such patients are usually prone to fluid overload due to alveolar-capillary destruction. Close monitoring and increased diuresis will be required to help prevent excessive fluid infusion.
Do not inject colloid on the first day, as this increases the water content in the lungs and thus increases the chances of getting pulmonary edema.
Ventilated patients with adequate hydration will have less water insensitivity and higher antidiuretic hormone levels. Both of these factors are responsible for smaller volumes of fluid.
Accompanying illnesses.
The presence of serious cardiovascular diseases or anomalies requires very close attention during infusion therapy, due to a decrease in the compensatory capabilities of the child's body.
- Serum potassium should be monitored as patients with cardioglucosides require normal serum potassium levels.
- In addition, if a burned patient with heart disease received diuretics prior to the burn, hypokalemia may occur.
Diabetics present several special challenges and will be as easy to care for as managing a diabetic before a burn.
- Burn hyperglycemia complicates urine output and osmolarity.
- The use of saline is risky in burnt children with diabetes, as hyperosmolar syndrome, including coma, can occur.
- When glucose and insulin are used, serum potassium levels should be monitored.
Resuscitation Delay
If there is a serious delay in fluid resuscitation in a patient with a large burn, poor perfusion, then shock or acidosis will accompany, which will then also require an increased volume of fluid.
If such delays occur, the calculation of fluids should be carried out from the time of the burn, and not from the time it arrived at the burn unit.
TO comorbidities appropriate to include:
- Consequences of postpartum trauma and CNS disease.
- SARS.
- Intestinal infection and disease.
- Traumatic injuries.
- Diseases of the urinary tract.
Title Burns: resuscitation and intensive care in the early stages.
_Author
_Keywords
Robert I Oliver, Jr, MD, Staff Physician, Department of Surgery, University of Louisville
Burns, Resuscitation and Early Management.
Last revised: May 1, 2003
The history of resuscitation of burn patients can be traced from observations made after the great city fires at the Rialto Theater (New Haven, Conn) in 1921 and the Coconut Grove nightclub (Boston, Mass) in 1942. Physicians noted that some patients with large survived the fire with burns, but died of shock during the observation period. In the 1930s and 1940s, Underhill and Moore put forward the concept of intravascular fluid depletion caused by thermal injury, and in 1952 Evans proposed formulas for early recovery of fluid depletion (Yowler, 2000). Over the next 50 years, significant progress has been made in the possibilities of resuscitation care, which has led to the emergence of many strategies for the treatment of burn shock.
The main development was the views on the systemic and local inflammatory response, final result which is the almost immediate transition of intravascular fluid into the surrounding interstitial space. This is due to changes in vascular permeability as the normal capillary barrier is disrupted by systemic inflammatory mediators such as histamine, serotonin, prostaglandins, platelet products, complement components, and kinins.
This process occurs in burned tissues and, to a lesser extent, in unburned tissues. The formation of a large number of neutrophils, macrophages and lymphocytes in these areas is associated with the release of a large number of inflammatory mediators that affect local and systemic capillary permeability. Rapid transcapillary alignment of intravascular components occurs in a state of iso-osmotic concentration, achieved in the interstitium, with a proportional ratio of proteins and the liquid part of the plasma.
During the formation of edema, almost all intact blood elements up to the size of an erythrocyte (mol. weight 350,000) are able to pass through the vessel wall of the burned tissue. However, some degree of limitation of the barrier function of the capillaries occurs in unburned tissues. As a result of increased capillary permeability, the replacement of the suffered vascular deficit leads to the accumulation of edematous fluid to maintain fluid balance, with almost half of the volume of injected crystalloids lost in the interstitium. When the extent of the burn approaches 15-20% of the total body surface area, shock develops if adequate replacement of the volume of lost fluid is carried out. The peak of this state occurs in the range from 6 to 12 hours from the moment of the burn, since the capillary barrier begins to restore its integrity, therefore, from this moment there is a decrease in the required volume of injected fluid in resuscitation formulas. From this point on, theoretically, supportive therapy with colloids should be carried out preferentially, which allows a careful stepwise decrease in the volume of fluid administered to reduce edema.
Other factors that cause burn edema include coagulation of the interstitium protein under the influence of high temperature. In adults with a burn surface area of 25-30% of the body surface, cell membrane damage occurs (as in all other types of hypovolemic shock), which is associated with a decrease in trans membrane potential and accumulation of intracellular sodium and water, resulting in cell swelling. Resuscitation measures are aimed at normalizing the transmembrane potential, but unlike hemorrhagic shock, in burn shock it can only be partially corrected and leads to multifactorial edema. Lack of aggressive replenishment of the volume deficit leads to a progressive decrease in membrane potential with possible cell death.
Classical description of the burn wound and surrounding tissues- a system of several peripheral zones emanating from the primary fired area as follows:
- Coagulation zone- non-viable tissues in the epicenter of the burn
- Area of ischemia or stagnation– tissues (both deep and superficial) surrounding the coagulation area that did not die initially but, due to microvascular hemorrhage, may undergo necrosis after a few days if resuscitation is not carried out properly
- Hyperemia zone - peripheral tissues, which undergo changes caused by vasodilation and release of inflammatory mediators, but are not critically damaged and remain viable,
Ischemic tissue can potentially be saved by proper resuscitation in the initial stages, proper burn wound debridement, and antimicrobial therapy during convalescence. As a result of improper intensive care, this area can transform into a deep dermal or all-subcutaneous burn in areas that were initially less damaged. Reassessment of the degree of burn of these areas occurs during the first few days, when it becomes clear which tissues need to be excised during surgical treatment. The burn patient should be assessed similarly to the trauma patient, starting with the ABCDE score. Need to pay Special attention for the presence of continued heat exposure through smoldering clothing or contact of a burnt surface with a chemical irritant.
