Nutrition Support for Oncology Patients

M. Patricia Fuhrman, MS, RD, LD, FADA, CNSD INTRODUCTION

Cancer is becoming a chronic disease. As a result, treatments for cancer— and especially chemotherapy and radiation therapy—can have both shortterm and long-term adverse effects on body systems, such as the gastrointestinal (GI) tract. Nutrition support is adjunctive therapy, rather than curative therapy, for oncology patients. The debate about if and when to initiate nutrition support revolves around the GI tract function, the prognosis of the patient, the experiences of healthcare providers, and the wishes of the patient and family. Patient autonomy should always be the decisive factor when determining the extent of providing nutrition and hydration.1

The American Dietetic Association’s (ADA) Evidence Analysis Library (EAL) oncology guidelines recommend medical nutrition therapy with individualized nutrition assessment, prescription, and counseling as the first line of nutrition intervention2 for patients diagnosed with cancer. It is well accepted that nutrition support should not be used routinely in cancer patients, but rather should be reserved for those patients who are unable to meet their nutrient needs orally.2-4 The provision of home nutrition support in terminally ill cancer patients who are not undergoing active therapy should be limited to those patients who have good functional status with a life expectancy greater than 40 days and supportive caregivers.4

Enteral Nutrition

Indications for Enteral Nutrition

Enteral nutrition (EN) is indicated when a patient cannot meet nutrient needs through oral diet and the GI tract is functional. Table 3.1 lists the indications, benefits, contraindications and burdens of enteral and parenteral nutrition.3- 5 6

Table 3.1 Comparison of Enteral and Parenteral Nutrition in Oncology Patients

Enteral Nutrition

Parenteral Nutrition

Indications

Functional GI tract

GI tract dysfunctional

Patient unable to meet

Patient unable to meet needs through

needs through oral diet

oral diet and/or tube feeding

Severe esophagitis, enteritis, vomiting,

and diarrhea

Bowel obstruction

Short bowel syndrome

Severe pancreatitis

Paralytic ileus

GVHD

Benefits

Less costly

Source of nutrition for those unable to

Less invasive

meet needs enterally

Fewer infectious

complications

Contraindications

GI obstruction

Functional GI tract

Peritonitis

No IV access

GI bleeding

Aggressive nutrition support not

Intractable vomiting/

warranted or desired by

diarrhea

patient/family

Hemodynamic instability

Inadequate GI perfusion

High-output fistula

Thrombocytopenia

Severe mucositis,

esophagitis, rhinitis

Aggressive nutrition

support not warranted or

desired by patient/family

Burdens

Obtaining and

Infectious complications

maintaining enteral

Cost

access

GI complications of

diarrhea, reflux, vomiting,

nausea

GI = gastrointestinal; IV = intravenous; GVHD = graft-versus-host disease.

Sources: A.S.P.E.N. Board of Directors and Clinical Guidelines Task Force. Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. JPEN J Parenter Enteral Nutr. 2002;26(suppl 1):82SA—85SA; DeChicco RS, Steiger E. Parenteral nutrition in medical or surgical oncology. In: Elliott L, Molseed LL, McCallum PD, eds., The Clinical Guide to Oncology Nutrition. 2nd ed. Chicago, IL: American Dietetic Association; 2006:156—164; Robinson CA. Enteral nutrition in adult oncology. In: Elliott L, Molseed LL, McCallum PD, eds., The Clinical Guide to Oncology Nutrition. 2nd ed. Chicago, IL: American Dietetic Association; 2006:138—155.

Benefits of Enteral Nutrition

The patients with cancer who appear to benefit the most from enteral nutrition are those with head and neck cancer, esophageal cancer, gastric cancer, and pancreatic cancer.6 Feeding tube placement should be distal to the tumor and/or surgical site.6 The ADA EAL states that EN can successfully maintain weight by increasing energy and protein intake in patients with esophageal cancer undergoing chemoradiation and in patients with stage III or IV head and neck cancer receiving intensive radiation therapy.2 Providing EN and maintaining nutritional status during radiation therapy for head and neck cancer may improve the patient’s ability to tolerate the therapy, thereby promoting a better outcome.2

Zogbaum et al.7 retrospectively reviewed 125 cases of head and neck cancer treated with radiation therapy. Seventeen patients who received tube feedings were matched with 17 controls who were not tube-fed. The tube-feeding group missed fewer days of radiation therapy (2.3 days ± 6.6 SD versus 5.5 days ± 4.0 SD; p < 0.1) and had less weight loss as measured by BMI (20.64 ± 4.2 to 20.18 ± 4.01 versus 24.32 ± 5.62 to 22.78 ± 5.51; p = .54) than the control group. However, enteral nutrition in patients with esophageal cancer has not been shown to improve tolerance to therapy or increase survival.2

Enteral nutrition is less expensive than parenteral nutrition and is associated with fewer infectious complications.8 Its utilization of the GI tract may be one of the major advantages of enteral nutrition in preventing infectious complications, as the GI tract is a major contributor to immunocompetence.

