Lidocaine Combined Dexmedetomidine for Obturator Nerve Block

Study Overview
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Brief Summary
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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
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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.

Official Title
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Effects of Dexmedetomidine as an Adjuvant on the Median Effective Concentration of Lidocaine for Obturator Nerve Block - A Perspective, Randomized，Blind Study

Conditions
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Nerve Block

Intervention / Treatment
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* Drug: Dexmedetomidine
* Drug: Normal Saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects scheduled to undergo elective operation of TURBT on lateral wall for whom ONB was needed diagnosed through cystoscopy or CT examination preoperatively. Subject's American Society of Anesthesiologists physical status is I-II. The subject's parent/legally authorized guardian has given written informed consent to participate. Exclusion Criteria: Subject has a diagnosis of abnormal coagulation function. Subject has a diagnosis of Diabetes mellitus. Subject has a preexisting neurologic deficits of the lower extremities. Subject has a history of alcohol or drug abuse. Subject is pregnant or breast-feeding. Subject is obese (body mass index >30kg/m2).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Dexmedetomidine<br>Dexmedetomidine is administrated as an adjuvant of lidocaine at a dose of 1.0 μg/ kg. | Drug: Dexmedetomidine<br>* Dexmedetomidine is administrated as an adjuvant of lidocaine at a dose of 1.0 μg/ kg.<br>|
| Placebo Comparator: Normal Saline<br>Normal Saline is administrated as an adjuvant of lidocaine. | Drug: Normal Saline<br>* Normal Saline is administrated as an adjuvant of lidocaine.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Median Effective Concentration(EC50) | Median effective concentration(EC50) was not calculated per-participants, the up-and-down sequential allocation method was used to determine the median effective concentration(EC50) of lidocaine, running the two groups in parallel. The concentration of lidocaine for the second and subsequent patients in each group were dictated by the response of the previous patient in the group, such that an effective block led to a decreased concentration of the next patient, an ineffective block led to an increased concentration. For each group, we collected: the logarithm of lidocaine concentration, the number of effective block, ineffective block, total number of the patient, and successful rate. Then lgEC50 and slgEC50 was calculated as formulas. The logarithm of confidence intervals(95% CI) was calculated as lgEC50±1.96slgEC50. All of the calculation can be performed by SPSS19.0 for windows. | 10min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Complication Related With Nerve Block | Complication related with nerve block is defined as the presence of either bradycardia, delayed recovery, persistent groin pain, neuropathy during operation and postoperatively | during operation, 0.5,24hour postoperatively | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dexmedetomidine, obturator nerve block, lidocaine, EC50