Correlation Between Sound Power And Toleration To The Treatment In High Intensity Focused Ultrasound Treatment Under Midazolam Combined With Fentanyl Anesthesia

Purpose: To investigate the feasibility of application of midazolam combined with fentanyl anesthesia in High Intensity Focused Ultrasound treatment and the correlation between sound power and toleration to the treatment.Materials and Methods: 42 New Zealands rabbits were randomly divided into 7 groups according to sound power (0W,100W,150W,200W,250W,300W,350W), then their thigh muscle were irradiated under the similar anesthesia state., and their behavior and vital signs were monitored through the experiment, then the tolerance time to the treatment was recorded (maintenance time of anesthesia), and the necrosis extent after irradiating was observed.Results: The maintenance time decreased gradually along with the increasing sound power, the difference between every two groups was significant (P<0.01), and there was linear relationship between sound power and maintenance time, the regression equation is y=46.721-0.102x. Compared with the control group (0W), the HR, R, MAP and T of the irradiating groups (100-350W) increased obviously (P<0.01). The vital signs of all the groups were stable, and the side reaction was rare.Conclusion: In the High Intensity Focused Ultrasound treatment, anesthesia is necessary, and midazolam combined with fentanyl anesthesia is feasible. The sound power is an important factor to impact on the toleration to the treatment.