Various studies have shown that gastric sonography can reliably provide information on both qualitative (nature of content) and quantitative (volume) aspects of gastric content. A recent study has suggested that a minimum of 33 scans is needed to achieve a 95% success rate in the qualitative assessment of gastric ultrasound. However, as the risk and severity of aspiration are also influenced by gastric volume, further study concerning quantitative assessment is warranted.

This study are conducted to affirm the feasibility of ultrasound for the qualitative assessment of gastric content, and determine the reliability of this novel tool in gastric volume measurements when performed by novice gastric sonographers. Two novels in gastric ultrasound learn from online materials, including educational videos and picture library through www.gastricultrasound.org and www.usra.ca. 1-hour lecture with discussion and 1-hour interactive hands-on with expert in gastric ultrasound. Then the novels were tested for the accuracy and reliability of their skills from 50 volunteers gastric ultrasound assessment.

Inclusion Criteria:

• age between 18 to 70 years old with an American Society of Anesthesiologist physical status class I to II

Exclusion Criteria:

• BMI > 40 kg/m2; pregnancy; diabetes mellitus; a history of upper gastrointestinal tract disease (including hiatal hernia and gastric tumors); and previous surgical procedures on the esophagus, stomach, or upper abdomen.

Fifty healthy volunteers