Gastric Content in Fasting Volunteers and in Tirzepatide Users: an Observational and Cross-sectional Study

Introduction Obesity and type 2 diabetes mellitus constitute a global public health problem. Medications with glucagon-like peptide-1 (GLP-1) receptor agonist activity are a modern therapeutic option for both diseases. Liraglutide, semaglutide, dulaglutide and tirzepatide are representatives of this drug class, whose mechanism of action results in delayed gastric emptying, reduced gastric motility and increased gastric volume. Tirzepatide, however, presents a dual agonist action, combining GLP-1 agonism with glucose-dependent insulinotropic polypeptide (GIP) agonism. The presence of gastric content during anaesthesia may lead to pulmonary aspiration and the development of chemical pneumonitis, a potentially devastating complication. However, when there is a risk factor for delayed gastric emptying, despite adequate fasting, the stomach may still present residual content, and bedside ultrasonography is an effective, non-invasive and rapid method to measure this content and stratify aspiration risk. Our hypothesis is that most individuals using tirzepatide present a full stomach even after fasting times recommended in the literature.