ABSTRACT
Clonidine, a preferential alpha 2 adrenergic agonist has been reported to have perioperative effects including reduction of anaesthetic requirements, improving haemodynamic stability and providing analgesia, however its clinical usefulness in cardiac surgery is not widely studied. Thirty-four consecutive patients undergoing coronary artery bypass graft surgery (CABG) were preoperatively administered clonidine and studied for its possible desirable effects. Seventeen patients (Gr B) received 2 microg/kg clonidine orally the previous night and again one hour prior to surgery. Seventeen patients did not receive the drug and served as control (Gr A). Heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), requirement of isoflurane, requirement of nitroglycerin, sedation score, extubation score and urine output were studied throughout the perioperative period. HR was observed to be lower at all time points in the clonidine group though the difference between groups was not statistically significant (p > 0.1). MAP was higher at all time points and significantly so after intubaton in the control group (P < 0.01). Patients receiving clonidine required significantly less isoflurane and nitroglycerin (P < 0.05). sedation score was significantly higher in the clonidine group. Other aspects studied were comparable in both groups. At the doses described in this study, clonidine seems to be a safe useful adjunct to anaesthesia for CABG surgery.