Enteral feeding

To nelp consei ve steam economy, venting is usually done from the steam chest of one effecl to the steam chest of the next. In this way, excess vapor in one vent does useful evaporation at a steam economy only about one less than the overall steam economy. Only when there are large amounts of noncondensable gases present, as in beet-sugar evaporation, is it desirable to pass the vents directly to the condenser to avoid serious losses in heat-transfer rates. In such cases, it can be worthwhile to recover heat from the vents in separate heat exchangers, which preheat the entering feed. 

When normal enteral feeding in not possible or is inadequate to meet an individual s nutritional needs, intravenous (IV) nutritional therapy or total parenteral nutrition (TPN) is required. Products used to meet the IV nutritional requirements of the patient include protein substrates (amino acids), energy substrates (dextrose and fat emulsions), fluids, electrolytes, and trace minerals (see the Summary Drug Table Electrolytes). 

Example 5.10 A liquid-phase, pilot-plant reactor uses a 12-ft tube with a 1.049-in i.d. The working fluid has a density of 860 kg/m, the residence time in the reactor is 10.2 s, and the Reynolds number is 8500. The pressure drop in the pilot plant has not been accurately measured, but is known to be less than 1 psi. The entering feed is preheated and premixed. The inlet temperature is 60°C and the outlet temperature is 64°C. Tempered water at 55°C is used for cooling. Management loves the product and wants you to design a plant that is a factor of 128 scaleup over the pilot plant. Propose scaleup alternatives and explore their thermal consequences. 

Flush enteral feeding tube with 20 mL water or saline... 

Adjust enteral feeding rate to maintain the same 24-h volume... 

Estimate kilocalorie and protein requirements of an enteral feeding candidate and design an enteral nutrition (EN) regimen to meet these. 

EN should not be used or should be used with extreme caution in certain conditions (Table 98-3). It is possible to use EN in some patients with these conditions depending on severity of illness, location of the abnormality and experience of the practitioners delivering care. Controversy surrounds some of these contraindications and precautions. For example, whereas some clinicians will deliberately avoid enteral feedings in the hemo-dynamically unstable patient for fear of worsening intestinal... 

Enteral feeding formulas can be categorized based on caloric density. Standard caloric density is 1 to 1.3 kcal/mL. More calorically dense formulas containing 1.5 to 2 kcal/mL are also available and have a higher osmolality. When choosing an EN formula, the patient s fluid status should dictate the caloric density selected. Fluid-overloaded patients may benefit from more calorically dense formulas. It should be recognized that... 

The newer generation of enteral feeding formulas marketed for use in these populations covers a broad spectrum of characteristics (Table 98-5). Whereas some are polymeric, others are oligomeric to address the malabsorption that sometimes accompanies high stress. Some of the formulas marketed for use in critical illness are calorically dense (1.5-2 kcal/mL) to... 

TABLE 98-5. Enteral Feeding Formulas Marketed for Use in High Stress, Pulmonary Disease, and Trauma... 

What effect would the enteral feeding be expected to have on the patient s blood sugar ... 

TABLE 98-7. Enteral Feeding Products Designed for Use in Renal Failure... 

Rehydration and maintenance of water and electrolytes are the primary treatment measures until the diarrheal episode ends. If vomiting and dehydration are not severe, enteral feeding is the less costly and preferred method. In the United States, many commercial oral rehydration preparations are available (Table 23-3). 

TABLE 58-2 Adult Enteral Feeding Formulation Classification System ... 

Medications with Special Considerations for Enteral Feeding Tube Administration... 

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