BBCMADE Nomogram Validation for High-Risk Gastric Content in Sedative Endoscopy

Pulmonary aspiration of gastric contents accounts for 10-30% of anesthesia-related deaths. Standard fasting guidelines do not guarantee adequate gastric emptying in all patients. The BBCMADE nomogram, developed and validated by Yan et al. (2024) in a Chinese population, demonstrated high discriminatory power for predicting high-risk gastric residual content in outpatients undergoing sedative GI endoscopy. This study will prospectively evaluate its validity in a Turkish population (n=533).

The seven predictor variables (BMI, history of cerebral infarction, cirrhosis, male sex, age, diabetes, gastroesophageal reflux) will be recorded preoperatively and entered into the web-based nomogram interface. Endoscopic gastric volume measurement will serve as the gold standard. Discriminatory performance will be assessed by AUROC. Secondary analyses will include sensitivity, specificity, PPV, NPV, and subgroup analyses.

Sample size: 533 patients (prevalence ~13%, α=0.05, power=95%, 15% dropout allowance; calculated using G*Power 3).

Inclusion criteria

• Age 18 years or older
• ASA physical status I-III
• Scheduled for elective gastrointestinal endoscopy under sedoanalgesia
• Deemed suitable for out-of-OR anesthesia by the anesthesiology outpatient clinic
• Provision of written informed consent

Exclusion criteria

• Age under 18 years
• Pregnancy or suspected pregnancy
• ASA physical status IV or higher
• Emergency procedures
• Unable or unwilling to provide informed consent
• History of upper airway obstructive pathology or difficult airway
• Not eligible for out-of-OR anesthesia
• Known hypersensitivity to anesthetic agents