Peri-operative nutritional support: controversies and debates.

BACKGROUND: Malnutrition continues to be a significant problem in patients undergoing surgery. The relationship between a poor nutritional status and subsequent post-operative morbidity and mortality is well recognised. It is logical, therefore, that malnourished patients should be given nutritional supplementation in the peri-operative period. However, the benefits of this approach have been debated and as we enter the new millennium there are many questions regarding then role of peri-operative nutritional support that remain unanswered. AIMS: This review aims to determine how we decide which patients are malnourished, which patients require nutritional support and what are the benefits, by what route (enteral or parenteral), and for how long should nuritional support be given are there key nutrients which should be given. RESULTS: Nutritional status can be assessed routinely in all patients, with clear definitions of undernutrition, overnutrition and nutritional risk indices being applicable to surgical practice. Peri-operative parenteral nutritional support does benefit patients who are malnourished but they should receive at least 7 to 10 days of support before surgery. The theoretical benefits of enteral nutrition are clear but whether or not this translates into clinical benefits remains contentious. Nutritional support supplemented with key nutrients does seem to be advantageous by reducing the risk of septic post-operative complications and reducing overall stay in hospital. CONCLUSION: Patients most likely to benefit from peri-operative nutritional support can be defined. Enteral nutritional support has advantages over parenteral nutrition and the administration of key nutrients has clinical benefits.