Calculation of the physiological need for fluid in children. Daily water requirement of an adult: online calculator. Enter: - in glucose solution

Abbreviations:

V- volume of infusion per day (ml.), D- fluid deficiency (ml.), FP- physiological need for fluid (ml / day), PP- pathological fluid loss (ml / day). BW - body weight (kg.).

Assess the need for infusion, taking into account the underlying and concomitant pathology.

Assess the possibility of enteral, oral fluid administration.

Assess the initial hydrobalance.

Blood loss should be compensated according to the method (see "Compensation for acute blood loss") in the first hours of therapy.

A) hypertonic

V = ½ D + FP + PP

B) Isotonic

V = 1.0 D + FP + PP

B) hypotonic

V = ½ D + FP + PP

For normal hydration:

V = 2/3 FP + RP, or V = FP + RP (negative fluid balance must be achieved)

The physiological need is calculated by the formulas:

FP \u003d 30 * MT (up to 65 years)

FP \u003d 25 * MT (65-75 years)

FP = 20 * MT (over 75 years)

Estimated diuresis = 0.6 * FP + infusion load (during forced diuresis), or + excess fluid during hyperhydration.

Pat. loss:

A) Fever - 10% FP - for every degree above 37 ° C

B) Breathing -

In spontaneous breathing without dyspnea, respiratory losses are included in the AF and amount to 20% (0.2 * AF).

For mechanical ventilation without warming and moistening the mixture (RO-6), add 600 ml / day.

When IVL with warming and moistening the mixture Pat. no respiratory losses (+0 ml/day).

With shortness of breath over 25 in 1 min. - add 1 ml / kg of BW per day for every 1 breath above 25.

D) With an open surgical wound

Min. interference (inguinal hernia), or open

wound in ICU conditions - 1-2 ml / kg / hour

Average traumatization (cholecystectomy) - 2-4

Severe trauma (intestinal obstruction) -4-6

D) Drainages, probes, vomiting, loose stools

Anuric mode (with acute renal failure, terminal stage of chronic renal failure)

Diuresis for the previous day + path.losses

Composition of the infusion:

FP is provided by saline solutions and glucose* (1:1)

Losses in drains, probe, vomiting - saline solutions and glucose * (1: 1)

Respiratory Loss – Glucose Only*

At least 1/3 of the infusion volume (if it exceeds 2400 ml/day)

should make colloidal preparations (from the standpoint of

electrolyte composition, they are considered as saline solutions).

* 5% glucose solution, considered as a hypotonic, hypoosmolar solution, source of osmotically free water, is used in the presence of dehydration, after rehydration it is advisable to use a 10% glucose solution, meaning it both as a source of water and as an energy donator (150 g of glucose - 1500 ml of 10% solution - provide a minimal nitrogen-sparing effect), more concentrated glucose solutions are used as component of parenteral nutrition.

When conducting parenteral nutrition, solutions of amino acids, lipid emulsions are considered in the total volume of infusion as saline solutions.

After surgery, any adult patient weighing more than 60 kg with normal kidney function should receive at least 2000 ml of fluid per day. After major surgery, most of the fluid is administered intravenously, and the volume may be greater. In the absence of comorbid kidney and heart disease, the goal of infusion is to provide a safe fluid load, allowing homeostatic mechanisms to self-distribute fluid and remove excess fluid. The required volume of infusion is calculated by determining the physiological need for fluid and taking into account additional existing and current losses.

With normal kidney function, the target is a urine output of 1 ml/kg/h. Diuresis determines the physiological need for fluid. With a weight of 80 kg, diuresis should be 80 ml / h. To draw up an infusion therapy plan, it is more convenient to assume that there are 25 hours in a day. This means that this patient will need 25x80=2000 ml of fluid per day. In this case, it's better to be a little generous and round up the values. To finally determine the volume of daily infusion, it is necessary to take into account a number of the following factors.

Fever and imperceptible loss

Imperceptible fluid loss through the skin and lungs is called; the normal volume of these losses is about 50 ml/h (1200 ml/day). During metabolism nutrients in the body, on the contrary, water is formed; its volume is usually subtracted from imperceptible losses. As a result, it turns out that the volume of imperceptible losses is about 20 ml/hour (500 ml/day). For fever and high fever environment the intensity of both processes increases. As a result, the increase in imperceptible losses (excluding water formed during metabolism) is 250 ml/day for every °C above 37°C.

