[Total parenteral nutrition. History. Present time. Future]

Total parenteral nutrition (TPN) has been available for only 30 years. However, history in this field goes back more than 350 years with the first landmark being the description of general blood circulation by William Harvey in 1628. His discovery is the anatomical basis for intravenous infusions. Many investigations were performed during the following centuries showing that solutions containing electrolytes and glucose could be given intravenously in man. The accumulated knowledge of protein metabolism formed the basis for studies on intravenous nutrition with protein hydrolysates, peptides and amino acids. The observation in the late 30-s by Robert Elman that amino acids in the form of protein hydrolysate could be safely administered intravenously in man was the first major step toward TPN. During the following years, major efforts were made to find methods to prepare infusion solutions with a high energy content and low osmotic pressure. The most realistic alternative seemed to be fat in the form of an emulsion. Many studies of a large number of various fat emulsions were made however, all of these emulsions caused severe adverse reactions in man. The first safe fat emulsion, intralipid, was made available in the early 60s. This was the second major step toward TPN. It was then no problem to include vitamins, electrolytes and trace elements in the fat emulsions and the solutions of amino acids and glucose. A few years later it was shown that a central venous catheter could be used to administer the infusion fluid intravenously. Many clinical investigations and reports have shown that the newly developed intravenous nutritional regimens are adequate alternatives to the ordinary diet. In this way it has been possible to maintain or obtain a good nutritional condition in most situations when oral or tube feeding can not be used. TPN has been shown to be of very great clinical importance to prevent and treat starvation often related to high morbidity and mortality.