Tetraspan

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

The drug is capable of reducing plasma viscosity and hematocrit values. When administered isovolemically, the volume-replacing effect is maintained for 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, shock resulting from trauma or bleeding, as well as sepsis, burns and blood loss associated with operations;
• active form of normovolemic hemodilution or therapeutic hemodilution;
• filling the AIC.

Release form

The medicinal product is released in the form of a solution – inside 0.5 l containers; there are 10 such containers inside a pack.

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

Pharmacodynamics

Tetraspan is an isooncotic liquid with 100% volumetric effect. The duration of volumetric effect is determined mainly by the molar substitution index 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 HEC are molecules with oncotic activity; they are excreted through the kidneys. [ 2 ]

The cationic composition of the drug is similar to physiological plasma electrolyte indices. Of the anions in the drug, there are acetates and chlorides with malates, which should minimize the likelihood of acidosis and hyperchloremia. Adding 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 rates affects the rate of excretion. Small molecules are excreted by glomerular filtration, while large molecules undergo enzymatic hydrolysis by α-amylase and are then excreted through the kidneys. The higher the substitution rate, the slower the rate of hydrolysis.

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

Dosing and administration

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

An adult can be administered 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 a drug to a child, the dose is selected individually, taking into account the hemodynamic status, as well as concomitant pathologies: a child aged 10-18 years is administered no more than 33 ml/kg per day, and a child aged 2-10 years is administered a maximum of 25 ml/kg.

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

If a life-threatening condition is observed, 0.5 l of fluid can be administered rapidly (under pressure).

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

• Application for children

Not for use in persons under 2 years of age.

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 be prescribed only in situations where the probable benefit is more expected than the risks of negative consequences for the fetus (especially in the 1st trimester).

Due to the lack of confirmed data regarding whether HES can be excreted in human milk, breastfeeding should be discontinued during therapy.

Contraindications

Among the contraindications:

• hyperhydria, including pulmonary edema;
• severe renal failure (accompanied by anuria or oliguria);
• bleeding inside the skull;
• severe hyperkalemia;
• severe stage of hypernatremia or -chloremia;
• severe liver failure (decompensated type);
• ZSN;
• severe sensitivity to the components of the drug.

Caution is required when used in individuals with bleeding disorders (especially in cases of suspected or diagnosed von Willebrand disease).

Side effects Tetraspan

Most often, side effects develop due to the medicinal effect of HEC fluids and the dosage used, i.e. hemodilution, which occurs due to the expansion of space inside the vessels without the introduction of blood elements. In addition, dilution of coagulation factors may be observed. Signs of intolerance appear sporadically and are not related to dosage.

Effects on the lymph and circulatory system.

Decreased hematocrit and plasma protein levels due to hemodilution.

Large enough doses of HEC cause dilution of coagulation factors, which leads to hemocoagulation disorder. When using large doses of the drug, the bleeding period and APTT index may increase, and the activity of the von Willebrand factor, on the contrary, may weaken.

Effect relative to biochemical values.

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

Anaphylactic manifestations.

The use of HEC may lead to the appearance of anaphylactic symptoms of varying severity. Because of this, patients who are administered Tetraspan must be constantly monitored to prevent the development of anaphylactic disorders. If they occur, the administration of the drug must be stopped immediately and emergency procedures must be carried out.

Overdose

Tetraspan intoxication causes hypervolemia. If such a disorder develops, the administration procedure is stopped immediately. If necessary, the patient can be given diuretics.

Interactions with other drugs

The use of HEC fluids together with drugs that have a potentially nephrotoxic effect (for example, aminoglycoside antibiotics) may lead to a potentiation of their negative effects on the kidneys.

It is necessary to take into account that Tetraspan contains electrolytes in its composition – because of this, when it is combined with substances that lead to the retention of elements Na or K, this effect can be enhanced.

Elevated calcium levels increase the likelihood of developing toxic effects from digitalis glycosides.

Storage conditions

Tetraspan should be stored in places closed to small children. Temperature – within 25°C. Do not freeze the medicine.

Shelf life

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

Analogues

The analogs of the drug are the medications Perftoran, Biocerulin with Promit infusion, Stabizol and Albumin with Gek infusion, as well as Gestar, Hetasorb and Refordez.