Respiratory support.
Respiratory support for burns is extremely important issue, which can lead to serious complications if not performed properly. The formation of edema in the resuscitation period also occurs in the airways. Oxygen therapy with real-time oxygen saturation monitoring (maintain saturation > 90%) should be given to all burn patients with any significant injury.
Almost all patients with major burns require immediate intubation and mechanical ventilation. In small-to-medium area burns, patients may initially have no respiratory problems, but may develop stridor within a few hours with increasing edema, requiring urgent intubation under less than ideal conditions. In addition, large amounts of drugs are used that also inhibit respiratory function.
Scorched head hair and sputum containing fumes are signs of respiratory tract damage, which subsequently leads to both respiratory dysfunction and volemic disorders. Indoor fires, where patients are found unconscious, are also often associated with significant inhalation injury. In non-intubated patients with possible inhalation injury, nasopharyngoscopy is an important additional research to assess the degree of inhalation damage to the respiratory tract and laryngeal edema, helping to assess the threat of impending respiratory failure. As an auxiliary assessment, conventional methods for determining the gas composition of blood, radiography are used. chest and determination of the level of carboxyhemobin (maintain at the level< 7 %).
intravenous access.
Rapid establishment of venous access through a large diameter vein is essential for rapid volume replacement in patients with severe thermal injury. No factor other than airway protection is as critical in the early stages of burn patients. Ideally, intravenous catheters should be placed away from burned tissue due to difficulty in isolating veins and venous access problems (more so than the risk of infectious complications; the natural flora of the skin has essentially been sterilized by the heat of the burn).
Most young patients with small to moderate burns do not require central venous catheterization due to the risk of catheter-related complications. However, if their use is necessary, they should be installed early, while the resulting swelling of the head and neck area does not complicate the installation of the catheter. If a catheter needs to be placed in a patient with severe head and neck swelling, assistance can be used to locate the access site. ultrasound. Central access through the femoral vein is usually avoided due to the high risk of infection, but this vein is sometimes the only large vein available in unburned tissues and should be used in this situation. This approach has been shown to be safe and effective in burn patients, and is acceptable with careful debridement of the skin around the catheter to prevent infection.
Additional score.
Patients with burns requiring fluid replacement should have a Foley catheter placed early to determine urine output. In addition, early insertion of a nasogastric tube and early start enteral nutrition.
Peripheral pulse assessment is critical for burn patients, especially those who arrive several hours after a burn injury. A weak pulse can be caused by insufficiently adequate resuscitation, as well as a sign of a developed compression syndrome that requires removal of the scab and fasciotomy.
In the resuscitation period, careful monitoring of the affected limbs is necessary. The formation of edema of well-perfused limbs can lead to their ischemia and kidney failure associated with the formation of myoglobin. Therefore, in the first 24-48 hours, it is necessary to carry out a gravitational outflow, raising the limbs above the level of the heart and Doppler control of vascular pulsation. Circular burn patients are at the highest risk of developing pressure syndrome and require the most careful monitoring. If there is no pulse in the limb, several problems must be considered. First, it is necessary to determine whether the absence of a pulse is the result of ineffective resuscitation in a patient who needs more fluid.
Second, it must be decided whether the injury is associated with possible vascular damage. Finally, it is necessary to find out if the compression syndrome has developed. The degree of compression can be measured with special portable devices or using an arterial catheter. Pressure remaining at approximately 30 mm Hg is considered high and is suggestive of a possible compression syndrome. The recorded pressure is 40 mm Hg, requiring emergency eschar removal or fasciotomy. It must be ensured that the electrocautery can be used at the patient's bedside. The scab is excised within healthy tissues. If the removal of the scab is sharply painful, this may mean that a weak pulse in the limb is not associated with a compression syndrome, and a reassessment of the volemic status is necessary.
The first step in assessing the severity of a burn patient and planning resuscitation involves a careful examination of all body surfaces. The standard Lund-Browder scale is available in most emergency departments for a quick assessment of burned body surface area. If there is no such scale, the "rule of nines" is quite exact method assessments in adult patients. The Rule of Nines looks like this: It should be taken into account that the patient's palm is approximately 1% of the total body surface area (TBSA), which can be used to evaluate heterogeneous areas.
- Head/Neck - 9% TBSA
- Each hand - 9% OPPT
- The anterior surface of the chest - 18% of the TPP
- The posterior surface of the chest - 18% of the TPP
- Each leg - 18% OPPT
- Perineum - 1% TBSA
In children, the head makes up a larger percentage of TPP, while upper limbs constitute a smaller percentage of FPRW. This difference is reflected in the pediatric Lund-Browder chart.
A useful tool for estimating the area of non-uniform burns is to estimate the area the size of the patient's palm, which is 1% of BSA.
