NUTRITIONAL INTERVENTION

NUTRITIONAL INTERVENTION

ORAL NUTRITION

When a patient is hospitalized, whether as an acute or a rehabilitation admission, oral intake is altered from the norm. Hospital food may be unacceptable, or it may be tolerable, but it is never exactly what the patient is accustomed to eating at home.

Sometimes patients do eat 100% of their meals. These patients are usually the exception and are typically categorized as "not at nutritional risk." Some patients may start out in this category, but during a lengthy admission, intake can begin to decline.

Nutritional intervention plans usually follow a progression from oral to enteral to parenteral. Oral nutrition is the starting point of all interventions. If the gut works, use it. Oral nutritional intervention consists of dietary change, as well as the addition of between-meal snacks and nutritional supplements.

A regular diet at any facility is considered a balanced diet with respect to the major macronutrients and food groups. It meets the nutritional needs of a general population, which consist of approximately 55% of calories coming from carbohydrates, 15% coming from protein, and 30% coming from fat.

The regular diet has no alterations in texture, no specialized foods, and no electrolyte/mineral restrictions.

Therapeutic diets are an alteration from the regular diet.

THERAPEUTIC DIETS

The goal of a prescribed diet is to optimize intake while the patient is hospitalized, to promote wound healing and to provide enough energy to allow the patient to undergo therapy.

A therapeutic diet may be contraindicated despite the fact that the patient's history includes an illness that generally calls for dietary alterations. Many of the diets listed above are unpalatable because of their composition and are limited in the variety of foods that can be provided. Optimal nutrition cannot be achieved if the patient is not inspired to eat the foods provided.

Complicated diet prescriptions need to be the exception, not the rule. The more diets that are prescribed (eg, mechanical soft, cardiac [sodium/cholesterol restricted], renal [protein/potassium/phosphorous restricted] with a 2-liter fluid restriction), the less likely it is that a patient will eat.

Nutrition is the 1 treatment modality over which the patient usually has control. A liberal attitude should be maintained, providing a diet that the patient will eat but that will not endanger his or her condition.

Adjusting a patient's diet is the initial intervention. If intake does not improve with dietary modification, the next step is to provide between-meal snacks. Again, snacks should be provided based on the patient's preferences, not arbitrarily given.

Snacks differ from facility to facility, but they usually are given 3 times per day, at morning, afternoon, and evening intervals. Small, frequent meals should be provided, since this generally optimizes daily intake. Snacks are a very cost-effective intervention.

The provision of a nutritional supplement is definitely not a first-line management technique for poor oral intake. Supplements should be an alternative rather than an automatic intervention. When prescribed appropriately, supplements easily can optimize intake. The goal is to provide a supplement that is appropriate to the patient's condition and that the patient will consume.

Supplements should never be overprescribed. Nothing is more overwhelming to a patient than constantly receiving supplements and having them pile up by his or her bedside. This tends to have the reverse effect on intake. The more supplements the patient receives, the less likely the individual is to eat them.

Food is not always the source of a patient's intake problems; these could instead be related to the act of eating. Upper extremity capabilities must be present to feed. If the patient has any upper extremity disabilities, independent feeding may be an issue.

Oral capacity also affects food intake, including in patients who may have the appetite to eat. Difficulty chewing food can result from a number of problems, including ill-fitting dentures, missing teeth, poor dental hygiene, oral infections, and discomfort following an oral procedure. Changes in food consistency are prudent in these situations, but only when they have been discussed with the patient.

MEDICATION ISSUES

Medications cannot be overlooked when patients are not eating well. They affect intake in a variety of ways and, with prolonged use, eventually cause changes in nutritional status.

Some drugs are secreted into saliva, causing an unpleasant taste. Some are unpalatable (eg, potassium preparations, cholestyramine), and some may cause a taste disorder by altering receptor function (eg, captopril, penicillamine). Facilitating relief by masking the drug's taste with food should be considered.

