Metabolic, hormonal and gastric fluid and pH changes after different preoperative feeding regimens

Purpose: To evaluate the metabolic, hormonal and gastric fluid and pH chang es after administration of a small volume of different preoperative feeding regimens, Methods: In a prospective, randomized, double-blind study 375 adult patient s were allocated to one of five groups. Patients ingested 60 mi honey, gluc ose-fructose-sucrose-maltose mixture (GFSM), apple juice or water two hours before surgery or continued their overnight fast (controls). Blood samples were obtained from an indwelling venous catheter before the administration of feeding regimens and before induction of anesthesia for determination o f glucose, triglycerides, insulin, epinephrine and norepinephrine concentra tions. Before anesthesia induction, patients were asked to grade the degree of thirst and hunger. After tracheal intubation residual gastric volume (R GV) was suctioned through an orogastric tube. Results: Administration of honey, GFSM, apple juice or water resulted in in creases in RGV without changes in the gastric pH. The median RGV values wer e 15 mi in controls and 20-25 mi in other groups. Thirst was noted after ad ministration of fluids containing sugars. Hunger was noted in the apple jui ce group. Plasma concentrations of glucose increased and triglycerides decr eased after ingestion of fluids containing sugars. Plasma insulin concentra tions decreased in GFSM and apple juice groups. Norepinephrine concentratio ns increased in the control, apple juice and water groups. Conclusions: Small volumes of fluid increased RGV (P < 0.05). Apple juice r esulted in increased incidence of thirst and hunger and plasma glucose and norepinephrine concentrations. Compared with GFSM or apple juice, honey had a gentler effect on plasma glucose and insulin concentrations.