Burn depth is classified into several fairly standardized categories: superficial burns (first degree), partial thickness (second degree), full thickness (third degree), and destructive full thickness (fourth degree).
Superficial (first degree) burns are limited to the epidermal layer and are equivalent to superficial tanning without blistering.
Second degree burns are otherwise known as dermal burns and can be superficial burns or deep, partial thickness burns. Superficial, partial thickness burns involve superficial papillary dermal elements and are pink, moist, and slightly painful on examination. Subsequently, a bubble forms. This type of burn usually heals well within a few weeks without skin grafting. Deep second-degree burns involve the deeper reticular layers of the skin. The color may vary from pink to white, the surface is dry. Sensitivity may be present but is usually somewhat diminished and capillary refills are sluggish or absent. Burns of this depth usually require skin grafting for satisfactory healing.
Full-thickness (third-degree) burns extend into the subcutaneous tissue and are firm and insensitive on examination. Thrombosed vessels can be seen through the scab.
Fourth degree burns - burns with the destruction of the entire thickness of the skin to the muscles and bones.
Burn Depth Assessment extreme degrees relatively easy. Differentiating the degree of burns at the dermal level is difficult, even for experienced surgeons. However, this distinction is more important for planning surgical treatment and skin grafting than for planning the extent of resuscitation. Some burns that initially appear to be limited to the epidermal layers (i.e., first-degree burns), and thus not included in the calculation of resuscitation, may develop blisters within a few hours, which is characteristic of a dermal-level burn.
When assessing the depth of a burn lesion, it is important to evaluate the depth of the burn depending on the factors that affect the depth of the burn. These factors are temperature, mechanism (eg, electrical, chemical), duration of contact, blood flow in a given skin area, and anatomical location. The depth of the keratinized epidermis can vary dramatically depending on the area of the body - from less than 1 mm in the thinnest areas (eyelids, genitals) to 5 mm (palms and plantar surfaces), providing varying degrees of thermal protection. In addition, the dermal elements of young children and elderly patients are somewhat thinner than those of adults. This explains the fact that burns in people of these age groups are usually more severe than similar lesions in other patient groups.
Reports about the size and depth of a burn are unfortunately usually inaccurate, especially from physicians with little experience with burns. Assessment of the patient's status and the size of the burn is correct only in a third of cases. With this in mind, one should always assume that the burn patient is in somewhat worse condition than described, and be prepared to completely overestimate the status of the burn patient, as The size of the burn has a significant impact on all aspects of the initial management of the patient.
Table 1. Differences in total body surface area by age
Novoroz- | 1 year | 5 years | 10 years | 15 years | Adult- |
|
Head | ||||||
Neck | ||||||
Anterior surface of the body | ||||||
Posterior surface of the body | ||||||
Buttock | ||||||
Crotch | ||||||
Hip | ||||||
Shin | ||||||
Foot | ||||||
Shoulder | ||||||
Forearm | ||||||
Brush |
Calculation formulas and infusion solutions.
Historically, fluid replacement in burn patients has been more of an art than a science and has been about finding the sweet spot between adequate volume replacement and avoidance of the harmful effects of fluid overload. The approaches and methods of resuscitation aids were highly individualized and could vary dramatically from one medical institution to another. However, in the last quarter of the last century, major publications have appeared on the results of studies analyzing the volume of fluid administered during resuscitation in patients with burns (Prof. Charles Baxter, Parkland Hospital at Southwestern University Medical Center, Dallas, Texas, 1960s) .
Based on the results of these studies, the well-known Parkland formula was derived, which is the standard for calculating the total volume of fluid administered to patients with burns in the first 24 hours. (With Ringer's lactate solution [RL] - approximately 4 ml/kg of body weight X percent burn of total body surface area). Half of the volume of fluid calculated by this formula is injected in the first eight hours, the other half in the next 16 hours after the burn. There are many formulas, with differences both in the calculation of volume depending on the weight, and the type (or types) of crystalloid or colloid-crystalloid combinations administered. To date, no single recommendation provides the most successful approach.
The time-dependent variables of all these formulas are calculated from the moment of injury, and not from the time when the patient began receiving qualified emergency care. A scenario that is not uncommon is that a burn patient transferred from a remote hospital a few hours after being burned is in serious or critical condition. Calculations of the required volume of fluid to be administered must take into account and reflect the reduced or increased volume of fluid that was administered at an early stage.
Ringer's solution- a relatively isotonic crystalloid solution, which is a key component of almost all resuscitation strategies, according to at least, during the first 24-48 hours. Ringer's solution is preferred over sodium chloride solution for large injection volumes, as has a lower sodium concentration (130 mEq/L vs. 154 mEq/L) and a higher pH level (6.5 vs. 5.0), which is closer to the physiological levels of these indicators. Another potential benefit of Ringer's solution is the buffering effect of metabolized lactate in metabolic acidosis.
Plasmalyte is another crystalloid solution whose composition is even closer to that of blood plasma than Ringer's solution. Plasmalite is used as a starting crystalloid solution for patients with large burns.
Regardless of the resuscitation formula or strategy used, the first 24-48 hours of patient management require frequent adjustment. The calculated volumes in all formulas should be considered as the recommended volumes of the respective liquids. Blind adherence to the volume received can lead to a significant excess of the resuscitation volume or an insufficient volume of fluid administered, if not interpreted within the clinical context. Volume overload can be a major cause of death for burn patients and can also lead to worsening pulmonary complications and premature eschar.
