Nutrition therapy for oncology patients
Malnutrition can be frequently observed among cancer patients: First, many cancers induce tumour cachexia, a wasting syndrome with metabolic derangements. Second, side effects of therapy such as sub acute/chronic radiation enteropathy, chemotherapy induced nausea and vomiting or oral mucosal ulcers often limit the intake of food.
Malnutrition in cancer patients has been associated with increased morbidity and mortality and decreased response to therapy. As the impact of cancer cachexia on patient outcome and healthcare resources is significant it is important to identify those patients at a risk of malnutrition. Early countermeasures intended to reverse cachexia or at least stop the progress of malnutrition are deemed important and nutritional support and parenteral nutrition might be indicated.
Routine screening of cancer patients is recommended by medical societies in order to start adquate nutrition therapy in time. Depending on the physical status of the patient, Enteral feeding, either by oral supplementation or tube feedings, is the preferred route of nutrition, whenever possible. Parenteral nutrition offers the possibility of increasing or ensuring nutrient intake in patients in whom normal food intake is inadequate and enteral nutrition is not feasible, is contraindicated or is not accepted by the patient.
Enteral Nutrition support is the provision of nutrients via the gastrointestinal tract by oral intake or through enteral feeding tubes.
Parenteral nutrition (PN) is defined as the supply of vital nutrients bypassing the digestive tract. Parenteral nutrition becomes necessary when it is not possible for the body to ingest sufficient nutrients via the oral/enteral route and to utilize these nutrients adequately. The choice between the enteral or parenteral route is decided very simply by the question "Is the gastrointestinal tract functional?"
As long as oral nutrition is sufficient, no additional access is needed. Feeding tubes for gastral or duodenal application of tube feeds are available for enteral nutritional support. When parenteral nutrition is necessary, many oncology patients receiving chemotherapy have an implanted intravenous catheter system (port or Hickman catheter) which can be used for nutrition also.
The need for preparation largely depends on the decision of the treating physician and availability of nutritional services in a given hospital. Oral sip feeds and tube feeds are readily available without the need of additional preparative steps. For parenteral nutrition, ready to mix multichamber bags are available which might require some additional vitamins or trace elements to be added. If compounding services are available, patient-specific nutritional regimen may be ordered and are then prepared in an equipped pharmacy.
The choice of route of nutrition is decisive for the application: For enteral tube feeds, the use of medical devices such as catheters and connectors of the EN fit system are strongly recommended as these are non-compatible with IV or intrathekal lines and thus prevent inadvertent mistakes of potentially fatal outcome. Additionally, infusion pumps with dedicated sets for Enteral and / or Parenteral Nutrition solutions assure the correct and safe administration.