The quantitative transperitoneal absorption of a fat emulsion: implications for intraperitoneal nutrition

Intraperitoneal (IP) administration of nutrients would be an attractive alternative to intravenous nutrition since it eliminates intravascular complications. If glucose alone were used as the nonprotein calorie source, associated fluid shifts might not be well tolerated by the patient. A fat emulsion does not have osmotic properties and thus might be incorporated into a program of IP nutrition as a calorie source. Transperitoneal absorption of a commercial fat emulsion (Liposyn 10%, Abbott Laboratories, N Chicago, IL) was studied in 12 beagle puppies divided into two groups. One group received 2.5 gm/kg of fat and the other group received a similar volume of 3.5% crystalline amino acids and 5% glucose in one IP dose. In the first group, the serum triglyceride (TG) increased three fold from 61 +/- 25 mg% to 185 +/- 61 mg% at 15 minutes and then decreased slowly while remaining significantly elevated (p less than 0.05) at 4 hours. 1.94 +/- 0.20 gm/kg of TG were absorbed from the peritoneal cavity over 4 hours. Concommitant IP administration of amino acids and glucose did not affect that absorption. Radiolabeled amino acids and glucose instilled IP were demonstrated in the blood immediately after administration and their absorption was not affected by the presence of a fat emulsion. Plasma free fatty acids showed a small increase at 4 hours (from 0.32 +/- 0.09 mEq/L to 0.59 +/- 0.22 mEq/L). Animals receiving no IP fat showed no change in serum TG. Serum glucose rose in both groups and serum cholesterol showed no changes in either group. Peritoneal fluid accumulation 4 hours after IP fat administration was minimal at 12.7 +/- 6.4 mL/kg. This study shows that a fat emulsion can be quantitatively absorbed from the peritoneal cavity over four hours and that IP nutrition may be feasible.