Tetraspan

Tetraspan is a plasma-substituting substance. It is a colloidal type liquid containing an HES element. It is a balanced electrolyte solution. The average molecular weight of HES is 130 thousand daltons, and the molar substitution rate is 0.42.

The drug is able to reduce plasma viscosity and hematocrit values. In the case of isovolemic application, the volume-replacing effect lasts for a period of at least 6 hours. [1]

Indications Tetraspan

It is used in the following cases:

• therapy and prevention of the development of absolute and relative forms of hypovolemia of the , shock state that appears due to injury or bleeding, and in addition sepsis, burns and blood loss associated with operations;
• active form of normovolemic hemodilution or therapeutic hemodilution;
• filling of the AIK.

Release form

The drug is released in the form of a solution - inside containers with a capacity of 0.5 liters; inside a pack - 10 such containers.

It can also be produced inside polypropylene bags with a volume of 0.25 or 0.5 liters; there are 20 such bags inside the box.

Pharmacodynamics

Tetraspan is an iso-oncotic liquid with 100% volemic influence. The duration of the volemic effect is determined mainly by the indicator of molar substitution of the HES component, and in addition (a less important factor) by the average value of its molecular weight.

The products formed during the hydrolysis of HES are molecules with oncotic activity; they are excreted through the kidneys. [2]

The cationic composition of the drug is similar to the physiological plasma parameters of electrolytes. Of the anions in the composition of drugs, there are acetates and chlorides with malates, which should minimize the likelihood of acidosis and hyperchloremia. The addition of malates with acetates to replace lactates reduces the likelihood of developing lactic acidosis.

Pharmacokinetics

HES is a substance that consists of molecules with different molecular weights and molar substitution rates. Each of these indicators has an impact on the rate of excretion. Small molecules are excreted during glomerular filtration, and large ones are involved in enzymatic hydrolysis by α-amylase and are then excreted through the kidneys. The higher the level of substitution, the lower the rate of hydrolysis processes.

About 50% of the applied portion of HES is excreted in the urine over a period of 24 hours. With a single use of 1 liter of drugs, the value of intraplasmic clearance is 19 ml per minute, and the AUC level is 58 mg × h / ml. The term serum half-life is 12 hours.

Dosing and administration

The medication is administered intravenously. The size of the daily portion and the rate of application are selected taking into account the volume of blood loss and hemodynamic characteristics.

An adult can enter no more than 50 ml / kg of solution per day. For a person weighing 70 kg, the dosage will be 3.5 liters of medicine.

When prescribing drugs to a child, a portion is selected personally, taking into account the hemodynamic status, as well as concomitant pathologies: a child of 10-18 years old is injected no more than 33 ml / kg per day, and a child 2-10 years old - a maximum of 25 ml / kg.

The maximum indicators of the rate of administration of the solution are determined by the clinical picture. Individuals with an active stage of shock are prescribed up to 20 ml / kg per hour.

If there is a life-threatening condition for the patient, a rapid application of 0.5 liters of fluid (under pressure) can be made.

The duration of the treatment course is selected taking into account the intensity and duration of hypovolemia, the hemodilution rate and the hemodynamic effect under the influence of the treatment.

• Application for children

Cannot be used on persons under the age of 2 years.

Use Tetraspan during pregnancy

At the moment, there is no reliable information regarding the use of Tetraspan during pregnancy; during this period, it is allowed to prescribe it only in situations where the likely benefit is more expected than the risks of negative consequences for the fetus (especially in the 1st trimester).

Due to the lack of confirmed information as to whether HES can be excreted in mother's milk, breastfeeding should be discontinued during therapy.

Contraindications

Among the contraindications:

• hyperhydria, including pulmonary edema;
• failure of the kidneys in severe form (accompanied by anuria or oliguria);
• bleeding inside the skull;
• intense hyperkalemia;
• severe stage of hypernatremia or -chloremia;
• severe liver failure (decompensated type);
• CHF;
• severe sensitivity to the elements of the drug.

Caution is necessary when used in persons with disorders of the blood clotting processes (especially in the case of suspected or diagnosed von Willebrand disease).

Side effects Tetraspan

Most often, adverse symptoms develop due to the medicinal effect of HES fluids and the dosage used, i.e. Hemodilution arising from the expansion of the space inside the vessels without the introduction of blood elements. In addition, there may be a dilution of the clotting factors. Signs of intolerance appear singularly and are not related to dosage.

The impact on the lymph and circulatory system.

Decrease in hematocrit and plasma protein values due to hemodilution.

Sufficiently large portions of HES cause dilution of clotting factors, which leads to a disorder of hemocoagulation. When using high dosages of drugs, the bleeding period and the APTT index may increase, and the von Willebrand factor activity, on the contrary, weaken.

Effect on biochemical values.

The use of HES fluids may cause a brief increase in serum α-amylase, but this should not be considered a pancreatic disorder.

Anaphylactic manifestations.

The use of HES can lead to the onset of anaphylactic symptoms of varying severity. Because of this, patients who receive Tetraspan must be constantly monitored to prevent the development of anaphylactic disorders. When they appear, you must immediately stop the introduction of drugs and carry out emergency procedures.

Overdose

Intoxication with Tetraspan causes hypervolemia. With the development of such a violation, the administration procedure is immediately stopped. If necessary, diuretics can be administered to the patient.

Interactions with other drugs

The use of HES fluids together with potentially nephrotoxic drugs (for example, aminoglycoside-type antibiotics) can lead to potentiation of their negative effect on the kidneys.

It should be borne in mind that Tetraspan contains electrolytes in its composition - because of this, when it is combined with substances that lead to the delay of Na or K elements, this effect can be enhanced.

An increased calcium index increases the likelihood of developing the toxic effects of digitalis glycosides.

Storage conditions

Tetraspan should be kept out of the reach of small children. Temperature - within the 25 ° C mark. Do not freeze the medicine.

Shelf life

Tetraspan can be used for a period of 24 months from the date of manufacture of the therapeutic substance.

Analogs

The analogs of the drug are the medicines Perftoran, Biocerulin with Promit-infusion, Stabizol and Albumin with Heck-infusion, as well as Gestar, Khetasorb and Refordez.