Which patients would be candidates for receiving parenteral nutrition?
A multidisciplinary approach to the management of patients receiving TPN is recommended to reduce complications, writes Deirdre McCormack Show Total parenteral nutrition is the aseptic delivery of nutrients into the circulatory system via a central venous catheter or the peripheral veins. TPN is used when the gut is not functioning and there are several indications that may suggest its use (see Table 1).
Access routes and duration Central vein cannulation is the most commonly used route, however peripheral feeding is an acceptable alternative for short-term feeding. A single dedicated lumen should be used for administration of TPN. Nutritional assessment A baseline biochemical assessment should identify any abnormal plasma electrolyte levels, liver function tests, renal function tests, glucose levels or lipid screen. Nutritional requirements Fluid Acute changes in fluid can also be determined by monitoring acute changes in biochemical parameters such as albumin, haemoglobin, mean cell volume, urea and sodium. To maintain fluid levels, the following is required:
Plus replacement of ongoing fluid losses, eg. pyrexia, urine, drains, excess wound exudates, stomas and high GI losses. Energy It is imperative that these equations are not used in isolation and that monitoring of the patient occurs to assess efficacy. Indirect calorimetry may be used. However, this is not practical in the acute setting. Nutritional requirements are also affected by medical conditions, thus alternate evidence based predictive equations exist for certain conditions such as liver disease, renal failure and the critically ill obese. Nitrogen The aim of nutritional support is to achieve a state of nitrogen balance using nitrogen balance data where available or general recommendations.2 The nitrogen in parenteral nutrition is provided in the form of an amINO acid solution. Electrolytes
Vitamins and trace elements
Monitoring Patients receiving TPN should have their nutritional requirements reviewed regularly, taking into account clinical condition, treatments (eg. dialysis), drug therapy, nutritional status, response to TPN and supporting laboratory data. Clinical assessment of the patient can reveal ascites, oedema, impaired wound healing or loss of muscle mass that may not be evident from monitoring weight and biochemical indices (see Table 2).
Complications
Standard versus tailored regimens Patients on TPN that are metabolically stable can tolerate slight under or over provision of nutrients, fluid or electrolytes with no complications. It is the careful assessment that will identify those patients who are likely to be substrate intolerant and require frequent manipulations or specifically tailored regimens. Albumin Novel substrates After injury/hypercatabolic conditions, profound intracellular glutamine depletion has been found, thus is regarded as a conditionally essential amINO acid. Studies have shown improvements in the clinical outcome of hypermetabolic patients. Optimal
management Deirdre Mc Cormack is a clinical nutritionist at St. James's Hospital Dublin References on request. All rights reserved by INMO. Please don't use without permission Which types of patients require parenteral nutrition and why?You may need parenteral nutrition for one of the following reasons:. Cancer. Cancer of the digestive tract may cause an obstruction of the bowels, preventing adequate food intake. ... . Crohn's disease. ... . Short bowel syndrome. ... . Ischemic bowel disease. ... . Abnormal bowel function.. Why would a patient need parenteral nutrition?There are many reasons for enteral and parenteral nutrition including GI disorders such as bowel obstruction, short bowel syndrome, Crohn's disease, and ulcerative colitis; as well as certain cancers or in comatose patients.
Which patient is most likely to be a candidate for total parenteral nutrition TPN rather than enteral nutrition?TPN is most often used for patients with crohn's disease, cancer, short bowel syndrome, or ischemic bowel disease. However, critically ill patients who cannot receive nutrition orally for more than four days are also candidates for TPN.
What medical conditions require TPN?Conditions for Which We Use Total Parenteral Nutrition. An abnormal connection between two organs (fistula). Bowel obstruction.. Crohn's disease (in severe cases). Gastrointestinal cancer.. Intestinal failure.. Malnutrition.. Gastrectomy.. Short bowel syndrome.. |