Enteral Nutrition Challenges

Enteral feeding may be problematic in some patients owing to the effects of their tumors and/or the antineoplastic therapies employed. Thrombocytopenia increases the risk of bleeding during tube placement and management. Platelet levels should be greater than 50,000 units/liter and the absolute neutrophil count greater than 1,000 cm2 before a feeding tube is placed either endoscopically or surgically.9

GI intolerance induced by chemotherapy and radiation therapy can inhibit oral intake and jeopardize tube-feeding success. Patients with mucositis, nausea, vomiting, and diarrhea may tolerate jejunal feedings better than gastric feedings.3 Feeding tube placement (nasal/orally placed tubes) may be more difficult in patients whose anatomy has been altered as a result of head and neck resection.10

Contraindications to Enteral Nutrition

Contraindications to enteral nutrition in oncology patients are similar to those in patients with other diseases and metabolic disorders. Specific contraindications include intestinal obstruction, peritonitis, GI bleeding, intractable vomiting or diarrhea, hemodynamic instability, inadequate GI perfusion, high-output fistulas, and the patient’s or family’s preference not to pursue enteral feeding.6 If nutrient and energy needs cannot be met through utilization of the GI tract, a combination of enteral and parenteral nutrition may be required.

Burdens of Enteral Nutrition

Obtaining and maintaining enteral feeding access can be a burden for some patients. If a feeding tube has to be inserted repeatedly, the amount of feeding provided and the patient’s comfort are diminished. Burdens of enteral nutrition include adverse effects such as diarrhea, reflux, nausea, and vomiting, which can sometimes outweigh the benefit of using the GI tract for feeding. The emotional burden of stool incontinence and the risk for wound infections in the patient with severe diarrhea can also necessitate discontinuation of enteral feeding. Uncontrolled nausea may negatively impact quality of life for the patient as well.

Enteral Nutrition Access

The least invasive type of enteral access is a nasoenteric feeding tube. Nasoenteric feeding tubes are generally recommended when enteral feedings are required for less than 4 weeks. Such tubes can be placed in several locations, including the stomach, duodenum, or jejunum. When enteral access is required for a longer period of time, the enteral access is typically more permanent, with an ostomy being created, such as a gastrostomy, jejunostomy, percutaneous endoscopic gastrostomy (PEG), percutaneous endoscopic jejunostomy (PEJ), or percutaneous endoscopic gastro-jejunostomy (PEGJ).

Tube type and placement will depend on the location of the cancer and the ability to place the feeding tube distal to the cancer and/or surgical intervention site. Patients with head and neck cancer generally tolerate enteral feedings into the stomach or jejunum; those with esophageal cancer usually have feedings into the stomach or duodenum; those with gastric cancer have feedings into the jejunum; and those with pancreatic cancer have feedings into the jejunum.6 In any event, each patient must be evaluated individually to determine the optimal enteral feeding access.

Enteral Feeding Formulas

The selection of an enteral nutrition formula depends on the presence of comorbidities, organ function, fluid tolerance, and GI function as well as the length of time for which feedings may be required. In general, it is best to use the most intact enteral formula that meets the patient’s nutrient needs and tolerance. The concentration of the formula (measured in kilocalories per milliliter [kcal/mL]) depends on the patient’s fluid status and volume tolerance. There is little support in the literature for the use of disease-specific formulas.11 The use of elemental or semi-elemental formulas should be reserved for those patients with impaired GI digestion and absorption. The addition of modular components to an enteral formula should be avoided because of the risk of formula contamination.

The use of arginine, vitamin E, or antioxidant supplements for patients with breast or oropharyngeal cancers is currently not recommended; consumption of antioxidant vitamins in excess of the upper tolerable limit is also not recommended for patients with lung cancer.2 Specialty enteral formulas designed for oncology patients contain immuno-enhancing nutrients. Oral consumption of 2 g of eicosapentaenoic acid (EPA) and 1 g of docosahexa-noic acid (DHA) per day, for example, has been associated with weight gain in patients with tumor-induced cancer cachexia.1213 In vitro, animal, and epidemiologic studies suggest that EPA may augment the effects of chemotherapeutic agents, and that the ratio of omega-3 (Q-3) inserted to omega-6 (Q-6) fatty acids may influence the risk and progression of breast, colon, and prostate cancers.14 Studies examining the effect of an immuno-enhancing tube feeding formula have yielded inconsistent results when the solutions were provided to patients with gastric cancer.11 Prospective clinical trials are still needed to determine the role of Q-3 fatty acids and other immuno-enhancing nutrients in the prevention and treatment of cancer and cancer cachexia.2, 14 It appears that the use of immuno-enhancing enteral formulas and supplements is not warranted and could even be potentially harmful in this patient population.4

Enteral formulas can be administered into the stomach as either a bolus, an intermittent infusion, or a continuous infusion. Small bowel feedings should be continuous. Continuous feeds can be infused over 24 hours or cycled over a shorter time frame depending on patient lifestyle and tolerance.

Complications of Enteral Nutrition

Enteral nutrition is associated with GI, metabolic, septic, and mechanical complications. Nutrition assessment focused on the patient’s risk factors related to complications and routine monitoring for potential complications can reduce the incidence and adverse outcomes of complications that do occur.

Potential GI complications include diarrhea, regurgitation, and constipation. Multiple factors contribute to diarrhea, and each must be evaluated separately to determine which treatment should be employed.15 Diarrhea is often the result of medications. Infection with Clostridium difficile is a frequent cause of diarrhea in patients who are treated with antibiotics.

