Nutritional Support and Enteral/Parenteral Feeding

Nutritional support is the provision of nutrients to patients who cannot meet their needs through ordinary eating, whether because of disease, surgery, or critical illness. When the gut is functioning, nutrients are usually delivered into the digestive tract as enteral nutrition, often through a feeding tube; when the gut cannot be used or is insufficient, nutrients are delivered intravenously as parenteral nutrition. Identifying patients at nutritional risk and supporting safe feeding are core responsibilities in medical-surgical nursing.

Definition

Nutritional support is the delivery of nutrients by enteral or parenteral routes to patients who cannot meet their nutritional requirements by normal oral intake, with the aim of preventing or treating malnutrition and supporting recovery.

Scope

The entry covers the concepts, routes, and management context of nutritional support as a reference subject for nursing. It addresses nutritional screening and assessment, the distinction between enteral and parenteral routes, and recognised hazards such as aspiration and refeeding syndrome, without specifying individualised feeding regimens, formulas, or doses.

Core questions

• How are patients at nutritional risk identified through screening and assessment?
• When is enteral nutrition preferred over parenteral nutrition, and why?
• What are the principal routes and access devices for artificial nutrition?
• What complications of feeding—such as aspiration and refeeding syndrome—must be anticipated and monitored?

Key concepts

• Nutritional screening and assessment
• Enteral nutrition (tube feeding)
• Parenteral nutrition
• "If the gut works, use it" principle
• Refeeding syndrome
• Aspiration risk
• Catheter-related and metabolic complications

Mechanisms

Nutritional support begins with screening to identify patients at risk and assessment to quantify needs, using standardised terminology and criteria for malnutrition (Cederholm et al., 2017). Where the gastrointestinal tract is functional and accessible, enteral nutrition is generally preferred because it maintains gut integrity and is associated with fewer infectious complications; nutrients are delivered into the stomach or small bowel through nasoenteric tubes or, for longer-term needs, gastrostomy or jejunostomy. When the gut cannot be used, parenteral nutrition supplies nutrients directly into the bloodstream through central or peripheral venous access. Both routes carry hazards—aspiration and tube-related problems for enteral feeding, catheter-related infection and metabolic disturbance for parenteral feeding—and rapid reintroduction of feeding in malnourished patients can precipitate refeeding syndrome (Singer et al., 2019).

Clinical relevance

Disease-related malnutrition is common in hospitalised and critically ill patients and is associated with worse outcomes, while feeding itself carries risks that must be anticipated. Understanding screening, route selection, and the recognition of complications such as aspiration and refeeding syndrome supports safe, coordinated nutritional care; this entry describes the field for reference and is not a basis for individual prescribing or feeding decisions.

Epidemiology

Disease-related malnutrition affects a substantial proportion of hospital inpatients and is especially prevalent among older adults, surgical patients, and the critically ill, where it is linked to longer stays, complications, and higher mortality. International guidelines, such as those of the European Society for Clinical Nutrition and Metabolism, set out screening, assessment, and route-selection frameworks across these populations (Cederholm et al., 2017; Singer et al., 2019).

Seminal works

• singer-2019-icu
• cederholm-2017
• bischoff-2020-liver

Frequently asked questions

What is the difference between enteral and parenteral nutrition?

Enteral nutrition delivers nutrients into the digestive tract, usually through a feeding tube, and is used when the gut is working, whereas parenteral nutrition delivers nutrients directly into the bloodstream through a vein and is used when the gut cannot be used or is inadequate.

What is refeeding syndrome?

Refeeding syndrome is a potentially dangerous set of metabolic and fluid shifts that can occur when nutrition is reintroduced too quickly in a severely malnourished person; recognising those at risk is an important part of safe nutritional support.