Determining residual gastric volume in healthy children using ultrasound

Area of Science:

• Pediatric Anesthesiology
• Gastroenterology
• Medical Imaging

Background:

• Fasting guidelines for children recommend restricting clear fluids 1-2 hours before procedures to prevent pulmonary aspiration.
• Gastric volumes below 1.5 mL·kg^-1 are generally considered safe, posing no increased risk of aspiration.

Purpose of the Study:

• To determine the time required for gastric fluid volume to decrease below 1.5 mL·kg^-1 in children after ingesting clear fluids.
• To evaluate the potential for liberalizing current pediatric fasting guidelines.

Main Methods:

• A prospective observational study involving 33 healthy children aged 2-14 years.
• Gastric ultrasound (US) was used to measure antral cross-sectional area (CSA) in the right lateral decubitus (RLD) position.
• A predictive model estimated gastric volume using RLD CSA and age, with measurements taken at 30, 60, 90, and 120 minutes after consuming 250 mL of clear fluid.

Main Results:

• The mean gastric volume per weight at baseline was 0.51 mL·kg^-1.
• After 30 minutes, the mean gastric volume was 1.55 mL·kg^-1.
• By 60 minutes, the mean gastric volume decreased to 1.17 mL·kg^-1, and by 90 minutes to 0.76 mL·kg^-1.
• At 120 minutes, the mean gastric volume was 0.58 mL·kg^-1.

Conclusions:

• Gastric fluid volume in children consistently fell below the 1.5 mL·kg^-1 threshold by 60 minutes post-ingestion.
• These findings suggest that current pediatric fasting guidelines for clear fluids may be liberalized.
• Further research could refine optimal fasting durations based on gastric emptying in pediatric populations.