Comparison of Dexmedetomidine, Esmolol and Sodium Nitroprusside for Hypotensive Anaesthesia in Functional Endoscopic Sinus Surgery

Background: This study has been designed to compare the controlled hypotensive effects of Dexmedetomidine (DEX), Sodium Nitroprusside (SNP) and Esmolol (ESM) during functional endoscopic sinus surgery (FESS). Method: In a prospective, double-blind study; we randomized 45 (15 in each group) ASA physical status I and II patients in the age group 18-60 years scheduled for FESS to receive either DEX (group 1) loading dose of 1µg/kg 10 mins before induction of anaesthesia followed by infusion at the rate of 0.4-0.8µg/kg/hr during maintenance of anaesthesia or SNP (group 2) 0.5-10µg/kg/min infusion after induction of anaesthesia or ESM group loading dose of 1mg/kg infused over 1 min followed by maintenance rate of 0.4-0.8mg/kg/hr. All the infusion rates were titrated to maintain the mean arterial pressure (MAP) between 60-70 mmHg so as to minimise the intraoperative bleeding. Results: DEX resulted in significant reduction in MAP, heart rate, better intraoperative field conditions and the time required for first rescue analgesia was longer. ESM and SNP were associated with significantly shorter extubation and recovery time than DEX. SNP provided a relatively poor surgical condition than observed in ESM/DEX. Conclusion: DEX is relatively safe and effective agent followed by ESM than SNP for controlled hypotension in patients undergoing FESS. Key-words: Anaesthesia,Dexmedetomidine, Esmolol, Sodium Nitroprusside, controlled hypotension, Functional endoscopic sinus surgery