Comparison of Magnesium Sulphate vs Tramadol as Adjuvants in Intrathecal Bupivacaine for Postoperative Pain in TURP Patients

This retrospective, randomized, double-blind clinical trial was conducted to compare the efficacy and safety of magnesium sulfate and tramadol as intrathecal adjuvants to hyperbaric bupivacaine in male patients undergoing transurethral resection of the prostate (TURP) under spinal anesthesia.

The primary aim was to evaluate:

The duration of postoperative analgesia, defined as the time from the completion of surgery to the patient's first request for rescue analgesia.

Intraoperative hemodynamic stability, assessed by monitoring mean arterial pressure, heart rate, and the incidence of hypotension or bradycardia.

A total of 60 adult male patients, aged 50 to 80 years, undergoing elective TURP were randomly allocated into two groups (30 patients each):

Group M (Magnesium Group): Received 12.5 mg of 0.5% hyperbaric bupivacaine with 50 mg of magnesium sulfate intrathecally.

Group T (Tramadol Group): Received 12.5 mg of 0.5% hyperbaric bupivacaine with 20 mg of tramadol intrathecally.

All patients received spinal anesthesia at the L3-L4 or L4-L5 interspace under aseptic conditions. Intraoperative monitoring included ECG, non-invasive blood pressure, and pulse oximetry. Data on hemodynamic parameters were collected at regular intervals throughout the procedure.

Primary Outcome Measures:

Time to first postoperative analgesic request (in minutes)

Mean arterial pressure and heart rate during the procedure

Secondary Outcome Measures:

Time to two-segment regression of the sensory block

Incidence of adverse events including hypotension, bradycardia, nausea, vomiting, pruritus, urinary retention, and respiratory depression

Blinding was maintained for both patients and the investigator recording postoperative outcomes.

The study was conducted in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. Ethical approval was obtained from the Institutional Review Board of Armed Forces Institute of Urology (AFIU), Rawalpindi. Written informed consent was obtained from all participants prior to inclusion in the study.

This trial was completed before registration and is being submitted retrospectively for transparency and publication compliance.

Inclusion criteria

• Male patients aged 50 to 80 years
• Scheduled for elective transurethral resection of the prostate (TURP)
• American Society of Anesthesiologists (ASA) physical status I-II
• Provided written informed consent

Exclusion criteria

• Known allergy or hypersensitivity to bupivacaine, tramadol, or magnesium sulfate
• Contraindications to spinal anesthesia (e.g., coagulopathy, infection at the injection site)
• History of chronic opioid use or substance abuse
• Severe hepatic, renal, or cardiac disease
• Neurological or psychiatric disorders affecting pain perception or reporting
• Participation in another clinical trial within the past 30 days