Using patients with varying degrees of trauma as their own controls we compared three isocaloric regimens in three-day crossover studies; 9.4 g of nitrogen as l-amino acids was also given daily. The urea production rate was used as an index of protein breakdown. We found that in catabolic patients, insulin and glucose produced a strikingly greater inhibition of protein breakdown that glucose alone, and that glucose alone was marginally more protein sparing than a regimen containing mainly fat (intralipid and sorbitol). These differences were not seen in noncatabolic patients (urea production rate less than 15 g daily). In the catabolic patients (urea production rate greater than 15 g daily) the protein-sparing effect of insulin was proportional to the initial urea production rate. We therefore concluded that insulin has important protein-sparing effects in severely ill traumatized patients, but little effect when there is no increased catabolic rate.

The traditional "Sliding Scale" is an inefficient and unreliable way of controlling blood glucose levels in ill patients receiving nutritional support in the Intensive Care Unit. In these patients, it is necessary to reassess insulin requirements frequently in the light of changing clinical circumstances. A significant improvement in control can be achieved by using a dynamic scale of instructions for changing the insulin dose rather than one of arbitrary dose levels. This scale adapts to any changes that occur without needing to be rewritten. It avoids confusion due to a proliferation of prescription charts, and has been readily accepted by nursing staff.

In 51 women with metastatic breast cancer calcium excretion per litre of glomerular filtrate (CaE) values were persistently higher in those with bone secondaries than in those with only soft tissue involvement despite a normal range of serum calcium in both groups. Measurement of CaE in 8 further patients who were severely hypercalcaemic as a result of their advanced breast cancer revealed the degree to which calcium resorption from bone secondaries and renal dysfunction contributed to the hypercalcaemia. Thus, in patients with breast cancer, CaE provides a reliable indicator of early changes of calcium homeostasis. It may provide an objective indication of progression of bone secondaries and also has important therapeutic implications in established hypercalcaemia.

No abstract

One of the subjects that has aroused great attention in hospital nutritional circles since the early 1970s is the relationship between energy and nitrogen metabolism. An enormous amount of confusion has arisen, largely through failure to differentiate between the metabolic changes of starvation and those of injury.Emphasis has largely been placed on N balance, either in terms of making negative balance smaller or achieving positive balance, and the importance of energy supply in its own right has been neglected until recently. This paper will attempt to give a brief overview of amino acid metabolism as a general background and then describe developments that have occurred over the last decade in the application of knowledge in this area. The relationship between energy intake, N intake and N balance in various clinical circumstances will also be described.