Preoperative Gastric Volume and High-Risk Gastric Content in Patients With Type 2 Diabetes Mellitus

This prospective observational study will evaluate adult patients with type 2 diabetes mellitus who are scheduled for elective surgery. Immediately before preoperative gastric ultrasonography, capillary fasting blood glucose will be measured. Gastric contents will be assessed qualitatively in the supine and right lateral decubitus positions, and residual gastric volume will be estimated using the antral cross-sectional area measured in the right lateral decubitus position. The primary objective is to evaluate the association between fasting capillary blood glucose and the presence of a high-risk stomach. A high-risk stomach will be defined as the presence of solid gastric contents, Perlas Grade 2 gastric contents, or an estimated gastric volume greater than 1.5 mL/kg. Secondary objectives include determining the prevalence of a high-risk stomach and evaluating its associations with demographic characteristics, diabetes-related factors, comorbidities, fasting duration, medication use, gastroparesis-related symptoms, and routine laboratory parameters.

Inclusion Criteria: * Age 18 years or older * Diagnosis of type 2 diabetes mellitus * American Society of Anesthesiologists (ASA) physical status II or III * Scheduled for elective surgery * Suitable for preoperative gastric ultrasonography * Provision of written informed consent Exclusion Criteria: * Pregnancy * Body mass index ≥40 kg/m² * Emergency surgery * History of gastric, esophageal, or upper gastrointestinal surgery * Presence of a nasogastric tube * Known gastroparesis or gastric outlet obstruction * Active vomiting * Systemic opioid or prokinetic drug use within the previous 72 hours * Anatomical or technical conditions preventing adequate gastric ultrasonographic assessment * Impaired consciousness or inability to provide a reliable medical history * Refusal to participate in the study