Objective:The aim of the present study was to find the safest and appropriate intraperitoneal injection dose of Ketamine-Xylazine cocktail for short to the medium-duration surgical procedure (ultrasound-guided liver biopsy) in rats suffering chronic liver injury.
Methods:Four anesthetic doses of Ketamine-Xylazine combination were compared for their safety and efficacy (death rate and surgical tolerance), using observations and reflex tests. Anesthesia evaluated during ultrasound-guided liver biopsy procedure. The reactions of physiological parameters to surgical stimuli were used to determine anesthesia depth and were correlated with reflex test results.
Results: Full dose of Ketamine-Xylazine (87 mg/ kg- 13 mg/ kg) rapidly induced a deep state of anesthesia that lasted for about 70 minutes followed by complete cessation of respiration and death. Three-quarters dose of the cocktail also, rapidly induced a deep state of anesthesia that lasted 45 minutes. Anesthesia was adequate to perform the procedure. Recovery was long. No postoperative complications detected. Half dose of the Ketamine-Xylazine cocktail was short acting. Very good analgesia and muscle relaxation were recorded. Anesthesia lasted for about 30 minutes that was adequate for performing the procedure. Physiological parameters decreased followed by rapid stabilization. Smooth recovery noted. No postoperative complication recorded. Quarter dose produced a state of sedation. Analgesia and muscle relaxation were poor. Animals showed pain during manipulation. The procedure could not be achieved.       
Conclusions:The optimal intraperitoneal dose of Ketamine-Xylazine cocktail for balanced anesthesia in lab rats suffering chronic liver injury is (43.5 mg/kg and 6.5 mg/kg) respectively.