Effects of pretreatment with different doses of dexmedetomidine and lidocaine on rocuronium injection associated pain

Abstract

Objective To compare the efficacy of pretreatment with dexmedetomidine (Dex) and lidocaine to prevent rocuronium injection pain.Methods One hundred and sixty patients (ASA Ⅰ-Ⅱ) scheduled for elective surgery were randomly divided into 4 groups(n=40):control group(Group C),Dex 0.2 μg/kg group(Group D1),Dex 0.4 μg/kg group(Group D2) and lidocaine 0.5 mg/kg group (Group L).Patients in Group D1,Group D2 and Group L received intravenous Dex 0.2,0.4 μg/kg and lidocaine 0.5 mg/kg respectively,while patients in Group C received intravenous normal saline with the same volume(10 ml) within 10 min.Then all patients are intravenously injected rocuronium 10 mg (1 ml) within 2 s.The pain score,sedation and side effects were recorded.Results Demographic parameters were similar among groups.Comparing to Group C,the incidence of pain in Group C (82.5％) was significantly higher than that in Group D1 (60.0％),Group D2 (40.0％) and Group L(32.5％)(P＜0.05).The frequency and intensity of rocuronium injection pain were statistically similar between Group D2 and Group L.The frequency of pain in the Group D2 and Group L was significantly less than the Group D1 (P＜0.05).Sendation score in the Group D2 was significantly higher than the other three groups (P＜0.05).Hypotension,bradycardia and side effects of injection were similar among groups.Conclusions Pretreatment with Dex and lidocaine was effective in reducing the frequency and severity of pain with rocuronium injection but pretreatment with Dex 0.4 μg/kg and lidocaine 0.5 mg/kg proved to be the most effective treatments. Key words: Dexmedetomidine; Lidocaine; Rocuronium; Injection pain