Enteric pathogens should be identified and treated before initiating antidiarrheals to avoid toxic megacolon.16 Chemotherapeutic drugs and radiation therapy can also result in rapid GI transit. A patient with an impaction could be oozing stool around the impaction.16 During the process of determining the etiology of the diarrhea, it is important to maintain hydration and electrolyte levels.15 Fiber-containing formulas may also assist with the management of both diarrhea and constipation. Formulas containing soluble fiber, for example, can help with GI motility as well as provide a source of fuel for the colonocytes with short-chained fatty acids (SFCA).11

Regurgitation and subsequent aspiration are always a concern with enteral feeding. To date, no evidence has been gathered that correlates a certain level of gastric residual volume with higher risk of aspiration.17, 18 Greater than 250 mL of gastric residual volume (GRV) on two consecutive occasions should be investigated for potential problems with poor gastric emptying, however.19 Elevating the head of the bed 30 to 45 degrees is the only evidence-based recommendation for preventing reflux and the risk of aspiration.19

Metabolic complications include refeeding syndrome and dehydration. Patients at the greatest risk of developing refeeding syndrome are those who have had inadequate intake for more than 7 to 10 days and who have lost a significant amount of weight.6 Starting at a low rate of 20 to 30 mL/h and increasing the amount of the feeding gradually to the infusion goal enables the clinician to monitor the metabolic response and correct any glycemic and electrolyte abnormalities as they occur. For patients with diabetes and glucose intolerance, it is recommended to avoid overfeeding and administer insulin as needed.11

A comprehensive nutrition assessment should also include the fluid requirements for all patients to assure adequate fluid intake, to reduce the risk of constipation, and to replace fluids lost, such as from diarrhea or vomiting. Overhydration must also be avoided, especially in patients with renal failure, liver failure, or congestive heart failure. Inadequate fluid intake can contribute to hypernatremia and pre-renal azotemia. Thirst cannot be counted on as a reliable indicator of whether more fluid is needed in elderly individuals and in patients who are unable to communicate. Instead, fluid needs should be estimated using any of several available mathematical formulas, and hydration status then routinely reevaluated based on clinical monitoring.

Mechanical complications may arise related to the feeding tube and equipment used to infuse the formula. Nasoenteric complications include inflammation of the nasal cavity and sinusitis. Sites where gastrostomy, jejunostomy, PEG, PEJ, and PEGJ tubes are placed can become tender and red. Excoriation and infection can also occur. The size of the tube may need to be changed as the patient gains or loses weight or, in the case of children, with growth.

It is imperative to flush the tube routinely with water to maintain patency. Minimal flushes should consist of 20 mL water every 4 hours with a continuous infusion, before and after intermittent and bolus infusions, and before and after medications are delivered.3 It may be prudent to flush the feeding tube and dilute fluids through the feeding tube with sterile water or saline, particularly in immunocompromised patients and in patients for whom there is concern about the safety of the water supply. Medications should be compatible with feeding tube administration and location of the feeding tube tip.

Home Enteral Nutrition Support

Patients who go home on enteral nutrition should be thoroughly evaluated for appropriateness of the enteral formula, feeding access, and capability of the patient and/or caregiver(s) to manage the therapy. It is imperative to teach patients how to prepare formula and manage their feeding access properly so that they know how to avoid the risk of contamination. A study by Thompson et al. examined the coping skills of patients receiving home enteral nutrition.20 In this study, patients who were successful at coping with the nutrition system accepted personal responsibility for life’s conditions, took charge of their own well-being, sought and accepted support from others, optimized their independence, and focused on the positive aspects of their lives. Given these considerations, the authors remind clinicians to work with their home enteral nutrition patients to facilitate these coping skills.

Parenteral Nutrition

Indications for Parenteral Nutrition

Parenteral nutrition (PN) should be reserved for patients who are unable to tolerate any or sufficient nutrient needs through the GI tract. Indications for PN may include severe esophagitis, enteritis, vomiting, and diarrhea, as well as bowel obstruction and short bowel syndrome. Other indications may include severe pancreatitis, paralytic ileus, and graft-versus-host disease (GVHD) involving the GI tract.5 PN should not be used unless there is an impediment to oral intake of nutrients and/or digestion or absorption of nutrients after consumption. The ADA EAL states that routine use of PN is not recommended for patients with esophageal cancer who are receiving chemoradiation therapy (CRT).2 To reiterate, PN should be reserved for only those patients who are unable to meet their nutritional needs through the GI tract.

Benefits of Parenteral Nutrition

Parenteral nutrition is a life-saving therapy for patients who are unable to tolerate enteral nutrition. The goal of providing parenteral nutrition is to meet nutrient needs until the patient can resume oral intake or tube feeding. Some patients will remain dependent on parenteral nutrition for the rest of their lives. Careful management can reduce the risk of complications during both short-term and long-term therapy.

