Gastric emptying and intestinal transit of various enteral feedings following severe burn injury

Background: Burn-induced delayed gastric emptying and intestinal transit limits enteral feeding/resuscitation. Aims: To study (1) the effects of burn injury on gastric emptying and intestinal transit at different time points following enteral feeding/fluids, and (2) the effects of enteral resuscitative fluids on gastric emptying, intestinal transit, and plasma volume expansion. Methods: Rats were randomized into sham-burn and burn groups. They were either enterally untreated or treated by a gavage of one or multiple doses of oral rehydration solution (ORS) or, Vivonex ^®, all mixed with phenol red as a marker, at different time points from 1 to 6 h after burn. Gastric emptying, intestinal transit and hematocrit values were assessed. Gastric emptying of a semi-solid methylcellulose meal served as a standard control for gastric emptying studies. Results: We found that (1) burn did not alter the gastric emptying of ORS, but delayed its intestinal transit at all time points; (2) burn delayed the gastric emptying of both methylcellulose or Vivonex and the intestinal transit of Vivonex, 6 h after burn; and (3) multiple doses of ORS normalized the elevated post-burn hematocrit values. The percentage of plasma volume expansion at 6 h resulting from the multiple-dose ORS was superior to that of Vivonex by 50%. Addition of Erythromycin to Vivonex improved its gastric emptying, intestinal transit, and plasma volume expansion. Conclusions: Burn delays the gastric emptying of semi-solids, but not the ORS. Enteral electrolyte solution (ORS) and feeding (Vivonex) provided plasma volume expansion. Prokinetic drugs may be able to maximize the effectiveness of early post-burn feeding.