Anesthesia for Intraocular Surgery in Rabbits
The purpose of the study was to assess a ketamine/xylazine combination along with retrobulbar block using 4% lignocaine HCl for performing intraocular surgery in rabbits. To do so ten healthy adult New Zealand White rabbits aged 1.5-2 years of either sex weighing 2-3 kgs were selected for unilateral cataract extraction by phacoemulsification . Xylazine HCl was used as preanesthetic at a dose rate of 5 mg/kg, i.m., followed by Ketamine HCl at a dose rate of 35mg/kg, i.m. A retro bulbar block was performed with 4% lignocaine HCL. The anesthetic depth was judged by ear pinching reflex. The time for onset and duration of anesthesia was found to be 7±0.5 minutes and 35.5±1.2 minutes respectively. A central eyeball fixation following retro bulbar block was obtained in all the cases. The mean values recorded before induction of anesthesia and during anesthesia of rectal temperature (38.090C±0.2 vs. 37.290C±0.2), heart rate in beats per minute (276±1.2 vs.272±1.1), arterial blood pH (7.35±0.02 vs. 7.32±0.02), bicarbonate (16.2±1.2 vs. 20.3±1.8), PaCo2 (26.09±2.3 vs. 27.52±2.3) and PaO2 (84.79±1.9 vs. 80.39±1.1) did not vary significantly (P>0.05). Recovery was smooth and complete in 32.5±2.8 minutes.
Conclusion: the anesthetic regimen provides adequate condition for conducting intraocular surgery in rabbits.