Rectus Abdominis Muscle Parameters and Postoperative Opioid Consumption in Geriatric Patients

April 16, 2026 updated by: İlke Dolgun, Istinye University

Association Between Ultrasound-Derived Rectus Abdominis Muscle Thickness and Thickening Fraction and Postoperative Opioid Consumption in Geriatric Patients Undergoing Abdominal Surgery: A Prospective Observational Study

This prospective observational study aims to evaluate the relationship between ultrasound-derived rectus abdominis muscle thickness and thickening fraction and postoperative opioid consumption in geriatric patients undergoing abdominal surgery. Preoperative ultrasonographic measurements will be performed during routine clinical care, and postoperative pain scores and analgesic requirements will be recorded within the first 24 hours. The findings may help improve individualized analgesic strategies by identifying patient-specific predictors of postoperative opioid needs.

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.

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.
62

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)
    • Merkez Mahallesi
      • Istanbul, Merkez Mahallesi, Turkey (Türkiye), 34250
        • Istinye University

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

  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of geriatric patients (≥65 years) scheduled for elective midline abdominal surgery at S.B.U. Haseki Training and Research Hospital. All participants will receive bilateral ultrasound-guided rectus sheath block as part of routine clinical practice under general anesthesia. Eligible patients who meet the inclusion criteria and provide written informed consent will be prospectively enrolled.

Description

Inclusion Criteria:

  • Age ≥65 years
  • Scheduled for elective midline abdominal surgery
  • ASA physical status I-III
  • Planned to receive bilateral ultrasound-guided rectus sheath block as part of routine clinical practice
  • Provided written informed consent

Exclusion Criteria:

  • Known allergy or hypersensitivity to local anesthetics
  • Infection or skin lesion at the injection site
  • Systemic infection or sepsis
  • Coagulopathy (INR >1.5 or platelet count <100,000/mm³)
  • Use of therapeutic anticoagulation not safely managed perioperatively
  • History of previous midline laparotomy
  • History of abdominal mesh implantation or abdominal wall reconstruction
  • Significant abdominal wall pathology (e.g., large hernia) affecting anatomy
  • Neuromuscular disease (e.g., myasthenia gravis, ALS, muscular dystrophy)
  • Inability to perform required maneuver for dynamic ultrasound measurement
  • Moderate to severe cognitive impairment or poor cooperation
  • Body mass index (BMI) >40 kg/m²
  • Cachexia or severe malnutrition
  • Chronic opioid use (≥3 months)
  • Chronic pain syndromes requiring regular analgesic use
  • Alcohol or substance abuse
  • Emergency surgery
  • Use of additional regional anesthesia techniques (e.g., epidural, TAP block)
  • Inadequate ultrasound visualization of the target anatomical plane

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

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
Postoperative Total Opioid Consumption
Time Frame: First 24 hours postoperatively
Total opioid consumption within the first 24 hours after surgery will be recorded and converted to morphine equivalents (mg). This measure will be used to evaluate the association between ultrasound-derived rectus abdominis muscle parameters and postoperative analgesic requirements.
First 24 hours postoperatively

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.
Istinye University

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.
April 25, 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.
October 1, 2026

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.
November 1, 2026

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).
April 16, 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.
April 16, 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.
April 22, 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.
April 22, 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.
April 16, 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.
April 1, 2026

More Information

Terms related to this study

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.
  • rektus kas kalınlığı

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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings