Background One of the most unpleasant aspects of surgery for a patient is postoperative discomfort. To treat the pain prophylactically, deliberate action should be taken. Exogenous opioids, such as morphine or fentanyl, have been used as the cornerstone of treatment to date. Opioid use is frequently linked to negative consequences. Ketamine is by far the most adaptable anesthetic medication accessible, possibly in all of medicine. Ketamine’s principal analgesic impact is because of its antagonism to N-methyl-D-aspartate receptors (NMDA) receptors. Ketamine affects pain processing in the central nervous system in this way. Ketamine has proven to be an effective antihyperalgesic, preventing opioid-induced hyperalgesia. Therefore, we investigated the impact of ketamine following spinal anesthesia on the duration of postoperative analgesia and the need for analgesics. Methods This was a prospective, randomized, double-blinded study done over a period of two years. A total of 60 patients undergoing elective surgeries under spinal anesthesia were randomized into two groups. After 10 min of spinal anesthesia and achieving the required level of sensory and motor blockade, both groups were given Inj. Midazolam 1 mg intravenously, followed by Inj. Ketamine 0.25 mg/kg, volume made up to 10 mL with normal saline, given intravenously in Group K and Inj. Normal Saline 10 mL was given intravenously in Group N. Hemodynamic monitoring was done intraoperatively, and the postoperative visual analog score (VAS), sedation score, the mean time for the first rescue analgesia, and the total dose of postoperative analgesic required in 24 h were tabulated. Results There was no statistical difference between the two groups in terms of age, weight, ASA grade, and duration of surgery. In Group K, the VAS scores were significantly lower and patients were comfortable when compared to Group N ( P-value <.01). The mean time to first rescue analgesia was longer in Group K (6.4 ± 1.69 h) when compared to Group N (2.9 ± 1.01 h), and the total dose of postoperative analgesia (Tramadol) required in 24 h was also significantly less in Group K (143.33 ± 56.83 mg) when compared to Group N (236 ± 49.01 mg). Changes in hemodynamic parameters (heart rate and mean arterial pressure (MAP) were statistically and clinically not significant in both the intraoperative and postoperative periods in both the groups. Conclusion Patients in Group K were more comfortable, had a longer duration of postoperative analgesia, and required less dose of rescue analgesia in the postoperative period. Ketamine is a safe drug that is readily available, and it decreases the use of opioids and opioid-related side effects. Therefore, ketamine can serve effectively as an adjunctive analgesic drug.
