1. Introduction

Scheduled surgery requires patients to undergo a preoperative fasting period of at least 6 hours to reduce the risk of perioperative pulmonary aspiration. However, certain medications and conditions may delay gastric emptying, potentially increasing aspiration risk. These include diabetic gastroparesis and the use of glucagon-like peptide-1 (GLP-1) receptor agonists for the treatment of diabetes and obesity.

GLP-1 receptor agonists are widely used due to their beneficial effects on glycemic control and weight reduction. However, one of their known effects is delayed gastric emptying, which may result in increased residual gastric content despite adherence to standard fasting guidelines. Recent reports have described cases of pulmonary aspiration during anesthesia in patients receiving GLP-1 receptor agonists, even after appropriate fasting.

Given the increasing use of these medications, there is a need for objective assessment tools to evaluate gastric content in the perioperative setting. Gastric ultrasonography has emerged as a non-invasive bedside technique that may help identify patients at increased risk of aspiration and guide airway management strategies.

2. Hypothesis

Gastric ultrasonography performed by trained anesthesiologists is a useful tool for assessing gastric content and may support clinical decision-making in airway management in patients treated with GLP-1 receptor agonists.

3. Methodology

This is a prospective, observational cohort study conducted at participating centers.

The study population consists of adult patients undergoing scheduled surgery under general anesthesia following a standard preoperative fasting period.

Inclusion criteria:

• Patients receiving treatment with GLP-1 receptor agonists
• Age ≥18 years
• Scheduled surgery after a fasting period between 6 and 8 hours
• ASA physical status I-III
• Ability to provide informed consent

Exclusion criteria:

• History of esophagogastric pathology or prior upper abdominal surgery

• Hiatal hernia or gastroesophageal reflux disease

• Autonomic nervous system disorders

• Neurological or neuromuscular diseases

• Use of medications affecting gastric emptying (e.g., opioids or prokinetics)

• Pregnancy

• Presence of clinically significant arrhythmias

  4. Description of the Intervention

Immediately prior to anesthesia induction, gastric ultrasonography will be performed by trained investigators at participating centers, with the patient in both supine and right lateral decubitus positions.

Qualitative, semi-quantitative, and quantitative assessments of gastric content and volume will be performed according to the methodology described by Perlas et al. Data will be recorded in a standardized study database.

Anesthetic and surgical management will proceed according to routine clinical practice.

5. Ethical, Legal, and Economic Considerations

Written informed consent will be obtained from all participants prior to study inclusion.

This is an observational study with no modification of standard clinical care. No additional risks beyond routine clinical practice are anticipated.

Gastric ultrasonography will be performed using equipment available at participating centers, and no additional costs are expected.

6. Results

Study data will be analyzed by the investigators. Results will be disseminated through scientific publications and presentations.

Inclusion Criteria:

Adults patients ,ASA I-III, taking GLP-1 analog medications, undergoing scheduled surgery.

Exclusion Criteria:

1. - History of esophagogastric pathology or previous abdominal surgery.
2. - Hiatal hernia/gastroesophageal reflux disease.
3. - Autonomic nervous system disorders.
4. - Neurological or neuromuscular diseases.
5. - Use of medications/drugs that affect autonomic regulation and delay gastric emptying (opioids) or potentiate it (prokinetics).
6. - Pregnancy.
7. - Presence of arrhythmias.

The reference population will consist of patients undergoing scheduled surgery with a conventional preoperative fasting period (at least 6 hours).