PROSPECTIVE STUDY TO COMPARE EFFECTIVENESS OFADENOSINE WITH MAGNESIUM SULPHATE AS ADJUVANTSTO ROPIVACAINE IN ULTRASOUND GUIDED TRANSVERSUS ABDOMINIS PLANE BLOCK FOR POSTOPERATIVEANALGESIA IN PATIENTS UNDERGOING OPEN ABDOMINAL SURGERY

Abstract

Background:Postoperative pain following abdominal surgeries significantly affects recovery andoutcomes. The transversus abdominis plane (TAP) block, a regional anesthesia technique, hasgained popularity for its ability to provide effective analgesia and reduce opioid consumption.

Aim: To determine the comparative effectiveness of adenosine and magnesium sulphate as adjuvants toropivacaine in TAP block for post-operative analgesia in patients undergoing abdominal surgeries.
Methods:A prospective comparative study included 100 patients undergoing elective abdominalsurgeries. Participants were allocated into two groups: one received ropivacaine with MgSO₄ andthe other with adenosine in ultrasound-guided TAP blocks. Demographic data, intraoperative andpostoperative hemodynamic parameters, pain scores (VAS), sedation levels (Ramsay SedationScore), rescue analgesic requirements, and complications were recorded. TAP blocks wereperformed using ultrasound guidance, ensuring precise placement of the local anesthetic andadjuvant. Postoperative pain was assessed at regular intervals up to 24 hours. Statistical analyseswere conducted to compare analgesic efficacy, duration, opioid consumption, and safety profilesbetween the two groups.

Results:Demographic characteristics were comparable between groups,with no significant differences. Both groups exhibited stable intraoperative hemodynamicparameters, no intraoperative complications were observed, underscoring the safety of bothadjuvants. Postoperative pain scores were initially similar but diverged significantly at 24 hours.The MgSO₄ group reported lower VAS scores (3.5 ± 1.3) compared to the adenosine group (4.1 ±1.3, p = 0.040). MgSO₄ also demonstrated superior analgesic duration,  with a longer time to firstrescue analgesia and longer duration of analgesia overall.  Patients in the MgSO₄ group requiredfewer tramadol boluses, with 62% needing only  one or two doses compared to 70% in theadenosine group requiring two or three  doses (p < 0.001). Sedation levels were comparable, though the MgSO₄ group  exhibited slightly lower scores at one hour postoperatively (p = 0.048).Magnesium  Sulfate (MgSO₄ ) significantly prolonged the duration of analgesia compared toadenosine, with a mean analgesia duration of 483.4 ± 48.1 minutes versus 415.3 ±  29.8 minutes (p< 0.001), and a mean time to first rescue analgesia does also being  longer than the adenosine grouppatients (421.5 ± 30.9 minutes vs 372.8 ± 38.2 minutes, p < 0.001).  Complications such as nauseaand vomiting were minimal and comparable between groups, with no significant differences.
Conclusion:Both MgSO₄ and adenosine proved to be safe and effective adjuvants in TAP blocksfor postoperative pain management. MgSO₄ demonstrated superior analgesic efficacy, prolongedduration, and reduced opioid requirements, making it particularly suitable for surgeries with higherpain profiles or extended recoveries. Adenosine provided adequate short-term analgesia, making it aviable alternative for low-pain or short duration procedures.