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Part II Nutrition Assessment, Consequences, and Implications Modular Enteral Formulas

Modular components of single macronutrients (ie, car- bohydrate, protein, and fat) may be used to alter the energy or protein content of a base formula or to create a new tube-feeding formula (19).

Special Considerations for

Older Adults A standard, 1 kcal/mL polymeric formula can meet the needs of many older adult clients. However, some older adults may need a specialized formula. Constipation is common among older adults and may be alleviated by a fiber-containing formula and suffi- cient free-water flushes. A high-nitrogen, 1 kcal/mL polymeric formula, which provides increased protein without increased energy, may be appropriate for older adults with increased protein needs, as energy needs tend to be lower than those of younger adults. Older adults with medical diagnoses requiring volume restriction, such as those with congestive heart failure, chronic obstructive pulmonary disease, or renal or hepatic failure, may benefit from a concentrated formula.

Administration Techniques The method of administration used to provide enteral nutrition support depends on the location of the feeding tube, tolerance to the feeding regimen, and overall nutrition goals. The two methods of tube feeding are continuous and intermittent/bolus (19).

Continuous feedings may be given by gravity drip or infusion pump and are provided 24 hours per day. Continuous feedings are used for immobile, comatose, or critically ill clients. When the feeding tube is in the jejunum, continuous feedings are required because of the lack of gastric holding capacity. Alternatively, tube feeding may be administered cyclically by infusion pump over a 10- to 18-hour period (typically during the night). Nocturnal feeding is beneficial when attempting to wean the tube feeding because it allows the client to eat during the day. Nocturnal feedings also allow the older adult to engage more easily in activities of daily living and in physical activity and therapies. Intermittent feedings can be given with a syringe as a bolus or via gravity drip or infusion pump for 20 to 30 minutes several times per day (usually five to six times per day).

Bolus feedings are characterized by the rapid delivery (10 minutes or less) of 250 mL to 400 mL of formula several times per day. Feedings are infused via syringe through the feeding tube into the stomach. This method is frequently used in the home and in nursing facilities. Careful attention to the amount given (which is frequently smaller in the older adult) will help

obviate complications such as nausea, diarrhea, vomit- ing, distention, cramps, or aspiration (20). Tube-feeding formulas—standard or hypertonic— should be initiated at full strength and at an appro priate rate (21). Isotonic feedings have an osmolality range of 280 mOsm/kg to 320 mOsm/kg, whereas hypertonic feedings exceed this range. If intolerance develops with initiation of a hypertonic feeding, decrease the rate of feeding, continuing with the same feeding schedule and working on increasing until the desired rate is achieved. Diluting a tube-feeding formula can result in contamina- tion and inadequate administration of nutrients over time. Continuous feedings can be initiated at 20 mL to 50 mL/h. Advancement may range from 10 mL to 25 mL/h every 4 to 24 hours until the goal rate is achieved. Intermittent feedings may be initiated at 120 mL every 4 hours and increased by an additional 60 mL every 8 to 12 hours to goal. Table 18.2 is an example of initiation and progression of tube feeding. The tube-feeding delivery container should be changed daily. Only the amount of feeding formula for a four- to eight-hour period should be added to an empty tube-feeding container, limiting hang time to 8 hours per feeding period in an open system. For a closed system, limit formula hang time to 48 hours or according to the manufacturer’s directions.

Medication Administration The administration of medications through enteral feeding tubes should be avoided if possible because of the risk of tube occlusion and incompatibility of medi- cations with tube-feeding formulas (22). Alternative routes for medication administration, such as oral, intravenous, or intramuscular, should be used. When medications must be administered through the enteral feeding tube, the following guidelines are suggested (16):

1. Flush the feeding tube with 15 mL to 30 mL of warm tap water before and after administering any single medication.

2. Use only water to flush feeding tubes. 3. Infuse each drug separately; flush with water before and after each medication.

4. Do not add drugs to tube-feeding formula. 5. Stop feeding while giving drugs. 6. Do not administer elixir medications, bulk-form- ing laxatives, time-release, or highly viscous med- ications via a feeding tube.

7. Avoid potential food-drug interactions by using alternative administration routes, alternating for- mulas or medications, altering feeding or medica- tion schedules as indicated, and using multidisci- plinary team input (19).