Some examples of drugs and their possible side effects include the following:

• Phenytoin - Gingival hyperplasia

• Antineoplastic agents - Delayed wound healing and microbial infections

• Broad-spectrum antibiotics - Candidiasis

• Anticoagulants - Bleeding gums

Prolonged use of antihistamines and bronchodilators may decrease olfactory receptor response. Additionally, medications may alter the oral environment and result in decreased intake. For example, antidepressants may cause dry mouth and broad-spectrum antibiotics may lead to candidiasis.

Consider decreasing dry, salty foods; offer moist, soft foods. Liquids should be increased at meal times, and spicy and acidic foods should be avoided.

Any medication taken orally can potentially cause gastric irritation (eg, nonsteroidal anti-inflammatory drugs [NSAIDs]). Drugs may stimulate or depress the appetite.

Appetite stimulants include antihistamines and psychotropic drugs. The antineoplastic drug megestrol acetate often is prescribed to stimulate appetite. Numerous drugs have the secondary effect of decreasing appetite. These agents include dextroamphetamine and methylphenidate.

Antineoplastic agents, levodopa, and sulfasalazine are a few drugs that may cause disagreeable symptoms (eg, nausea, vomiting). Digitalis derivatives can stimulate chemoreceptor triggers directly and initiate vomiting.

Suggestions include offering small quantities of foods that are easily digestible, serving carbonated liquids as the patient requests, maintaining adequate hydration, offering cold foods instead of hot foods (if the aroma of hot foods causes problems), and avoiding fried, greasy foods.

CONSTIPATION

The main offenders include anticholinergics, sedatives, hypnotics, and narcotics. To aid relief, adequate hydration should be maintained, daily fiber intake should be increased, and dependency on laxatives should be avoided.

DIARRHEA

Cancer chemotherapeutic agents, antibiotics, laxatives, and antacids have the potential to cause diarrhea. To aid relief, a bland diet should be provided in small amounts, and the following should be avoided:

• Caffeine

• Highly spiced foods

• Concentrated sweets

• Uncooked fruits and vegetables

• Whole grain breads and cereals

EATING ENVIRONMENT

Although a patient's dining environment is probably the easiest problem to solve, it is the issue that is the most likely to be overlooked. If the patient dines at his or her bedside, the clinician should assess the surroundings.

CLEANLINESS

Clutter on the bedside tray makes eating an unpleasant and difficult experience. Care needs to be taken to make sure the patient's bedside tray table is clear of extraneous items (eg, urinals, tissues, newspapers, magazines). The dining experience should be made into one that can be enjoyed.

LIGHTING

Proper lighting should be emphasized. Open the patient's curtains. Turn on the lights. Let the patient see what he or she is going to eat.

SEATING

Eating from a bed is very difficult. An easy solution is to transfer the patient to a chair for meals if possible. Perhaps the tray table does not adjust to proper height for the chair or bed. A quick adjustment to the level of the bedside table can make all the difference in the world.

POSITIONING

Comfort is the key. Patients need to be relaxed, and proper positioning improves the comfort level. Increased comfort creates an increased ability to sit up and eat; optimally, this means increased oral intake.

ROOM OCCUPANCY

Arguments have been made for privacy and for company when it comes to pleasurable dining. The ideal environment should be discussed with the patient, and attempts should be made to accommodate dining wishes.

If a roommate is acceptable but the roommate has a medical condition that prevents quality dining, such as a persistent cough, vomiting, diarrhea, or flatulence, consider an adjustment of the meal location.

With cafeteria-style dining, the same issues are present. The cafeteria needs to be clean, to have adequate lighting and comfortable chairs, and to be wheelchair accessible. Again, table assignments need to be discussed. If patients are not comfortable with their dinner company, their intake will suffer. Encourage family members to visit at mealtime, perhaps bringing in a favorite dish or dessert.

The dietitian should make daily meal rounds. This type of direct observation provides significant information and often provides clues as to why a patient may not be eating.

ENTERAL NUTRITION

When the patient is unable to consume adequate nutrition orally, more aggressive support needs to be considered. Going back to the saying, "If the gut works, use it," enteral support is an alternate route of intervention.

A patient with a functional GI tract is a candidate for enteral support when he or she will not, should not, or cannot take nutrition orally.

