Parenteral and Enteral Nutrition

Enteral nutrition and parenteral therapy are vital to half the patients who can not properly nourished by mouth and who are therefore at risk of malnutrition and its effects, among which include susceptibility to infection, weakness and immobility, which in turn predispose to aspiration pneumonia, pulmonary embolism, decubitus ulcers, all of which delay recovery from illness and increase mortality.

The term refers to enteral feeding via the gut and, therefore, includes normal food, but in this context refers to the administration of preparations through a probe placed on the upper digestive tract. Parenteral administration refers to the nutrient solutions directly into the bloodstream. Although these two criteria are different nutritional treatment, their goals are generally the same.

Whenever feasible, the preferred route is the enteral nutrition (enteral, EN), because it keeps the digestive, absorptive and barrier of the digestive immune nutrition. Thanks to various developments, tube feeding is now easier and more tolerable for patients. The folding of small caliber probes have been replaced, generally speaking, the rubber tubes of high caliber, and currently has double-lumen tubes with gastric suction arm and an arm jejunal feeding in cases of risk retention of gastric contents and pulmonary aspiration.

Enteral feeding tubes can be placed in the stomach or jejunum entering through the nose for long-term use, directly through the abdominal wall by endoscopic, radiological or surgical procedures. Once created, the entire duct skin, instead of the probe protruding portal can use a button for penetration.

The complete feeding intravenously with calories, amino acids, minerals and vitamins sufficient to allow healing of wounds, recovery of normal body composition of cachectic patient or growth in children became possible thanks to the development of high-flow central catheters. At present, with parenteral nutrition (parental nutrition, PN) in all hospitals and for selected patients at home.

The decision process for using enteral or parenteralLa decision to use specialized nutritional support nutrition (Specialized nutrition support, SNS) should be based on possibilities exist that the quality of life of the patient or the resilience of a serious illness improved by avoiding ran-ge or malnutrition. Between 15 and 20% of hospitalized patients show signs of malnutrition. Some improve with specialized nutritional support, but for others the consumption is an unavoidable part of a terminal illness. Figure 63-1 shows the algorithm of the steps to determine whether nutritional support should be provided specialized and, if so, how.



Algorithm for the decision to undertake specialized nutritional support (Specialized nutrition support, SNS) and the method of administering it. PICC, peripherally inserted central catheter (Peripherally inserted central catheter), CVL, CVL (central venous line).

The first step requires consideration of the nutritional impact of the process: the disease tend to worsen or treatment appetite or food intake and absorption over an extended period? The second step is to establish whether the patient is already malnourished enough so that lean body mass has decreased and essential functions are affected as healing and breathing. Must detect the presence or absence of metabolic stress, as wounds or infections may trigger the secretion of cytokines and hormonal factors that reduce the effectiveness of nutrient replenishment.

It is likely that thinning lacks physiological condition without adverse consequences. The physiological condition is often important when you lose more than 20% of the proteins in the body, and is more likely when the organ system under consideration is directly affected by the disease. Once detected malnutrition or risk of it, the question should be whether specialized nutritional support will positively influence the response to the disease and improve quality of life. This aspect involves ethical considerations and risk-benefit ratio. Although the supply of water and food is a staple of medical care, nutritional support via the gut or parenteral involves risks and discomfort and should only be advised when potential benefits outweigh the risks, and should be undertaken only with the consent the patient. Like all life support measures, it is difficult to stop once started these procedures.

If preventive or curative measures of malnutrition through the NHS are appropriate, need to assess the nutritional needs and choose the route of administration of nutrients. The latter depends rather on the degree of bowel function, but also to some extent, the available technical resources.

Risks and benefits of nutritional support especializadoLos risks depend predominantly patient-specific factors such as alertness and swallowing sufficiency, route of administration and clinical staff supervisor experience. The safest strategy is less expensive and do not use specialized nutritional support, as far as possible, which is achieved by paying careful attention to food intake, adding a liquid supplement to administer drugs orally and appetite stimulants. The nutrient input is monitored by frequent caloric value, this strategy is the most effective physiological from the metabolic point of view, because the normal consumption triggers the cephalic phase of digestion. Tube-fed infants grow better if that phase is stimulated by the small sucking a pacifier.

Anorexia, the condition of swallowing or intestinal diseases may reduce intake or absorption of food, in which case the intestinal nutrition will be the next option. The gut and associated digestive organs get 70% of the nutrients they need directly from the intestinal lumen. In addition, glutamine, short chain fatty acids and nucleotides may be of particular importance in preserving the integrity of the intestine. Enteral feeding also maintains intestinal function by stimulating the splanchnic blood flow, neuronal activity, release of IgA antibodies and the secretion of gastrointestinal hormones such as epidermal growth factor, which promotes the intestinal trophic activity. All these factors contribute to making the intestine an immune barrier against intestinal microorganisms. For these reasons, whenever possible be administered nutrition part of the intestinal tract, even if parenteral nutrition is required to provide the bulk of the support. Long ago it was believed that bowel rest achieved by parenteral nutrition was the cornerstone of treatment of many serious digestive processes, but now generally accepted the importance of maintaining, whenever possible, part of the feed intestinal tract and are rarely advised strict bowel rest.

Parenteral nutrition alone is still appropriate in severe hemorrhagic pancreatitis, necrotizing enterocolitis, prolonged ileus and distal intestinal obstruction.

Specialized nutritional support is expensive, since it represents more than 1% of total health expenditure in dollars. As a result, risk-benefit studies require strict clinical outcomes such as mortality rates, incidence of major complications and length of hospital stays. They are no less far-reaching acceptable targets, such as improvement of nitrogen balance, increased serum albumin levels and the improvement of hypersensitivity. Table 63-1 summarizes the clinical studies that evaluated the use of specialized nutritional support in various diseases. The data were obtained from randomized comparative studies and in many cases were combined with meta-analysis. The research highlighted that the NHS is more beneficial in disorders involving protein calorie malnutrition deep or if it is impossible to use the mouth for longer periods of nine days, for example.

One practical aspect to consider is the experience in the placement of tubes or catheters, particularly in patients in critical condition. The placement of a central venous catheter is a technique practiced directly, and efficiently performed with specially trained personnel, for which uses the peripheral catheter from penetrating up to a central vein. The placement of a nasogastric tube is a direct method, but many patients are deficient in gastric emptying, and intragastric feeding increases the risk of aspiration pneumonitis. To gain access to the jejunum enteral usually require the use of fluoroscopy in the endoscopy unit or radiology. If required a surgical laparotomy can be placed at that time a jejunal tube feedings. Studies have indicated that the tubes in question should be placed beyond the ligament of Treitz, to avoid bronchial aspiration, an intraduodenal tube is safer than intragastric.

Almost all methods are made in NHS hospitals, but some patients need this technique for a long time. If you have a safe environment and willingness to learn self-care procedures, the SNS can be at home. Parenteral nutrition at home made usually at night is planned in cycles, so that the patient has more freedom in daytime periods. The cyclic administration requires managing nutrients for 1 h, and discontinue use a similar period in order to avoid sudden changes in blood glucose. In patients in the terminal phase is not appropriate the NHS, although it is an option if the patient and family request that you use this method and can be expected if a good quality of survival for several months.

Source: articulosdemedicina.com

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