Tubes are passed through the nose to various points in the GI tract and are named with reference to the location of the terminal end of the feeding tube. Examples include nasogastric, nasoduodenal, and nasojejunal tubes.
Tubes are placed either laparoscopically, operatively, or percutaneously. Examples include esophagostomy, gastrostomy (PEG), percutaneous endoscopic jejunostomy (PEJ), needle catheter jejunostomy (NCJ), operative laparoscopic gastrostomy, operative laparoscopic jejunostomy.
Disadvantages
To promote tolerance, enteral tube feedings should be initiated at rates of 50 cc/hr in adults. Most currently available formulas are isotonic (300 mOsm/L) and are well tolerated at full strength when delivered into the stomach or small intestine. The rate of administration of isotonic formulas can usually be advanced in 20-25 cc/hr increments every 8 hours until goal rate is achieved. It is often more realistic to calculate goal rates based on 20-22 hours/day allowing for interruptions in delivery.
2. Calculate Additional Free Water Requirements
Most patients on enteral nutrition therapy will require
additional fluid to meet minimum fluid requirements. To
calculate additional fluid requirements begin by determining the
patient's total fluid needs (see Section III part D). Then determine
the amount of free water provided by the tube feeding formula
by multiplying the percent free water content
(information available in diet manual, on enteral formulary cards, or
by contacting a dietitian) by the total volume of tube
feeding formula to be administered each day. Subtract the free
water supplied by the formula from the calculated total free
water requirement which equals remaining volume of free water
and divide the remaining into 3 or 4 boluses per day.
Example:
A 50 year old female weighing 55 kg requires full strength Isosource HN at 55 mL/hr to meet her energy and protein requirements and 1800-2000 mL fluid/d. Isosource HN is 82% free water. Then 55 mL/hr x 24 hr x 0.82 = 1082 mL free water/d provided by the enteral formula. Her additional fluid needs are 1800 - 1082 = 718 mL/d or about 3 boluses of 250 mL each.
3. Transition to Cyclic or Bolus Feedings
Hospitalized patients may initially benefit from a continuous infusion to establish tolerance to enteral nutrition therapy and later transition to an intermittent infusion schedule. Intermittent infusion (bolus feedings) can be administered by gravity dip or syringe bolus for those patients with gastric feeding tubes.
Cyclic feeding using a pump can be used in patients with intestinal feeding tube sites (duodenum or jejunum). Cyclic feeding infuse formula for a set number of hours (e.g. 8-12 hours overnight). A cyclic feeding schedule should be considered for patients for whom free time off the pump is desired.
4. Vitamin and Mineral Requirements
Enteral formulations contain varying amounts of vitamins
and minerals and may not be sufficient to meet patient
needs. Consult a dietitian for the micronutrient content of
specific products and for assistance in determining
supplementation for these patients.
Routine nursing care includes checking gastric residuals every 4-6 hr in patients receiving gastric feedings until desired rate is established. Infusions are held for 1 hour if gastric residual is >(1.0 to 1.5) x hourly rate or >150 mL before bolus or intermittent feeding.
Daily weights, I/O records, serum electrolytes, phosphorus, magnesium, and ionized calcium should be monitored until tolerance is established and patient is stable (see Section VII).
Confirm feeding tube placement by KUB before initiating enteral nutrition.
Document location of the terminal end of the feeding tube in the orders for initiating tube feeding.
Order desired formula and indicate initial strength, initial rate (mL/hr), desired progression regimen and goal strength and rate.
Order additional fluid (e.g. sterile water or normal saline) to flush tube with at least 30 mL every eight hours and provide needed hydration.
Note that 20-30 mL sterile water should be used to flush feeding tube before and after administering medications via the feeding tube.
Order all routine monitoring parameters, baseline and routine lab tests.
If the patient is able to take medications by mouth, the oral route is preferred over administration via the feeding tube
For certain medications that pose a particular problem for enteral administration (e.g. repreatedly clogs tube, unavailable in suitable liquid or crushable form, unpredictable absorption, etc.), alternative routes of administration that bypass the tube or even therapeutic alternatives should be considered. Alternative routes may include IV, IM, PR, SL, or transdermal.
