A Prospective, Randomized, Double-blinded Control study on evaluation of low dose dexmedetomidine infusion in patients undergoing cataract surgery under peribulbar block

Abstract

Background: The cataract surgeries are usually done in elderly patients under monitored anaesthesia care with or without sedation. Dexmedetomidine is a non-opioid sedative and analgesic and is devoid of respiratory depression. The objective of this present study is to evaluate the sedative effects of low dose dexmedetomidine infusion for unilateral cataract surgery. The patient and surgeon satisfaction scores were also recorded. Methods: Sixty patients scheduled for unilateral cataract surgery were randomly assigned to two groups: Group 1 receiving dexmedetomidine 0.5mcg/kg diluted in 100ml normal saline infusion over 15min while group 2 received normal saline. The patients in both the groups received premedication with alprazolam 0.5mg two hours prior to surgery. The hemodynamics, sedation score, patient and surgeon satisfaction scores and any adverse effects were recorded. Ramsay sedation score (RSS) of 3 was kept as a satisfactory sedation for the patient. Results: All the patients in group 1 achieved RSS of 3 while in group 2 only 47% of patients reached the target score. The patient and surgeon satisfaction scores were better with group 1. There was a significant fall in heart rate and blood pressure between 15 and 25 min after dexmedetomidine infusion. In group 1, two patients had bradycardia and four patients developed hypotension which was easily manageable. Conclusion: Dexmedetomidine, when administered as a low dose infusion provides reliable sedation and is a useful anaesthetic adjuvant for monitored anaesthesia care in cataract surgery. The patient and surgeon satisfaction scores were also better with dexmedetomidine infusion. Keywords: Cataract, Dexmedetomidine, Monitored anaesthesia care, Patient and Surgeon satisfaction scores, Sedation