Effect of dexmedetomidine on spinal epidural anesthesia sedation

Abstract

Objective To evaluate the efficacy and safety of dexmedetomidine aiding spinal-epidural anesthesia for sedation. Methods Ninety ASAI-II female patients scheduled for elective spinal-epidural anesthesia were randomly divided into 3 groups( 30 cases for each group) according to the digital table method.An epidural catheter was inseted at L2-3 after satisfactory anesthesia, sedative drugs was intravenous.Group A received midazolam 0.05μg/kg initial loading dose for 10min and maintaining with 0.5μg·kg-1·h-1.Group B received midazolam 0.06μg/kg for 5min and maintaining with 0.5mg·kg-1·h-1.Group C received first intravenous injection of propofol 0.5 mg/kg, injection time 60s, maintaining with 0.3-1.2mg·kg-1·h-1.The infusion rate was adjusted to increase or decrease in order to maintain the desired level of sedation(Ramsay score of 3) during operation.The sedation efficacy and adverse reactions of three groups were compared. Results The onset time[(11.2±2.8)min]in group A was longer than that of group B[(6.4±2.4)min], group C[(5.0±2.1)min](t=7.12, 9.70, all P<0.05). The offset time of group A, B[(12.3±2.4)min, (13.8±2.5)min] were longer then those of group C[(7.4±2.3)min](t=8.36, 7.95, all P<0.05). But 5 and 6 patients in the group B and C occurred hypoxia, and there were 8 and 9 patients developed partial airway obstruction due to relaxation of jaw muscle.At the time 30min, 60min and the end of surgery, the HR of the group A decreased deeply than the other two groups(t=5.02, 4.92, 4.90, 3.95, 5.71, 4.09, all P<0.05), 10, 5, 6 patients were given atropine for increasing the HR in the group A, B and C respectively. Conclusion Dexmedetomidine is more safe and effective for the sedation of spinal-epidural anesthesia, compared with midazolam and propofol, but with lower HR and longer onset time. Key words: Dexmedetomidine; Midazolam; Propofol; Anesthesia, caudal; Deep sedation