Evaluating the effectiveness of ketamine on muscle pain (myalgia), headache and restlessness (agitation) after electroconvulsive therapy in patients with major depression disorder

INTERVENTION: Control group: In this group 2 ml normal saline (placebo) will be injected before any other drugs in zero time. Intervention 1: Control group: In this group 2 ml normal saline (placebo) will be injected before any other drugs in zero time. Intervention 2: Study group: In this group 30 Mg Ketamine that had been diluted in 2 ml normal saline will be injected before any other drugs in zero time. Prevention Study group: In this group 30 Mg Ketamine that had been diluted in 2 ml normal saline will be injected before any other drugs in zero time. CONDITION: Electroconvoulsive therapy induced myalgia. ; Myalgia Myalgia PRIMARY OUTCOME: Agitation. Timepoint: In the recovery period. Method of measurement: 1. Yes: motor restlessness, severe motor movement, and besides, un‐aimed try to leave the bed, wanting to get up from bed, high loud crying, pulling catheters, confusion and poor response to verbal commands) 2 . No: not mentioned in any of the above scenarios. Headache. Timepoint: In the first 24 hours after ECT. Method of measurement: Visual Analoge Scale. Myalgia. Timepoint: At 6, 12, 24 and 48 hours after ECT. Method of measurement: Myalgia graded as follow: absence of myalgia = no; stiffness or muscle pain did not need treatment = mild; muscle pain or stiffness reported spontaneously by the patient, and required therapy = moderate; very severe discomfort = severe. SECONDARY OUTCOME: Heart Rate. Timepoint: Befor induction of anesthesia , after induction of anesthesia ,and after termination of seizure. Method of measurement: Beat /minute. Mean arteial blood preasure. Timepoint: Befor induction of anesthesia ,after induction of anesthesia ,and after termination of seizure. Method of measurement: Milimeter of Hg. Seizure duration. Timepoint: After induction of ECT. Method of measurement: Second. INCLUSION CRITERIA: INCLUSION CRITERIA: Major depression based on DSM 4 criteria, physical condition in accordance with ASA Class 1 or 2, ability and capacity to sign informed consent sheet. Exclusion criteria: history of major systemic disease, history of neuromuscular disease, history of myalgia.