“…SINCE the original work of Cuthbertson (1930Cuthbertson ( , 1932, Moore and Ball (1952) and Moore (1959), it has been well established that following trauma, including surgery, there is a 'catabolic phase' during which there is a temporary alteration in the metabolism as a whole, with an increase in the urinary output of nitrogen, resulting in a negative nitrogen balance. The reports of Abbott and Albertsen (1963), Johnston et al (1966), Irving and Rushman (1971), Walker and Johnston (1971) and Johnston et al (1972) have suggested that parenteral nutrition with a high calorie and nitrogen content can reduce, or even reverse, the negative nitrogen balance during the postoperative catabolic phase.…”