Abstract: AIM: To determine the effect of dexmedetomidine on muscle relaxant effect of cisatracurium in patients with epilepsy. METHODS: Sixty patients undergoing elective neurosurgery, aged from 18 to 59 years old, were divided into three groups (n=20) according to the maximum onset time of dexmedetomidine: immediate induction group after dexmedetomidine infusion (Group A), induction group 15 minutes after dexmedetomidine infusion (Group B) and normal saline infusion (Group C). The neuromuscular conduction function was monitored by muscle relaxation monitor, and the ulnar nerve was stimulated in TOF mode (frequency 2 Hz, wave width 0.2 ms, stimulation current 70 mA, string interval 12 s). Patients in group A were given dexmedetomidine 1 μg/kg after entering the room, and anesthesia induction was started immediately after 10 min pumping; Group B patients were given dexmedetomidine 1 μg/kg after entering the room, and anesthesia induction was started 15 minutes after 10 minutes of pump injection; Patients in group C began induction immediately after pumping the same milliliter of normal saline within 10 min. During anesthesia induction, 0.15 mg/kg cisatracurium was injected intravenously, and endotracheal intubation was performed when T1 reached the maximum inhibition. The modified method was used to evaluate the conditions of endotracheal intubation. When T1 recovered to 25%during the operation, cisatracurium 0.05 mg/kg was injected intravenously. The onset time (Tonset), peak time (Tpeak), 25%recovery time (T25%), 25%-50%recovery time (T25-50%), 50%-75% recovery time (T50-75%) and 75%-100%recovery time (T75-100%) of cisatracurium were recorded. Record the operation time, anesthesia time and fluid replacement volume, record the total dosage of propofol, remifentanil and cisatracurium, and calculate the dosage per unit body weight. RESULTS: There was no significant difference in Tonset, Tpeak, T25%, T25-50%, T50-75% and T75-100% among the three groups (P>0.05), but Tpeak, T25-50% and T50-75% in group C were greater than those in group A and B; There was no significant difference in tracheal intubation conditions, body weight per unit time and dosage of cisatracurium among the three groups (P>0.05); The dosage of propofol in group C was significantly higher than that in group A and B (P<0.05). CONCLUSION: Dexmedetomidine has no effect on the muscle relaxation effect of cisatracurium in patients with epilepsy. 

Key words: dexmedetomidine, neuromuscular block, cisatracurium, muscle relaxation, epilepsy