In addition, not all burns require the use of the Parkland formula for resuscitation. Rapidly delivered adult patients with burns of less than 15-20% of total body surface area without inhalation injury usually do not develop a systemic inflammatory response, and these patients can be successfully rehydrated primarily by mouth and a small volume of intravenous fluid.
The main indicators of the state of the body.
Routine indicators of the state of the body, such as blood pressure and heart rate, can be very difficult to assess the condition of a patient with large burns. The release of catecholamines within hours of a burn may maintain blood pressure despite extensive intravascular depletion. The formation of limb edema may limit the usefulness of non-invasive blood pressure measurements. The assessment of blood pressure levels can also be erroneous due to peripheral vasospasm and high level catecholamines. Tachycardia, usually due to hypovolemia, may be the result of a response to pain and adrenergic status of the body. Thus, the trend in the above parameters is much more useful than a single recording of them.
Vitamin C.
There is great interest in using antioxidants as an adjunct to resuscitation to try to minimize the oxidative stress component in the inflammatory response cascade. In particular, the introduction of large doses of vitamin C during resuscitation was studied some time ago. Some animal models have shown that administration of vitamin C within 6 hours of a burn can reduce the calculated resuscitation volumes by more than half. Whether this phenomenon can be successfully replicated in humans has not been clearly demonstrated.
There is no consensus on the proper dosage. A number of researchers have used the method of dilution to 10 g per liter of Ringer's solution administered at a rate of 100 ml/h (1 g/h of vitamin C). This volume was included in the calculation of the total resuscitation volume (as part of it). Recently, data have been published on the use of vitamin C at a dose of 66 mg/kg/h for the first 24 hours in a small group of patients, resulting in a decrease in the required resuscitation volume by 45%. Safety high doses vitamin C in humans has been proven, at least for short-term use, but this strategy is probably less safe in pregnant women, in patients with renal insufficiency, and with a history of oxalate stones.
Endpoints of resuscitation.
The end points of resuscitation remain controversial, but hourly urine output is a well-known parameter for monitoring the adequacy of the volume of fluid administered. The volume of fluid administered should be titrated against urine output of 0.5 ml/kg/h or approximately 30-50 ml/h in most adults and older children (> 50 kg). In young children, the goal should be approximately 1 ml/kg/h (see
). If these goals cannot be achieved, it is necessary to carefully increase the volume of the injected fluid by about 25%.
It is important to keep in mind that a gradual increase in volume is much more beneficial than a bolus of fluid when urine output is low. Bolus administration of fluid leads to an increase in hydrostatic pressure gradients, which further increases the flow of fluid into the interstitium and leads to an increase in edema. However, one should not be afraid to bolus patients in the early stages of shock resuscitation. Urine output greater than 30-50 ml/h should be avoided. Fluid overload during the critical hours in the early management of a burn patient results in edema and pulmonary dysfunction. This can lead to painful expulsion of the eschar and require more artificial ventilation.
There are several factors that make it difficult to control urine output as a major criterion for volumetric status and end-organ perfusion. The presence of glucosuria can lead to osmodiuresis and increased urine production. In addition, older patients who have been taking diuretics for a long time may be dependent on them and may not be able to produce adequate urine despite a seemingly adequate resuscitation fluid volume. The placement of a Swan-Gans catheter is an important component in deciding how much fluid to inject and prescribing diuretics in these patients.
Other physiological parameters that reflect the adequacy of resuscitation include improving the underlying deficit and maintaining cardiac index in patients undergoing invasive monitoring. Due to several factors, such as pulmonary vasoconstriction, the same interpretation problems exist for measurements of central venous pressure and pulmonary capillary wedge pressure. Swan-Gans catheters are not routinely used, but may play some role in elderly patients with reduced cardiac function. Again, the clinical response and overall trends in these cases are much more useful for calculating volume administered and drug therapy to maintain cardiac function than isolated measurements.
Some patient populations often require larger resuscitation volumes than calculated. Respiratory tract patients are perhaps the best studied subgroup, requiring 30% to 40% more fluid to be administered for adequate resuscitation than that calculated by the Parkland formula (about 5.7 ml/kg per %). The delay in the start of resuscitation also requires an increase in the volume of injected solutions by 30%. Patients treated with diuretics prior to the burn often have a free fluid deficit in addition to burn shock. Escharation or fasciotomy can significantly increase the loss of free fluid through the wound surface. Patients with electrical burns, in which the large volume of affected tissue is often underestimated, also require a larger volume of fluid to be administered.
It should not be forgotten that the collection of anamnesis in patients with burn injury is often extremely difficult. Therefore, an unexpected increase in the volume of fluid required should prompt a careful re-examination of the patient to detect any missed lesion. The strategy that has been used since famous success for refractory burn shock, was developed by researchers at the University of Cincinnati and involves plasma transfusion. Candidates for this treatment technology are those patients who have more than twice the estimated fluid requirement.
Table 2.