Contraindications to Parenteral Nutrition

If the gut works adequately to meet the patient’s nutritional needs, parenteral nutrition should not be used. Likewise, PN may be contraindicated when the patient has no intravenous (IV) access. It may also be inappropriate to start or to continue PN when aggressive nutrition support is not warranted or if it is not desired by the patient and his or her family. Communication between the patient, family, and clinicians is necessary to determine the goals of feeding and to clarify the expectations for nutrition support.21

Burdens of Parenteral Nutrition

PN is not indicated when the burdens of providing PN outweigh the bene-fits—for example, when the patient’s prognosis is extremely poor. Although PN is not a curative therapy for oncology patients, it can help sustain them nutritionally during curative and palliative therapy when they cannot meet their nutrient needs via the GI tract. As the end of life approaches, the patient and family must evaluate the burdens and benefits of this nutritional therapy. Laboratory monitoring, preparation and infusion issues, and risk of infection from the IV catheter must all be considered. If the patient is seeking hospice care, it may not be possible to continue PN after hospice admission.21

Access for Parenteral Nutrition

Central IV access is required for PN. Like enteral access, parenteral access can be either temporary or permanent. Temporary access involves a direct puncture into a central vein, such as the internal jugular, subclavian,

or femoral vein. Permanent central access is achieved either through a tunneled catheter, an indwelling port, or a peripherally inserted central catheter (PICC).

Peripheral parenteral nutrition (PPN) does not require access to a central vein but rather is delivered through the small veins in the hand and distal arm or via a peripherally inserted catheter (PIC). The tip of a PIC is generally placed in a deep peripheral vein. This means of access should not be confused with a PICC, which has its tip in the superior vena cava or right atrium. PPN is generally not used because of the volume required to dilute the formula for peripheral infusion and its large lipid load for adequate energy. For best tolerance, the osmolality should be less than 600 to 900 mOsm/L.22

Parenteral Nutrition Components and Formulations

Parenteral formulations can contain dextrose, lipids, amino acids, multivitamins, trace elements, electrolytes, water, and compatible medications (Table

3.2). These components may be combined in one bag, referred to as a total nutrient admixture or 3-in-1, or lipids can be infused separately in conjunction with a 2-in-1 (dextrose and amino acids along with micronutrients and medications).

Macronutrients include dextrose, lipids, and amino acids. A minimum of 100 to 150 g/day dextrose is appropriate, with an upper limit of 4 mg/kg/min in the critically ill patient and an upper limit of 7 mg/kg/min in the stable patient.23 Lipids provide an additional source of energy that can help reduce the dextrose load. Intravenous delivery of lipids limited to 0.11 g/kg/h has not been associated with adverse effects.24 Minimizing the lipid amount to approximately 1 g/kg or less than 30% of the individual’s total kilocalories per day has not been associated with complications.23, 25 Although no consensus has been reached regarding how much lipids should be given, it is prudent to limit the amount provided to avoid potential complications. If a patient does not receive lipids for greater than 2 weeks, a minimum of 10% of the total caloric provision from lipids should be administered to prevent essential fatty acid deficiency (EFAD).5

Micronutrients include vitamins, trace elements, and electrolytes. Vitamins and trace elements should be added to the PN solution on a daily basis.26 If the patient is on anticoagulation therapy, it is important to be aware of the vitamin K content of the multivitamin preparation and to adjust the anticoagulation therapy accordingly. Multivitamin preparations are available without vitamin K, though these solutions should not be used routinely. By contrast, trace element preparations containing zinc, chromium, copper, manganese, and selenium are recommended for routine use.27 Copper and

Component

Recommendations

Amino acids

10—20% total estimated or measured energy needs Adjust based on organ function and metabolic stress

Dextrose

Consider all sources of dextrose (IVF, medications) Initiate with 100-200 g/day 4 mg/kg/min maximum in critically ill 7 mg/kg/min maximum in stable patients Maintain normal glucose levels

Lipids

Include propofol infusion in lipid sources Lipid should be less than 1 g/kg or 20-30% of total kilocalories Limit lipids with serum TG levels > 400 mg/dL

Fluid

Volume depends on patient tolerance/requirements

Electrolytes

Amounts depend on patient tolerance. Higher requirements may occur with refeeding syndrome and GI losses; decreased requirements occur with organ failure.

Sodium

1-2 mEq/kg

Potassium

1-2 mEq/kg

Phosphorus

20-40 mMol/day

Calcium

10-15 mEq/day

Magnesium

8-20 mEq/day

Chloride and acetate

Proportions vary depending on acid-base status

Vitamins

A

3,300 IU

D

200 IU

E

10 IU

K*

150 mcg

Thiamin

6 mg

Riboflavin

3.6 mg

Niacin

40 mg

Pyridoxine

6 mg

Cyanocobalamin

5 mcg

Folacin

600 mcg

(continues)

Component

Recommendations

Pantothenic acid

15 mg

Biotin

60 mcg

Ascorbic acid

200 mg

Trace Elements

Increased needs may

occur with large GI losses.

Zinc

2.5-5 mg

Copper

0.3-0.5 mg

Chromium

10-15 mg

Manganese

20-100 mcg

Selenium

40-120 mcg

Medications

Check with the pharmacist to verify compatibility and doses based on patient’s comorbidities and metabolic needs.

*Multivitamin preparation available without vitamin K.

GI = gastrointestinal; IVF = intravenous fluids; TG = triglyceride.

