Dexmedetomidine as an adjuvant to local anesthetics in ophthalmic surgery

Vitreoretinal surgery aims to restore the structural relationships of the posterior segment of the eye, with the possibility of partial or complete restoration of visual functions, and imposes certain requirements to the anesthetic support of operations. These are injuries, operations length, age, and concomitant pathology of organs and systems of patients. In this regard, there is a recent tendency to use different pharmacological groups as adjuvants to local anesthetics to enhance or prolong their analgesic effect. Purpose to evaluate the effectiveness of dexmedetomidine as an adjuvant in retrobulbar blockades. Materials and methods. Retrobulbar block bupivacaine with dexmedetomidine at a dose of 0.25 mg/kg was performe in the 1st group (n = 22), retrobulbar block was performed with a mixture of bupivacaine in the 2nd group (n = 22). Changes in hemodynamics at the stages of surgery were evaluated. To assess the oxidative status, the evaluation of the redox coefficient (FORT/FORD) was conducted before and after the surgery. The level of comfort of the operation by the surgeon and the patient. Assessment of pain was performed by a VRS in the points. Results. In patients of the 1st group the decrease in SAD was more pronounced and persisted throughout the entire period of surgical treatment. 54.5% of patients of group 1 and 18% of group 2 had no pain 8 hours after the surgery. 82% of patients of group 2 reported moderate pain that required medication (p < 0,05). In patients of group 1, it increased from 0.45 ± 0.5 to 0.62 ± 0.2 (p < 0,005) by 37% of the initial value, in patients of group 2, it was shown to decrease by 5% (p > 0,05). In group 1, the comfort of the operation was estimated by ophthalmic surgeons as «satisfactory» in 77.3%, and in group 2 in 54.5% (p < 0,05). Conclusion. The use of dexmedetomidine as an adjuvant of local anesthetics in ophthalmic surgery provides the necessary analgesia, hemodynamic profile of the patient, antioxidant effect and affects the quality of the surgeon’s work, which affects the duration of operations.