Xylazine-Lidocain Combination for Retrobulbar Block in Goats

Objective- This study was performed to investigate the analgesic effects of lidocaine, xylazine and lidocaine/xylazine combination in eye regional anesthesia. Design- Experimental Study. Animals- Twenty adult goats were randomly designed in 4 groups. Procedures- In group L: 10 ml mixture of lidocaine 2% (5 mg/kg bw) and normal saline, In group LX: 10 ml mixture of lidocaine 2% (5 mg/kg bw), xylazine 2% (0.05 mg/kg bw) and normal saline, In group X: 10 ml mixture of xylazine 2% (0.05 mg/kg bw) and normal saline and In group C: 10 ml of normal saline were injected into the retrobulbar space of left eyes via four point method. Onset and duration of eyelids analgesia and glob analgesia/akinesia were compared between the groups. The images were studied serially and compared anatomically with two dissected head and intact goat skulls. Results- The results of this study demonstrated that eye regional anesthesia have not been observed in group C. In group X, sedative effect of xylazine without complete loss of eyelids and glob anaesthesia was observed. There was no significant difference in onset of eyelids and glob anaesthesia between groups L and LX (p>0.05). Duration of eye regional anesthesia in group LX was significantly more than group L (p<0.05). The animals in groups X and LX were sedated during the study but in group L the animals were alert and nervous. Conclusion and Clinical Relevance- According to results of present study, addition of xylazine to lidocaine for retrobulbar block causes a sedative effect and increased duration of eye regional anesthesia.