Effect Of Pre-injection On Rapid Neuromuscular Blocking Induced By Cisatracurium

Abstract: Objective: We compared different priming doses of agents （rocuronium and cisatracurium） at a priming time of 3 minutes and their effects on the intubation time, the onset time, the intubation conditions and the recovery phase of cisatracurium to investigate the safe and efficient priming-doses of cisatracurium or rocuronium on rapid neuromuscular blocking induced by cisatracurium. Methods: From March 2010 to July 2010, 140 cases （38 male and 102 female） of abdominal surgery patients aged 18 to 64 years old were selected in Sichuan Provincial People’s Hospital and graded from I to II with American Society of Anesthesiologists （ASA） physical status. General anesthesia was induced with propofol （TCI） （1.0μg/ml 4.0μg/ml）. After the patients lost their consciousness, neuromuscular function was monitored by train-of-four （TOF） stimulation accelerometry and the first twitch response T₁ reached 100%. The patients were randomized （using envelope randomization） into 7 groups : Group C₀ received 3 mL of normal saline as a priming dose and served as the control group; Group C₁, Group C₂ and Group C₃ received cisatracurium at a dose of 0.005mg/kg (10%ED₉₅), 0.010mg/kg (20%ED₉₅) and 0.015mg/kg (30%ED₉₅) respectively as a priming dose; Group R₁, Group R₂ and Group R₃ received rocuronium at a dose of 0.03mg/kg (10%ED₉₅), 0.06mg/kg (20%ED₉₅) and 0.09mg/kg (30%ED₉₅) respectively as a priming. A 3-minute priming period, anesthesia was induced with the fentanyl （3.0ug/kg） and an intubation doses of cisatracurium （Group C₀, 0.150mg/kg; Group C₁and Group R₁, 0.145 mg/kg; Group C₂ and Group R₂, 0.140mg/kg; Group C₃ and Group R₃ 0.135 mg/kg）. The priming and intubation doses of cisatracurium in Group C₀, Group C₁, Group C₂ and Group C₃ were 0.15mg/kg (3ED₉₅) respectively. When T₁ reached 5%, endotracheal intubation was performed. During anesthesia, propofol （4.0μg/ml 6.0μg/ml） and fentanyl （0.05mg/time 0.1mg/time） were used for maintenance. Additional muscle relaxants were not administered before T₂₅. In all patients, indices were monitored and recorded, including hemodynamic parameters （the pre-injection , the end of 3-minute priming period and the 3-minute after introduction）, TOFs at the end of priming interval, intubation time, intubation conditions, onset time, PTC counts, recovery phase (T₅, T₂₅ ) and adverse reactions. Results: Patient characteristics （sex, body mass indices, hemoglobins, total protein contents, PH values, temperatures and other general conditions） were not significantly different among the 7 groups （P>0.05） by statistical test. Compared with those in Group C₀, the heart rate and mean arterial blood pressure were not significant changed （P>0.05） in the other 6 groups during the pre-injection , the end of 3-minute priming period and the 3-minute after introduction. Compared with that in the control group C₀, TOFs at the 3-minute priming interval in Group R₂ and Group R₃ were significantly inhibited （P<0.05）, and in the other four groups TOF levels were not suppressed significantly （P>0.05）. It significantly reduced the onset time for cisatracurium by using cisatracurium （Group C₁, Group C₂ and Group C₃） and rocuronium （GroupR₁, GroupR₂ and GroupR₃） as priming drugs at an interval of 3 minutes. And rocuronium groups （Group R₁ ,Group R₂ and Group R₃） got a shorter onset time for cisatracurium compared with cisatracurium groups （Group C₁, Group C₂ and Group C₃）.The more priming dose, the faster speed of onset （P<0.05）. The speed of intubation in Group C₃ （63.5±57.1s） and Group R₃ （76.7±51s） were the most significant. The intubation conditions, PTC counts and recovery phase (T₅, T₂₅) among 7 groups were not significantly different （P>0.05）. T₅ and T₂₅ were 39 min 60 min and 43 min 64min respectively. Two patients occurred facial flushing and erythema in face and chest after given the introduction dose of cisatracurium for 20 minutes. The phenomenon in one case went away without treatment. In another case those disappeared after using intravenous injection of 10 mg of dexamethasone. The remaining 138 patients had no allergic reactions or other adverse reactions. Conclusion: Priming with 0.03mg/kg (10% ED₉₅) rocuronium or 0.015mg/kg (30%ED₉₅) cisatracurium for 3 minutes significantly accelerated the onset of cisatracurium. It didn’t cause obvious clinical symptoms or side effects. Knowledge of time sequences for priming and associated side effects can help us make plans for safe and efficient induction in patients.