[Acid-base parameters in postoperative infusion therapy]

[Differences in postoperative metabolism after pre- and postoperative beginning of total parenteral nutrition]

In this study we intended to investigate the influence of a 24-h-preoperative total parenteral nutrition (TPN) therapy--10 surgical patients, group 1--compared with the postoperative beginning of TPN--9 surgical patients, group 2--on the postoperative metabolism. Most probably due to preoperatively depleted glycogen storages in G 2, the urinary carbohydrate losses declined more rapidly postoperatively compared with G 1. 45 mMol/l of sodium did not cover the postoperative requirements of G 1. Although we administered 90 mMol/l of potassium/24 h, several patients of G 1 needed an additional substitution. No additional phosphate substitution was necessary in either group. Except for a slight positive balance on the operation day, fluid balance was well balanced on all the other days in G 1. From postoperative day 2 on, G 2 developed a deficit of free water. It could be demonstrated very clear in this study that the postoperative fluid and electrolyte requirements are strongly influenced even by a short-term preoperative fasting period.

[Studies on the pharmacokinetics of carbohydrates as a basis for their use in parenteral feeding]

Metabolic effects of glucose, fructose, sorbitol, xylitol and their combinations during intravenous application in men were investigated. The totale and metabolic clearance, the renal and metabolic elimination, the half-time and the turnover rate were measured. For all sugars intravenous long-term infusions from six to twelve hours were performed. Up to a dosage of 0.75 g/kg/h for glucose 0.5 g/kg/h for sorbitol and 0.25 g/kg/h for fructose and xylitol a steady state of substrates and metabolites has been found. If these dosage-limits are exceeded during glucose application a hyperglucosemia, after sorbitol a continous rise in sorbitol blood level, during fructose a rise in lactate and during xylitol infusion clinical side effects occurred. It could be shown that during simultaneous application of glucose, fructose and xylitol the utilization of glucose rises whereas the utilization of fructose and xylitol remain on such levels as if these sugar were infused alone.