Sedative and Analgesic Effects of Dexmedetomidine Versus Ketamine in Patients Undergoing Varicocelectomy Under Spinal Anaesthesia: A Prospective Randomized Comparative Trial

Overview

The demand for safe and effective sedation during spinal anesthesia has increased in recent years, particularly in ambulatory and minor surgical procedures. The ideal sedative agent should provide adequate anxiolysis and comfort, maintain cardiorespiratory stability, and allow rapid recovery without significant adverse effects . Ketamine, a phencyclidine derivative, produces sedation, analgesia, and amnesia while maintaining airway reflexes and spontaneous respiration. However, it is often associated with undesirable psychomimetic reactions and sympathetic stimulation, including tachycardia and hypertension . In contrast, dexmedetomidine, a highly selective α2-adrenergic agonist, provides cooperative sedation, analgesia, and reduced anesthetic requirements, but it may cause bradycardia and hypotension, particularly at higher doses . The combination of ketamine and dexmedetomidine (often referred to as "Ketadex") has recently gained attention due to its synergistic effects. Evidence suggests that this combination improves hemodynamic stability, decreases emergence agitation, and provides superior analgesia compared to either agent alone \[4,5\]. Moreover, ketamine counteracts the bradycardia and hypotension induced by dexmedetomidine, while dexmedetomidine mitigates ketamine-induced psychomimetic side effects . Despite these advantages, the optimal dosing regimen and comparative efficacy of the two drugs when used individually remain subjects of clinical debate. Recent randomized controlled trials comparing intravenous dexmedetomidine and ketamine during spinal anesthesia reported differences in sedation quality, hemodynamic stability, and recovery profile . Therefore, this study aims to compare the sedative and hemodynamic effects of intravenous dexmedetomidine versus ketamine infusion in patients undergoing varicocelectomy under spinal anesthesia. the study aim to Compare sedative, analgesic efficacy, and safety profile of intravenous dexmedetomidine versus ketamine in patients undergoing varicocelectomy under spinal anaesthesia