1174: Ultrasound to Assess Aspiration Risk in Critically Ill Children: A Prospective Observational Study

Introduction: Shorter fasting durations are safe against aspiration for healthy children undergoing sedated procedures. However, the optimal fasting interval in critically ill pediatric patients remains unclear. Ultrasound (US) is a validated tool to assess gastric volume, and a threshold of < 1.2 mL/kg is commonly accepted as a safe gastric volume. We hypothesize that no significant difference in gastric volumes after 3 versus 6 hours of fasting exists in critically ill children. Methods: We conducted a prospective observational study of critically ill pediatric patients fasting for extubation or procedures. Abdominal US scans were performed at 3 and 6 hours post-fasting by a trained pediatric intensivist. In the right lateral decubitus position, the gastric antrum was identified in the sagittal plane and the antral cross-sectional area (CSA) was measured using the free trace tool. Gastric volume was calculated using the validated Spencer formula: (3.5 × CSA) + (0.127 × age in months) − 7.8. Volumes were normalized to weight and categorized as low (< 1.2 mL/kg) or high (>1.2 mL/kg) aspiration risk. To standardize measurements, antral CSA was recorded between peristaltic contractions at the level of the aorta and/or superior mesenteric artery. We used logistic regression analysis to identify risk factors associated with a full stomach. Incidence of aspiration events were recorded. Results: We enrolled 28 patients. 23 patients had gastric volumes < 1.2 mL/kg at 3 hours, suggesting low aspiration risk (P-Value 0.017) 5 had elevated volumes at 3 hours; of which 3 remained above threshold at 6 hours, indicating persistent aspiration risk despite the wait. There was no correlation between age, opioid dose, formula type, or length of stay with gastric emptying. No aspiration events were reported. Conclusions: There was no difference in aspiration risk between the two fasting intervals. This supports procedural safety after 3-hour-fasting in critically ill pediatric patients with US offering real-time objective assessment if needed. This may reduce unnecessary delays in procedural sedation, minimize patient discomfort from prolonged fasting, and improve ICU workflow efficiency. Larger studies are needed to validate this finding and define the target population for whom gastric US assessment should be performed.