Comparison of low-dose ketamine infusion versus lignocaine infusion for post-operative pain in patients undergoing laparoscopic cholecystectomy under general anesthesia
Abstract
Background & objective: Effective management of postoperative pain is challenging, as numerous patients encounter severe pain or face adverse events linked to analgesic medication. The study aims to compare the effect of intravenous low-dose ketamine versus lignocaine infusion on post-operative pain in patients undergoing laparoscopic cholecystectomy under general anesthesia in a tertiary care hospital.
Methods: This randomized controlled trial was performed in the Department of Anesthesia at Fazaia Ruth Pfau Medical College, PAF Hospital, Karachi, from January to November 2024. Group K received ketamine at a 0.2 mg/kg bolus intravenously and the same dose per hour throughout the surgery, whereas Group L received lignocaine at a rate of 1 mg/kg bolus and the same dose per hour throughout the surgery. Pain status was monitored postoperatively at 0, 2, 4, 6, 12, and 24 hours using the Numerical Rating Score (NRS).
Results: Fifty patients were studied in each arm. Postoperative pain score was similar in Group K and Group L at 0 hour (1.5 ± 0.8 versus 1.4 ± 0.5, P = 0.395), 2nd hour (2.3 ± 0.9 versus 2.4 ± 1.2; P = 0.847), 4th hour (2.8 ± 1.3 versus 2.9 ± 1.1, P = 0.872), 6th hour (2.8 ± 1.3 versus 2.8 ± 1.1, P = 1.000) and 12th hour (2.2 ± 1.2 versus 2.1 ± 0.8, P = 0.714). Mean pain score was found to be significantly different between Group K and Group L at 24th hour (1.3 ± 0.5 versus 2.2 ± 0.4, P < 0.001). The time to first rescue analgesia and total analgesic consumption did not differ significantly between the two groups.
Conclusions: The findings suggested that both low-dose ketamine and lignocaine had similar pain relief effect in early postoperative period. However, ketamine was found to be superior to lignocaine at 24 hours in terms of lower pain score.
Abbreviations: LC: laparoscopic cholecystectomy, NRS: Numerical Rating Score, NMDA: N-methyl-D-aspartate
Keywords: Laparoscopic Cholecystectomy; Lignocaine; Low-dose Ketamine; Pain; Post-operative analgesia
Citation: Rehman SH, Rao ZA, Sammiuddin S, Abbasi MS, Khalid M. Comparison of low-dose infusions of ketamine with lignocaine for post-operative pain in patients undergoing laparoscopic cholecystectomy under general anesthesia. Anaesth. pain intensive care 2025;29(8):861-867. DOI: 10.35975/apic.v29i8.3008.
Received: June 30, 2025. Revised: August 17, 2025. Accepted: August 22, 2025