Sources: A.S.P.E.N. Board of Directors and Clinical Guidelines Task Force. Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. JPEN J Parenter Enteral Nutr. 2002;26(suppl 1):82SA—85SA; Sacks GS, Mayhew S, Johnson D. Parenteral nutrition implementation and management. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: American Society for Parenteral and Enteral Nutrition; 2005:108—117; Lenssen P, Bruem-mer BA, Bowden RA, Gooley T, Aker SN, Mattson D. Intravenous lipid dose and incidence of bacteremia and fungemia in patients undergoing bone marrow transplantation. Am J Clin Nutr. 1998;67:927-933; McMahon MM. Management of parenteral nutrition in acutely ill patients with hyperglycemia. Nutr Clin Pract. 2004;19:120-128; Lipkin AC, Lessen P, Dickson BJ. Nutrition issues in hematopoietic stem cell transplantation: State of the art. Nutr Clin Pract. 2005;20:423^39.

manganese may be omitted when a patient develops hyperbilirubinemia. In such a case, the patient should be monitored closely because copper deficiencies can lead to pancytopenia over time.28 Electrolytes are added daily in amounts based on laboratory values and the patient’s current condition. GI and urinary losses as well as organ function should be considered in determining electrolyte content of the PN.5 Although electrolytes are listed as individual minerals, they are added to the PN as salts; for example, sodium can be provided as sodium chloride, sodium acetate, and sodium phosphate.

Water can be added to the PN solution for patients who need additional fluid and to dilute a peripheral solution to achieve the osmolality compatible with this route of infusion. It may also be necessary to concentrate the PN formula by using the most concentrated source of dextrose (70%), lipids (30%), and amino acids (20%). In any event, fluid status and sources of other IV fluids should be regularly assessed with PN administration.

Medications commonly added to PN include regular insulin, heparin, and famotidine.5 It is not recommended to use PN as a drug delivery method. Always confirm drug and PN compatibility with the pharmacist.

Infusion of parenteral nutrition can be either continuous or cycled. Most infusions begin as continuous and then are converted to a cycle schedule as indicated by patient activities or in anticipation of discharge home on PN. When cycling PN, it is recommended to taper the infusion for 1 to 2 hours when starting and stopping the infusion. Some debate has arisen over whether it is necessary to taper PN infusions before stopping the infusion,29- 30 but the potential risk of rebound hypoglycemia can be avoided by tapering.

Complications of Parenteral Nutrition

Concern about the potential complications associated with PN often prompts clinicians to use it only as a last resort. As a result, they sometimes wait past the point when maximum benefit could be realized before initiating this type of nutritional therapy. Careful management and monitoring, however, can reduce the risk of complications.

Metabolic Complications Ensuring glycemic control in which blood sugars remain within normal levels improves outcomes in critically ill patients.31 Glucose levels of 80 to 120 mg/dL in critically ill patients and 100 to 150 mg/dL in non-critically ill patients have been recommended.32 Initiating PN with 150 to 200 g dextrose can enable the clinician to monitor glycemic response and maintain glucose levels within acceptable ranges. When blood glucose levels are within an acceptable range, the PN dextrose content can be increased.

A general rule of thumb for adding insulin to PN in patients with a history of diabetes or insulin resistance or currently with hyperglycemia is to provide 0.1 unit of regular insulin for each 1 g of dextrose.32 Additional insulin needs can be covered by using an insulin sliding scale. A portion (generally one half or two thirds) or all of the amount of sliding-scale insulin required during a 24-hour period can be added to the next bag of PN.

Hypoglycemia can occur with abrupt disruption of PN or overzealous addition of insulin to PN. If PN is abruptly interrupted, a 10% dextrose solution should be given for an hour. Hypoglycemia can also be treated with oral carbohydrate or by giving an ampule of 50% dextrose intravenously. A PN bag that contains more insulin than necessary and that results in hypoglycemia should be discontinued.5

Refeeding syndrome occurs more often with PN than EN because PN is often started at the goal rate rather than implementing a gradual increase in the infusion rate over a few days, as happens with EN. In patients at risk, it is prudent to start PN with 150 to 200 mg/day of dextrose and to monitor glucose levels as well as potassium, phosphorus, and magnesium. Correct the patient’s serum glucose and replace electrolytes before increasing the dextrose content.5

For patients on long-term home PN, there is a valid concern about PN-associated liver disease. In one study, a reduction in severe liver dysfunction in home parenteral nutrition patients was seen with a modest provision of kilocalories (approximately 25 kcal/kg), generous protein (approximately 1.45 g/kg), and a lipid infusion rate of 0.28 g/kg per day.33 Note, however, that this study involved a heterogeneous group of patients requiring home PN; only a small percentage had an underlying diagnosis of cancer.

Infectious Complications Poor glycemic control contributes to both mortality and morbidity (including infectious complications) in critically ill patients receiving PN.19, 31 Glycemic control should be maintained to reduce the risk of infection in immunosup-pressed oncology patients. Using sterile technique in catheter placement and catheter care can also reduce the risk of infectious complications.

