The rapid adoption of GLP-1 receptor agonists has changed the preoperative picture for a large and growing share of surgical and procedural patients. A recent brief from The Medical Letter on Drugs and Therapeutics summarizes an important development for anyone who manages sedation or anesthesia: the FDA-approved labeling for this entire drug class has been updated to reflect rare postmarketing reports of pulmonary aspiration.
For clinicians and educators, the practical takeaway is not simply that a new warning exists. It is that current multisociety guidance identifies point-of-care gastric ultrasound as the tool of choice for resolving uncertainty at the bedside on the day of the procedure.
According to the brief, package inserts were updated for dulaglutide (Trulicity), exenatide (Byetta, Bydureon BCise), liraglutide (Saxenda, Victoza), and semaglutide (Ozempic, Rybelsus, Wegovy), along with the dual GIP/GLP-1 receptor agonist tirzepatide (Mounjaro, Zepbound). The new language addresses reports of pulmonary aspiration in patients undergoing elective procedures requiring general anesthesia or deep sedation who were found to have residual gastric contents in spite of following preoperative fasting instructions.
That last detail is the one worth sitting with. Fasting status alone did not reliably predict an empty stomach in these cases.
The reason is well understood. This drug class slows gastric emptying, which is part of how these medications produce satiety and glycemic benefit. Nausea, vomiting, and abdominal distension are common side effects, though the brief notes these tend to lessen with long-term use.
Delayed gastric emptying, however, carries a downstream consequence. When protective airway reflexes are blunted by general anesthesia or deep sedation, retained gastric contents raise the risk of regurgitation and aspiration. The brief points out that while several case reports have been published, randomized controlled trials evaluating aspiration risk in this population are not yet available.
The clinical community's response has evolved in an instructive direction.
In 2023, the American Society of Anesthesiologists issued consensus guidance recommending that these medications be withheld before elective surgery: on the day of the procedure for daily formulations, and one week in advance for weekly formulations. As the brief describes, some endocrinologists raised a reasonable objection. Interrupting therapy risks hyperglycemia, which brings its own perioperative consequences, including a higher likelihood of infection and other postsurgical complications.
Newer joint guidance, developed by the American Society of Anesthesiologists together with the American Gastroenterological Association, the American Society for Metabolic and Bariatric Surgery, the International Society of Perioperative Care of Patients with Obesity, and the Society of American Gastrointestinal and Endoscopic Surgeons, takes a different approach. It indicates that most patients can continue their GLP-1 receptor agonist or tirzepatide ahead of elective procedures.
When there is specific concern about delayed gastric emptying, the recommended pathway is a liquid-only diet for at least 24 hours beforehand, followed by point-of-care gastric ultrasound on the day of the procedure to confirm gastric status. If concern about retained contents persists after imaging, rapid sequence induction for tracheal intubation may be considered.
In other words, the field has moved from blanket medication holds toward individualized assessment. Ultrasound is what makes that individualized assessment possible.
Placing gastric ultrasound in a decision pathway assumes that the clinician performing it can acquire and interpret the images reliably. That is a real skill set, and it is more specific than general abdominal scanning experience.
Competent gastric assessment requires knowing where to look and what the findings mean. That includes identifying the gastric antrum and distinguishing it from surrounding structures, understanding how patient positioning changes what is visible, recognizing the different sonographic appearances of clear liquids, thick liquids, and solid contents, calculating antral cross-sectional area to estimate gastric volume, and applying a grading framework such as the Perlas antral grading system to translate images into a risk assessment.
These are pattern recognition skills. They develop through repetition across a range of gastric states, which is precisely what is difficult to arrange in a clinical setting. You cannot schedule the patient who ate solids two hours ago alongside the patient who has been NPO for eight hours.
This is the gap that simulation-based training is designed to close. SonoSim's Gastric Ultrasound Training covers exam indications, regional and sonographic anatomy, transducer selection, patient positioning, cross-sectional area calculation, and the Perlas antral grading system, alongside common imaging pitfalls and clinical decision-making pointers.
Learners then move into hands-on practice in the SonoSimulator®, working through seven adult scanning cases drawn from real patients. Those cases span the range of gastric states clinicians actually need to differentiate, including early and late solid intake, early thick liquid ingestion, clear liquids at one hour, and NPO status at two and eight hours. Learners scan in both supine and right lateral decubitus positioning using a linear transducer, with imaging windows covering the gastric antrum and pylorus, body, and fundus.
The result is repeated, standardized exposure to the exact findings that drive perioperative decisions, available on a laptop rather than dependent on patient availability; an approach that has exhibited proven efficacy in developing ultrasound image acquisition and interpretation skills across 55+ studies.☨
GLP-1 receptor agonist prescribing continues to expand, which means more patients arriving for elective procedures with pharmacologically delayed gastric emptying. The guidance that has emerged does not ask clinicians to avoid these medications. It asks them to assess.
Gastric ultrasound is how that assessment gets done. As the patient population grows, so does the number of clinicians who need this capability in their skill set.
In Brief: New FDA Warning of Pulmonary Aspiration with GLP-1 Receptor Agonists. Med Lett Drugs Ther. 2024;66(1718):201-2. doi:10.58347/tml.2024.1718a. Read the full brief at The Medical Letter