A Comparison Between the Effectiveness of Ketamine Bolus and Intradermal Lidocaine in Reducing Acute Postoperative Pain

Background and objective In light of the scarcity of data and research about the management of pain in a low-resource setting, we conducted this study with a view to assessing the effectiveness of intravenous ketamine in comparison to that of intradermal lidocaine in reducing postoperative pain. Postoperative pain can lead to significant morbidity, longer hospital stay, and the development of chronic pain. Our study was formulated to assess the effectiveness of a ketamine bolus in comparison to intradermal lidocaine at the wound site in terms of decreasing pain scores postoperatively. Methods In our study, 99 patients were randomly selected to undergo inguinal hernia repair under spinal anesthesia. After obtaining informed consent from the participants and approval from the hospital ethical committee, the patients were randomly classified into the following three groups: the lidocaine group (group A), the ketamine group (group B), and the control group (group C). The patients in the lidocaine group received 0.6 mL/kg of 0.25% lidocaine (1.5 mg/kg) infiltration at the wound site. The ketamine group was given a 50-mg ketamine bolus at the end of the operation, and the control group did not receive either ketamine or intradermal lidocaine at the wound site. Postoperative pain was recorded using the Visual Analog Scale (VAS) scoring and the results were compared. The time of the first request for analgesia was also recorded. Results The pain scores measured via VAS scores were higher in patients who received intradermal lidocaine (group A) at the wound site as compared to group B that received a bolus of 50-mg ketamine (p<0.0001); the control group (group C) had pain scores higher than both groups A and B (p=0.0001). Conclusion Based on our findings, administering ketamine bolus can significantly decrease VAS scores and reduce the incidence of chronic post-surgical pain as compared to lidocaine infiltration. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, provides excellent pain relief and analgesia, which decreases overall pain scores.