Objective: Ketamine is a promising drug for analgesia in emergency medicine, but the high rate of side effects is a barrier to widespread usage. We hypothesized that ketamine bolus followed by ketamine infusion would provide a more even and longer duration of analgesia and lower rates of side effects in comparison to bolus-only administration. Methods: This was a double-blinded clinical trial. Eligible trauma patients were randomly allocated with the numeric rating scale ≥6 in two study groups. The first group received a dose of 0.3 mg/kg of ketamine over 1 minute, followed by an infusion of saline 0.9% over the next 30 minutes (bolus-only group). The second group was given 0.15 mg/kg of ketamine over 1 minute, followed by an infusion of 0.15 mg/kg over the next 30 minutes (bolus-and-infusion group). The primary outcome was to measure the average reduction in pain scores. Results: In total, 80 patients were recruited. Of these, 77 patients were analyzed. Both groups achieved a statistically significant decrease in pain scores (all P<0.001). After 30 minutes, patients in the bolus-and-infusion group reported lower pain scores in all intervals with lower rates of need for rescue analgesia, but this difference was not statistically significant. Vital signs remained stable during the study in both groups. No statistically significant difference was observed between study groups for any side effect (P<0.05). Conclusion Both administration protocols resulted in significant pain control. No statistically significant difference was observed between study groups in terms of analgesic efficacy and side effects.

Urolithiasis is one of the most common urological diseases worldwide, usually presenting as renal colic that leads to severe pain that requires analgesic treatment. This study aimed to compare the efficacy of ketamine and desmopressin in the pain management of renal colic patients. Methods This double-blind, randomized clinical trial was conducted on renal colic patients referred to the emergency department from June 2021 to July 2022. Patients were randomly assigned to three groups. In the desmopressin group, patients were treated with intranasal desmopressin and intravenous ketorolac. The ketamine group was treated with intranasal ketamine and ketorolac. The control group received ketorolac and an intranasal placebo. Vital signs were evaluated at baseline and 60 minutes; and pain scores were assessed at baseline, 10, 30, and 60 minutes after treatment. Results Enrollment included 135 patients, the mean (standard deviation) age was 44.1±11.4 years, and 82 (60.7%) were men. The mean visual analog scale scores were significantly lower at 10, 30, and 60 minutes in the ketamine group (5.6±1.2, 3.0±1.1, and 0.9±0.9, respectively) compared to the control (8.2±1.1, 5.1±2.0, and 2.3±2.6, respectively) and desmopressin (6.7±1.8, 4.2±2.2, and 1.3±1.4, respectively) groups (P<0.05). Although patients in the desmopressin group had lower mean pain scores than the control group at 10, 30, and 60 minutes, this difference was only significant at 10 minutes after the intervention (P<0.05). No significant differences in vital signs were found at 60 minutes after treatment. Conclusion Ketamine showed more favorable analgesic effects in renal colic patients than desmopressin, although desmopressin showed efficacy in the first minutes posttreatment.