The benefits of enteral support include the following:

Ø  Maintenance of GI structure/integrity

Ø  Improved utilization of nutrients

Ø  Cost effectiveness

Ø  Ease of administration

Ø  Lowering of hypermetabolic response

The feeding route is the first consideration in enteral support. This decision is based on the duration of feeding, the patient's medical status, and the risk of aspiration. Short-term feeding is considered to be less than 6 weeks, and long-term feeding is greater than 6 weeks.

ENTERAL FEEDING ROUTES 

CONTINUOUS / BOLUS FEEDINGS

Feedings may be continuous or bolus. Continuous feeding is a more reliable route of nutrient delivery, as a feeding pump is required. Feedings are given over 16-24 hours. This method has been associated with lower residual volumes, a decreased incidence of diarrhea, and a decreased risk of aspiration.

Continuous feeding is recommended at the initiation of enteral support, as it is much better tolerated than a bolus infusion. As the small bowel tends to be sensitive to large volumes, the continuous feeding method is recommended when feeding post pylorically.

Bolus infusions via gravity or syringe generally are used in the medically stable patient, as well as in the homebound or rehabilitation patient. Feedings are given quickly (2 cans over 30 minutes, 4-6 times per day), mimicking a regular meal.

The maximum amount recommended is 400-500 mL per feeding; however, 250-400 mL is the most common infusion amount. Establish tolerance with continuous feeding, and then transition to bolus feedings when tolerance has been established.

INITIATION AND ADVANCEMENT SCHEDULE

Prior to the initiation of tube feeding, placement of the nasogastric feeding tube must be verified. Radiographic confirmation is the most reliable method of determining placement. Use of a promotility agent (unless contraindicated) before insertion increases the chances of transpyloric placement, which is better tolerated initially.

The following agents are recommended 30 minutes before placement:

• Metoclopramide - 20 mg IV

• Erythromycin - 200-400 mg IV

No standard initiation/advancement schedules appear in the literature; however, reasonable schedules can be recommended based on the type of feeding formula, location of the feeding, the type of patient, and the patient's condition.

Examples include the following:

Ø  Isotonic formula / gastric feedings can be initiated full strength at a rate of 20-25 mL/hr and advanced every 8 hours in increments of 20-25 mL until the desired rate is achieved.

Ø  Hypertonic formula / small bowel feedings should be initiated full strength at 10-15 mL/hr and increased every 12 hours in increments of 10-15 mL until the desired rate is achieved.

Tube feeding initiation should also be based on the type of patient.

• Hypometabolic

  • This individual is seen as a marasmic type of patient, unstressed and clinically starved.

  • Such patients are at risk of developing refeeding syndrome. Refeeding syndrome is an electrolyte disturbance that accompanies an overzealous nutrition regimen. It can lead to death if left untreated.

  • Nutrition support should be cautious, with an aim to rebuild.

  • The initiation rate should be low, and the advancement schedule should be conservative. It may take several days to achieve the target.

• Hypermetabolic

  • This individual is seen as a patient of the kwashiorkor type, is clinically stressed from injury/trauma, and is considered catabolic.

  • Such patients are at risk of overfeeding.

  • Nutritional support should be aggressive but not excessive.

  • Targets need to be achieved in a timely manner, since the patient is in need of optimal nutrition to deal with a hypercatabolic situation.

Initial infusion rates and the subsequent advancement schedule also depend on the overall condition of the patient, as follows:

• Altered mental status - Initiate and advance feeding slowly because of an increased risk of aspiration.

• Recent use of GI tract - Prolonged nonuse of the GI tract requires cautious initiation and advancement schedules.

• Nutritional status - The feeding schedule can be more aggressive with patients of normal nutritional status.

• Functional status of GI tract - Assess partial versus full function; if the gut works a little, use it a little.

All hospitals have an enteral formulary. Physicians should obtain a formulary card to help make product decisions. Several formula categories should be considered when selecting a product for enteral nutrition support.

COMPLICATIONS

Complications associated with enteral support are largely preventable through formula selection, proper administration, and careful monitoring.

