The effect of adding dexmedetomidine to local anesthetic mixture for peribulbar block in vitreoretinal surgeries

Abstract

The purpose of this study was to compare the effect of adding different doses of dexmedetomidine to local anesthetic mixture for peribulbar block in vitreoretinal surgeries as regards duration, efficacy and pain relief. Materials and methods: In this prospective randomized double blind clinical study, 160 patients were equally divided into four groups: Group C (the control group) (n = 40) received 10 ml mixture of lidocaine 2% and bupivacaine 0.5% with 120 IU of hyaluronidase, group D15 (n = 40) received a 10 ml mixture of lidocaine 2% and bupivacaine 0.5% with 120 IU of hyaluronidase + 15 lg dexmedetomidine, group D20 (n = 40) received a 10 ml mixture of lidocaine 2% and bupivacaine 0.5% with 120 IU of hyaluronidase + 20 lg dexmedetomidine and group D25 (n = 40) also received a 10 ml mixture of lidocaine 2% and bupivacaine 0.5% with 120 IU of hyaluronidase + 25 lg dexmedetomidine. The onset of globe anesthesia and akinesia and their duration, the intraocular pressure (IOP), patient comfort and surgeon satisfaction were all assessed. Data were analyzed and the results were presented as mean ±SD (Standard Deviation) and Ranges, number (%) and median (IQR) (Inter quartile range). Chi-square test (x2) was used to compare nonparametric variables. Comparison between groups was done using Analysis of Variance (ANOVA-One Way) as a parametric test and Kruskal Wallis Analysis of Variance by ranks as a nonparametric test. P values less than 0.05 (p < 0.05) was considered to be significant. Results: The onset of globe anesthesia was shorter in dexmedetomidine groups in comparison with control group. The difference was statistically significant in group D25 and group D20 in comparison with the control group (p > 0.05). Regarding the duration of globe analgesia, adding dexmedetomidine to the local anesthetic mixture prolonged the duration of globe analgesia, and this difference was statistically significant in group D25 in comparison with the control group (p > 0.05). Regarding the duration of globe akinesia although there was prolongation of the

Magnesium sulphate versus dexmedetomidine as an adjuvant to local anesthetic mixture in peribulbar anesthesia

“…This study in agreement with the results of Hafez et al [18] who evaluated the effect of three doses of dexmedetomidine 15 mg, 20 mg, 25 mg when added to a mixture of lidocaine 2%, bupivacaine 0.5%, and 120 IU of hyaluronidase for peribulbar anesthesia in vitreoretinal surgeries on 160 patients and they found that dexmedetomidine accelerated onset of sensory and motor block and increased its duration and the analgesia time. They found that the best dose was 25 mg dexmedetomidine.…”

Dexmedetomidine vs. Magnesium Sulphate as an Adjuvant to Rocuronium Bromide, and Local Anaesthetic Mixture in Peribulbar Anaesthesia for Viteroretinal Surgery

“…this could be explained by that dexemedtomidine in these studies was given either parentrally or neuroaxilally resulting in a central action by decreasing the sympathetic outflow and norepinephrine release. While our results were similar to Hafez M et al [38] study who failed to find any statically significant effects of peribulbar dexemedtomidine on haemodymaics.…”

“…This is in contrary to Hafez et al [38] who found no significant effect to Dexmedetomidine addition in different doses on VAS score when compared to the control group.…”

“…Also, Hafez M et al [38] study found a significant reduction in IOP at 5 and 10 min after injection in higher dose (D25) group compared to the baseline in the same group and also with the control group, while he found nonsignificant reduction in IOP in the smaller dose group.…”

“…Hafez M et al [38] studying the effect of adding different doses of Dexmedetomidine to peribulbar block in 160 patients undergoing vitreoretinal surgeries found a shorter onset time of corneal anesthesia in all groups which was statically significant in higher doses (D20, D25) when compared with the control group , as regards the onset of akinesia none of the groups had a statistically significant effects when compared with control group while the duration of analgesia and akinesia were statistically prolonged only in the D25 Group when compared with the control group. or neuraxially) blocks produced different effects.…”