Rolando Berger, MD F.C.C.P;[unkeyab...

Rolando Berger, MD F.C.C.P;[unkeyable] and Linas Adams, M.D.[unkeyable]

ORAL AND TUBE FEEDING

Oral feeding should be attempted first, if possible. Otherwise, if the GI tract is functional, tube feeding is easier, safer, and les expensive than parenteral nutrition.[224-226] Enteral feeding may also allow better nutrient utilization,[227-231] help maintain mucosal integrity, and decrease the incidence of stress-induced hemorrhagic gastritis.[232]

fresh feeding tubes are made of nonreactive materials (eg polyurethane), have weighted tips to facilitate insertion, are les traumatic and more comfortable to the patient because of their small diameter, and may be safer than larger tubes.[233,234] Representative examples include the Corpack Silk Nasogastric Feeding Tube (Corpack Co about $1050 each), the Kangaroo Enteral Feeding Tube (Sherwood Medical, about $11 each), and the Entriflex and Dobbhof Feeding Tubes (Biosearch Medical produces about $12 and $16 each, respectively). Generally, a nasogastric or nasoenteral tube is adequate for a small in number weeks. If prolonged (> five weeks) or permanent support is necessary, a gastrostomy or jejunostomy is usually a better choice, especially since newer tubes can be placed percutaneously with simultaneous endoscopic visualization, thus avoiding a surgical procedure[235-237] An example of a decision-tree to help picked the best type of nutritional support for a given patient is shown in Figure 1

FORMULAS

Although there are several others, we favor the following classification of enteral feeding formulas.[238]

Polymeric Formulas

These are semi-isotonic or hypertonic solutions, greatest in number of which have a relatively high carbohydrate/fat ratio, contain intact or almost intact protein, are gentle in residue and sodium, and are usually lactose-free. Exceptions to the latter include Meritane (Sandoz), Sustacal, and Sustagen (Mead Johnson) Different caloric yields, protein appeases and proportions of fats are available, and daily vitamin and mineral requirements are provided (Table 1) These preparations are adequate for the majority of patients and relatively inexpensive. Since they are reasonably palatable, they can also be used for oral feeding.[238,239]

Oligomeric Formulas

These preparations are usually hyperosmolar. They contain oligopeptides or amino acids as protein and oligosaccharides or disaccharides as carbohydrates, and thus are easier to digest. Oligomeric formulas also contain all essential vitamins and minerals, still they taste bad and are more expensive than a nutrient-equivalent polymeric preparation. Their main use is during periods of digestive insufficiency, eg after GI surgery or ileus, or for patients with special requirements, eg hepatic or renal failure (Table 1) [TABULAR DATA OMITTED]

Modular Formulas

For patients with to a high degree unusual requirements, "dietary modules" can be used to prepare custom-made feedings or to counterpart a fixed-ratio preparation. Complete modular feeding, however, is expensive, requires expertise,[240] and is seldom necessary. Examples of nutrition module include: Polycose (Ros Laboratories), Sumacal (Sherwood Medical), and ModuCal (Mead Johnson) for carbohydrates; Microlipid (Sherwood Medical) for fats; Casec (Mead Johnson) Propac (Sherwood Medical), and ProM (Ros Laboratories) for proteins; and Nutrisource (Sandoz) for a ended line of modular feedings, including module containing electrolyte vitamins, and trace elements

Regardless of prototype proper administration of tube feeding is essential. Generally, continuous infusion is better tolerated than intermittent administration,[241] may allow better nutrient utilization,[242,243] and may decrease the risk of aspiration.[238,242] Optimal continuous infusion, however, requires a feeding cross-examine (eg, Kangaroo-330, Sherwood Medical, $400 to $500/ea) and in like manner is more expensive. Further, to minimize the risk of aspiration, the patient should be kept sitting, semisitting, or with the head up at 30 [degree] and in the lateral decubitus position. This is impractical or impossible in one cases.

Intermittent administration of feedings, each 3 to 6 h, each through 30 to 60 min, is a reasonable alternative to continuous infusion. This approach is les expensive, more convenient, and better simulates a normal feeding pattern,[244] further the incidence of intolerance and complications may be higher. Thus, using small boluses and a dead infusion rate is recommended, as well as keeping the patient in a head-up position for 1 to 2 h after each feeding.

Tube feeding is usually started with 25 to 50 ml of formula diluted to 1/2 or 1/4 might If tolerated, the formula's concentration is gradually increased before increasing the mass or rate of feeding. If preferr the whirl or rate of infusion can be increased first, especially if a duodenal or jejunal tube is being used. In either case, supplemental oral intake, if possible, should be encouraged. Finally, extended (days) or frequent interruptions of tube feedings must be avoided. If this is not possible, supplemental parenteral nutrition should probably be considered (Fig 1) to avoid building a larger nutritional deficit.