Ultrasound-Based Assessment of Gastric Fluid Volume in the Pediatric Population Undergoing Elective Surgery: A Prospective, Randomized, Double-Blind Comparison of Carbohydrate-Rich Clear Fluid Versus Water at One- and Two-Hour Fasting Intervals.

Summary

In this prospective, randomized, double-blind trial of 140 ASA I-II children, drinking 3 mL/kg of carbohydrate-rich clear fluid one hour before anesthesia produced a higher gastric fluid volume than two-hour fasting, but no child exceeded the 1.5 mL/kg risk threshold. The one-hour carbohydrate-fluid regimen also produced better comfort, supporting its use in appropriately selected healthy children undergoing elective surgery.

Key Findings

• All 140 children completed the study, and no participant exceeded a gastric fluid volume of 1.5 mL/kg.
• Mean gastric fluid volume was 0.947 mL/kg after one-hour carbohydrate-fluid fasting versus 0.340 mL/kg after two-hour carbohydrate-fluid fasting.
• Comfort was significantly higher after one-hour carbohydrate-fluid fasting, with no pulmonary aspiration episodes observed.

Clinical Implications

For healthy children undergoing elective non-gastrointestinal surgery, 3 mL/kg of a carbohydrate-rich clear fluid one hour before induction may be a feasible alternative to a two-hour clear-fluid fast, potentially improving comfort without exceeding the assessed gastric-volume safety threshold. The findings should not automatically be extrapolated to emergency surgery, gastrointestinal disease, aspiration-risk conditions, or other populations.

Limitations

• The sample consisted of healthy ASA I-II children undergoing elective non-gastrointestinal surgery, limiting generalizability.
• The study was not powered to detect rare pulmonary aspiration events, and gastric ultrasound was used as a surrogate rather than direct aspiration outcome.

Future Directions

Larger multicenter studies should evaluate one-hour carbohydrate-fluid fasting in infants, children with comorbidities or aspiration risk, emergency settings, and diverse fluid formulations, while monitoring actual aspiration and perioperative outcomes.