After the infusion method has been determined, a formula needs to be selected. There are many formulas on the market, ranging from elemental preparations of predigested nutrients to more complete and complex formulas that mimic oral nutrition intake. Specialized formulas are available for specific health conditions such as diabetes mellitus and compromised renal function. Modular formulas that are not nutritionally complete but add specific nutrients such as protein, fat, and carbohydrate are also available. These preparations can be added to an existing formula to provide additional benefit.
Glutamine, an amino acid, is a key energy source for the gut and has been shown to help maintain gut health and integrity and to protect the gut from damage from radiation and chemotherapy.[29,30] The use of supplemental glutamine in tube feedings in addition to L-arginine and omega-3 fatty acids is gaining popularity. These potentially beneficial nutrients are now available in formulas and as oral supplements. More research needs to be done, however, to thoroughly evaluate the benefits and possible disadvantages.
When a formula is being chosen, the institution nutrition formulary for available preparations, modular formulas, and additions such as glutamine or fiber should be considered. Consideration should also be given to the patient's medical condition, gastrointestinal function, and financial resources.
Transition to Home
A significant number of patients using enteral nutritional support in the hospital are discharged to home while still on therapy. This can be done successfully and requires that the following conditions are met:
- The patient and/or caregiver is given enough time for education and is proficient in the use of the tubes, site care, and the use of the pump.
- The patient is discharged to a safe and clean environment.
- Regular medical follow-up is arranged to ensure appropriate function of the feeding tube and optimization of the nutrition plan.
Parenteral nutrition may be indicated in select individuals who are unable to use the oral or enteral route (i.e., those who have a nonfunctioning gut), such as those with obstruction, intractable nausea and/or vomiting, short-bowel syndrome, or ileus. Additional inclusive conditions common in the cancer population are severe diarrhea/malabsorption, severe mucositis or esophagitis, high-output gastrointestinal fistulas that cannot be bypassed by enteral intubation, and/or severe preoperative malnutrition.[27,29]
Contraindications for use of parenteral nutrition are a functioning gut, a need for nutritional support for a duration less than 5 days, an inability to obtain intravenous (IV) access, and poor prognosis not warranting aggressive nutritional support.[27,29] Additional conditions that should cause hesitation are the following: patient or caregiver does not want parenteral nutrition, patient is hemodynamically unstable or has profound metabolic and/or electrolyte disturbances, and/or patient is anuric without dialysis.[27,29]