RESUMEN
Pain following propofol injection was reported between 28- 90%. Ketamine have lesser cardiovascular depression effect and also local anesthetic effect. In this study effect of ketamin were analyzed when it given before propofol injection. In a randomized double blind clinical trial selected 120 ASA I, II Ptients with 15-65 years old. They were candidated for elective surgery, in half of the patients 100 /xg/kg ketamine in 2 ml volume and in another half, 2 ml distilled water were given before propofol injection. Severity of injection pain was evaluated according to 4 scale criteria [none, mild, moderate, or severe] fifteen seconds after injection of 25% of the calculated dose of propofol. Heart rate [HR] and noninvasive blood pressure were recorded before and after propofol injection, immediately and 3 minutes after intubation. The data were analysed by Mann Whitney U, Pooled t-Test and the Chi-squared test. Pain was not sensed in 51.56% and 75% of control and case groups respectively. In cases group showed little decrease in systolic and diastolic pressures after anesthetic induction [p = 0.012 and p = 0.005]. There were upper diastolic pressures after intubation [p = 0.00] and 3 minutes after intubation [p = 0.000]. During intervention heart rate changes had not significant difference between two groups. Ketamine pre-treatment was an effective method in reducing pain and providing hemodynamic stability after propofol induction