-Original-

Gastric Emptying of a Carbohydrate-electrolyte Solution in Healthy Volunteers Depends on Osmotically Active Particles

Chol Kim¹, Tadashi Okabe², Minoru Sakurai³, Koji Kanaya³, Keiichi Ishihara³, Tetsuo Inoue¹, Shin-ichiro Kumita⁴ and Atsuhiro Sakamoto⁵

¹Department of Anaesthesia, Nippon Medical School Chiba Hokusoh Hospital
²Department of Anesthesia, Hitachinaka General Hospital
³Clinical Imaging Center for Healthcare, Nippon Medical School
⁴Department of Radiology, Nippon Medical School
⁵Department of Anesthesiology, Nippon Medical School

Background: Preoperative ingestion of only clear fluids until 2 hours before induction of anesthesia is a common preoperative fasting regimen. Gastric emptying times, however, vary among clear fluids. We therefore investigated the gastric emptying of 2 clear glucose-electrolyte drinks.
Method: A 2-way crossover study was performed in 10 healthy volunteers. After fasting, the volunteers drank 500 mL of either OS-1^®, an oral rehydration solution, or Pocari Sweat^®, a popular sports drink, over 3 minutes in a standing position. Magnetic resonance imaging was performed before, immediately after, and 30 minutes after the drinking of each test fluid. The difference in gastric emptying between OS-1^® and Pocari Sweat^® was evaluated by comparing gastric fluid volume, flow rate, and residual ratio. We also compared the flow rates of sodium, potassium, carbohydrates, and osmotically active particles in the 2 test fluids.
Results: Gastric fluid volume 30 minutes after drinking was significantly smaller for OS-1^® (76.0 ± 57.0 mL) than for Pocari Sweat^® (158.1 ± 73.5 mL, p<0.01), although the volumes did not differ before or immediately after drinking. The flow rate was significantly faster for OS-1^® (10.66 ± 3.34 mL) than for Pocari Sweat^® (8.68 ± 3.02 mL/min, p<0.05), and the residual ratio was significantly smaller for OS-1^® (21 ± 14% than for Pocari Sweat^® (41 ± 19%, p<0.01). The flow rates of sodium, potassium, and glucose differed significantly between OS-1^® and Pocari Sweat^®, whereas the flow rate of osmotically active particles did not.
Conclusions: Gastric emptying is significantly faster for OS-1^® than for Pocari Sweat^®.

J Nippon Med Sch 2013; 80: 342-349

Keywords
gastric emptying, clear fluid, osmotically active particles

Correspondence to
Chol Kim, Department of Anaesthesia, Nippon Medical School Chiba Hokusoh Hospital, 1715 Kamagari, Inzai, Chiba 270-1694, Japan
ckim@nms.ac.jp

Received, October 15, 2012
Accepted, April 9, 2013