Ultrasound Assessment of Preoperative Gastric Contents for Predicting Aspiration Risk in Surgical Patients: A Scoping Review and Future Directions

Yuzhou Li,1,2 Li Tang,1,2 Shuying Zou,2,3 Xiangnan Zhu,1 Bo Zhang,2 Caixia Xie2 1School of Medicine, University of Electronic Science and Technology of China, Chengdu, People’s Republic of China; 2Department of Nursing, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, People’s Republic of China; 3College of Nursing, Chengdu University of Traditional Chinese Medicine, Chengdu, People’s Republic of ChinaCorrespondence: Caixia Xie, Department of Nursing, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, People’s Republic of China, Email [email protected]: This scoping review aims to summarise studies evaluating gastric contents in surgical patients using preoperative ultrasound, discuss current challenges, and propose future directions.Methods: The system retrieved data from 8 databases, including PubMed, with a search period spanning from the inception to May 11, 2025. The scoping review follows the JBI scoping review framework and the PRISMA-ScR reporting guidelines.Results: A total of 44 studies were included. The research involved various perioperative populations and surgical procedures, with a “full stomach” rate ranging from 0% to 57.7%. Ultrasound operators included anesthesiologists, sonographers, and medical consultants. Assessment methods comprised qualitative, quantitative, or combined approaches. Evaluation metrics included gastric contents nature, Perlas 3-point grading system, gastric antral cross-sectional area (CSA), and gastric volume.Conclusion: Preoperative gastric ultrasound can provide information about gastric contents, thereby aiding in the identification of aspiration risk and enabling the adoption of appropriate anaesthesia strategies. However, existing studies still face limitations, including restricted study populations and sample sizes, variations in operator training, a lack of consensus on an evaluation metric threshold value, and diverse gastric volume calculation models. Future studies should expand their scale, enhance training for clinicians in gastric ultrasound, and standardise assessment positions, threshold values, and selection criteria for calculation models. Furthermore, we believe that integrating artificial intelligence with gastric ultrasound can overcome the limitations of manual measurement, offering a direction for precise and convenient preoperative assessment of gastric contents.Keywords: gastric ultrasound, gastric contents, aspiration, gastric antral cross-sectional area, anesthesia