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

September 26, 2026 updated by: Fatma Cigdem Ozakin, Bakirkoy Dr. Sadi Konuk Research and Training Hospital

Clinical and Metabolic Determinants of High Residual Gastric Volume 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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

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.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
120

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Turkey (Türkiye)
    • Istanbul
      • Istanbul, Istanbul, Turkey (Türkiye), 34147
        • Bakırköy Dr. Sadi Konuk Training and Research Hospital
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Adult patients with type 2 diabetes mellitus who are scheduled for elective surgery at University of Health Sciences, Bakirkoy Dr. Sadi Konuk Training and Research Hospital and who meet the study eligibility criteria.

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: COHORT
  • Time Perspectives: PROSPECTIVE

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Preoperative Patients With Type 2 Diabetes Mellitus

Adult patients with type 2 diabetes mellitus, ASA physical status II or III, who are scheduled for elective surgery and undergo preoperative gastric ultrasonography and capillary fasting blood glucose measurement.
Diagnostic test: Preoperative Gastric Ultrasonography

The gastric antrum will be evaluated in the supine and right lateral decubitus positions before anesthesia induction and sedative premedication. Gastric contents will be assessed qualitatively, and antral cross-sectional area and estimated residual gastric volume will be calculated quantitatively.

Diagnostic test: Capillary Fasting Blood Glucose Measurement

Capillary fasting blood glucose will be measured by fingertip sampling immediately before gastric ultrasonography. The measured glucose concentration will be evaluated as the primary exposure variable in relation to high-risk gastric findings.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Presence of a High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment immediately before anesthesia induction

A high-risk stomach will be defined as the presence of at least one of the following findings on preoperative gastric ultrasonography: solid gastric contents; clear fluid visible in both the supine and right lateral decubitus positions (Perlas Grade 2); or an estimated gastric volume greater than 1.5 mL/kg.
On the day of surgery, during the preoperative assessment immediately before anesthesia induction

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Association Between Age and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Age will be recorded in years from the patient's medical record. The association between age and the presence of a high-risk stomach (yes/no) will be evaluated .
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Sex and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Sex will be recorded as male or female from the patient's medical record. The association between sex and the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Body Mass Index and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Body mass index will be calculated as body weight in kilograms divided by height in meters squared and reported in kg/m². The association between body mass index and the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Duration of Type 2 Diabetes Mellitus and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Duration of type 2 diabetes mellitus will be recorded in years based on the patient's medical history and medical records. Its association with the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Diabetes-Related Complications and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

The presence of diabetes related target organ complications will be determined from the patient's medical history and medical records and recorded as present or absent. The association between the presence of diabetes-related complications and a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Comorbidities and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

The presence of comorbidity will be assessed from the patient's medical history and medical records. Prespecified comorbidities will include hypertension, gastroesophageal reflux disease, obstructive sleep apnea, hypothyroidism, chronic kidney disease, dialysis treatment, and liver dysfunction. Participants will be classified according to the presence or absence of at least one of these comorbidities. The association between the presence of any prespecified comorbidity and a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Gastroparesis-Related Symptoms and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Gastroparesis-related symptoms will be assessed by preoperative patient interview. Prespecified symptoms will include loss of appetite, early satiety, and postprandial fullness. Participants will be classified according to the presence or absence of at least one of these symptoms. The association between the presence of any gastroparesis-related symptom and a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Solid Food Fasting Duration and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

The time elapsed since the last solid food intake will be determined from the patient's history and clinical records and recorded in hours. Its association with the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Clear Fluid Fasting Duration and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

The time elapsed since the last clear fluid intake will be determined from the patient's history and clinical records and recorded in hours. Its association with the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Smoking Status and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Smoking status will be assessed by patient interview and categorized as current smoker, former smoker, or never smoker. The association between smoking status and the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Antidiabetic Medication Use and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Current antidiabetic medication use will be determined from the patient's medication history and medical records. Antidiabetic medications will include oral antidiabetic drugs, insulin, GLP-1 receptor agonists, and SGLT-2 inhibitors. Participants will be classified according to the presence or absence of current use of at least one antidiabetic medication. The association between any current antidiabetic medication use and the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Proton Pump Inhibitor Use and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Proton pump inhibitor use will be determined from the patient's medication history and recorded as yes or no. Its association with the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between HbA1c and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

HbA1c will be obtained from routine preoperative laboratory results and recorded as a percentage (%). The association between HbA1c and the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Hemoglobin Level and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Hemoglobin concentration will be obtained from routine preoperative laboratory results and recorded in g/dL. The association between hemoglobin concentration and the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Blood Urea Level and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Blood urea concentration will be obtained from routine preoperative laboratory results and recorded in mg/dL. The association between blood urea concentration and the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction
Association Between Serum Creatinine Level and High-Risk Stomach
Time Frame: On the day of surgery, during the preoperative assessment before anesthesia induction

Serum creatinine concentration will be obtained from routine preoperative laboratory results and recorded in mg/dL. The association between serum creatinine concentration and the presence of a high-risk stomach (yes/no) will be evaluated.
On the day of surgery, during the preoperative assessment before anesthesia induction

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Bakirkoy Dr. Sadi Konuk Research and Training Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Fatma Çiğdem Özakın, MD, Bakirkoy Dr. Sadi Konuk Research and Training Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 21, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 21, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 25, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 30, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 26, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2026/317

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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