Complications fall into gastrointestinal, mechanical, and metabolic categories, as follows:

• Gastrointestinal complications

  • Diarrhea is the most common complication of enteral feeding. Diarrhea is defined as 4 bowel movements per day or a large liquid stool (>250 g). The most common causes of diarrhea associated with enteral support include the following:

    • Medication - This is mainly related to antibiotics, antacids, potassium supplementations, cimetidine, sorbitol-containing medications, or medications in the form of an elixir.

    • Hypoalbuminemia - An albumin level of less than 2.5 g/dL results in decreased colloidal osmotic pressure with accompanying peripheral edema.

    • Malabsorption

    • Bacterial contamination

    • Lactose intolerance

    • Lack of fiber

    • Altered bacterial flora

    • Rapid administration

  • Constipation is defined as no stools for 3 or more days and is less common in the acute care setting. Possible causes include the following:

    • Dehydration

    • Lack of fiber

    • Dysmotility and GI obstruction

  • Nausea/vomiting - If vomiting occurs, tube feeding should be discontinued to prevent possible aspiration. Aspiration is the most serious complication of enteral support. If undetected, aspiration may become life threatening. Potential causes include the following:

    • Delayed gastric emptying

    • Neurologic impairment

    • Decreased intestinal motility

    • Presence of a nasoenteric tube and tube migration

    • Nausea and/or vomiting can be prevented with the following techniques:

      • Using a small bore feeding tube (<10 French).

      • Elevating the head of the bed 30° during feeding.

      • Having the patient ambulate whenever possible.

      • Monitoring for tube migration.

      • Positioning the tube postpylorically.

      • Recommending a continuous administration schedule versus bolus feeding.

      • Positioning the patient on the right side to facilitate passage of the gastric contents through the pylorus.

      • Having the patient use promotility agents 30 minutes before eating.

      • Checking residual volumes periodically. No consensus has been reached concerning acceptable gastric residuals; however, if a residual volume is greater than 200 mL with a nasogastric tube or greater than 100 mL with a gastrostomy tube, it would be prudent to delay the feeding.

• Mechanical complications result from placement of the feeding tube, from the presence of a feeding tube, or when a tube becomes blocked.

• Metabolic complications involve changes in laboratory values, fluid status, and/or clinical conditions.

METABOLIC COMPLICATIONS OF ENTERAL SUPPORT

TRANSITION FROM ENTERAL TO ORAL FEEDING

The goal of rehabilitation is to return the patient to normal function. Return to normal function is the goal of nutritional management as well. The goal with enteral support is a gradual transition from tube feeding back to an oral diet, if that is a possibility.

The following options are suggested to accomplish an effective transition without compromising the patient's nutritional status:

• Never discontinue the tube feeding all at once. If the patient is on 100% enteral support, resume oral diet without adjusting tube feeding.

• Monitor oral calorie/protein intake initially and then on a periodic basis to determine the percentage of calories/protein being met by the oral diet. Decrease tube feeding to meet the patient's needs. For example, if the patient is consuming 50% of his or her needs orally, cut the tube feeding in half.

• Tube feed nocturnally, allowing the patient time away from tube feeding during the day in hopes of producing an appetite.

• Continue calorie counts and decrease time of enteral infusion as appropriate.

• Do not be impatient. If patient intake remains poor and he or she complains of not being hungry secondary to tube feeding, turn it off for 24 hours. Do not pull the feeding tube. Complete calorie count during that time to see if intake increases without nocturnal support. If intake improves to more than 75% of needs, one can feel confident that the patient will progress nutritionally. If intake fails to improve, it is unlikely that the tube feeding is causing inadequate intake. At this point, incremental goals need to be established with the patient in an effort to motivate the patient toward tube-free nutrition.

PARENTERAL NUTRITION

This type of nutritional support is indicated for patients with a nonfunctioning GI tract and an inability to tolerate oral or enteral nutrition. As with enteral nutrition, duration of support is the decision between the 2 available routes (peripheral parenteral nutrition [PPN] and central or total parenteral nutrition [TPN]).

PPN is considered to be a short-term/adjunct intervention. A time frame of less than 14 days is recommended, as PPN is used for transitional therapy when the patient's oral intake is improving but still is inadequate to support his or her nutritional needs or when tube feeding is only partially successful.

