Evaluating Dexmedetomidine and Ketamine for Control of Post-Operative Pain in Lower Segment Caesarean Section Surgeries

Background: Effective control for postoperative pain that follows lower-segment cesarean section (LSCS) remains a clinical challenge, with the opioid-related side effects prompting the use of multimodal analgesia. Dexmedetomidine and ketamine have shown synergistic analgesic effects, but optimal dosing of dexmedetomidine in this combination is not well established. To compare the analgesic efficacy and safety of three different doses of dexmedetomidine combined with a fixed dose of ketamine for postoperative pain control after LSCS. Methods: In this randomized controlled trial RCT Registered (NCT07022821), 90 participants undergoing elective LSCS under spinal anesthesia were assigned to one of three groups (n=30 each) from March to May 2025 at Department of Anesthesia FMH Lahore. A random sampling technique was used for sample size distribution. All received ketamine 0.25 mg/kg/hr, with Group A receiving dexmedetomidine 0.02 µg/kg/hr, Group B 0.3 µg/kg/hr, and Group C 0.4 µg/kg/hr. Infusions continued for 24 hours postoperatively. Pain was assessed using the Visual Analog Scale (VAS) at multiple intervals. Secondary outcomes included opioid consumption, time to rescue analgesia, and adverse effects. Data were analyzed using SPSS v25. p < 0.05 was considered significant. Results: Group C consistently exhibited the lowest VAS scores across all time points (p < 0.001), significantly lower opioid use (4.1 ± 1.3 mg nalbuphine), and the longest time to first rescue analgesia (8.3 ± 2.3 hrs). Mild sedation was more frequent in Group C, but it was not clinically significant. Conclusion: A dexmedetomidine dose of 0.4 µg/kg/hr combined with ketamine provides superior postoperative analgesia after LSCS, with reduced opioid requirements and acceptable safety. This regimen may enhance the recovery and comfort of patients in obstetric anesthesia.