IJSR International Journal of Scientific Research 2277 - 8179 Indian Society for Health and Advanced Research ijsr-10-1-33188 Original Research Paper Effect of Preemptive Clonidnine Versus Pethidine and Ketamine on Postoperative Shivering During Spinal Anesthesia Praveen Kumar Singh Dr. Dr. Chandeshwar Choudhary Dr. January 2021 10 1 01 02