For individual doses of most medications, the tube should be flushed with at least 30 mL of sterile water before and after administration. This serves to clear the tube for drug delivery, facilitate drug transport to the intestine, and indicates whether the tube is cleared.
When several medications are to be administered, all medications should be given seperately and the tube flushed with at least 5mL of water after each dose.
Most drugs in suspension, elixir, or other liquid form are hypertonic. Highly concentrated drug solutions and suspensions should be diluted with at lest 60 mL of water before administration to decrease gastric mucosal irritation and prevent osmotic diarrhea.
For patients recieving many medications via the feeding tube or for critically ill patients, the volume required for diluting, flushing, and administering medications may be significant. Alternative routes of administration may need to be considered.
Medications should never be added directly to the feeding formulation. The potency, stability, and availability of the medication as well as the stability of the enteral formulation cannot be ensured.
For most medications, the enteral feeding should be stopped for at lest 15 minutes before and after drug administration. Certain drugs have increased bioavailability, produce more predictable blood levels, and/or are better tolerated on an empty stomach. Some drugs may require feedings to be held for longer intervals. For example, dilantin administration requires that the feeding be stopped for one hour prior to and after dosages. Multiple interruptions in formula delivery maay compromise nutrition support and shoudl therefore be avoided. Other routes of drug administration may need to be considered.
Stop gastric feedings 1/2 hour prior to and after treatment or procedures requiring the Trendelenberg position (e.g. chest physiotherapy, central line insertion).
Call Pharmacy for any questions regarding the availability of dosage forms and routes, contents of a specific formulation, specific drug administration techniques, or timing of drug administration with enteral feedings.
Drugs can not be but down NCJ.
Table III: Complications of Enteral Nutrition Therapy: Possible Causes & Management
| Complications | Possible Cause | Suggested Management |
| Gastrointestinal | ||
|---|---|---|
| diarrhea (>4 BM per day or large loose stool) |
medications |
|
| fat intolerance |
|
|
| bacterial overgrowth |
|
|
| contaminated formula |
|
|
| osmotic overload |
|
|
| decreased bulk |
|
|
| nausea or vomiting | patient position |
|
| volume overload |
|
|
| delayed gastric emptying |
|
|
| specific nutrient intolerances |
|
|
| GI tract obstruction |
|
|
| constipation (no stool x 3 days |
dehydration & impaction |
|
| decreased fiber |
|
|
| GI tract obstruction |
|
|
| Mechanical | ||
| pulmonary aspiration | patient lying flat |
|
| absent or depressed gag reflex |
|
|
| reflux |
|
|
| improper tube placement |
|
|
| tube obstruction | acid precipitation of formula |
|
| insufficient tube irrigation |
|
|
| medications |
|
|
| mucosal damage | extended use of large bore tubes |
|
| Metabolic | ||
| overhydration | refeeding |
|
| fluid overload |
|
|
| dehydration | high osmolality formula |
|
| diarrhea |
|
|
| excessive protein intake with inadequate fluid intake |
|
|
| hyperglycemia | insulin deficiency |
|
| hypoglycemia | sudden cessation of feedings |
|
| hyperkalemia | metabolic acidosis |
|
| renal insufficiency |
|
|
| anabolic metabolism |
|
|
| hypokalemia | refeeding syndrome |
|
| insulin administration |
|
|
| diuretics |
|
|
| diarrhea |
|
|
| hyperphosphatemia | renal insufficiency |
|
| hypophosphatemia | refeeding syndrome, insulin administration |
|
| hypomagnesemia | refeeding syndrome, alcoholism |
|
| hyponatremia | fluid overload |
|
| elevated BUN | renal failure excess protein (nitrogen) intake dehydration medications diuretics, steriods) |
|
| rapid, excessive weight gain |
excess calories, excess fluid, electrolyte imbalance |
|
| insufficient weight gain | inadequate calories |
|
| malabsorption |
|
|
| catabolic state |
|
|
| depression, withdrawal, non-compliance |
altered body image |
|
| loss of oral gratification |
|
|