Formula | Solutions on the first day | Crystalloids on the second day | Colloids on the second day |
Parkland | Plasmalite (PL) or Ringer's lactate solution (RL) 4 ml/kg X percent burn | 20-60% of estimated plasma volume | Titration to achieve a urine output of 30ml/h |
Evans (Yowel, 2000) | Sodium chloride 0.9% 1ml/kg X percent burn, 2000 ml 5% dextrose and colloids 1 ml/kg X percent burn | ||
Slater (Yowel, 2000) | PL (RL) 2 liters/day plus fresh frozen plasma 75 ml/kg/day | ||
Brooke (Yowler, 2000) | PL (RL) 1.5 ml/kg x percent burn, colloids 0.5 ml/kg x percent burn and 2000 ml 5% dextrose | 50% of the volume administered on the first day |
|
Modified Brooke | PL (RL) 2 ml/kg X burn percentage | ||
metrohealth | PL (RL) with 50 mEq of sodium bicarbonate per liter, 4 ml/kg X percent burn | Half sodium chloride titrated against urine production | 1 U fresh frozen plasma for each liter of half sodium chloride plus 5% dextrose, if necessary in the presence of hypoglycemia |
Monafo hypertonic | 250 mEq/l saline titrated against urine production 30 ml/h, dextran 40 in sodium chloride 2 ml/kg/h for 8 hours, PL titrated against urine production 30 ml/h, fresh frozen plasma 0.5 ml/h within 18 hours, starting from the 8th hour from the moment of receiving the burn | 1/3 sodium chloride, titrated against urine production. |
Because of certain risks associated with large volume resuscitation, there is interest in using various colloidal solutions, both to reduce edema and replenish fluid requirements, and because of the phenomenon of severe myocardial depression in large burns. important reason for adding colloids in the first 24 hours - loss of capillary integrity in the early period of burn shock. This process develops early and takes place within 8-24 hours. A strategy for testing whether capillary permeability has begun to resolve involves replacing Ringer's solution with an equal volume of albumin solution. An increase in urine production indicates that at least part of the capillary permeability has resolved and that further administration of colloids will help to reduce the fluid load. Albumin is the plasma protein that contributes the most to intravascular oncotic pressure. With intravenous administration of an albumin solution in an amount of 5% of the total plasma volume, approximately half of the volume remains in the vascular bed, while crystalloid solutions - 20-30%. Alternatively, some centers prefer to use fresh frozen plasma instead of albumin because of the theoretical advantage of replacing a range of lost plasma proteins.
The recommended standard for such an infusion is 0.5-1 ml/kg X percentage of the burn during the first 24 hours, starting 8-10 hours after the burn was received, in addition to the resuscitation volume of Plasmalite (Ringer's solution).
Dextran is a polymeric solution with high molecular weight glucose chains, the oncotic pressure of which is almost twice that of albumin. Dextran improves microcirculation by reducing erythrocyte aggregation. Proponents of dextran justify its use by reducing edema in healthy tissues. However, the edema-reducing property persists as long as the infusion is in place, but once the infusion is stopped and glucose is metabolized, there is a rapid flow of fluid back into the interstitium if increased capillary permeability persists. Demling et al. have successfully used dextran 40 in the early post-burn period (starting at 8 h) at 2 ml/kg/h along with Plasmalite (Ringer's solution) before adding albumin or fresh frozen plasma plus a combination of dextran with Plasmalite (Ringer's solution) for the next 18 hours.
Hypertonic sodium chloride solution with a sodium concentration of 180-300 mEq/L has many theoretical advantages. These advantages are due to a decrease in volume demand due to the mobilization of intracellular fluid into the vascular bed by an increased osmotic gradient. The result is intracellular dehydration, but it is well tolerated. Careful monitoring of serum sodium levels is necessary, which should not exceed 160 mEq / dL.
As a compromise strategy to limit the risk of hypernatremia and sodium retention, some institutions use Ringer's solution with 50 mEq of sodium bicarbonate per bag, equal to 180 mEq of sodium per liter, and infuse during the first 8 hours of resuscitation. This infusion replaces the administration of hypertonic sodium chloride solution. Then, after the first 8 hours, resuscitation with Ringer's solution is carried out. The administration of hypertonic saline should be carefully titrated for both urine production and serum sodium levels and should be carried out in specialized burn centers. The safety and efficacy of hypertonic resuscitation concerns pediatric and elderly patients, but it is safer to use lower final concentrations. The introduction of a hypertonic solution is especially indicated for patients with the most limited pulmonary-cardiac reserve, i.e. with a burn of the respiratory tract, and with burns with an area of more than 40%.
Precisely when to add, how much and whether to add colloidal solutions at all is a difficult problem. As mentioned earlier, in most formulas, colloids are added during resuscitation, at least on the second day. However, it must be recognized that despite the generally accepted view that the use of colloids is justified and beneficial, especially for burns over 40%, it is difficult to demonstrate results demonstrating an improvement in the course of the disease and mortality. Some studies have shown detrimental effects leading to increased pulmonary edema and renal dysfunction as a manifestation of impaired renal filtration.
For 20-40% burns without airway involvement, management of patients on Plasmalyte (Ringer's solution) titrated against urine production is a safe and well-tested strategy.
Patients for whom colloids are indicated are patients with burns of 40% TSA or more, with a history of heart disease, the elderly, and patients with respiratory burns.
