Parenteral Nutrition has considerably increased the responsiveness to medical or surgical treatment of a patient. All the nourishing infused substances are in an elementary state, ready for a direct utilization by the cells. They offer a caloric and proteinous contribution which is necessary to the metabolic demands of an organism that grows in case of fewer, traumas, scalds, in post surgical time, or in hypermetabolic pathologies. The physician, nurse, and dietician decide the necessity to Total Parenteral Nutrition, valuing the patient's parameters such as: loss of weight, azotic budget, percentage of loss of muscular and lean mass, the patient's inability to tolerate food through gastroenteric way. A careful valuation and a scrupulous treatment by physician and nurse can reduce the risk of complications during parenteral feeding.