Chapter 18 Nutrition Support

TABLE 18.2 Example of Initiation and Progression of Tube Feeding Delivery Method

Rate Continuous tube feeding

50 mL/h 75 mL/h 100 mL/h

Intermittent/bolus tube feeding

120 mL every 4 h 180 mL every 4 h 240 mL every 4 h

Monitoring

Appropriate monitoring may prevent or reduce compli- cations associated with tube feeding (21). Monitoring is more critical in older adults because of diminished compensatory mechanisms. Tube-fed persons should have the following parameters monitored daily: body weight, presence of edema/ascites, fluid intake/output, bowel function, vital signs, and medications. Those with diabetes or glucose intolerance may need to have blood glucose levels monitored several times daily until a consistent feeding regimen is tolerated. Gastric residual volume (GRV), the amount of feeding left in the stomach at a point of time during enteral feeding, should be checked for nasogastric feed- ings only (23). The A.S.P.E.N. guidelines for GRV in patients who are critical suggest that feedings should not be stopped for volumes less than 500 mL unless there are other signs and symptoms of feeding intolerance (24). Emesis, abdominal distention, constipation, abdominal pain, nausea, or diarrhea are signs of intoler- ance and require a reevaluation of the feeding regimen. These GRV recommendations, based on critically ill individuals, state that after 48 to 72 hours of feeding with acceptable GRV, measurement of GRV is no longer needed. Additionally, in patients who are awake and can provide verbal communication on tolerance, GRV mea- surement is not necessary. Laboratory studies, including electrolytes (ie, sodium, potassium, and chloride), blood urea nitrogen (BUN), creatinine, phosphorous, calcium, liver function tests, magnesium, albumin, and transfer- rin, should be checked on initiation of enteral nutrition and as needed for medically unstable clients (21). Laboratory studies may only need to be monitored every six months for stable, long-term, tube-fed older adults.

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Time

1st 8 h 2nd 8 h 3rd 8 h

Goal: 24 h

1st 8 h 2nd 8 h 3rd 8 h

Goal: 24 h Complications

Although generally considered to be safe, tube feeding is not without complications (23). Problems related to the delivery of tube feeding may be classified as mechanical, infectious, gastrointestinal, or metabolic.

Mechanical Issues

Feeding-tube displacement and migration is a serious mechanical complication of enteral nutrition and may result in aspiration, diarrhea, or peritonitis (with gas- trostomy or jejunostomy tubes). Verification of tube placement by x-ray is necessary before feedings are started or when tube malposition is suspected. Nasogastric and nasoenteric tubes are associated with pressure necrosis. This may also lead to sinusitis, mucosal ulceration, abscess formation, and perforation. The tube should be rotated in the nares and converted to a gastrostomy as soon as long-term need is identified.

Clogging

Clogging of the feeding tube can be obviated with proper flushing and medication administration (26,27). Formula coagulation, obstruction by pill fragments, tube kinking, and precipitation of incompatible medi- cations may lead to feeding-tube obstruction. It is pref- erable to dislodge the obstruction rather than to replace the tube (26). (See the “Medication Administration” section of this chapter for guidelines regarding the delivery of medications via feeding tubes). Specialized products are available to assist in unclogging a feeding tube. Only specific products should be used, and the guide wire should never be used to unclog a feeding tube (16).

Other

Gastroesophageal reflux can occur as a result of dimin- ished gastric emptying. Pulmonary aspiration, which may result from reflux, is one of the most serious