II. Indications
- Peri-Procedural Sedation Evaluation of aspiration risk
- Increased aspiration risk (e.g. Delayed Gastric Emptying)
- GLP1 Agonist use
- Gastroparesis
- Esophageal Stricture
- Third trimester pregnancy
- Recent large meal
III. Technique
- Patient lies supine
- Curvilinear Ultrasound probe positioned with indicator toward patient's head
- Identify the gastric antrum at the liver tip (anterior to aorta)
IV. Interpretation: High Risk Aspiration Findings
- Solid food with complex appearance within the Stomach (supine position) OR
- Anechoic fluid present (supine) AND measuring >100 ml (right lateral decubitus)
- Patient rolls into the right lateral decubitus position
- Measure antral cross-sectional area
- Machine calculation based on tracing the antrum margins OR
- Calculate from the Anteroposterior and Craniocaudal measurements
V. Management
- Delay elective, non-emergent procedures if either of criteria present above
VI. References
- Swaminathan and Derr (2026) GUARD, accessed 7/5/2026