Within 24-30 hours after injury, the patient should be provided with adequate resuscitation support with almost complete replacement of transcapillary fluid loss. At this stage, according to the recommendations of the authors, it is possible to manage patients on Plasmalite (Ringer's solution) or their combinations with albumin and 5% dextrose. The indication for the introduction of albumin is considered to be a massive loss of protein that occurred in the first 24 hours after the burn. Replenishment of this deficiency by continuous administration of a 5% or 20% albumin solution maintains a plasma albumin concentration of more than 2, which helps to reduce tissue edema and improve bowel function. Water losses associated with damage to the skin barrier can be replenished with electrolyte-free solutions, such as 5% dextrose, which serves to restore the isotonic state of the extracellular space, especially if hypertonic solutions were used during resuscitation.
The formula for calculating the required volume of 5% albumin is as follows:
0.5 ml/kg X percent burn = ml albumin per ml within 24 hours,
The formula for calculating free water is as follows:
(25 + percent burn) X BCA (m2) = ml/h free water requirement.
The US Army Institute of Surgical Research uses a similar approach, but takes into account an estimate of the patient's total body surface area in the albumin calculation. For burns of 30-50%, they use 0.3 ml/kg per burn percentage; for burns 50-70%, 0.4 ml/kg per burn percentage; and for burns of 70% or more, they use 0.5 ml/kg per burn percentage.
A potential trap is iatrogenic hypernatremia resulting from titration of a sodium-rich albumin solution. Serum sodium levels should be monitored at least once a day. The mean volume of albumin administered is titrated against urine production and monitored by sodium levels. When the serum sodium level rises above the permissible level, the volume of 5% dextrose administered is increased until the serum sodium level normalizes.
Summing up the above, it should be recognized that the success of each of the above methods of fluid management of patients with burns has been proven. Replenishment of volume deficits to support tissue perfusion and correct metabolic acidosis can be achieved with many types of fluids, the use of which has been validated for treatment for almost 70 years. Only the views on their significance for the periphery have changed. Real progress in understanding the complex pathophysiological processes that occur in burn shock is reflected in the use of newer drugs to provide crystalloid resuscitation. Further progress, obviously, will concern the optimization of the timing of the introduction of colloids and hypertonic solutions and studies of the possibility of influencing the main mediators of burn shock.
Several important differences exist in pediatric burn resuscitation. Intravenous fluid resuscitation is usually required for patients with minor burns (in the range of 10-20%). Venous access in young children can be a serious problem, and jugular vein catheterization is an acceptable alternative for the short term. Children have proportionately larger body surface areas than adults; burn areas should be assessed using pediatric modifications to the Lund-Browder tables. This leads to higher calculated volumes based on weight ( almost 6 ml/kg x burn percentage) Recommended endpoints also higher in children. Urine production of approximately 1 ml/kg/h is greater than in adults, and is on target. For children approaching 50 kg, resuscitation parameters and calculations for adults (30-50 ml/h urine output) are probably best applied.
Another danger for this category of patients is the small reserves of glycogen in the liver, which can be quickly depleted, so sometimes Plasmalite or Ringer's solution needs to be replaced with 5% dextrose to prevent life-threatening hypoglycemia. For this reason, glycemic testing every 4-6 hours should be routine during the entire period of hypermetabolism, especially for patients with large burns.
Pediatric resuscitation protocols are based on the following formula (H - height [cm], W - weight [kg]):
body surface area = / 10,000
Pediatric resuscitation protocols are as follows:
- Shriners Burns Institute (Cincinnati) - 4 ml/kg X percent burn plus 1500 ml/m2 BSA
- First 8 hours - Ringer's solution with 50 mEq of sodium bicarbonate per liter
- Second 8 hours - Ringer's solution
- Third 8 hours - Ringer's solution plus 12.5 g of 25% albumin solution per liter
- Galveston Shriners Hospital - 5000 ml/m2 body surface area burned plus 2000/m2 body surface area, Ringer's solution plus 12.5 g of 25% albumin solution plus 5% dextrose solution is used if correction of hypoglycemia is required.
The most important thing to remember about fluid management of burn patients is that any of the above methods have proven effective. Replacement of the volume deficit to ensure tissue perfusion and correct metabolic acidosis can be achieved with various types of fluids. Only the views on their significance for the periphery have changed. Real progress in understanding the complex pathophysiological processes that occur in burn shock is reflected in the use of newer drugs to provide crystalloid resuscitation. Further progress, obviously, will concern the optimization of the timing of the introduction of colloids and hypertonic solutions and the study of the possibility of influencing the main mediators of burn shock.
Bibliography:
- Arturson G: Microvascular permeability to macromolecules in thermal injury. Acta Physiol Scand Suppl 1979; 463:111-22
- Baxter CR, Shires T: Physiological response to crystalloid resuscitation of severe burns. Ann N Y Acad Sci 1968 Aug 14; 150(3): 874-94
- Baxter CR: Fluid volume and electrolyte changes of the early postburn period. Clin Plast Surg 1974 Oct; 1(4): 693-703
- Carvajal HF: Fluid therapy for the acutely burned child. Compr Ther 1977 Mar; 3(3): 17-24
- Demling RH, Mazess RB, Witt RM, Wolberg WH: The study of burn wound edema using dichromatic absorptiometry. J Trauma 1978 Feb; 18(2): 124-8
- Demling RH Fluid resuscitation. In: Boswick JA Jr, ed. The Art and Science of Burn Care. Rockville, Md: Aspen; 1987.
