Abstract:Objective To study the effect of different dosages of Dexmedetomidine (Dex) on the awakening quality of the patients receiving resection of tumors in the brain functional areas. Methods Eighty-eight patients with brain functional area tumors, who underwent elective surgery from April 1, 2016 to May 31, 2017, were randomly divided into four groups: Dex1 group, Dex2 group, Dex3 group and control group with 22 in each group. The patients in the Dex1, Dex2 and Dex3 groups had intramuscular injection of 1.0, 1.5 and 2.0 g/kg Dex respectively at 15 min before the end of surgery, while the patients in the control group had intramuscular injection of the same amount of saline. The systolic pressure, diastolic pressure, heart rate, pulse and oxygen saturation at different time were compared. The spontaneous breathing recovery time, awakening time and extubation time of each group were recorded. The sedation and analgesic scores, and adverse reactions occurred during the recovery period were compared. Results The time of spontaneous breathing recovery, awakening time or extubation time was not significantly different among the 4 groups (P > 0.05). The sedation and analgesic scores in the Dex groups were significantly different from those in the control group at 5 and 15 min after extubation (P < 0.05). The plasma cortisol levels of the Dex 2 and Dex 3 groups were significantly lower than that of the control group at the time of extubation (P < 0.05). The levels of Dex 2 and Dex 3 were significantly lower (P < 0.05). The incidences of recovery period agitation, elevation of blood pressure and tachycardia in the Dex 3 group were significantly lower than those in the Dex1 and control groups (P < 0.05). Conclusions Intramuscular injection of 1.5 μg/kg Dex at 15 min before the end of surgery could promote the stabilization of hemodynamics during the awakening period in the patients receiving operation in the functional areas of the brain, significantly reduce the stress response in the awakening phase, effectively improve the awakening quality of the patients, suggesting that this dosage is more appropriate.