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

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

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 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

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

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

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)

April 25, 2026

Primary Completion (Estimated)

October 1, 2026

Study Completion (Estimated)

November 1, 2026

Study Registration Dates

First Submitted

April 16, 2026

First Submitted That Met QC Criteria

April 16, 2026

First Posted (Actual)

April 22, 2026

Study Record Updates

Last Update Posted (Actual)

April 22, 2026

Last Update Submitted That Met QC Criteria

April 16, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID 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.

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