- Demling RH, Kramer GC, Gunther R, Nerlich M: Effect of nonprotein colloid on postburn edema formation in soft tissues and lung. Surgery 1984 May; 95(5): 593-602
- Du GB, Slater H, Goldfarb IW: Influences of different resuscitation regimens on acute early weight gain in extensively burned patients. Burns 1991 Apr; 17(2): 147-50
- Leape LL: Initial changes in burns: tissue changes in burned and unburned skin of rhesus monkeys. J Trauma 1970 Jun; 10(6): 488-92
- Merrell SW, Saffle JR, Sullivan JJ, et al: Fluid resuscitation in thermally injured children. Am J Surg 1986 Dec; 152(6): 664-9
- Monafo WW: The treatment of burn shock by the intravenous and oral administration of hypertonic lactated saline solution. J Trauma 1970 Jul; 10(7): 575-86
- Moore FD: The body-weight burn budget. Basic fluid therapy for the early burn. Surg Clin North Am 1970 Dec; 50(6): 1249-65
- Navar PD, Saffle JR, Warden GD: Effect of inhalation injury on fluid resuscitation requirements after thermal injury. Am J Surg 1985 Dec; 150(6): 716-20.
- O "Neill JA Jr: Fluid resuscitation in the burned child--a reappraisal. J Pediatr Surg 1982 Oct; 17(5): 604-7
- Sakurai M, Tanaka H, Matsuda T, et al: Reduced resuscitation fluid volume for second-degree experimental burns with delayed initiation of vitamin C therapy (beginning 6 h after injury). J Surg Res 1997 Nov; 73(1): 24-7
- Sheridan RL, Petras L, Basha G, et al: Planimetry study of the percent of body surface represented by the hand and palm: sizing irregular burns is more accurately done with the palm. J Burn Care Rehabil 1995 Nov-Dec; 16(6): 605-6
- Tanaka H, Matsuda T, Miyagantani Y, et al: Reduction of resuscitation fluid volumes in severely burned patients using ascorbic acid administration: a randomized, prospective study. Arch Surg 2000 Mar; 135(3): 326-31
- Underhill FP: The significance of anhydremia in extensive surface burns. JAMA 1930; 95:852-7.
- Warden GD, Stratta RJ, Saffle JR, et al: Plasma exchange therapy in patients failing to resuscitate from burn shock. J Trauma 1983 Oct; 23(10): 945-51
Infusion therapy
The range of solutions used in infusion therapy in burn patients is extremely wide - from pure colloids to a combination of colloid-crystalloids to exclusively crystalloid solutions. The composition of any of the transfused solutions must necessarily contain sodium. The principles used to calculate the required volume of fluid in adult patients cannot be transferred to pediatrics.Completely different ratios of body surface and mass and more high speed metabolic processes in childhood lead to significant errors when these calculations are applied to children. The most rational use of the modified Parkland formula, which provides for the daily administration of the solution
Ringerlactate at the rate of 3-4 ml/kg/% burn. Half of this volume is given in the first 8 hours, the second half in the remaining 16 hours. This scheme makes infusion therapy easy to practical application, inexpensive and safe. The introduction of colloidal solutions into the scheme increases the cost of treatment without providing any special advantages.
When using hypertonic solutions, relatively small volumes of fluid are required and edema develops to a lesser extent, but there is a significant risk of hypernatremia. hyperosmolar coma, renal failure and alkalosis. In the literature, there is even a description of a case of central pontine myelinolysis in hyperosmotic coma in a burn patient.
Infusion therapy must be constantly adjusted and corrected. In any given situation, the child may, depending on the response to treatment, require more or less fluid. Deeper burns and airway involvement greatly increase fluid requirements.
When carrying out infusion therapy, one should focus primarily on the state of the function of vital organs, the amount of diuresis and the patient's well-being. Diuresis should be maintained at a level not lower than 1 ml/kg/hour for children weighing up to 30 kg and not less than 30-40 ml/hour for children weighing over 30 kg. A reliable indicator of the success of fluid therapy is the absence of dysfunction of internal organs. This indicator is more important than the focus on maintaining a certain level of central venous pressure.
Fluid loss associated with an increase in capillary permeability is noted to the greatest extent in the first 12 hours after the burn and progressively decreases over the next 12 hours. Therefore, colloids must be administered from the second day, further repeating their administration daily to maintain serum albumin at a level not lower than 290 µmol/l.
The rate of crystalloid administration can be reduced to a maintenance level and adjusted according to diuresis. During the second day after the burn, 5% dextrose in saline is administered. Tube feeding begins 12 hours after the injury, which improves bowel function and stimulates immune processes.
Nutrition for a patient with a burn
The metabolic response of a child's body to a severe burn injury can be considered in time sequence. The first 24-48 hours are characterized as a period of relative hypermetabolism, which is replaced by a phase of pronounced catabolism and massive loss of tissue protein and fat. This phase continues as long as there is open wound, and this course is often exacerbated by episodes of infection, chills, stress, pain, anxiety, and surgery. As soon as the wounds are closed, metabolism begins to normalize, and anabolic processes dominate in this period with the restoration of protein reserves in tissues and organs.The catabolic phase of a burn injury is characterized by an increase in the levels of cortisone, epinephrine, norepinephrine, glucagon, aldosterone, and antidiuretic hormone. The basal metabolic rate can then double.