Lipids containing Q-6 fatty acids can affect the reticuloendothelial system adversely when they are given in large doses over short periods of time.34 When given judiciously—for example, as 30% of total kilocalories or less— no adverse effects from providing lipids have been noted.25

Gastrointestinal Complications Gastrointestinal complications of PN result from the lack of GI stimulation when the GI tract cannot be utilized. These complications can include GI atrophy, bacterial overgrowth, and bacterial translocation. Liver disease and metabolic bone disease are also associated with PN. Prevention and management of these complications includes using the GI tract as much as feasible, even if trickle feeds are all that the patient can tolerate. To date, researchers have not determined the amount of enteral stimulation required to maintain GI integrity. Other recommendations are to avoid overfeeding, control hyperglycemia, and provide micronutrients daily.

Special Considerations for Nutrition Support

Cancer Cachexia

The symptoms of cancer cachexia are the essence of malnutrition: anorexia, fatigue, inadequate nutrient and energy intake, weight loss, and wasting of muscle and fat mass. Current theories regarding the etiology of cancer cachexia center on the effects of a cytokine cascade and hormones on metabolism.4- 35 As yet, the specific mediators have not been defined, making it problematic to determine the optimal therapeutic approach for treatment.36 Cancer cachexia is not reversed with adequate nutrient intake. Interventions should treat the symptoms of anorexia, nausea, vomiting, and mucous membrane inflammation.4- 35 Alternative therapies such as acupuncture, guided imagery, hypnosis, and music therapy have also been used to stimulate appetite.35 Unfortunately, effective therapy is complex because the etiology of symptoms is multifactorial.

Hematopoietic Cell Transplantation

PN was historically part of the standard of care for patients undergoing a bone marrow transplant. However, the combination of autologous transplants, new medications, peripheral stem cell harvesting, and less toxic conditioning regimens have eliminated the need for routine use of PN in this patient population.37

If nutrition support is required to compensate for poor intake, EN should be considered in patients whose inadequate intake is expected to continue for longer than one week.9 Patients who may tolerate EN include those who receive non-myeloablative therapy; have chronic GVHD; suffer neurological complications that impede swallowing, or are on mechanical ventilation; and in those patients whose appetite does not improve after engraftment.9

Inability to use the GI tract due to severe GI toxicity from the conditioning regimen and severe intestinal GVHD may necessitate the implementation of PN in malnourished patients until oral intake can be resumed.3, 38 There continues to be insufficient evidence to recommend PN supplemented with glutamine in patients following hematopoietic cell transplantation (HCT).3 While PN has not been found to affect either the length of hospital stay or mortality in breast cancer patients undergoing autologous HCT, an increased risk of infectious complications does exist.2 PN should be reserved for those HCT patients who are unable to meet their nutrient and energy requirements by oral diet or tube feeding.

PN has been shown to maintain nutritional status and restore hematopoietic function in patients undergoing HCT.39 In one study, 35 patients undergoing HCT received either PN (n = 19) or an oral diet (n = 16).39 The criteria for providing PN included oral intake of less than 50% of estimated nutrient needs over 2 days. Patients on PN were encouraged to eat what was tolerated; if their oral intake exceeded 50% of their nutrient needs, the PN was gradually tapered off over 1 to 2 days. The PN was given for an average of 9.4 days and provided 25-30 kcal/kg, including 20-30% of total kilocalories as lipids and 1-1.5 g protein/kg per day. There was no difference in development of malnutrition or hematopoietic recovery between the groups, demonstrating the safety of PN in patients who are assessed to require nutrition support during HCT.

Feeding the Tumor

Tumor growth increases when patients are aggressively fed, but a difference in overall clinical outcome has not been shown in patients who are aggressively fed versus those who are not aggressively fed.40 A study in patients with metastatic melanoma and renal cell carcinoma (n = 37) showed a 50% decrease in complete and partial responses to chemotherapy when it was given concurrently with PN for 14 days.41 In terms of nutrients, the patients on PN received 25 kcal/kg, whereas the patients on oral diet received only

2.5 kcal/kg. Tumor progression was found to occur 17% faster in the PN group, but there was no difference in overall survival between the two groups.41 In contrast, in another study, a group of GI cancer patients given PN and chemotherapy preoperatively demonstrated an improved nutritional status without an increase in the proliferation of tumor cells and did not have an increase in postoperative complications.42

Despite the conflicting results of studies evaluating the use of nutrition support in oncology patients, it is more important to address the clinical needs of the patient, rather than the pathology, when making determinations about nutritional needs.40, 43, 44 Feeding the patient may result in more rapid growth of the tumor, but starving the patient can result in debilitation while the tumor continues to thrive. PN should not be avoided in malnourished patients who are unable to tolerate sufficient nutrients and energy delivered via the GI tract.

Home Parenteral Nutrition Support

Some patients may require home parenteral nutrition (HPN). Home nutrition support is appropriate for a patient who has a safe home environment and supportive and capable caregiver(s). One study of patients with cancer who were receiving HPN showed that the quality of life was improved and nutritional status was preserved for patients on PN for more than 3 months.45

In another study, involving 17 HPN patients with inoperable malignant bowel obstruction, researchers examined the efficacy of HPN as rated by both patients and their physicians.46 The mean survival rate for the patients was 53 days. In this study, 14 (82%) patients and their families rated HPN as beneficial or highly beneficial. The clinicians managing the care of the patients agreed with 11 of these patient ratings. The 3 patients with whom the clinicians did not agree were patients whose duration of therapy was less than 25 days. Patients who survived 40 days or longer and had a committed and supportive family benefited from palliative HPN with few complications. It appears that delaying the initiation of PN could result in less benefit for patients who require it.

