D-FAB-POUR Trial: Dexmedetomidine vs Fentanyl as Adjuvants to Bupivacaine on Postoperative Urinary Retention

Launched by TRIBHUVAN UNIVERSITY TEACHING HOSPITAL, INSTITUTE OF MEDICINE. · Aug 9, 2025

Keywords

ClinConnect Summary

This clinical trial is studying two different medicines, dexmedetomidine and fentanyl, to see which works better when added to a common spinal anesthetic called bupivacaine during lower limb (leg) surgery. The main goal is to find out which combination causes fewer problems with urination after surgery, a condition known as postoperative urinary retention (POUR). POUR can make it hard to pee, cause discomfort, and sometimes means patients need a catheter (a small tube) to help empty their bladder. Dexmedetomidine is a newer medicine that might reduce this problem compared to fentanyl, which is more commonly used but may increase the risk of urinary problems.

Adults aged 18 to 60 who are scheduled for planned lower limb surgery under spinal anesthesia may be eligible to join the study. Participants need to be generally healthy enough for surgery (classified as ASA physical status II or III) and tall enough (at least 150 cm) to ensure the medication is given safely. If accepted, patients will be randomly assigned to receive either dexmedetomidine or fentanyl along with the spinal anesthetic, and neither the patients nor the doctors will know which medicine is given until the study ends. This helps make the results fair and unbiased. The study will take place in a hospital in Nepal and plans to include 190 adult patients. This trial aims to help doctors choose the best medicine combination to manage pain during surgery while minimizing urinary problems afterward.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Adults aged 18 to 60 years
• • Scheduled for elective lower limb surgery under spinal anesthesia
• • Classified as American Society of Anesthesiologists (ASA) physical status II or III
• • Minimum height of 150 cm (to ensure uniform drug volume)
• • Able to understand the study procedures and provide written informed consent (in English or Nepali)
• Exclusion Criteria:
• • Contraindications to spinal anesthesia (e.g., coagulopathy, infection at injection site, hemodynamic instability)
• • Known allergy or hypersensitivity to bupivacaine, fentanyl, or dexmedetomidine
• • Chronic pain conditions or long-term opioid use
• • Neurological, Cardiac, Renal, or uncontrolled diabetic conditions
• • Current treatment for prostatic pathology or use of alpha-2 blockers
• • Presence of a Foley's catheter preoperatively
• • Estimated surgical duration: \>2.5 hours
• • Inability or unwillingness to provide informed consent