Losses in the "third space"

In the area of ​​massive tissue damage, edema is formed (Chapter 1). This fluid accumulated in the interstitial space does not exchange with other fluid spaces of the body. This anatomically non-existent space was called the "third" (in addition to the two real ones - extra- and intracellular). In the third space, a lot of fluid can accumulate after laparo- and thoracotomy, as well as with massive damage to soft tissues. To compensate for losses in the third space on the day of surgery or injury (only on this day), an additional amount of fluid should be added to the infusion therapy regimen - at least 40 ml / h (1000 ml / day).

Losses in the gastrointestinal tract

Fluid loss to the stomach is easy to account for with a properly placed nasogastric tube. Complete obstruction of the exit from the stomach leads to the loss of more than 3 liters of fluid per day. If a nasogastric tube is not placed, then prolonged ileus leads to the accumulation of the same amount of fluid in the intestine. At the same time, it is not possible to quantify losses, and the regimen of infusion therapy should take into account early latent losses. In the following days, these losses are best compensated by adding fluid when symptoms of hypovolemia appear, as described below.

Bleeding (see also chapter 6)

Lost blood is primarily replaced by a transfusion of colloidal solutions. If the volume of losses can be measured (for example, in the suction reservoir), then it can serve as a guide in the planning of infusion-transfusion therapy. More often, lost blood remains within the body or its volume cannot be measured (for example, blood on tampons, napkins, surgical underwear). The hemoglobin level in the blood should be repeatedly measured in order to start the red blood cell transfusion in a timely manner. There are different opinions as to what level of hemoglobin should be maintained during blood loss with the help of blood transfusion. The author believes that it should be at least 100 g/l with concomitant diseases of the heart, lungs or cerebral ischemia and at least 80 g/l in the absence of these diseases. Hemodilution, which is carried out by the introduction of colloidal solutions, reduces hemoglobin below the level at which it will later settle on its own, therefore it is quite safe to maintain a hemoglobin level of at least 80 g / l (in the absence of concomitant diseases).

Massive blood loss may require transfusion of fresh frozen plasma, cryoprecipitate, platelets, antifibrinolytics, and other procoagulants (Chapter 6). When conducting infusion-transfusion therapy, the volume of these drugs should be taken into account.

Polyuria

Some forms of kidney failure are characterized by very high diuresis, which greatly increases fluid requirements. Diuresis up to 150 ml / h is regarded as a favorable sign after surgery, as it allows you to more fully remove the breakdown products of proteins and drugs.

Liquid requirement calculation

The amount of fluid administered is often scheduled by the clock, and it is much easier to calculate fluid requirements based on the patient's weight in kilograms. These hourly fluid calculations assume that the patient received adequate fluid therapy during surgery. If this was not the case, then it is first necessary to replenish the previous fluid deficiency.

The fluid requirement is calculated as follows:

1. Physiological fluid requirement: 25 ml / kg / h - approximately 2000 ml / day.

2. Insensible loss: 20 ml/h - approximately 500 ml/day.

3. For fever: add 10 ml/h (250 ml/day) for every °C above 37°C.

4. With suspected intestinal paresis: add 20 ml / h (500 ml / day) - only in the first 24 hours after surgery.

5. In case of losses in the third space after laparotomy or thoracotomy: add 40 ml/h (1000 ml/day) - only in the first 24 hours after the operation.

6. Compensate for any other measurable losses. See also table 26.

Table 26 Calculation of fluid requirements in the postoperative period in a man weighing 70 kg without comorbidities

Principles of infusion rehydration therapy

General rules drawing up an infusion therapy program

1. Colloidal solutions contain sodium salts and belong to saline solutions and their volume should be taken into account in the total volume of saline solutions.

2. In total, colloidal solutions should not exceed 1/3 of the total daily volume of fluid for infusion therapy.

3. In children younger age the ratio of glucose and salt solutions is 2:1 or 1:1; at an older age, the amount of saline solutions increases (1:1 or 1:2).

