Efficacy of Dexmedetomidine Versus Clonidine to Control Delirium in Patients Undergoing CABG

This prospective, randomised, double blinded, controlled clinical trial will be conducted in 147 patients between 60 yr and 70 yr , ASA physical status II and III, undergoing CABG. Patients will be randomly allocated to either dexmedetomidine or clonidine (control) groups .Upon arrival to ICU, in the dexmedetomidine group, patients will receive an infusion of 0.5-0.7 μg/kg/h then 1.4 μg/kg/h if Richmond assessment sedation score from +1 to +4 Taking into consideration if the heart rate less than 60 per minute or persistent hypotension reduce infusion rate by 0.2 μg/kg/h. Once the patient will be extubated, wean the infusion by 0.1μg/kg/h till reaching 0.2μg/kg/h. Slow the weaning rate if evidence of withdrawal reactions as agitation or hypertension occur. In clonidine group, the patients will receive 0.5μg/kg then 0.1-0.2 μg/kg/h.Primary end point of the study is the incidence of delirium.The secondary endpoints will be the the duration of extubation, the length of ICU stay, need for inotropic support or vasopressors, hospital stay , mean arterial blood pressure and heart rate , hospital mortality rate , all additional sedatives including overall doses of morphine and haloperidol the incidence of adverse events as bradycardia