Comparative study of dexmedetomidine versus midazolam in monitored anaesthesia care in tympanoplasty surgery

Abstract

Background: Monitored anaesthesia care (MAC) has become increasingly used for middle ear surgeries. Midazolam is most commonly used for sedation in MAC; likewise, dexmedetomidine has gained popularity for intravenous sedation for the procedures to be done under MAC. The present study was undertaken to evaluate and compare the perioperativeeffects of inj. dexmedetomidine and midazolam with respect to sedation, analgesia and hemodynamic stability. Method: Study was approved by the Institutional Medical Ethics Committee and written informed consent was obtained from all patients participating in the study. Total 60 patients of ASA Grade I and II, aged 18 - 60 years, undergoing tympanoplasty surgery under local anaesthesia with 2% Lignocaine plus adrenaline 1:200000 and sedation with infusion of either dexmedetomidine or midazolam drug. Patients were divided in two groups of 30 patients in each group by chit block method. Group D received Dexmedetomidine 1 mcg/kg IV bolus over 10 min followed by continuous IV infusion at 0.5 mcg/kg/hr. Group M received midazolam 40 mcg/kg IV over 10 min followed by continuous IV infusion at 20 mcg/kg/hr. Results: Perioperatively, sedative effects of dexmedetomidine and midazolam were almost comparable, analgesic effects of dexmedetomidine was better than midazolam IV infusion. The significant reduction in haemodynamic variables was noted with dexmedetomidine (p=0.001) provided better hemodynamic stability than midazolam. Oxygen saturation and respiratory rate were maintained within normal limits in both the groups. 80% of surgeons in either group showed significant satisfaction but the difference was not statistically significant between two groups. Conclusion: Dexmedetomidine is a safe agent as sedative in patients undergoing tympanoplasty surgery under local anaesthesia with MAC.