Gastric Point-of-Care Ultrasound: A Modern Approach to Managing Perioperative Aspiration Risk

Summary

Gastric point-of-care ultrasound allows clinicians to visualize the stomach’s antrum in real time in order to preoperatively assess gastric content and pulmonary aspiration risk.

Pulmonary aspiration of gastric content remains a significant perioperative risk despite decades of progress in anesthesia safety. There is an urgent need for objective, reliable methods to preoperatively assess gastric content and aspiration risk.

A closed claims analysis published in Anesthesiology found 115 cases in which pulmonary aspiration was the primary reason for legal action. Strikingly, 57 percent of these cases resulted in death and 14 percent in permanent injury. These are not isolated incidents, as the analysis revealed the cases were split evenly between emergency and elective surgeries, challenging the assumption that aspiration risk is confined to urgent procedures. Furthermore, anesthetic management was deemed substandard in 59 percent of the claims, highlighting the need for improved assessment and prevention strategies.

The Role of Gastric Point-of-Care Ultrasound

Gastric point-of-care ultrasound (POCUS) allows clinicians to visualize the stomach’s antrum and assess its content in real time. Importantly, the contents of the antrum correlate well with the content of the entire stomach. The technique involves placing a curvilinear probe in the epigastric area and interpreting images in both the supine and right lateral decubitus positions. An empty antrum is reassuring, while the presence of clear fluid or solids—especially in both positions—signals increased risk.

Case Example: POCUS in Action

An 82-year-old patient presented with an unstable cervical spine fracture after a fall. Despite fasting for more than 12 hours and having no diabetes, obesity, or GLP-1 agonist use, the patient was extremely nauseous and regurgitated a small amount of gastric content. The initial plan was to perform an asleep fiberoptic intubation, but the clinical team was concerned about the possibility of a full stomach despite the fasting period.

A gastric ultrasound was performed, revealing a very distended antrum with clear fluid—an area of 37 cm², corresponding to more than 400 mL of gastric content. This finding was inconsistent with the expected fasting state and indicated a high risk of aspiration. The ultrasound findings prompted the team to insert a nasogastric tube while the patient was awake, suction approximately 450 mL of fluid, and repeat the scan, which then showed an empty antrum. With confirmation of an empty stomach, the team proceeded with the planned fiberoptic intubation, and the patient had an uneventful anesthetic period and was discharged home three days later.

This case highlights the power of gastric POCUS to change patient management in real time, prevent adverse outcomes, and avoid unnecessary delays or cancellations. It demonstrates that gastric ultrasound may provide useful information, particularly when the risk of aspiration is equivocal based on clinical information alone.

GLP-1 Agonists: Evolving Guidance and Clinical Implications

The use of GLP-1 medications has increased drastically in recent years, with nearly 12 percent of Americans using them according to a recent RAND report. These medications, while beneficial for many patients, introduce complexities that traditional fasting guidelines alone may not fully address.

Current case reports and clinical experience have highlighted the unique perioperative risks associated with GLP-1 receptor agonists (such as semaglutide and tirzepatide). These medications can delay gastric emptying and increase the risk of retained solid gastric content, even in patients who have fasted well beyond standard guidelines.

Multi-society clinical practice guidance now recommends continuing GLP-1 agonists for most patients but extending fasting for solids to 24 hours and for clear fluids to four hours before surgery. On the day of surgery, asymptomatic and appropriately fasted patients are considered to have a low risk of aspiration. Those who are symptomatic (nausea or vomiting) or who have not fasted adequately should be evaluated with gastric ultrasound if available or assumed to have a full stomach if ultrasound is not accessible.

Diagnostic Accuracy, Limitations, and Recommendations

Gastric POCUS demonstrates high diagnostic accuracy, with a sensitivity of 100 percent and a specificity approaching 97.5 percent. However, limitations exist, particularly in patients with prior gastric surgery (such as banding, bypass, or partial gastrectomy) or large hiatal hernias, when anatomical changes may render the exam inconclusive or less reliable.

Even in optimal conditions, a small percentage of exams may be inconclusive, emphasizing the importance of operator training and experience. Risk management guidelines include:

• Use POCUS when gastric content is questionable; for example, in cases of equivocal fasting intervals, gastrointestinal symptoms despite fasting, patients with comorbidities—such as diabetic gastroparesis, end-stage renal disease, liver disease, or severe GERD—and patients on GLP-1 agonists.
• Incorporate POCUS findings into fasting guidelines, American Society of Anesthesiologists (ASA) classification, and patient care. Note that safe anesthetic management may require preoperative gastric emptying or decompression with a nasogastric tube (in cases of a large volume of clear fluid) even when not required by the surgeon for the planned procedure. Findings may also direct that a procedure be postponed (in elective situations) or require an alternative anesthetic technique such as a rapid sequence induction and intubation aimed at preventing pulmonary aspiration.
• Recognize patient anatomical limitations and ensure proper POCUS acquisition and interpretation.
• Document the indication for gastric POCUS, the images that were acquired, the findings from the images, and the decisions made based on the findings.
• Require practitioner training (for example, through gastricultrasound.org or the ASA Gastric POCUS Certificate).
• Provide opportunities for practice and mentoring of newly acquired skills (accuracy improves after performing approximately 33 exams).
• Regularly review gastric POCUS findings and patient outcomes for quality improvement.

Incorporating gastric POCUS into perioperative practice represents a significant advancement in patient safety. It provides a direct, real-time, objective assessment of gastric content, complements existing fasting guidelines, and supports individualized anesthetic management.

Decades of progress in anesthesia safety have dramatically reduced many perioperative risks, yet the incidence of aspiration has not changed as much. In addition, the landscape continues to evolve with the introduction of new therapies such as GLP-1 agonists. By bridging the gap between established protocols and the nuanced challenges of modern medicine, gastric POCUS empowers anesthesiologists to make informed decisions and enhance patient safety while adapting to emerging aspiration risks.

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The Doctor’s Advocate is published by The Doctors Company to advise and inform its members about loss prevention and insurance issues.

The guidelines suggested in this newsletter are not rules, do not constitute legal advice, and do not ensure a successful outcome. They attempt to define principles of practice for providing appropriate care. The principles are not inclusive of all proper methods of care nor exclusive of other methods reasonably directed at obtaining the same results.

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