Enteral and Parenteral Nutrition

6. Enteral and Parenteral Nutritional

(See Chapter 12 for more detail)

Assisted Feeding and Enteral Nutrition

For many gastrointestinal diseases, a period of assisted feeding is required. The rapid and thorough attention to the nutritional management of inappetent patients can decrease morbidity and mortality. Diets may be applied either by syringe or as small solid boli depending on the underlying disease or the preference of the patient or owner. Feeding tubes are an accepted way of providing nutritional support to animals unable or unwilling to consume adequate calories on their own (Wortinger, 2006).

Enteral feeding is preferred and can be achieved by nasal, pharyngeal, esophageal, gastric or jejunal feeding tubes (Ireland et al., 2003). The diameter of the tube should be large enough to permit feeding of the chosen diet, either specific enteral products or blended canned food that may be additionally diluted with water. Percutaneous endoscopic gastrostomy tubes have traditionally been considered to be the best-tolerated feeding device, but they are not without complications (vomiting and stomal site infection) and they require specific equipment and training. Esophagostomy tubes are an alternative and are simpler to place and have lower complication rates. For esophagostomy tubes, vomiting, scratching at the tube and bandage, removal of the tube and mechanical difficulties have been described (Ireland et al., 2003).

Parenteral Nutrition

Total parenteral nutrition (TPN) is used to fulfill the total nutrient requirements in cats that are anorectic for longer periods and that cannot be maintained on an enteral feeding regime. Although the technique of parenteral nutrition is well established in many veterinary hospitals, it requires some training and equipment to avoid complications. Metabolic (hyperglycemia, hyperkalemia), mechanical (catheter dislodgement, cellulitis), or septic problems may be related to the improper installment of parenteral nutrition in cats (Crabb et al., 2006). Often these complications are mild and can be managed without discontinuation of TPN or adjustment of the infusion protocol. A more conservative estimate of energy requirements appears to be associated with a lower risk of hyperglycemia.

Using partial parenteral nutrition (PPN) delivers only a certain part of the required nutrients and energy. The risk of metabolic problems in cats is considerably reduced by this approach, although septic and mechanical complications may also occur (Chan et al., 2002). Animals on combined enteral and parenteral nutrition can have a better clinical outcome than those receiving parenteral nutrition exclusively.