Conditions: Nerve Block
Keywords: Dexmedetomidine obturator nerve block lidocaine EC50
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 60
Healthy volunteers: no

Brief summary:
Hypothesis: Dexmedetomidine as an adjuvant of lidocaine can decrease the median effective concentration(EC50) of lidocaine for obturator nerve block during transurethral resection of bladder tumor

Detailed description:
A selective obturator nerve block(ONB) is an effective alternative to suppress the obturator nerve reflex which is defined as a sudden, violent adductor muscle spasm when the obturator nerve is stimulated directly by the electronic resector during transurethral resection of the tumor on the lateral bladder wall. Studies showed Dexmedetomidine as an adjuvant to local anesthetic prolongs peripheral nerve block duration without any nerve toxicity. In the following randomized, non-crossover study, the investigators test if Dexmedetomidine as an adjuvant can decrease the median effective concentration(EC50) of lidocaine for obturator nerve block during transurethral resection of bladder tumor.

Arms:
arm 1: Dexmedetomidine is administrated as an adjuvant of lidocaine at a dose of 1.0 μg/ kg. arm 2: Normal Saline is administrated as an adjuvant of lidocaine.

Interventions: intervention 1: Dexmedetomidine intervention 2: Normal Saline
Intervention descriptions: intervention 1: Dexmedetomidine is administrated as an adjuvant of lidocaine at a dose of 1.0 μg/ kg. intervention 2: Normal Saline is administrated as an adjuvant of lidocaine.

Protocol document: