Systemic appearance of nutrients placed into the peritoneal cavity

The use of the peritoneal cavity as a route for delivery of nutrients in patients on continuous ambulatory peritoneal dialysis as well as patients not in renal failure has been proposed. In earlier studies we found dogs could be maintained for 30 days through continuous peritoneal infusion of a solution of amino acids, glucose, and lipids. We then conducted experiments to observe the rate of absorption of nutrients from the gut compared to the peritoneal cavity, the relative rate absorption of amino acids, sugars, and fats, and the absorption of of glucose polymers from the peritoneal cavity. These latter experiments are the subject of this report. In a dog model we observed D-xylose was more rapidly absorbed through the peritoneal cavity than through the gut, but amino acids were absorbed at the same rate. Glucose and amino acid are absorbed at the same rate through the peritoneal cavity, but lipids do not appear in the system circulation for 2 1/2 hr. Intraperitoneal glucose polymer produces an increase in serum glucose concentration that is lower and more sustained than what occurs after giving an equal amount of plain glucose. It is concluded that the peritoneal cavity rapidly transports glucose, amino acids, and glucose polymers and slowly transports lipids into the systemic circulation. Consideration of this route for delivery of nutritional support seems reasonable, but further studies of appropriate concentrations and rates of delivery will be required.