The Effect of Emulsified Sevofluran on Muscular Relaxation through Selective Blockage of Peripheral Nerves

Objective To identify the site that emulsified sevoflurane influences in the nerve system. Methods Thirty-six healthy New Zealand rabbits were randomly and equally divided into low concentration emulsified sevoflurane group 〔4 mL/（kg·h）〕, medium concentration 〔6 mL/（kg·h）〕group, high concentration group〔10 mL/（kg·h）〕and intralipid control group. Emulsified sevoflurane was infused through arterial to selectively block peripheral nerves, neuro-muscular junctions and muscle fibers. The anterior tibial muscle resting tensions and muscle contraction forces were compared before and after the infusions. Results Significant differences of blood sevoflurane pressure between femoral veins and internal jugular veins appeared in rabbits in all the groups ( P<0.05). No significant changes in the resting tension of anterior tibia muscles were found in terms of single contractions and tetanic forces with the low and medium levels of infusion of sevoflurane compared to the base values. High level of infusion of sevoflurane resulted in decreased single contraction forces and tetanic forces of anterior tibia muscles ( P<0.05). Conclusion A rabbit model with selective blockage of peripheral nerves was established. Peripheral nerves are not the primary site which low and medium levels of emulsified sevoflurane influence skeletal muscle relaxations.