Ketamine Versus Propofol as ICU Sedation

this study is to assess the hemodynamic profile of ketamine compared with propofol in critically ill, mechanically ventilated adult Patients study will be carried out on 100 mechanically ventilated patients who received one sedative agent propofol or ketamine The patients will be randomized into two equal groups to receive either ketamine or propofol Group 1 (Ketamine group): ketamine is initiated at 0.5 mg/kg/h and titrated by 0.25 mg/kg/h every 15 minutes to a maximum dosage of 4 mg/kg/h to achieve appropriate sedation. Group 2 (Propofol group): Propofol is initiated at 0.3 to 0.6 mg /kg/hr. and titrated by 0.3 to 0.6 mg/kg/h every 5 to 10 minutes up to a maximum dosage of 4.5 to 4.8 mg/kg/hr. to achieve appropriate sedation.