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Home Enteral Nutrition
Carol S. Ireton-Jones, PhD, RD, LD, CNSD, Coram Healthcare
The most common home infusion therapy provided today is home enteral nutrition (HEN) or tube feeding. HEN should be used in patients who cannot meet their nutrient requirements by oral intake, yet have a functional gastrointestinal (GI) tract, and who are able to receive therapy outside of an acute care setting. It is estimated that more than 344,000 people of all ages in the US are receiving enteral nutrition at home The following article will review the indications for HEN, the nutritional considerations in developing the feeding regimen, enteral access and formula selection, and monitoring.
Indications for Enteral Nutrition
Enteral nutrition support can be accomplished in a wide variety of patients with many disease processes, from dysphagia to short bowel syndrome. Often quoted is the phrase, “if the gut works, use it”. A minimum of 100 cm jejunal and 150 cm ileal length of functioning small bowel, with the ileocecal valve intact, is necessary for sufficient absorption of nutrients in the GI tract. Patients with high output fistulas, or severe nausea, vomiting or diarrhea are probably not candidates for enteral feeding. In addition, no mechanical obstruction of the GI tract or GI hemorrhage should be present.
Discharging a Patient on HEN
When a patient is identified as a candidate for HEN and a tube is inserted, education for the patient, and caregiver should be initiated. Because of shorter hospital stays this may be done primarily at home. The patient and caregiver’s ability to be trained and perform the tasks associated with HEN, reimbursement for HEN and the home environment, should be evaluated prior to sending a patient home as these are important determinants of the success of HEN. A qualified HEN provider should be selected by the physician in coordination with the discharge planner and patient/caregiver. The HEN provider may be a home care company, home infusion company or a DME (durable medical equipment) company. It is important that the HEN provider for supplies (and potentially nursing and nutrition services) is introduced to the patient and caregiver prior to discharge if possible. Often when the patient is referred, the HEN provider is given the patient’s name, age, diagnosis and enteral feeding order. If the patient or family has been trained on enteral feeding techniques in the hospital, the HEN provider may simply supply product and appliances (bags, tubing, pump).
Prior to initiating enteral nutrition, it is important that a patient receive a nutrition assessment to determine his or her nutritional status and therefore nutrient needs. The American Dietetic Association defines a nutrition assessment as, “A comprehensive approach, completed by a registered dietitian, to defining nutritional status that uses medical, nutrition, and medication histories; physical examination; anthropometric measurements; and laboratory data. Further, it includes the organization and evaluation of information to declare a professional judgment.” Objective measurements of nutrition status include biochemical measurements of serum proteins, electrolytes and other chemical indices. Subjective analyses include evaluation of nutritional history for weight, appetite, and dietary intake changes, presence or history of GI symptoms/problems, functional capacity, and physical symptoms of nutritional deficiency such as a wasted or cachectic appearance. A nutrition assessment may be conducted in the hospital prior to discharge, in the physician’s office or in the home. The nutrition assessment may also be done from a telephone conversation with the patient or caregiver after he/she has arrived home.
Energy and protein requirements are determined based on the patient's nutritional and medical status. Energy requirements are most often estimated from energy equations. Most individuals require a range of 20-35 kcal/kg of body weight/day. Protein requirements usually range from 1.0-1.5 gram/kg body weight/day, with modifications (seldom >1.5 g/kg body weight/day) to account for increased needs due to healing wounds, or acute or chronic disease. If a patient is malnourished, nutrient needs may be greater at first to restore nutritional status. Adequacy of wound healing and return or improvement of physical strength may be useful indicators of restored protein status in the person receiving HEN.
Fluid requirements must be determined, and then provided daily to the patient through the formula and other sources. Fluid needs are calculated for adults and children as follows:
• 35 ml/kg body weight/day
• 100 ml/kg/day for the first 10 kg body weight
• add 50 ml/kg/day for the second 10 kg of body weight
• For each additional kg of body weight add 20 ml/kg per day.
