ABSTRACT
BACKGROUND: Both ketamine and priming may accelerate the onset time of neuromuscular blocking agents. We investigate the effect of low dose ketamine and cisatracurium priming on the intubating condition and onset time of cisatracurium. METHODS: After Institutional Review Board approval, 120 consecutive patients undergoing general anesthesia were randomly assigned to one of 4 groups. All patients were injected one of normal saline (group C), cisatracurium 0.01 mg/kg (group P), ketamine 0.5 mg/kg (group K) and combination of cisatracurium 0.01 mg/kg, and ketamine 0.5 mg/kg (group PK) diluted into a 5 ml solution, followed 3 minutes later by cisatracurium 0.15 mg/kg in group C and K, and 0.14 mg/kg cisatracurium in priming group. Onset time was recorded the electromyographical responses using single twitch and intubating conditions were evaluated at 60 seconds after cisatracurium administration. RESULTS: The mean onset time was most significantly accelerated in Group PK and was also significantly more accelerated in Group P and K compared with Group C (P < 0.008). It was 112.7 +/- 13.2, 91.4 +/- 17.9, 84.9 +/- 12.7 and 76.4 +/- 8.3 seconds in Group C, P, K, and PK, respectively. Intubating conditions were significantly improved in Group P, K and PK than Group C (P < 0.008). Especially, Group PK showed most significant improvement of intubating conditions. CONCLUSIONS: The combination of the low dose ketamine and cisatracurium priming accelerated the onset time and was improved the intubating conditions.