Increased gut blood flow with early enteral feeding in burned guinea pigs.

The hemodynamic responses to early enteral feeding were assessed with fluid-resuscitated, 30% total body surface area-burned guinea pigs fed by means of tube gastrostomies. Regional blood flow and cardiac output were determined by a reference sample method, injecting 15 microns radiolabeled microspheres. During the initial 24 hours after burn injury, animals were given the same volume by continuous infusion of either lactated Ringer's solution (LR group) or a liquid diet (20% protein, 12% lipid, and 68% carbohydrate; 175 kcal/kg/24 hr) (diet group). Although cardiac outputs in the LR and diet groups were not different from each other at 24 hours and no less than that in unburned control animals, the diet group showed higher blood flow to the jejunum (+55.7%) and cecum (+98.7%) than did the LR group. Burn injury caused little change of blood flow to tissues other than the intestine. In addition, early feeding after burn injury suppressed excessive cortisol response to burn shock. The increase in gut blood flow associated with enteral feeding could have an impact on mucosal barrier function.