Most “standard” 1 kcal/ml enteral formulas contain about 80% water so a patient receiving 1500 kcals would receive 1200 ml of water from the formula. If the patient weighs 60 kg, he needs an additional 700 ml of water each day. It is important to account for other fluid losses from fever, diarrhea and vomiting, and to provide additional fluid replacement to meet these needs. Failure to account for fluid needs can lead to dehydration and rehospitalization. For the most part, enteral formulas contain 100% of all vitamins and minerals required when at least 1000 kcals are taken each day. Infrequently, a vitamin and mineral supplement or specific nutrients may be added to compensate for a nutritional deficiency, but this is uncommon. More frequently inadequate nutrition in HEN patients is due to inadequate infusion, which is why careful monitoring is important.
Successful HEN is dependent upon a reliable, low-risk, comfortable method of enteral access. Frequent or prolonged interruptions in therapy related to enteral access are frustrating for patients, caregivers, and clinicians. Well thought out decisions about the type and location of enteral access are necessary to minimize complications. In determining the type of enteral access to be used, the physician must consider how long the patient will receive the enteral feeding (short or long term) as well as the type and viscosity of the feeding solution, volume of solution to be provided and the administration rate.
In general, there are five placement methods for enteral access devices: nasally placed tubes which may end in the stomach, duodenum, or jejunum; the other tubes are located in the stomach or jejunum and placed surgically, endoscopically, laparoscopically, or radiologically. Each of the placement techniques has advantages and disadvantages and they differ in their suitability for long vs. short-term therapy. The physician and patient should discuss these options prior to the placement of a feeding tube.
Length of Therapy
Nasogastric or nasointestinal tubes are most suitable for short-term therapy (< 6 weeks). These tubes can be placed in an outpatient or home setting; however, their position should be confirmed radiologically after insertion to ensure proper placement. Nasally placed tubes aren’t used often for HEN, but they can be used with caution for patients who are meticulous in recognizing and reporting possible tube displacement, and are often the preferred approach in small infants.
Surgically, endoscopically, laparoscopically, or radiologically placed tubes located in the stomach or jejunum are recommended for long-term (> 6 weeks of therapy) or lifetime HEN. They are less likely to become displaced than nasally placed tubes. Signs of displacement include a change in the length of the external portion of the tube, difficulty in infusing or flushing, leakage of formula or flush solution from the exit site, or a stationary tube that is painful.
The level of gastric function, and the risk of aspiration determine the feeding site. Duodenal or jejunal feeding allows patients with impaired gastric emptying to be fed safely. Aspiration risk is believed to be higher for patients with impaired gag reflex, altered level of consciousness, prior history of aspiration, and known alteration in gastroesophageal reflux and therefore duodenal feedings may be preferred.
Selection of Formula
Functional status of the GI tract and absorptive capacity are the predominant factors in choosing a formula. Other considerations include: nutritional status/medical therapy; renal function; fluid tolerance/electrolyte balance, and route of delivery. Formulas are categorized according to their type and amount of protein and calories; some are tailored for different disease states. It is important for a registered dietitian to be involved in the selection of formula and substitution of a product, if necessary.
As the science of nutrition has evolved, so too, has the development of formulas. Standard formulas are now available that can meet the needs of most patients. To avoid lactose intolerance, the majority of enteral supplements and formulas are lactose-free or contain only a trace amount of lactose. Most formulas contain whole protein and are used for patients with a GI tract that is able to digest and absorb intact proteins. Standard whole protein formulas can be flavored or unflavored. Unflavored formulas are usually isotonic (concentration of all nutrients in the formula is the same as the concentration of the blood, approximately 300 mOsm/kg water). Isotonic formulas are well tolerated, but products with osmolarities greater that 300m/kg water may draw water into the GI tract, causing diarrhea. The addition of flavoring to enteral formulas enhances the taste, but at the same time, usually increases the osmolarity of the solution.
High calorie or calorically dense formulas provide 1.5-2.0 kcal/mL and are used for patients who have elevated calorie needs (ranging from 25-35 kcal/kg) or require fluid restriction. High protein formulas are designed for patients with increased protein requirements, or normal protein, but reduced calorie, requirements. These formulas usually contain 20-25% of the calories from protein as compared to 14-16% of calories from protein in standard formulas.