3.1. The type of dehydration affects the ratio of glucose-salt solutions in the composition of infusion media.

4. All solutions must be divided into portions ("droppers"), the volume of which for glucose usually does not exceed 10-15 ml / kg and 7-10 ml for colloidal and saline solutions. The container for one drip injection should not contain more than ¼ of the volume of liquid calculated per day. It is unrealistic for a child to carry out more than 3 drip injections per day.

With infusion rehydration therapy, 4 stages are distinguished: 1. anti-shock measures (1-3 hours); 2. Compensation for extracellular fluid deficiency (1-2-3 days); 3. maintenance of water and electrolyte balance in conditions of ongoing pathological losses (2-4 days or more); parenteral nutrition (full or partial) or therapeutic enteral nutrition.

To maintain the state of homeostasis, it is necessary to ensure a balance between the fluid introduced into the body and the fluid that the body removes in the form of urine, sweat, feces, with exhaled air. The amount and nature of losses varies depending on the nature of the disease.

The amount of fluid needed to compensate for the physiological losses of the body in children different ages, not the same.

Table 1. 69.Age related fluid and electrolyte requirements for children

Physiological need for sodium in children early age is 3-5 mmol/kg; in older children 2-3 mmol / kg;

The need for potassium is 1-3 mmol/kg;

The need for magnesium is, on average, 0.1 mmol / kg.

The need for fluid and electrolytes necessary to compensate for physiological losses can be calculated by several methods.

The daily maintenance fluid (fluid requirement) can be calculated in several ways: 1) based on the body surface area (there is a correlation between these indicators); 2) energy method (there is a relationship between energy needs and body weight). The minimum water requirement is 100-150 ml/100 kcal; 3) according to the Aberdeen nomogram (or tables made on its basis - Table 1.69).

In some pathological conditions, the loss of water and/or electrolytes can increase or decrease significantly.

Tab. 1.70.Current pathological losses. Conditions that change the need for fluid

To cover the need for fluid, it is necessary to take into account the physiological need for fluid (1500-1800 ml / m 2) or calculated from the tables (Table 1.69), or by the energy method and add to them the fluid losses identified in the patient.

General principles calculation of the required fluid:

SJ \u003d SZHP + ZHVO + ZhVTPP, Where SJ– calculated daily fluid, SZHP- daily maintenance fluid, GVO– dehydration compensation liquid, ZhVCCI- fluid compensation for current pathological losses.

Water plays important role in the human body: it is a medium for the movement of biologically active compounds and substances, participates in the process of thermoregulation, removes toxins, normalizes metabolism, accelerates protein synthesis, while reducing its decay. An online calculator will help you control your daily need, which will quickly calculate the required rate based on individual characteristics.

How to calculate daily water requirement?

For an adult, the daily need for water is calculated based on the norm from 30 to 40 ml per 1 kg of body weight, which averages 2.0-2.5 liters.

In the form of a free liquid (water, juice, compote, tea, soup, etc.), a person consumes 1-1.3 liters. From food products(meat, fish, bakery products, vegetables, fruits, etc.) approximately 1 liter enters the body, and 0.2-0.4 liters are formed naturally as a result of metabolic processes.

The daily drinking requirement of the body is directly affected by physical activity, the higher it is, the more fluid should be consumed.

What is the daily human need for water?

Every person's daily fluid requirement is different. On average, with light physical activity, the norm is 2.0-2.5 liters per day.

People suffering from kidney disease and of cardio-vascular system, it is recommended not to go beyond the indicated norm of the drinking regime, so as not to load the organs with an additional load, to prevent the removal of minerals from the body, which can upset the salt balance.

The norm for the trainee

The daily water requirement of a training person is much higher than the norm. During intense physical activity, sweating increases, which can remove up to 1 liter of fluid from the body. Timely replenishment of the moisture balance allows you to effectively assimilate the exercises done, normalizes metabolism and protein synthesis, and helps to remove toxins from the body.

Trainers recommend drinking 2 to 3 glasses a few hours before the start of a workout and the same amount after it ends. During training, the use of 1 glass every 20 minutes is shown to increase sports performance.

