Gastric ultrasound reveals no association between prolonged fasting duration and gastric residual volume in pediatric patients

Prolonged preoperative fasting is common in pediatric anesthesia, yet its effect on gastric residual volume (GRV) remains inadequately explored. We conducted a prospective observational cross-sectional study to examine the association between prolonged fasting duration and GRV measured using point-of-care gastric ultrasonography. A total of 491 children aged 1–12 years scheduled for elective surgery under general anesthesia after fasting more than 8 hours were included. GRV was measured using point-of-care gastric ultrasonography and calculated using a validated formula, then normalized to body weight. The primary outcome was the association between fasting duration and weight-adjusted GRV (GRV/WT). Among the participants (median age 89 months; 308 boys), fifteen patients (3.05%) had a full stomach (GRV/WT > 1.25 mL·kg⁻¹) and 29 (5.91%) showed high-risk gastric antrum morphology. Prolonged fasting duration was not associated with GRV/WT. GRV/WT correlated positively with age and negatively with body mass index. These findings suggest that prolonged preoperative fasting does not reliably reduce GRV in pediatric patients.