Palliative Care

Palliative care is the bridge from curative therapy to hospice care.21 The goal of palliative care is to decrease suffering and provide comfort when a cure is no longer feasible or being pursued. The aggressiveness of the palliative therapies provided will depend on the prognosis and personal wishes of the patient and family. Nutrition support can provide hydration and reduce nutrient deprivation, thereby improving the quality of life for some patients. Nutrition support and hydration decisions should be based on effective communication between clinicians, patients, and families, with the ultimate decision being based on the wishes of the patient and family.47

SUMMARY Nutrition support with enteral and parenteral nutrition should be considered only when the patient is unable to meet his or her nutrient needs through the oral diet. Tube feeding should be the first choice for nutrition support whenever feasible. Parenteral nutrition should be used when the enteral route— either by oral diet or by tube feeding—cannot be used or is insufficient to meet the patient’s nutrient and energy needs. Careful monitoring and management is essential for effective nutrition support in the oncology patient.

REFERENCES

1. Position of the American Dietetic Association: Ethical and legal issues in nutrition, hydration, and feeding. J Am Diet Assoc. 2002;102:716-726.

2. Oncology guideline. ADA Evidence Analysis Library. http://www.adaevidence library.com. Accessed September 1, 2007.

3. A.S.P.E.N. Board of Directors and Clinical Guidelines Task Force. Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. JPEN J Parenter Enteral Nutr. 2002;26(1S):82SA-85SA.

4. August DA. Nutrition and cancer: Where are we going? Top Clin Nutr. 2003; 18(4):268-279.

5. DeChicco RS, Steiger E. Parenteral nutrition in medical or surgical oncology. In: Elliott L, Molseed LL, McCallum PD, eds. The Clinical Guide to Oncology Nutrition. 2nd ed. Chicago, IL: American Dietetic Association, 2006;156—164.

6. Robinson CA. Enteral nutrition in adult oncology. In: Elliott L, Molseed LL, McCallum PD, eds. The Clinical Guide to Oncology Nutrition. 2nd ed. Chicago, IL: American Dietetic Association ed. The 2006:138—155.

7. Zogbaum AT, Fitz P, Duffy VB. Tube feeding may improve adherence to radiation treatment schedule in head and neck cancer: An outcomes study. Top Clin Nutr. 2004;19(2):95-106.

8. Braunschweig C, Levy P, Sheenan PM, Wang X. Enteral compared with parenteral nutrition: A meta-analysis. Am J Clin Nutr. 2001;74:534-542.

9. Charuhas PM, Lipkin A, Lessen P, McMillen K. Hematopoietic stem cell transplantation. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: American Society for Parenteral and Enteral Nutrition; 2005:187-199.

10. Trujillo EB, Bergerson SL, Graf JC, Michael M. Cancer. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: American Society for Parenteral and Enteral Nutrition; 2005:150-170.

11. Marian M, Carlson SJ. Enteral formulations. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: American Society for Parenteral and Enteral Nutrition; 2005:63-75.

12. Barber MD, Fearon KC, Tisdale MJ, McMillan DC, Ross JA. Effect of a fish oil-enriched nutritional supplement on metabolic mediators in patients with pancreatic cancer and cachexia. Nutr Cancer. 2001;40:118-124.

13. Fearon KCH, von Meyenfeldt MF, Moses AGW, et al. Effect of a protein- and energy-dense Q-3 fatty acid enriched oral supplement on loss of weight and lean tissue in cancer cachexia: A randomized double blind trial. Gut. 2003;52:1479-1486.

14. Lee S, Gura KM, Kim S, Arsenault DA, Bistrian BR, Pruder M. Current clinical applications of Q-6 and Q-3 fatty acids. Nutr Clin Pract. 2006;21:323-341.

15. Fuhrman MP. Diarrhea and tube feeding. Nutr Clin Pract. 1999;14:83-84.

16. Lord L, Harrington M. Enteral nutrition implementation and management. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: American Society for Parenteral and Enteral Nutrition; 2005:76-89.

17. McClave SA, DeMeo MT. Proceedings of the North American summit on aspiration in the critically ill patient. J Parenter Enteral Nutr. 2002;26(suppl):S1-S85.

18. McClave SA, Lukan JK, Stefater JA, et al. Poor validity of residual volumes as a marker for risk of aspiration in critically ill patients. Crit Care Med. 2005;33:324-330.

19. Critical illness guideline. ADA Evidence Analysis Library. http://www.ada evidencelibrary.com. Accessed September 1, 2007.

20. Thompson CW, Durrant L, Barusch A, Olson L. Fostering coping skills and resilience in home enteral nutrition (HEN) consumers. Nutr Clin Pract. 2006; 21:557-565.

21. Fuhrman MP, Herrmann VM. Bridging the continuum: Nutrition support in palliative and hospice care. Nutr Clin Pract. 2006;21:134-141.