Daily water requirement calculator

For normal life, it is important to maintain a daily balance between fluid intake and its removal from the body. Online calculator instantly calculate the required daily drinking rate according to individual indicators. To calculate, you just need to enter your weight and level of physical activity on this moment, and then get the results that you should be guided by.

• Daily physical. fluid requirement

• cerebral edema (and its threat)- the total volume of the liquid should not exceed 2/3 of the FP, while the in/in part should not exceed ½ of the FP.

• respiratory failure- at II Art. limit to ½ FP, with DN III Art. - 1/3 FP.

• heart failure- the maximum V / in infusion is not more than ½ - 1/3 of the AF, with hyposystole, a complete cessation of IT.

• kidney failure- with the exception of prerenal acute renal failure V / in infusion, not more than the sum of "imperceptible" losses (25 ml / kg / day in young children and 10 ml / kg / day in older children) and diuresis for the previous day

Clinical signs of dehydration

Clinical signs of dehydration (continued)

Infusion rate (cap/min)=

• …..liquid volume (ml)….

• number of hours of infusionX3

• In shock behind first hour introduced 10-15ml/kg

• With exicosis I-II degree for the first 6-8 hours rehydration, it is advisable to introduce (together with nutrition) a volume of liquid approximately equal to its original extracellular volume deficiency:

• Calcium FP=0.1-0.5 mmol/kg/day

• (in newborns, premature babies 1-3 mmol / kg / day)

• Ca chloride 10%=1 ml=1 mmol

• Ca gluconate 10%=1 ml = 0.25 mmol

• We introduce 10% solution 0.5 ml/year/day (CaCl) -1 ml/year/day (Ca gluc.)

• (no more than 10 ml), for 1-2 injections

Potassium FP= 1.0-2.0 mmol/kg/day

• Potassium FP= 1.0-2.0 mmol/kg/day

• The rate of administration of K should not exceed 0.5 mmol / kg / hour!

• Enter: - in glucose solution

• - with diuresis

• - divide the daily dose into 2 injections

• - concentration of K in the solution is not more than 1%

• 7.5% solution = 1 ml = 1 mmol

• 4% solution = 1 ml = 0.5 mmol

• Enter 7.5% solution 1-2 ml/kg/day

• 4% solution 2-4 ml/kg/day

Magnesium FP = 0.1-0.7 mmol/kg/day

• Magnesium FP = 0.1-0.7 mmol/kg/day

• 25% = 1 ml = 2 mmol

• We introduce glucose into the solution at the rate of 0.5-1 ml/kg/day no more than 20 ml for 2 times

• Sodium FP = 2 - 4 mmol / kg / day

• 10% NaCl=1 ml = 1.71 mmol

• 0.9% NaCl=10ml = 1.53 mmol

Soda

• Soda

• (correction of decompensated metabolic acidosis)

• Volume of 4% soda (ml) = BE*weight/2

• The resulting volume is divided by 2,

• we introduce it in the solution of glucose 1: 1, repeat the KOS

• If there is no KOS, then enter 2 ml/kg

• Do not inject soda in violation of ventilation

• It is impossible to strive for complete and rapid compensation of acidosis, as soon as the pH reaches a level of 7.25 or more, the infusion is stopped and KCL is administered, since hypokalemia may occur due to the transition of K into the cell

Clinical

• Clinical

• Weight control 2 times a day

• Hourly diuresis monitoring

• Normalization of hemodynamics (heart rate, blood pressure)

• Laboratory

• Biochemical indicators (Electrolytes, glucose, urea, creatinine, protein, acid-base balance, coagulogram)

• UAC with Ht

• OAM with specific gravity

Absolute amount of urine liquid volume

• Absolute amount of urine, allocated for a certain time, must be correlated with liquid volume introduced into the body for the same time interval.

• You need to keep a spreadsheet

Hourly diuresis

If against the background of rehydration

• If against the background of rehydration

• Diuresis does not increase:

• exclude acute renal failure

• possible overdose of saline solutions

• Urine output exceeds volume received liquid

• introduced excess solutions containing water (5% glucose)

• because of excess concentrated solutions glucose, the patient developed osmotic diuresis