Fiber containing formulas are useful in patients requiring bowel management. Fiber can help manage diarrhea by absorbing excess water from the stool, and can help manage constipation by providing bulk to the stool. Soy polysaccharide is the fiber most often used in formulas and it contains 95% insoluble and 5% soluble fiber. The soluble fiber provides benefits in blood glucose control, management of blood lipid levels, and can be fermented to short chain fatty acids which are a fuel for the colonic lining cells.
Elemental diets are for patients with a GI dysfunction impairing their ability to digest and absorb nutrients. In these diets smaller molecules called peptides replace whole proteins. The carbohydrate source is usually glucose in the form of glucose oligosaccharides or maltodextrin. Fat is provided from a blend of medium chain triglycerides (MCT) to enhance fat absorption and polyunsaturated long chain triglycerides (LCT) to prevent essential fatty acid deficiency. There are elemental formulas available that are isotonic which makes them easier to tolerate.
Sometimes, but not often, specialized enteral formulas may be necessary if there is specific organ dysfunction. Disease specific enteral formulas are available for pulmonary, renal and hepatic disease. These should be used under the close supervision of the clinical team with careful monitoring of outcome.
There are three ways a patient may pay for HEN: through their insurance company, a government insurance program such as Medicare or Medicaid, or out of their own pocket. Insurance companies (also called “payors”) vary in what they will reimburse for HEN based on the employer’s requests when the insurance is purchased. Often, payors reimburse for the feeding tube, enteral pump and feeding supplies, but not for the enteral formula, which they consider “food” that the patient would be purchasing routinely. Medicaid reimbursement varies and is determined on a state-by-state basis. Medicare does reimburse for HEN; however Medicare recipients must be enrolled in Medicare Part B and meet stringent criteria. For Medicare patients, documentation of permanence, diagnosis and other factors are required to initiate HEN, and extra documentation is required for specialized enteral feedings such as disease specific or elemental formulas.
Complications of Enteral Nutrition
The complications associated with HEN fall into one of two categories for the most part: physiological or mechanical. Physiological complications have to do with the patient’s intolerance or adverse reaction to the formula, whereas, mechanical complications are mostly associated with the tube or equipment. The Oley Foundation’s HEN Complication Chart is a valuable tool for patients, caregivers and clinicians, and is available by calling (800) 776-OLEY or (518) 262-5079.
Mechanical complications of enteral access devices include displacement, occlusion, and breakage. Displacement of naso-gastric or intestinal tubes can go unrecognized by caregivers and patients, and pose the risk of unintended administration of the formula into the nasopharynx, esophagus or peritoneal cavity. Patients and caregivers should learn techniques to detect tube displacement, such as measuring and marking the length of the tube outside of the patient’s body, and should check for tube displacement prior to administering formula. They should also learn to recognize situations in which the tube is likely to become displaced, such as violent coughing, vomiting, and accidental tugging on the tube. Patients with nasointestinal tubes should report vomiting of tube feeding formula to his or her physician.
Most long-term enteral access devices have replacement end adapters for leaks or breakage. Home care clinicians should carefully document the type, brand, and size of permanent feeding tubes, and develop a plan for replacement or repair of the tube with the family should breakage occur.
Occlusion of the tube is better prevented than treated. Primary factors that may contribute to occlusion (blockage) include the use of small bore tubes for medication administration and inadequate flushing. Putting anything into the tube that has not been recommended or reviewed with the home care team should be avoided. The patient may be able to digest home cooked food, but the size of the tube may make that option almost impossible. Any “approved” food item should be completely blenderized and then strained through a medium strainer before being instilled into the tube. If at all possible, medications should be administered via another route or be provided in liquid form. Crushed pills and fiber containing laxatives should not be given via the tube or in the feeding bag. Substances that are added to the feeding formula increase the risk of tube occlusion (blockage).
Water is the best flush solution. Often, patients who receive HEN do not receive adequate amounts of free water (water not in the formula). Unless fluid is restricted, most patients should flush their tubes frequently with a liberal amount of water (60 to 120 ml) and infuse additional free water to meet his/her daily fluid requirement.
