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

Overview

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.

This is a single-center, prospective observational study involving adult patients with type 2 diabetes mellitus scheduled for elective surgery. On the day of surgery, participants will be evaluated in the preoperative preparation area before anesthesia induction and before administration of sedative premedication. Demographic data, diabetes duration and treatment, diabetes-related complications, comorbidities, smoking status, symptoms potentially associated with gastroparesis, fasting duration, and routinely available laboratory parameters will be recorded. Capillary fasting blood glucose will be measured immediately before gastric ultrasonography and will constitute the primary independent variable. Gastric ultrasonography will be performed by a trained and experienced investigator using a low-frequency convex transducer. The gastric antrum will be assessed first in the supine position and then in the right lateral decubitus position. Gastric contents will be classified as empty, clear fluid, or solid content. Clear fluid findings will additionally be classified according to the Perlas grading system. For quantitative assessment, anteroposterior and craniocaudal diameters of the gastric antrum will be measured and the antral cross-sectional area will be calculated. Estimated gastric volume will be calculated from the right lateral decubitus antral cross-sectional area and expressed both in mL and mL/kg. A high-risk stomach will be defined by at least one of the following findings: solid gastric contents, clear fluid visible in both the supine and right lateral decubitus positions (Perlas Grade 2), or estimated gastric volume greater than 1.5 mL/kg. No experimental treatment or additional invasive intervention will be administered as part of the study. If clinically relevant high-risk gastric findings are identified, the responsible anesthesia team will be informed and subsequent anesthetic management will be determined by the clinical team.