Two intravenous boluses of 2-3 mg/kg each of ketamine will be administered 5 minutes apart and immediately followed by a continuous infusion of 5-10 mcg/kg/min. Based on both clinical or electrographic responses, dosage will be increased every 10 minutes or longer, using 2 to 10 mcg/kg/ min increments, up to 60 mcg/kg/min. Maximum duration of infusion will be of 7 days.

Midazolam intravenous will be increased every 5 minutes, using 2 mcg/kg/min increments, up to 12 mcg/kg/min and Thiopental intravenous will be increased every 30 minutes or longer, using 1 mg/kg/h increments, up to 6 mg/kg/h and Propofol intravenous will be increased every 5 minutes or longer, using 1 mg/kg/h increments, up to 5 mg/kg/h.

Maximum duration of infusion for each drug will be 48 hours.

Intravenous administration in continuous