Nutritional Support

Surgery Essay

Outline the principles involved in the nutritional support of the surgical patient The pre-op patient must not be malnourished as this will result in: decreased wound healing, muscle weakness and an increased tendency to infection. Hospital patients become malnourished due to: decreased appetite, increased nutritional demands, impaired digestion, dislike of hospital food, interruptions of meals by scheduled tests and ‘nil by mouth’ orders. If oral intake is not anticipated within 7-10 days from surgery (perhaps even 5 days for the malnourished), then nutritional support is indicated. The main indication for pre-op support is a weight loss greater than 10%. Nutritional support ranges from a supplementation of vitamins, or proteins only to complete replacement of foodstuffs. Enteral diets are those given via the gut, and includes oral intake. The ideal scenario would be that the patient ingests all the required nutrients, however when this is not possible, enteric feeding is the next best option. This involves passing food to the gut such as through an NG tube or for longer term ,the use of gastrostomy/Jejunostomy. In the gut the food is absorbed as normal. This is ideal for surgical patients having problems swallowing such as after a stroke or oesophageal obstruction. Complications include diarrhoea and vomiting, but this can be prevented by reducing the rate of infusion. Whenever possible, enteral nutrition is preferred to parenteral as the latter has more serious complications. Parenteral feeding 1

Surgery Essay

is given to people who cannot take enteral feeding, such as those with short gut syndrome, where large pieces of gut have been removed surgically. Parental feeding can be combined with enteral feeding, where it is given through a cannula in a peripheral vein. Total Parenteral Nutrition (TPN) is used to deliver complete nutritional supplements. The TPN has a high osmolality and hence toxic to veins. Hence, TPN is given via a central line, where a small cannula is inserted into a vein with a high rate of blood flow. For longer use, a Hickman is preferred, as it is inserted subcutaneously to make it more secure and has a Dacron cuff to prevent infection. The disadvantages of parenteral nutrition include infection; villous atrophy, as enteral cells derives nutrition from the lumen. Electrolyte imbalances are common, as well as hyperglycaemia, fatty liver and a cholestatic picture with increased alkaline phosphatase, therefore LFTs are important. The requirements include water: depending on the negative water balance of the patient, energy: about 1800kcal obtained from carbohydrates and fats, Nitrogen 8-20g/day in protein, vitamins: fat-soluble vitamins need careful adjusting to avoid over-dose, minerals: sodium, potassium, calcium, magnesium, phosphate and trace elements: zinc, copper, and iron. A multidisciplinary team including the surgeon, dietician, pharmacist and nurses is important for a patient’s nutritional support. The best indicators of success in nutria of a patient are the physical appearance and weight. And the best chemical marker of nutritional status for day to day monitoring is prealbumin. 2

Surgery Essay

01/02/09

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