Parenteral nutrition is a type of artificial nutrition used in seriously ill people. It ensures that those affected receive essential nutrients without passing through the gastrointestinal tract. But when should you be artificially fed?
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If a sick person can no longer eat on their own, there is a risk of uncontrolled weight loss and deficiency symptoms. Parenteral nutrition with nutrient solution is then necessary. Even those who are already affected by malnutrition can benefit from artificial nutrition using a nutrient solution, which serves as a life-sustaining measure.
Article content at a glance:
Nutrient deficiency: recognizing deficiency symptoms
Parenteral nutrition indications
Patients are especially often dependent on artificial nutrient supply after serious operations. Serious disorders of the gastrointestinal tract, such as short bowel syndrome and unwanted weight loss as a result of cancer, AIDS, or autoimmune diseases, are also indications. The elderly and the chronically ill are also often among those artificially fed.
Diseases and various stages of disease can have a major impact on nutrient requirements, energy requirements, and changes in metabolism. Therefore, nutritional therapy has an important place in the treatment of diseases. Parenteral nutrition therapy can also have a positive effect on the chances of recovery.
How parenteral nutrition works
With parenteral nutrition, nutrients are infused directly into the bloodstream. This means that both the mouth and throat as well as the gastrointestinal tract are avoided. This is necessary, for example, when the stomach or intestines are not able to process food, for example in the case of a tumor, short bowel syndrome or a narrowing of the intestine. If someone is fed only parenterally, the doctor must ensure that the daily nutrient requirement is adjusted to the individual’s needs.
The following nutrient intake is possible with an infusion:
Proteins in the form of amino acids.
Trace elements such as iron, zinc, copper, manganese, molybdenum, chromium, selenium, iodine, and fluorine
Vitamins: vitamin A, vitamin C, vitamin D, vitamin E, vitamin K, vitamin B1 (thiamin), vitamin B2 (riboflavin), vitamin B6 (pyridoxine), niacin, pantothenic acid, biotin, folic acid, and vitamin B12
There are finished drugs that are industrially manufactured and contain standardized amounts of ingredients. On the other hand, there are individually manufactured parenteral preparations, also known as modular solutions, with which the exact need can be administered. Individual ingredients can be omitted or added. The downside of these nutrient solutions is that they are more expensive and prone to impurities (contamination) when mixed.
How do you feed yourself artificially?
The nutritional solution is injected into the blood intravenously. Depending on the period of artificial nutrition and the concentration of the nutrient solution, different types of vein access can be selected:
Duration of feeding 5 to 7 days and low concentration: With an indwelling cannula, several veins that are close to the surface of the skin (peripheral veins) can serve as access. This is often only possible if those affected are able to eat a proportion of other foods.
Duration of feeding greater than 7 days. with a high concentration – a central venous catheter ensures that large amounts of nutrients enter the bloodstream in the long term. The catheter must be placed and maintained under strict sterile conditions. It should be made of Teflon, polyethylene, polyurethane, or silicone rubber and should be replaced after about seven days.
It must be artificially fed in the long term. so-called Hickman-Broviac catheters or a port may be used. A port catheter is surgically implanted under the skin or, rarely, in the abdomen to access the blood system. It may consist of one or more cameras. A thin tube runs from the chambers to the vein. The solution can be injected into the chambers from the outside with a syringe used specifically for this purpose.
What is the difference between enteral and parenteral nutrition?
Basically, parenteral nutrition with an infusion bag is the last resort. If those affected can take food elsewhere, for example by enteral nutrition, this is preferred. Both forms of artificial nutrition often complement each other.
Unlike parenteral nutrition, enteral nutrition uses the digestive tract. The nutrient combinations are administered below the oral cavity, for example, by means of a gastric tube. In most cases, the tube, a flexible plastic tube, is passed through the nose and into the stomach (transnasal). Rarely, the tube is moved through the abdominal wall with a PEG tube in one operation. For example, when the nose and throat area is too narrow or injured. If patients have severe swallowing difficulties, they can also consume high-calorie liquid foods.
Compared to parenteral nutrition, enteral nutrition is cheaper and carries fewer risks, as the risk of contamination is lower. In addition, it is easy to administer and maintains the function of the gastric and intestinal mucosa. The goal of artificial feeding is always to return to oral feeding. If a person on total parenteral nutrition is recovering, both forms of nutrition can also be used. There are the following options:
- exclusive parenteral nutrition
- predominantly parenteral nutrition and minimal enteral nutrition
- partially parenteral and partially enteral nutrition
- complete enteral nutrition
- minimal oral and enteral nutrition
- enteral and partial oral nutrition
Ambulatory artificial nutrition
Not only patients in the intensive care unit or during a hospital stay can be artificially fed. Since the 1970s, outpatient enteral or parenteral nutrition has also been available. Therefore, patients can also use artificial nutrition at home or in care settings. PEG tubes are used for enteral feeding, which must be cleaned and checked regularly. This reduces the risk of complications such as inflammation.
With home parenteral nutrition, an implanted port or catheter system should be chosen that involves the fewest complications and is easy to use. This should also be checked regularly by trained nursing staff. Those affected, relatives and trained nursing staff must pay special attention to hygiene in the maintenance of access routes.
Legal situation in artificial nutrition
Legally, no one can be forced to undergo artificial nutrition. If someone is no longer capable of making decisions, an authorized person takes over this task. Artificial nutrition is often necessary in the elderly and in the dying process. Here it must be decided whether the artificial supply of nutrients is accompanied by an increase in the quality of life or whether the inevitable death is artificially prolonged. If artificial nutrition occurs against the patient’s will, this counts as physical injury.
The agents, in most cases family members, are emotionally affected and do not want their loved ones to go hungry or die of thirst. However, if artificial nutrition is no longer medically necessary, it should not be given. This situation can be difficult for everyone involved. An intense discussion between family members and the treating specialist can help create clarity and re-evaluate whether artificial nutrition relieves the suffering of the person in question or possibly prolongs it.
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