Background: Shivering is a frequent complication after spinal anesthesia [SA]. It is also more common after transurethral resection of the prostate [TURP] that may be due to the absorption of a large volume of the irrigating fluid.

The Aim of the work: The current work aimed to assess the effect of intraoperative dexmedetomidine, ketamine, and magnesium sulfate to prevent shivering during and/or after SA for TURP

Subjects and Methods: 80 patients arranged for TURP were included, and divided into four groups; the first received normal saline [control group], the second for dexmedetomedine, the third for ketamine and the fourth for magnesium sulphate. All were assessed systematically in the preoperative period, monitored for hemodynamics and adverse effects intra- and postoperatively, till the end of the first postoperative day.

Results: There was a significant decrease of intra-and/or post-operative shivering in treatment groups than the control group. The lowest rate of shivering was registered with dexmedetomedine [10.0%], followed by ketamine [15.0%] and magnesium sulfate [25.0%]. It was 55% in the control group. There was a significant variance between studied groups regarding the duration of analgesia and anesthesia. Mean arterial pressure revealed a statistically significant decrease in the study than the control group at 20, 30, 40, 50 and 60 minutes after induction. The highest reduction registered for dexmedetomidine followed by magnesium sulfate and ketamine. There was a statistically significant difference among groups regarding visual analogue scale [VAS] for pain, with the lowest score in dexmedetomidine and magnesium sulfate groups. Finally, there was a statistically significant increase of hypotension and bradycardia in dexmedetomidine than other groups.

Conclusion: Intravenous infusion of dexmedetomidine exerted a useful effect as an antishivering and sedating agent during SA without any major adverse effects. Thus, dexmedetomidine infusion could be considered as a good choice during SA to reduce postoperative shivering.