Intrathecal Versus Epidural Morphine for Post-Cesarean Analgesia

Intrathecal Versus Epidural Morphine for Post-Cesarean Analgesia: A Randomized Controlled Trial

Cesarean section is one of the most commonly performed surgical procedures worldwide, making effective management of acute postoperative pain a key issue in obstetric anesthesiology. Post-cesarean analgesia should promote rapid maternal recovery, support newborn care, and consider the pharmacological implications for breastfeeding.

According to recent PROSPECT® guidelines from ESRA, neuraxial opioids play a central role in post-cesarean analgesia and are at least as effective as other techniques, such as continuous local anesthetic infusion. However, the optimal route of opioid administration remains unclear. While earlier studies favored epidural morphine, more recent evidence suggests that intrathecal morphine may provide superior analgesia. Due to limited and conflicting data, no definitive conclusion can be drawn. Given that epidural morphine remains standard practice at Hospital Central do Funchal, a randomized clinical trial is proposed to compare the analgesic efficacy of intrathecal versus epidural morphine after elective cesarean section.

Study Overview

• Status: Recruiting
• Conditions: Analgesia; Patient Satisfaction; Post Operative Pain; Cesarean Section Pain; Analgesia Obstetrical
• Intervention / Treatment: Drug: Intrathecal Morphine; Drug: Epidural Morphine

Detailed Description

This unicentric randomized clinical trial aims to determine whether intrathecal morphine provides superior postoperative analgesia compared with epidural morphine during the first 24 hours following cesarean section. The study population will consist of pregnant women undergoing elective cesarean delivery at Hospital Central do Funchal.

Participants will be randomly assigned to one of two groups. One group will receive postoperative analgesia with intrathecal morphine (80 mcg). The second group will receive epidural morphine, administered as a 2.5 mg bolus at the end of surgery, followed by an additional 2.5 mg bolus 24 hours postoperatively.

The primary outcome will be the assessment of pain during the first 24 postoperative hours. Secondary outcomes will include pain assessment during the first 48 hours, the need for rescue analgesia, levels of sedation, incidence of nausea and vomiting, pruritus, the impact of pain on mobilization and other activities, and overall maternal satisfaction.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Phase 4

Contacts and Locations

Study Locations

• Portugal
  • Madeira
    • Funchal, Madeira, Portugal, 9004-514
      • Recruiting
      • Hospital Central do Funchal
      • Contact: Joao Salgado Costa; Phone Number: +351914633659; Email: joaomscosta1@gmail.com
      • Principal Investigator: João Salgado Costa

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Pregnant women scheduled for elective cesarean section;
• Age > 18 years;
• Willingness to participate in the study, as demonstrated by signed informed consent.

Exclusion Criteria:

• American Society of Anesthesiologists (ASA) physical status classification > III;
• Chronic kidney disease with a glomerular filtration rate < 60 mL/min;
• Relevant drug allergies (particularly to protocol medications);
• Opioid tolerance;
• Contraindication to neuraxial anesthetic techniques.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intrathecal morphine; Postoperative analgesia with intrathecal morphine 80 mcg	Drug: Intrathecal Morphine; Postoperative analgesia with intrathecal morphine 80 mcg
Experimental: Epidural morphine; Postoperative analgesia with epidural morphine 2.5mg	Drug: Epidural Morphine; Postoperative analgesia with epidural morphine 2.5mg

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative pain control	Comparison between intrathecal morphine versus epidural morphine analgesia assessed using the Numeric Rating Scale (NRS) as part of the PAIN OUT questionnaire.	Evaluation at 24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total rescue opioid consumption		Evaluation at 24 hours and 48 hours after surgery
Adverse effects associated with analgesia	To evaluate adverse effects associated with intrathecal versus epidural morphine administration, namely sedation, nausea, vomiting, and pruritus.	Evaluation at 24 hours and 48 hours after surgery
Patients satisfaction with analgesia	Evaluated using the satisfaction-related items of the PAIN OUT questionnaire, scored on a Numeric Rating Scale.	Evaluation at 24 hours and 48 hours after surgery
Postoperative pain control	Comparison between intrathecal morphine versus epidural morphine analgesia assessed using the Numeric Rating Scale (NRS) as part of the PAIN OUT questionnaire.	Evaluation at 48 hours after surgery

Collaborators and Investigators

• Sponsor: Hospital Central do Funchal

Study record dates

Study Major Dates

• Study Start (Actual): May 20, 2024
• Primary Completion (Estimated): July 31, 2026
• Study Completion (Estimated): July 31, 2026

Study Registration Dates

• First Submitted: January 16, 2026
• First Submitted That Met QC Criteria: January 27, 2026
• First Posted (Actual): February 4, 2026

Study Record Updates

• Last Update Posted (Actual): February 4, 2026
• Last Update Submitted That Met QC Criteria: January 27, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Intrathecal Morphine; Post-Cesarean Analgesia; Epidural Morphine
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Neurobehavioral Manifestations; Perceptual Disorders; Pathological Conditions, Signs and Symptoms; Behavior; Signs and Symptoms; Treatment Adherence and Compliance; Health Behavior; Pain, Postoperative; Agnosia; Patient Satisfaction
• Other Study ID Numbers: E24060638

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

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