Children with low fat stores and little muscle mass develop protein metabolism disorders rapidly if not provided adequate nutrition, because through the burn wound there is a significant loss of protein.
Various nutrient solutions and mixtures are available to meet the caloric needs of burnt children, which typically provide 1800 kcal/m2 plus 2200 kcal/m2 of the burn surface.
The patient's energy expenditure at rest is accurately measured by indirect calorimetry. Data from studies conducted in children of the first 3 years of life with burns of more than 50% of the body surface showed that nutritional needs can be met by providing 120-200% of the basal metabolic rate at rest. These figures are even somewhat less than those provided by most solutions used in this category of patients.
Protein should make up 20-25% of total calories, carbohydrates 40-50%, and fats the remaining calories. The use of modern modified nutrient solutions and mixtures reduces immune suppression, the intensity of metabolic reactions and mortality, reduces the length of the patient's stay in the hospital and strengthens the barrier (in relation to the penetration of bacteria) properties gastrointestinal tract(GIT).
These solutions cover 20% of energy requirements from whey protein, 2% arginine, 0.5% cystine, 0.5% histidine and 15% lipids. Half of the fat calories come from fish oil and 50% from vegetable (safflower) oil. The remaining caloric needs are met by carbohydrates.
The optimal method of nutrition is, of course, enteral, requiring in most cases the placement of a gastric tube. Tube enteral nutrition is better absorbed when serum albumin is maintained at or above 360 µmol/L. If at this method nutrition is not absorbed, then it is necessary to switch to the parenteral method, which usually requires the placement of a central catheter, since adequate calories can rarely be provided through peripheral veins.
Daily measurement of body weight and calculation of the resulting calorie is necessary. In patients on tube feeding or parenteral hyperalimentation, the levels of serum electrolytes, urea, creatinine, albumin, glucose, phosphorus, calcium, hemoglobin, hematocrit should also be determined daily. urine glucose. Liver function indicators, prealbumin, transferrin, magnesium, cholesterol, triglycerin are examined weekly.
All burnt children should receive at least the minimum recommended daily allowance (RDA) of kitamiion, minerals and micronutrients. Vitamin C is added to the injected solutions or mixtures in the amount of 5-10 RCH, zinc - 2 RCH, B vitamins - at least 2 RCH.
Local treatment of burn wounds
Most (95%) burns in children are minor and can be treated on an outpatient basis. The dressing is performed twice a day - the wound is washed, cleaned, polymyxin B sulfate (polysporin) or bacitracin is applied and a gauze bandage is applied. Healing usually occurs within 10-14 days. Superficial minor burns can also be treated with semi-permeable synthetic films, which facilitate home care and reduce pain.For third-degree burns, when the depth of the lesion is beyond doubt, necrectomy is indicated with wound closure with autotransenlantate. Intervention is carried out immediately, as soon as hemodynamics is stabilized. However, it is important to note that in the early stages it can be difficult to determine the depth of the lesion, especially with hot liquid burns, which are the most common in children.
At the same time, early, too active surgical treatment of all wounds with third-degree burns (even if there are doubts about the correctness of determining the depth of the burn) is fraught with the loss of a significant amount of tissue, and sometimes in cases where the wound could heal on its own without pronounced scarring. Therefore, with an unclear depth of the burn, it is necessary, refraining from necrectomy, to bandage twice a day (toilet of the wound, local preparations) until it becomes possible (according to clear signs) to reliably determine the depth of the lesion (this usually takes 10-14 days).
Ideal tools for local treatment should not cause pain when used and allergic reactions, prevent drying, penetrate deeply into the burn wound and have bactericidal-bacteriostatic properties. The drug should neither interfere with epithelialization, nor adversely affect viable cells. Silvaden, although not an ideal remedy, meets almost all of the listed requirements to a greater extent than any other drug. Its use is painless, gives minimal side effects, it is slightly absorbed and has a good antibacterial spectrum.
With extensive burns, a combination of cerium nitrate and silver sulfadiazine is more effective. The cerium component prevents the development of gram-negative organisms, and silver sulfadiazine affects the fungal and gram-positive flora.
Mafenide continues to be a valuable drug due to its ability to penetrate the burn eschar and actively affect both gram-negative and gram-positive flora. However, it does not have antifungal properties. Some other topical medications are listed in Table 9-1, with benefits, limitations, and indications for each.
Table 9-1. Preparations for local treatment
An important aspect of wound care, especially for burns of the hand, is to ensure that the limb is in a certain position. Swelling, inflammation and restriction of movement accompanying the burn are the three main forces that lead to impaired function, and therefore require appropriate preventive measures. Therapeutic exercises, elevated limb position, adequate splint immobilization, and early wound closure help reduce disability. The splint is applied in the functional position of the hand. Raising and active arm exercises should begin very early. All joints should be dealt with actively and passively several times a day.
Deep perineal burns do not require surgical diversion of urine and feces. An analysis of 20 years of experience in the treatment of burns of this localization did not reveal an increase in infectious complications associated with the refusal to impose intestinal and urinary fistulas.
K.U. Ashcraft, T.M. Holder