TPN is intended for full nutritional support and is recommended for a minimum of 7 days for improvement in patient outcome to occur.

Access for aggressive nutritional support is dependent on the duration of therapy, as discussed above, as well as the patient's medical condition, energy requirements, and fluid tolerance.

Peripheral access may be obtained by nonsurgical staff using a standard venipuncture method. The patient must have adequate peripheral veins and be able to tolerate hypertonic solutions, as PPN solutions are generally 600-900 mOsm/L. Peripheral access is hard to maintain; hence, the 2-week limit is enforced.

Central access is determined by the expected duration of nutritional support. Short-term access is available using single-, double-, or triple-lumen catheters. The tip of the central catheter is positioned in the superior vena cava.

Peripherally inserted central catheter (PICC) lines can be placed by a trained nurse and do not require a surgical procedure. The line is placed in the antecubital vein and threaded into the subclavian vein.

Single-, double-, or triple-lumen catheters are also available for long-term access. The catheter is placed surgically and tunneled subcutaneously away from the insertion site. The exit site is in the chest wall. PICC lines may be used for long-term access as well.

Unlike enteral support, parenteral nutrition should be infused continuously over a 12-24 hour period. Cyclic infusion rates are reserved for the more stable patient or the patient who is likely to be discharged on TPN.

Since PPN is restricted to a maximum of 10% dextrose (5% final concentration), patients can tolerate initiation of the infusion at the target rate. TPN, with its higher concentrations of dextrose, requires an advancement schedule.

Skipper's recommendations for initial parenteral infusion rates for the first 48 hours of infusion are outlined in the following list :

• First 24 hours

  • Volume should be based on patient tolerance. If fluid tolerance is unknown, begin with 1 liter or less.

  • Carbohydrate - Dextrose can be concentrated maximally into 1 liter if glucose control is acceptable. With hyperglycemia, diabetes, or refeeding syndrome, begin with a 10-15% dextrose solution.

  • Protein - Maximum protein (ie, 60-70 g) usually can be given.

  • Lipid - Administer lipids during this period if baseline triglycerides are less than 400 mg/dL.

  • Electrolyte/mineral - Adjust the level as needed; replete deficiencies.

• 24-48 hours

  • For most patients, the target rate can be achieved by the second day.

  • Volume - Increase the volume to the goal per fluid tolerance.

  • Carbohydrate - Advance to the goal if glucose is less than 200 mg/dL.

  • Protein - If volume is not an issue, advance to the goal.

  • Lipid - Maintain triglycerides at less than 400 mg/dL during continuous feeds and at less than 250 mg/dL 4 hours after infusion.

  • Electrolytes/minerals - Adjust the level as needed; replete deficiencies.

• Formula selection

  • Nonprotein calorie (NPC) sources are made up of 2 macronutrient groups (ie, carbohydrates [CHO], lipids).

  • The following (Table 10) is a summary of recommendations for infusion and general information:

SUMMARY OF RECOMMENDATIONS FOR INFUSION

The optimal infusion schedule is not less than 12 hours.

Dextrose is the carbohydrate source, as well as the major source of non-protein calories (NPC) in parenteral nutrition. The carbohydrate load provided should be adequate to spare protein for wound healing/metabolic demands without exceeding patient tolerance (hyperglycemia).

SUMMARY OF THE VARIOUS DEXTROSE CONCENTRATIONS

Intravenous lipid infusions are necessary as a source of essential fatty acids. They are also a concentrated source of NPC. The calories yielded depend on the concentration of the lipid emulsion used.

Examples of lipid emulsions and their calories yielded are 10% lipid (1.1 kcal/cc) and 20% lipid (2 kcal/cc). Lipid infusion schedules vary by institution and can range from twice a week to daily. Lipids are made up of egg phospholipid. Therefore, patients with an egg allergy may not tolerate lipid infusions.

COMMON TPN SCHEDULES (500 CC)

NB: When using a 3-in-1 TPN, the lipids are added to the TPN daily.

