IRCT2012112811597N1 IRCT 2013-02-24 Vice chancellor for research, Ahvaz Jundishapur University of Medical Sciences Analgesia of Fentanyl and Ketamine during Propofol Injection Comparison of Analgesia of Fentanyl with Ketamine during Injection of Propofol 2013-04-19 anticipated 66 Complete https://irct.ir/trial/11800 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Prevention, Other design features: Patients are assigned randomly to 3 groups using a computerized allocation schedule for the coded syringes containing the study drugs. After randomization, the coded syringes are prepared by an anesthesiologist not involve in the administration of the drug, patient care and data collection. 2-3 Pain during injection. Intervention 1: Drug: Ketamine Dose: 0.1mg/kg IV Injection Number of using: Once Factory name: Rotexmedica Manufacturing Country's name: Germany Administration time: 45 seconds before Propofol administration. Intervention 2: Drug: Fentanil Dose: 1mcg/kg IV Injection Number of using: Once Factory name: Chekad Manufacturing Country's name: Iran Administration time: 45 seconds before Propofol administration. Intervention 3: Placebo: Normal Saline 0.9% Dose used: 2 ml IV Injection Number of using: Once Factory name: Samen Pharmacy CO. Manufacturing Country's name: Iran Administration time: 45 seconds before Propofol administration.