22. Krzywada EA, Edmiston CE. Parenteral nutrition access and infusion equipment. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: American Society for Parenteral and Enteral Nutrition; 2005:90-96.

23. Sacks GS, Mayhew S, Johnson D. Parenteral nutrition implementation and management. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: American Society for Parenteral and Enteral Nutrition; 2005:108-117.

24. Klein S, Miles JM. Metabolic effects of long-chain and medium-chain triglyceride emulsions in humans. JPEN J Parenter Enteral Nutr. 1994;18:396-397.

25. Lenssen P, Bruemmer BA, Bowden RA, Gooley T, Aker SN, Mattson D. Intravenous lipid dose and incidence of bacteremia and fungemia in patients undergoing bone marrow transplantation. Am J Clin Nutr. 1998;67:927-933.

26. Berger MM, Shenkin A. Vitamins and trace elements: Practical aspects of supplementation. Nutrition. 2006;22:952-955.

27. Mirtallo J, Canada T, Johnson D, et al. Task Force for the Revision of Safe Practices for Parenteral Nutrition. Safe practices for parenteral nutrition. JPEN J Parenter Enteral Nutr. 2004;28(suppl):S52-S57.

28. Fuhrman MP, Herrmann VM, Masidonski P, et al. Pancytopenia after removal of copper from total parenteral nutrition. JPEN J Parenter Enteral Nutr. 2000;24:361-366.

29. Krzywda EA, Andris DA, Whipple JK, et al. Glucose response to abrupt initiation and discontinuation of total parenteral nutrition. JPEN J Parenter Enteral Nutr. 1993;17:64-67.

30. Eisenberg PG, Gianino S, Clutter WE, et al. Abrupt discontinuation of cycled parenteral nutrition is safe. Dis Colon Rectum. 1995;38:933-939.

31. van den Berghe G, Wouters P, Weekers F, et al. Intensive insulin therapy in critically ill patients. N Engl J Med. 2001;345:1359-1367.

32. McMahon MM. Management of parenteral nutrition in acutely ill patients with hyperglycemia. Nutr Clin Pract. 2004;19:120-128.

33. Salvino R, Ghanta R, Seidner DL, Mascha E, Xu Y, Steiger E. Liver failure is uncommon in adults receiving long-term parenteral nutrition. JPEN J Parenter Enteral Nutr. 2006;30:202-208.

34. Seidner DL, Mascioli EA, Istfan NW, et al. Effects of long-chain triglyceride emulsions on reticuloendothelial system function in humans. JPEN J Parenter Enteral Nutr. 1989;13:614-619.

35. Finley JP. Management of cancer cachexia. AACN Clin Issues ADV Pract Acute Crit Care. 2000;11(4):590-603.

36. Argiles JM, Meijsing SH, Pallares-Trujillo J, Guiraro X, Lopez-Soriano FJ. Cancer cachexia: A therapeutic approach. Med Res Rev. 2001;21:83-101.

37. Lipkin AC, Lessen P, Dickson BJ. Nutrition issues in hematopoietic stem cell transplantation: State of the art. Nutr Clin Pract. 2005;20:423-439.

38. Torino J. Parenteral nutrition in adult hematopoietic stem cell transplantation: The evolution of clinical practice. Support Line. 2006;28(6):3-9.

39. Skop A, Kolarzyk E, Skotnicki AB. Importance of parenteral nutrition in patients undergoing hemopoietic stem cell transplantation procedures in the autologous system. JPEN J Parenter Enteral Nutr. 2005;29(4):241-247.

40. Canada T. Clinical dilemma in cancer: Is tumor growth during nutrition support significant? Nutr Clin Pract. 2002;17:246-248.

41. Samlowski WE, Wiebke G, McMurray M, et al. Effects of TPN during high-dose interleukin-2 treatment for metastatic cancer. J Immunol. 1998;21:65-74.

42. Jin D, Phillips M, Byl es J. Effects of parenteral nutrition support and chemotherapy on the phasic composition of tumor cells in gastrointestinal cancer. JPEN J Parenter Enteral Nutr. 1999;23:237-241.

43. Bozzetti F. Home total parenteral nutrition in incurable cancer patients: A therapy, a basic humane care or something in between? Clin Nutr. 2003;22:109-111.

44. Bozzetti F, Gavazzi C, Mariani L, Crippa F. Glucose-based total parenteral nutrition does not stimulate glucose uptake by human tumors. Clin Nutr. 2004;23:417-421.

45. Bozzetti F, Cozzaglio L, Biganzoli E, et al. Quality of life and length of survival in advanced cancer patients on home parenteral nutrition. Clin Nutr. 2002;21:281-288.

46. August DA, Thorn D, Fisher RL, et al. Home parenteral nutrition for patients with inoperable malignant bowel obstruction. JPEN J Parenter Enteral Nutr. 1991;15 (3):323-327.

47. Casarett D, Kapo J, Caplan A. Appropriate use of artificial nutrition and hydration: Fundamental principles and recommendations. N Engl J Med. 2005;353:2605-2612.

Рекомендуем к просомтру

www.kievoncology.com благодарны автору и издательству, которые способствует образованию медицинских работников. При нарушении авторских прав, сообщите нам и мы незамедлительно удалим материалы.