Novel Preoperative Carbohydrate Drinks Versus Commercial Syrup-Based Drinks on Gastric Emptying, Glycemic Responses, and Fasting Discomfort: A Pilot Randomized Crossover Trial

Abstract

Background: Enhanced Recovery After Surgery (ERAS) guidelines recommend preoperative carbohydrate loading; however, local hospitals often use syrup concentrate sweet drinks rather than specialized carbohydrate formulations. We compared gastric emptying, glycemic response, and fasting discomfort of a novel carbohydrate drink versus syrup concentrate sweet drinks. Methods: In this pilot randomized, crossover trial at Prince of Songkla University Hospital, Thailand, 16 healthy volunteers received three interventions with a 1-week washout period: novel carbohydrate drink 400 mL (C400), novel carbohydrate drink 250 mL (C250), and syrup sweet drink 250 mL (SYR). The primary outcome was gastric antral cross-sectional area (CSA) measured using ultrasonography at baseline, 10, 60, 120, and 180 min post-ingestion. Secondary outcomes included glycemic response and visual analog scales for thirst and hunger. Results: All drinks showed comparable gastric CSA, peaking at 10 min (5.5–6.5 cm2, p < 0.01) and returning to baseline by 120 min. Novel carbohydrate drinks produced higher glucose peaks at 60 min (C400: 147.4 mg/dL [28.0]; C250: 148.7 mg/dL [21.7]) than SYR (123.1 mg/dL [22.4], p = 0.006) with sustained elevation through 120 min. All drinks similarly reduced thirst and mouth dryness scores at 60 min (p < 0.05), though hunger increased progressively after 120 min across all groups. Conclusions: Both 400 mL and 250 mL volumes of novel carbohydrate drinks demonstrated safe gastric emptying profiles comparable to syrup concentrate sweet drinks while providing more sustained glycemic responses.