Comparative Effect of Intravenous Ketamine and Tramadol on Hemodynamic Parameters, Pain, Sedation, and Postoperative Nausea and Vomiting in Patients Undergoing Urological Surgery Under Spinal Anesthesia: A Triple-Blind Randomized Clinical Trial.

Background: Spinal anesthesia is widely used in urological surgeries but is often associated with hemodynamic instability, insufficient sedation, and postoperative nausea and vomiting (PONV). While ketamine and tramadol have been employed as adjuncts, their comparative effects on perioperative parameters remain underexplored. This study aimed to compare the efficacy of intravenous ketamine and tramadol in modulating hemodynamic stability, sedation, pain, and PONV in patients undergoing urological surgery under spinal anesthesia.

Methods: In this triple-blind randomized clinical trial, 90 patients undergoing transurethral or ureteroscopic urological surgeries under spinal anesthesia were randomly allocated into 3 equal groups: ketamine (0.5 mg/kg IV), tramadol (0.5 mg/kg IV), or saline. Hemodynamic parameters, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), and oxygen saturation (SpO₂), were recorded at multiple intraoperative and postoperative time points. Secondary outcomes included pain scores, sedation levels, and incidence of PONV. The data were entered into SPSS software, Version 21, and analyzed using the chi-square test, independent sample t-test, and repeated-measures analysis of variance with post-hoc Bonferroni tests.

Results: The study population exhibited demographic consistency. Ketamine demonstrated significantly superior hemodynamic stability compared to tramadol and saline, with less reduction in SBP, DBP, and MAP over time (MAP: P < 0.001, η² = 0.33). The heart rate was also more stable in the ketamine group (P < 0.001, η² = 0.11). The ketamine group showed the highest sedation scores (mean increase: -0.91, P ≤ 0.001) and the lowest incidence of PONV (3.3%) compared to tramadol (16.7%) and saline (10%) (P = 0.017, φ = 0.34). Pain scores showed no significant differences among groups. No serious adverse effects, including hallucinations or hypersensitivity reactions, were reported.

Conclusion: Intravenous ketamine significantly enhances hemodynamic stability, increases sedation, and reduces PONV when used as an adjunct to spinal anesthesia in urological surgeries. These findings support the clinical use of ketamine to optimize perioperative outcomes and patient safety. These findings possess external validity and may be extrapolated to broader populations undergoing urological procedures under spinal anesthesia.