One of the most common complications after surgical gastrostomy, percutaneous endoscopic gastrostomy (PEG) and radiologic gastrostomy, is infection around the wound exit site (or abdominal wound following surgical gastrostomy). The tube exit site and abdominal wound, if present, should be carefully assessed for edema, erythema (redness), drainage, or necrotic material. Patients should care for the tube exit site using the method described by the physician when the tube is newly placed. Mild soap and water can be used to cleanse around the tube exit site once it heals. Patients should clean carefully under the external portion of their tube to remove debris and to check for excessive pressure. In most cases, it is better to avoid placing a dressing over the site once it has healed. Leakage of gastric secretions around the gastrostomy site is usually corrected by tightening, though sometimes by loosening, the external bolster. A bolster that is too loose permits leakage; but one that is too tight poses the risk of internal pressure necrosis, and distorts the exit opening that permits also leakage. Granulation tissue that forms around the exit site may require cautery with silver nitrate sticks to prevent bleeding and scabbing. With the physician’s prescription topical Lidocaine (2% solution) can be used prior to cauterization to keep the patient comfortable. Patients should report any drainage, pain, bleeding, swelling, or irritation at the tube exit site to their physician.
Aspiration risk should be considered when determining where to place the tube. Aspiration can be avoided by using appropriate feeding techniques, including elevating the head of the bed at least 30 degrees during and for at least one hour following the tube feeding. (Note: Put head of the bed on 6” blocks for feedings taken in bed. Feeding while sitting up or using wedge pillows increases intra-abdominal pressure and can aggravate reflux.)
Physiological complications revolve around GI intolerance manifested as nausea or vomiting, diarrhea, or constipation (Table 1). Such things as inappropriate formula administration, lactose intolerance, or drug therapy may cause these GI symptoms. Many medications are hypertonic and may cause diarrhea if given at the same time as an enteral formula. If these symptoms occur, the patient or caregiver should contact the physician or home care clinician.
Although most HEN patients are seen only occasionally by the primary physician or when a problem arises, monitoring at regular intervals is necessary to ensure the nutrition regimen is working. Some of the problems encountered by HEN patients include: poor understanding of the feeding regimen; inadequate administration of free water; too many or too few bag changes; significant, but unrealized weight changes; exacerbated bed sores; and inadequate feeding regimens. These types of problems can only be uncovered if a qualified home care clinician or health care professional is monitoring the HEN patient.
In home care, subjective measures of nutritional status such as evaluation of daily intake and body weight changes reported by the HEN consumer can be the most useful data in ongoing monitoring of success of home enteral therapy. Body weight is useful to monitor nutritional status unless the patient is bed-bound and cannot be weighed. In these cases, a follow up home nutrition assessment is useful to identify signs of skin breakdown or deterioration. For children receiving enteral feedings, an appropriate growth rate would indicate the nutrition regimen is adequate. On-going communication between the home care clinician and the patient or caregiver is important to assure that the feeding regimen is adhered to and is appropriate for the patient as time progresses. Some patients may require daily telephonic follow-up when beginning HEN, then progress to weekly and then monthly contact, where a long-term, stable patient may require follow-up only quarterly or twice per year. Table 2 lists some suggestions for HEN patients to use in monitoring their own progress.
HEN is an effective, relatively safe and common method of providing life sustaining nutrients to some one who cannot adequately consume nutrients orally. Proper planning, patient education and monitoring is needed to assure success. This can be accomplished by the physician and hospital or ambulatory setting care team working in tandem with the home enteral provider’s multidisciplinary health care team.
This article is a revision of an article written by the author and Marsha Orr, MSN, RN, and Kathy Hennessy, MSN, RN. References/bibliography available upon request.
Common Physiologic Complications of Enteral Nutrition Support
Home Enteral Nutrition Consumer Monitoring Checklist
My enteral formula: _____________________________________
My administration schedule: _______________________________
(what time of the day do you like to receive the feeding, how much and how)
My goal weight:________________
Contact numbers: Physician:___________________________________
Home care provider:__________________________________________
*If any of these last 3 days, or are severe, contact your clinician.
#If activity level changes for a continued period, contact your physician as your kcal needs may be increased or decreased.
+Alert my home care provider and primary care physician of any changes in medications or hospitalization.