Parenteral food is not a preferable way of nutritive support in view of higher risk of development of various complications. In particular, parenteral food can be followed by risk of development of a hyperglycemia, electrolytic rasstroistvo, overloads the volume (overhydratation), an immunodeficiency, an oxidizing stress and increase in frequency infectious a complication ̆. Carrying out parenteral food demands regular control of level of glucose and electrolytes in blood. In addition, hyper caloric parenteral causes pitny gepatosteatoz, a gipertriglitseridemiya and a hypercapnia. Nevertheless, in the absence of an opportunity at the patient to receive nutrients enterally, parenteral food remains the only available way of nutritive support.
The essence of parenteral food consists in introduction to the patient intravenously of all necessary components of nutritive support: proteins (solutions of amino acids), fats (lipidic emulsions) and carbohydrates (glucose solutions). At the same time they can be used both in the form of separate drugs, and in the form of one. Separate administration of medicines for parenteral food demands use of several infusional lines ̆ that increases the probability of development infectious a complication ̆. But also for parenteral food in mnogokamerno ̆ to packing patients with obesity or patients to whom restriction of volume infusional ̆ is shown to therapy and also at patients to whom it is shown individual ̆ selection of a dose of protein and energy will have impossible use of drugs. Besides, use of drugs in mnogokamerno ̆ to packing reduces catheter service life. One more nuance consists that it is not recommended to store mixes of amino acids and glucose more than 24 hours in view of the fact that at the same time chemical stability of solution is broken.
If to speak about use of carbohydrates at parenteral food, then their minimum quantity is 2 g/kg/days. The chemical form of glucose in solution is presented in the monohydrate form, energy value makes 3.4 kcal on 1 gram. At patients in a critical state the maximum speed of oxidation of glucose is 4–7 mg/kg/min. (that is a day the patient has 400–700 grams of glucose with a weight ̆ bodies of 70 kg). At the same time for reduction of risk metabolic a complication ̆ the maximum speed of infusion of glucose should not exceed 5 mg/kg/min.
The glucose level recommended ̆ in blood at patients in critical states is 8–10 mmol/l. At glucose level in blood more than 10 mmol/l correction is shown by insulin. At patients in a stable state use of hypodermic administration of insulin as it provides longer ̆ effect is preferable. To patients in a critical state appoint administration of insulin intravenously via the doser. It is also necessary to note that routine addition of insulin in glucose solutions, widespread in some clinics, is not recommended.
As for amino acids, when carrying out parenteral food their dose makes 1.3-1.5 g/kg ideal ̆ body weights in day. Besides, maintaining amino acids demands adequate ensuring power requirements ̆ the patient therefore it is recommended to enter solutions of amino acids along with glucose ̆ or lipids.
Energy value of protein makes 4.1 kcal/g that should be considered at the general calculation of power requirements ̆. The recommended rate of administering of solutions of amino acids makes no more than 0.15 g/kg/h. For ensuring exact speed of dosing it is preferable to use infusional pumps.
Lipidic emulsions which are used for carrying out parenteral food incorporate triglycerides (ethers of fatty acids and glycerin) with phospholipids which are used in solution as emulsifiers.
It is known that the majority of fatty acids can be synthesized in an organism and are replaceable. 18 carbon fatty acids — linoleic and alpha and linolenic belong to irreplaceable fatty acids. Daily need of patients of OITR averages 9–12 g for linoleic ̆ acids and 1–3 g for an alpha linolenovoi ̆. Irreplaceable ZhK in large numbers contains in the oils received from a plant ̆.
Energy value of fats makes 9 kcal/gram. The dose of a lipidic emulsion makes 0.7-1.5 grams/kg during 12–24 h. At the same time the speed of infusion of a lipidic emulsion has to be 0.11 g/kg/h. It is simpler to provide a certain rate of administering if for infusion the infusional pump is used. Infusion of lipidic emulsions does not demand existence of the central venous catheter and can be provided through peripheral ̆ venous ̆ access.
When performing infusion of lipidic emulsions it is necessary to control the level of triglycerides in blood. At development of a gipertriglitseridemiya it is necessary to reduce the speed of infusion of LE, and in case of the gipertriglitseridemiya expressed ̆ ("хилёз" plasmas) infusion LE should be stopped.
It is necessary to remember that use of lipidic emulsions is followed by risk of development serious a complication ̆, especially when using the lipidic emulsions consisting of long-chain fatty acids which infusion increases average pressure in pulmonary ̆ arteries pulmonary ̆ the shunt and reduces respiratory ̆ coefficient, worsening oxygenation. Also lipidic emulsions can cause injury of a liver.