Comparison of Intrathecal Morphine and Rectus Sheath Block for Postoperative Pain Management After Lower Abdominal Surgery With Midline Incision

Efficacy of Analgesic Methods for Pain Control After Lower Abdominal Surgery With Midline Incision

This study aims to evaluate the efficacy of intrathecal morphine and rectus sheath block compared with standard postoperative analgesia for pain management in patients undergoing lower abdominal surgery with a midline incision. Effective postoperative analgesia is essential to enhance recovery, reduce opioid consumption, and improve overall patient comfort.

In this prospective randomized controlled trial, eligible patients scheduled for lower abdominal surgery through a midline incision will be randomly assigned to one of three groups: intrathecal morphine, rectus sheath block, or control (standard postoperative analgesia without regional intervention). Postoperative outcomes will include pain scores, quality of recovery (QoR) scores, functional recovery parameters, patient satisfaction, incidence of postoperative nausea and vomiting, and rescue analgesic requirements.

The findings of this study may provide evidence on the comparative effectiveness of these analgesic strategies and contribute to the development of optimized multimodal pain management protocols in lower abdominal surgery.

Study Overview

• Status: Active, not recruiting
• Conditions: Pain Management; Postoperative Analgesia
• Intervention / Treatment: Procedure: Intrathecal Morphine; Procedure: Rectus Sheath Block

Detailed Description

This study aims to evaluate the efficacy of intrathecal morphine and rectus sheath block compared with standard postoperative analgesia for pain management in patients undergoing lower abdominal surgery with a midline incision. Effective postoperative analgesia is essential to enhance recovery, reduce opioid consumption, and improve overall patient comfort.

In this prospective randomized controlled trial, eligible patients scheduled for lower abdominal surgery through a midline incision will be randomly assigned to one of three groups: intrathecal morphine, rectus sheath block, or control (standard postoperative analgesia without regional intervention). Postoperative outcomes will include pain scores, quality of recovery (QoR) scores, functional recovery parameters, patient satisfaction, incidence of postoperative nausea and vomiting, and rescue analgesic requirements.

The findings of this study may provide evidence on the comparative effectiveness of these analgesic strategies and contribute to the development of optimized multimodal pain management protocols in lower abdominal surgery.

• Study Type: Interventional
• Enrollment (Estimated): 66
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye)
    • Marmara University School of Medicine
  • Istanbul, Turkey (Türkiye)
    • Marmara University School of Medicine, Istanbul

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients over 18 years old
• Patients undergoing lower abdominal surgery via midline incision.

Exclusion Criteria:

• Patients with solid organ dysfunction
• Patients who receive opioid or corticosteroid medication prior to surgery
• Patients with bleeding diathesis
• Patients with psychiatric disorders
• Patients who can not be contacted after surgery

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Intrathecal Morphine; Patients in this group will receive intrathecal morphine administered prior to general anesthesia as part of their perioperative analgesic regimen for postoperative pain control following lower abdominal surgery with a midline incision. Standard postoperative care will also be provided.	Procedure: Intrathecal Morphine; Patients in this group will receive 200 mcg of intrathecal morphine administered at the L3-L4 interspace prior to general anesthesia as part of their perioperative analgesic regimen for postoperative pain control following lower abdominal surgery with a midline incision. As part of standard perioperative care, all patients will receive 8 mg dexamethasone and 1.5 mg/kg intravenous tramadol. Postoperatively, all patients will have intravenous tramadol PCA (10 mg/kg). Rescue analgesia with 3 mg intravenous morphine will be administered if the numeric rating scale (NRS) pain score is 4 or higher.
Active Comparator: Bilateral Rectus Sheath Block; Patients in this group will receive a bilateral rectus sheath block administered after general anesthesia but prior to surgical incision, in addition to standard postoperative analgesia for pain management following lower abdominal surgery via midline incision.	Procedure: Rectus Sheath Block; Patients in this group will receive a bilateral rectus sheath block after induction of general anesthesia but prior to surgical incision, with 20 ml solution (10 ml of 0.25% bupivacaine and 10 ml of normal saline) administered to each side, in addition to standard perioperative analgesia. As part of standard care, all patients will receive 8 mg dexamethasone and 1.5 mg/kg intravenous tramadol. Postoperatively, all patients will have intravenous tramadol PCA (10 mg/kg). Rescue analgesia with 3 mg intravenous morphine will be administered if the numeric rating scale (NRS) pain score is 4 or higher.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Opioid Consumption	The total amount of intravenous tramadol administered during the first 24 hours after surgery will be recorded to evaluate postoperative analgesic requirements.	24 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
NRS Score	Postoperative pain will be assessed using the Numeric Rating Scale (NRS: 0= no pain to 10= worst pain) at 24 hours after surgery.	24 hours postoperatively
Functional recovery	Functional recovery will be assessed by recording the time to first mobilization, time to first oral intake, and time to return of bowel function within the first 24 hours after surgery.	24 hours postoperatively
Rescue Analgesic Consumption	Total amount of rescue analgesics (intravenous morphine) administered within the first 24 hours postoperatively will be recorded.	24 hours postoperatively
Change in QoR-15 score	Quality of recovery (QoR) will be assessed using the validated QoR-15 questionnaire both preoperatively and at 24 hours after surgery. The primary analysis will evaluate the change in score from baseline to 24 hours. The total score ranges from 0 (very poor recovery) to 150 (excellent recovery).	preoperative baseline and 24 hours postoperatively

Collaborators and Investigators

• Sponsor: Marmara University

Study record dates

Study Major Dates

• Study Start (Actual): February 24, 2025
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): July 30, 2026

Study Registration Dates

• First Submitted: March 18, 2026
• First Submitted That Met QC Criteria: March 18, 2026
• First Posted (Actual): March 24, 2026

Study Record Updates

• Last Update Posted (Actual): March 30, 2026
• Last Update Submitted That Met QC Criteria: March 25, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: postoperative analgesia; lower abdominal surgery; intrathecal morphine; rectus sheath block
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neurobehavioral Manifestations; Perceptual Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Agnosia
• Other Study ID Numbers: 09.2025.174

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No