Evaluation of the effect and safety of dexmedetomidine as an additive to local anesthesia in peribulbar block for vitreoretinal surgery.

Purpose: We conducted a prospective, randomized study to evaluate the efficacy of dexmedetomidine as an additive to peribulbar block for vitreoretinal surgery in terms of onset time of block, hemodynamic stability profile, patient comfort, and surgeon satisfaction. Methods: One hundred patients of American Society of Anesthesiologists grade 1 and 2 scheduled for vitreoretinal surgery were randomly assigned into two groups: control group (n = 50) received lignocaine bupivacaine block, and Dex group (n = 50) received lignocaine bupivacaine plus 20 μg dexmedetomidine peribulbar block. Information regarding time for onset of block, hemodynamic data, visual analog scale for pain, sedation levels, total duration of surgery, and surgeon satisfaction levels were collected. Results: All the demographic characteristics including age, gender, American Society of Anesthesiologists grade, onset of anesthesia, and duration of surgery were comparable in both groups. At the baseline, there was no statistically significant difference in heart rate, mean arterial pressure, diastolic blood pressure, and respiratory rate between the two groups, with a difference noted in systolic blood pressure at the baseline. There was significant difference noted in the systolic blood pressure and mean arterial pressure at different time intervals with a decreasing trend as time progressed. The mean sedation score was significantly higher in the Dex group than that in the control group. The surgeon satisfaction was higher in the Dex group than that in the control group. Conclusion: Dexmedetomidine is a useful and safe drug in combination with lignocaine bupivacaine in peribulbar for vitreoretinal surgery as it maintains hemodynamic stability and provides sedation, which enables full cooperation and potentially better operating conditions.