Comparison of Gastric Residual Volume After Ingestion of A Carbohydrate Drink and Water in Healthy Volunteers with Obesity: A Randomized Crossover Study.

Introduction: Preoperative carbohydrate intake is essential to enhance postoperative recovery. However, its safety for individuals with obesity remains unclear. This study investigated the safety of preoperative carbohydrate consumption compared to water intake in obese populations through gastric volume assessment.

Methods: A prospective randomized crossover study enrolled 30 healthy volunteers aged 18-65 years with a body mass index ≥ 30 kg/m², following a minimum 6-h fast. The participants received either 400 ml of a carbohydrate drink (group C) or water (group W). Gastric ultrasonography, blood glucose level, hunger, and thirst assessments were conducted at baseline (T) and various time points (T2 to T6). The protocol was repeated with reverse interventions at least 1 week later.

Results: Group C had significantly higher gastric volume at T3, T4, and T5 compared to group W, with a prolonged time to empty the gastric antrum (94.4 ± 28.5 vs. 61.0 ± 33.5 min, 95% CI 33.41 [17.06,24.69]). However, glucose levels, degrees of hunger, and thirst showed no significant differences between the groups.

Conclusion: Administering 400 ml of preoperative carbohydrates to healthy obese individuals 2 h preoperatively is safe and comparable to water intake. These findings support the integration of carbohydrate loading into perioperative care for obese individuals, consistent with the enhanced recovery after surgery protocols. Further research is warranted to refine preoperative fasting protocols and improve surgical outcomes in this population.