Dexmedetomidine infusion for prevention of emergence agitation in patients undergoing percutaneous nephrolithotomy under sevoflurane anesthesia: a prospective double-blinded randomized placebo study

Introduction
Percutaneous nephrolithotomy (PCNL) under general anesthesia is more susceptible for developing emergence agitation (EA).
Aim
This randomized double-blinded, prospective, comparative, clinical study was aimed to evaluate dexmedetomidine efficacy for EA prevention in patients undergoing PCNL.
Patients and methods
A total of 44 patients with American Society of Anesthesiologists grades I–II aged between 21 and 70 years, experiencing an elective PCNL under general anesthesia, were included in the study. Patients were randomly allocated to one of two groups: group C and group D. Placebo was given to group C, whereas a bolus dose of dexmedetomidine 1.0 µg/kg was given to group D patients, followed by 0.4 µg/kg/h after anesthesia induction. Adjustment was made to end-tidal sevoflurane to keep bispectral index at 45–55. Sevoflurane and the study drug were stopped when surgical dressing was applied. Evaluation of EA was made from extubation until the patients was transferred to postanesthesia care unit. EA incidence was the primary outcome, whereas sevoflurane requirement, hemodynamic stability, and recovery from anesthesia were the secondary outcomes.
Results
There was a significant reduction of EA incidence (group C 54.5%; group D 9.1%) with dexmedetomidine infusion to 90.9% (=0.0001). There was also significant lowering of the end-tidal sevoflurane concentration and an average 38.87% reduction in required concentration in group D, in contrast to group C (<0.001). There was significantly higher average mean arterial blood pressure and heart rate in group C compared with group D (<0.001). There is significantly lesser time to extubation, lesser time to achieve bispectral index 90, and lesser time in reacting to verbal command in group C when compared with group D (<0.0001).
Conclusion
The EA incidence and sevoflurane requirement among patients experiencing PCNL are significantly decreased by dexmedetomidine infusion. Moreover, dexmedetomidine was associated with delayed extubation time, residual sedation, and prolonged postanesthesia care unit stay.