The role of protein in TPN is to maintain nitrogen balance, inhibiting the breakdown of skeletal muscle. The amount of protein necessary is based on a patient's metabolic needs, as discussed earlier. Note that an amount below 0.5 g protein/kg does not promote positive nitrogen balance.

In a healthy population, protein should be provided as 11-20% of total kcal. In a stressed population, 40% of total kcal is common. Protein in TPN is in the form of crystalline amino acids that provide 4 kcal/g. All amino acid mixtures contain intrinsic electrolytes.

AN EXAMPLE OF THE INTRINSIC ELECTROLYTES IN SOME COMMON AMINO ACID FORMULATIONS 

When a standard electrolyte formula is ordered, it is made up of the intrinsic electrolytes with a Hyperlyte mixture added. The following section on electrolytes further discusses this issue.

The electrolyte composition in parenteral nutrition is designed to maintain normal body function. Customized electrolytes are an option based on the patient's underlying disease process/stressful situations. The available commercial preparations are intended to meet normal range requirements.

TPN can affect the metabolic acid/base imbalance. Therefore, the chloride and acetate in the TPN can be adjusted. For a metabolic acidosis, the maximum acetate should be used. For a metabolic alkalosis, the maximum chloride should be employed.

REQUIREMENTS AND STANDARD AMOUNTS OF ELECTROLYTES

Parenteral supplementation is based on recommendations from the American Medical Association Nutrition Advisory Group.

The daily parenteral requirements for vitamins and minerals for adults are as follows:

• Thiamine - 3 mg

• Riboflavin - 3.6 mg

• Niacin - 40 mg

• Folic acid - 400 mc g

• Pantothenic acid - 15 mg

• Pyridoxine - 4 mg

• Cyanocobalamin - 5 mcg

• Biotin - 60 mcg

• Ascorbic acid - 100 mg

• Vitamin A - 3300 IU

• Vitamin D - 200 IU

• Vitamin E - 10 IU

• Chromium - 10-15 mcg

• Copper - 0.3-0.5 mg

• Manganese - 60-100 mcg

• Zinc - 2.5-5 mg

COMPLICATIONS FROM PARENTERAL NUTRITION

Parenteral nutrition support has a lengthy list of potential metabolic complications, which is the reasoning behind the judicious monitoring of nutrition support teams.

METABOLIC COMPLICATIONS FROM PARENTERAL NUTRITION

Consequences of protein calorie overfeeding are as follows:

Ø  Carbohydrates - >5 mg/kg/min

o    Lungs

§  Increased CO2 production

§  Possible respiratory failure in patients with limited pulmonary reserve and prolonged mechanical ventilation

o    Hyperglycemia - >220 mg/dL

o    Hyperinsulinemia

§  Impaired phagocytosis and neutrophil chemotaxis

§  Increased intracellular transport of K+ and phosphorus

o    Liver

§  Fatty liver infiltration

§  Increased serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, and alkaline phosphatase

§  Hepatomegaly

§  Cholestasis

Ø  Fat - >2 g fat/kg/d

o    Increased serum triglyceride clearance impaired

Ø  Protein - >2 g protein/kg/d

o    Decreased renal function

o    Ureagenesis

TRANSITION FROM PARENTERAL TO ENTERAL TO ORAL NUTRITION

As with enteral support, the goal with parenteral support is a gradual transition back to tube feeding or oral nutrition. Treatment options have been developed to make the transition effective without compromising the patient's nutritional status.

Recommendations for this transition include the following:

• Never discontinue TPN all at once, as it could cause a rebound hypoglycemia. Tapering down is recommended. The taper down should be based on the adequacy of the patient's tube feeding or oral intake.

• If the patient is on tube feeding, increase the rate of the tube feeding while decreasing the rate of the TPN. Combination rates should meet both protein and calorie needs.

• If the patient is on an oral diet, calorie counts are recommended. If the patient is able to consume 50% of his or her needs orally, consider changing TPN to a cyclic infusion. Discontinue the TPN during the day and provide 50% of the patient's nutrition over 10-12 hours during the night. Tube feed nocturnally, allowing the patient time during the day away from tube feeding in hopes of producing an appetite.

• Continue calorie counts and decrease time/amount of parenteral infusion as appropriate.