Overview of randomized clinical trials of total parenteral nutrition for malnourished surgical patients.

The past decade has seen a maturation of the art and science of perioperative nutritional support. We now have sufficient data to make informed and reasonable judgments regarding when we should and should not provide perioperative TPN. These judgments can be considered medically sound and fiscally responsible. The following guidelines are proposed: (1) Postoperative TPN should be considered when oral or enteral feeding is not anticipated within 7 to 10 days in previously well-nourished patients or within 5 to 7 days in previously malnourished or critically ill patients. (2) Preoperative TPN should be considered in patients who cannot or should not eat or receive enteral feedings if the operation must be delayed for more than 3 to 5 days. (3) Preoperative TPN should be considered in the most severely malnourished surgical candidates if an operative delay is not contraindicated. In patients with only mild to moderate degrees of malnutrition preoperative TPN is not indicated.