Comparative Study between Dexmedetomidine and Midazolam in Inducing Conscious Sedation in Patients Undergoing Vitreoretinal Surgery Under Peribulbar Block

Background and Aim: For many ophthalmic surgeons, local anesthesia has become the preferred option over general anesthesia because of the quicker rehabilitation and the avoidance of possible complications of general anesthesia, including retrobulbar, peribulbar, sub-tenon s block, and even topical anesthesia combined with sedation which can be provided by many drugs with a relative risk of oversedation and disorientation, confusion or increased risk of respiratory depression. The aim of this study is to compare between dexmedetomidine and midazolam as regard efficacy in achieving satisfactory level of consious sedation without hazards.Subject and Method: 50 patients were received peri-bulbar block and randomely allocated to receive either dexmedetomidine (Group D, n=25) or midazolam (Group P, n=25).Results: The ability to achieve RSS 3 was successfully done in group D (5.95±0.32) minutes while in Group M these patients failed to achieve RSS3 in 22 patients (88%) and achieved RSS 5-6 throughout the procedure, the mean intraocular pressure was significantly lower in Group D (Before 20.8±2.3 after 15±2.4) cm H2O than Group P (before 17.4 ±2.8 after 17.4±2.8) cm H2O (p-value 0.001), the median pain score was significantly lower in Group D than Group M during the first 6 hours postoperative (p-value 0.001).Conclusion: Dexmedetomidine appears to provide more cardiovascular stability, more significant reduction of intraocular pressure, better patient and surgeon satisfaction and less adverse events.