When a patient cannot ingest the necessary nutrients by eating food, either because of illness, injury, surgery, dysphagia, or changes in absorption, enteral nutrition (EN) can be used to fill the void. Enteral nutrition refers to the act of taking nutrients into the body through the gastrointestinal (GI) tract. In medical terms, we typically think of EN as supplying specialized nutrition support via tube feedings. Parenteral nutrition (see Chapter 33) provides nutrition intravenously, entirely bypassing the GI tract. In general, if the GI system is functional, it is preferable to use enteral nutrition rather than parenteral feedings.1
Enteral nutrition is used in various clinical situations. It may be used to provide nutrition acutely when a patient cannot ingest or absorb adequate nutrition from oral intake or to provide nutrition during periods of extended illness. In general, if an otherwise well-nourished patient cannot take food by mouth for 7 to 14 days, EN should be considered. Enteral nutrition may be the only means of energy intake, or may be used as a supplement to food when oral intake alone is insufficient. Enteral feedings are preferred to parenteral feedings (provision of nutrients through the venous system) for several reasons. Enteral feedings make use of a functional or partially functional gut; reducing the risk of gut atrophy. Enteral nutrition also reduces the risk of infection by removing the need for venous access, and it is also less costly than parenteral nutrition.2
The decision to initiate enteral nutrition therapy must be based on determination of risk to benefit. The potential benefit for the patient must outweigh the risks of tube placement as well as risk of complications. There are a variety of factors that must be considered when initiating EN in any patient. These issues are discussed below.
Several considerations dictate the route of administration. The level of GI dysfunction and disease state determines where nutrients should enter the GI tract. Feeding should be initiated at the highest level of functional gut, consistent with the patient's disease. This will maximize the nutrient absorption as well as maintain the gut function at the highest level possible. Patients with gastroparesis or other motility disorders may benefit from tube placement in the jejunum or duodenum as opposed to the stomach. Another consideration is anticipated length of treatment; short-term therapy is typically achieved through use of a nasogastric, orogastric, nasoenteric, or oroenteric tube, but longer therapy usually requires percutaneous placement (Table 32-1).3 With nasogastric tubes, placement is often made at bedside. The feeding tube which is quite flexible and soft at room or body temperature becomes rigid when iced, easing placement.
TABLE 32-1 Enteral Feeding Routes ||Download (.pdf)
TABLE 32-1 Enteral Feeding Routes
|Tube||Type/Insertion Technique||Clinical Uses||Potential Complications|
Placed into the stomach through the nose
Position verified by injecting ...