Nerve Block
Conditions
Keywords
Dexmedetomidine, obturator nerve block, lidocaine, EC50
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.
Interventions
DRUGDexmedetomidine
Dexmedetomidine is administrated as an adjuvant of lidocaine at a dose of 1.0 μg/ kg.
DRUGNormal Saline
Normal Saline is administrated as an adjuvant of lidocaine.
Sponsors
Tianjin Medical University General Hospital
Guolin Wang
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
1. Subjects scheduled to undergo elective operation of TURBT on lateral wall for whom ONB was needed diagnosed through cystoscopy or CT examination preoperatively. 2. Subject's American Society of Anesthesiologists physical status is I-II. 3. The subject's parent/legally authorized guardian has given written informed consent to participate.
Exclusion criteria
1. Subject has a diagnosis of abnormal coagulation function. 2. Subject has a diagnosis of Diabetes mellitus. 3. Subject has a preexisting neurologic deficits of the lower extremities. 4. Subject has a history of alcohol or drug abuse. 5. Subject is pregnant or breast-feeding. 6. Subject is obese (body mass index \>30kg/m2).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Median Effective Concentration(EC50) | 10min | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Complication Related With Nerve Block | during operation, 0.5,24hour postoperatively | Complication related with nerve block is defined as the presence of either bradycardia, delayed recovery, persistent groin pain, neuropathy during operation and postoperatively |
Countries
China
Participant flow
Pre-assignment details
The patients with the following condition was excluded from the study: ASA III orIV; weight \<50 or \>100 kg；BMI\<19 or \>30kg/m2；age younger than 18 yr or older than 80yr；preexisting neurologic deficits of the lower extremities, DM; alcohol or drug abuse; abnormal coagulation function
Participants by arm
| Arm | Count |
|---|---|
| Normal Saline Normal Saline is administrated as an adjuvant of lidocaine. | 30 |
| Dexmedetomidine Dexmedetomidine is administrated as an adjuvant of lidocaine at a dose of 1.0 μg/ kg. | 30 |
| Total | 60 |
Baseline characteristics
| Characteristic | Normal Saline | Dexmedetomidine | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 12 Participants | 9 Participants | 21 Participants |
| Age, Categorical Between 18 and 65 years | 18 Participants | 21 Participants | 39 Participants |
| Age, Continuous | 62 years STANDARD_DEVIATION 14 | 68 years STANDARD_DEVIATION 9 | 65 years STANDARD_DEVIATION 12 |
| Region of Enrollment China | 30 participants | 30 participants | 60 participants |
| Sex: Female, Male Female | 6 Participants | 7 Participants | 13 Participants |
| Sex: Female, Male Male | 24 Participants | 23 Participants | 47 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 30 | 0 / 30 |
| serious Total, serious adverse events | 0 / 30 | 0 / 30 |
Outcome results
Primary
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.
Time frame: 10min
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Normal Saline | Median Effective Concentration(EC50) | 5.7 mg/ml(the concentration of lidocaine) |
| Dexmedetomidine | Median Effective Concentration(EC50) | 2.9 mg/ml(the concentration of lidocaine) |
Secondary
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
Time frame: during operation, 0.5,24hour postoperatively