Effect of Oral Clonidine Premedication on Perioperative Cardiac Workload for Patients Undergoing Surgeries Under General Anaesthesia

Introduction: Term premedication refers to the drugs that are administered to patients before conduct of anesthesia with specific objectives for intended anesthesia technique. During conduct of general anesthesia there are occasions that leads to increase in cardiac workload that may be harmful in patients having prior chronic cardiac and respiratory diseases[1]. To control the deleterious effects of enhanced sympathetic activity which results from increased catecholamine release, alpha2 agonist Clonidine hydrochloride has also been tried as oral premedication drug to control perioperative hemodynamic changes affecting the cardiac workload (RPP) in patients undergoing surgery. Proposed study was designed to evaluate the effects of oral clonidine premedication on cardiac workload,pain relief & sedation in patients undergoing abdominal surgeries. Methodology: On the approval of the Institutional Ethical Committee 50 adult patients belonging to ASA grade I and II scheduled for elective surgery were divided in two groups of 25 each.Group I:Patients were given Tablet clonidine 150 mcg orally 90 mins before induction of anaesthesia.Group II: Patients were given Vitamin C tablets 100 mg (placebo) orally 90 mins before induction of anaesthesia.After 90 minutes, the patients were shifted to operating room and the preoperative hemodynamic parameters – Heart rate,ECG,SBP,DBP, MAP recorded along with Ramsay sedation score. Results: The clonidine-induced reduction in blood pressure and heart rate decreases the cardiac workload. The drug is also beneficial in patients with coronary artery disease, and appears to have a coronary vasodilating effect thus enhancing the effect as premedication. The reduction in Rate pressure product was significantly higher in clonidine treated patients.Conclusion:The magnitude of increase in mean rate pressure product was higher in control group than study group patients during all periods of observation indicating its use as premedication is effective to control cardiac workload because of sympathoadrenal activation.Postoperatively study group of patients were cooperative,oriented and responding to verbal commands according to Ramsay sedation score.